Dissertationen: „Adhesive plaster“

1

Liu, Yifan. „Preparation and properties of oral adhesive plaster containing Periplaneta extract“. Магістерська робота, Kyiv National University of Technology and Design, 2021. https://er.knutd.edu.ua/handle/123456789/19275.

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This research is devoted to the development of a new type of oral adhesive tablet that combines polymer materials and natural biological extracts (Periplaneta americana). It has good adhesion, long adhesion time and high material quality. The medicine uses the natural extract of Periplaneta americana and uses its unique membrane repair effect. The material adopts high tensile strength, strong adhesion carbomer 941 and hydroxypropyl methyl cellulose polymer materials. MTT assay was used to determine the toxicity of drug-loaded adhesion layer matrix on Hela cells. The results show that ulcer patch had good biocompatibility. Finally, the drug release behavior from the ulcer patch was studied by an amino acids analysis in the release medium using amino acid analyzer. The results show that the active components of amino acids can be effectively released from the matrix of ulcer patch, which laid a foundation for the therapeutic effect.The slow-release effect of the film provides a more efficient way to treat oral ulcers. The key production process of the product in industrial production is introduced, and the corresponding suggestions are put forward.

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2

Komarova, O. P., und I. Y. Korneev. „Development of a new sticky material for medical adhesive plaster“. Thesis, Харківський національний медичний університет, 2015. http://repository.kpi.kharkov.ua/handle/KhPI-Press/19466.

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3

Roberts, Alan Clive. „The Development of Facial Prosthetics and Adhesives in Plastic and Reconstructive Surgery. A study in the application of prosthetic materials and devices used in plastic and reconstructive surgery together with tissue adhesives as an alternative to conventional ligation“. Thesis, University of Bradford, 1988. http://hdl.handle.net/10454/5065.

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Various silicone elastomers have been evaluated for use in the prosthetic reconstruction of facial defects. Their strength, texture, flexibility, hardness, ease of preparation, pigment receptivity and retention, and their resistance to cleaning were compared and the data consulted when an elastomer was chosen to restore defects, improve aesthetics and reestablish the confidence of a selection of patients. Detailed case reports are provided, together with information on the adhesives or mechanical methods available for retaining the facial prosetheses. Cyanoacrylate adhesives for use on skin surfaces and as tissue adhesives have been studied in detail. A novel n-butyl 413 cyanoacrylate has been developed with a viscosity, haemostatic property and stability to make it particularly suitable for use in skin grafting and tissue repair. It has already been used with good results on patients with severe burns. An improved formulation, containing a fluorescent dye, can be precisely applied through a specially constructed foot-controlled dispenser illuminated by a fibre-optic supplying UV-light. Cyanoacrylates are already being used as tissue adhesives in place of the conventional but potentially disfiguring suture. The availability of improved, imperceptible adhesives and a precision applicator, which can be used in a modern operating theatre, will extend their effectiveness and satisfy some of the needs of Plastic, and Oral and Maxillo-Facial Surgeons. Portable applicators have potential use in battlefield and in veterinary surgery and overcome the imprecision characteristic of earlier methods.

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Phung, Kent, und Charles Chu. „Adhesives for Load-Bearing Timber-Glass Elements : Elastic, plastic and time dependent properties“. Thesis, Linnéuniversitetet, Institutionen för bygg- och energiteknik (BE), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-27386.

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This thesis work is part of an on-going project regarding load-bearing timber glass composites within the EU program WoodWisdom-Net. One major scope of that project is the adhesive material between the glass and timber parts. The underlying importance of the bonding material is related to the transfer of stress between the two materials – the influence of the adhesive stiffness and ductility on the possibility of obtaining uniform stress distributions. In this study the mechanical properties of two different adhesives are investigated, an epoxy (3M DP490) and an acrylate (SikaFast 5215). The differences of the adhesives lay in dissimilar stiffness, strength and viscous behaviour. In long term load caring design is important to understand the materials behavior under a constant load and a permanent displacement within the structure can cause major consequences. Therefore the main aim in this project is to identify the adhesives strength, deformation capacity and possible viscous (time dependent) effects. Because of the limitation of equipment and time this study is restricted to only three different experiments. Three different types of tensile tests have been conducted: monotonic, cyclic relaxation tests.The results of the experiments show that 3M DP490 has a higher strength and a smaller deformation capacity as compared to the SikaFast 5215. Thus, the SikaFast 5215 is more ductile. The 3M DP490 exhibits a lower loss of strength under constant strain (at relaxation). SikaFast 5215 showed also a large dependency of strain level on the stress loss in relaxation.

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5

Chan, Edward King-Long. „A study of moisture diffusion at the epoxy/copper interface for plastic IC packages /“. View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?MECH%202006%20CHAN.

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6

Falk-Brynhildsen, Karin. „The effect of peroperative skin preparation on bacterial growth during cardiac surgery“. Doctoral thesis, Örebro universitet, Institutionen för hälsovetenskap och medicin, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-31039.

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Routine products are used and procedures are followed in order to prevent and minimize the bacterial contamination of the surgical wound, and thus reduce the risk of postoperative wound infections. The overall aim of this thesis was to investigate the effect of different preoperative skin preparation before cardiac surgery. In study I, 10 healthy volunteers were compared in time to recolonization of the skin and bacterial growth with or without plastic adhesive drape. Bacterial samples were taken as paired samples on both side of the sternum. Plastic drape on disinfected skin seems to hasten recolonization compared with bare skin. In study II, 135 cardiac surgery patients were comparing plastic adhesive drape versus bare skin on the chest regarding intra-operative bacterial growth. Plastic adhesive drape did not reduce the bacterial recolonization or wound contamination, P. acnes colonizes males more often than females and P. acnes is not affected by disinfection with 0.5% chlorhexidine in ethanol. Study III, compared the leg harvesting site with or without microbal skin sealant in 135 CABG patients regarding intraoperative bacterial growth and postoperative wound infection. Almost no bacterial growth was found during surgery regardless of the use of microbial skin sealant and bare skin. A high incidence of postoperative wound infections (16.8%) in 2 month follow up was present and SSI was largely caused by S. aureus, i.e. other bacterial species than observed intraoperative. Study IV, a descriptive study using phenotypic and genotypic methods investigate susceptibility to chlorhexidine among S. epidermidis indicating that S. epidermidis isolates following preoperative skin disinfection are sensitive tochlorhexidine.

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Brückner, Julian Karl. „Adhäsionskräfte von Artikulationsgipsen an Typ 3 und 4 Modellgips. Eine in vitro Studie“. Doctoral thesis, Universitätsbibliothek Leipzig, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-168928.

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Einleitung Artikulationsgips dient der sicheren Verankerung von zahnärztlichen Gipsmodellen im Kausimulator. Eine Norm zur Quantifizierung der Haftfähigkeit dieses speziellen Dentalgipses an Gipsmodellen existiert bisher nicht. Ziel der vorliegenden Untersuchung ist es, Unterschiede zwischen Artikulationsgipsen bezüglich ihrer Adhäsion an Modellgipsen festzustellen und die neu entwickelte Methode zu bewerten. Material und Methoden Zur Untersuchung wurden die Artikulationsgipse dentona® arti-base® 60, piccodent® A 50, AmannGirrbach Artifix® und KerrTM Snow White Plaster No.2 an einen Typ 3 (dentona® dento dur® 110) und 4 Gips (dentona® sockel plaster® GT 160) gegossen. Die zylindrischen Prüfkörper enthielten zentrisch eingegossene Retentionen, die zur Verankerung in einer Universalprüfmaschine dienten. Prüfkörper aus Typ 3 und 4 Gips wurden vor dem Angießen des Artikulationsgipses 48 h getrocknet. Die Messung der Adhäsionskraft (in N) erfolgte mittels Zugversuch, 1 h nach der Erstarrung des Artikulationsgipses. Für jede Kombination wurden 10 Versuche durchgeführt. Die Datenauswertung erfolgte mittels t Test bei unabhängigen Stichproben und Dunnett´s T3 Vergleichstest (α=0,05). Ergebnisse Aus den 80 ermittelten Werten konnte ein Ranking der Gipskombinationen erstellt werden (Max. 1950,77 N, Min. 495,97 N). Es zeigten sich signifikante Unterschiede zwischen den einzelnen Kombinationen aus Modell- und Artikulationsgips. Innerhalb der Kombinationen mit Typ 3 Gips ergaben sich signifikante Unterschiede. Die Gruppen mit Typ 4 Modellgipses unterschieden sich hingegen nicht signifikant. Eine weitere Analyse zeigte bei zwei Artikulationsgipsen einen signifikanten Unterschied zwischen der Verwendung von Typ 3 und 4 Modellgips. Schlussfolgerung Es zeigte sich, dass die neu entwickelte Methode für die Untersuchung der Haftfähigkeit von Artikulationsgipsen geeignet ist. Aneinander gegossene Artikulations- und Modellgipse erreichen unterschiedlich hohe Adhäsionskräfte. Ein Vorteil für die Verwendung des Typ 3 gegenüber dem Typ 4 Modellgips ergab sich nicht. Am besten erschien in unserer Untersuchung die Kombination von dentona® dento dur® 110 und dentona® arti-base® 60.

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Oporto, Velásquez Gloria S. „Characterizing the Mechanism of Improved Adhesion of Modified Wood Plastic Composite (WPC) Surfaces“. Fogler Library, University of Maine, 2009. http://www.library.umaine.edu/theses/pdf/OportoVelasquezGS2009.pdf.

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9

Moosa, Naina Mohamed Lebbai. „Improvement of interfacial adhesion in plastic packages--dimples, metallic coatings and black oxide /“. View Abstract or Full-Text, 2002. http://library.ust.hk/cgi/db/thesis.pl?MECH%202002%20MOOSA.

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10

Batra, Ashish. „Stress relieving technique for plastic packages in a high volume manufacturing environment“. Diss., Online access via UMI:, 2009.

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Thesis (Ph. D.)--State University of New York at Binghamton, Thomas J. Watson School of Engineering and Applied Science, Department of Systems Science and Industrial Engineering, 2009.
Includes bibliographical references.

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11

Cookson, Mary Catherine. „An elastic-plastic interface constitutive model for combined normal and shear loading : application to adhesively bonded joints“. Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62527.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2010.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 111-112).
The behavior of mechanical adhesive interfaces when subjected to a variety of separation and slide loading modes, strain rates, and thermal conditions are of interest in many technical areas. An elastic-plastic constitutive model for adhesive interfaces subjected to combined normal and shear loading has been developed and numerically implemented in a finite element software package. The traction-separation behavior is defined for the normal and shear mechanisms and a displacement jump angle is found to drive the behavior of the initial strength values, as well as the critical and failure displacement jumps of the separate mechanisms that are used to define the model. A set of calibration experiments are performed to fully define an aluminum/adhesive/aluminum system subjected to five different combined loading angles. Tension and shear tests on the aluminum/adhesive/aluminum system at three different rates are used to determine the sensitivity of the adhesive interface to strain rate. The capability of the constitutive model is then explored for the geometry of bonded curvilinear blocks at different loading angles and for a notched four point bend geometry. In addition, a rate dependent elastic-plastic interface constitutive model for combined normal and shear loading is presented, and an initial calibration of inelastic strain rate sensitivity parameters are found.
Sponsored by the Department of the Air Force FA8721-05-0002
by Mary Catherine Cookson.
S.M.

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12

Khan, Minhaj A. „Development of rules for the design of adhesively bonded fibre-reinforced plastic composite joints in aerospace applications“. Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/848672/.

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This thesis describes progression towards developing an enhanced design methodology for laminated composite bonded joints in aerospace applications. The premise of a universal failure criterion is impractical given the number of adhesive-adherend configurations available. However, for a finite number of joint configurations, design rules can be developed based on experimental test data and detailed finite element modelling. By using these techniques rather than the traditional, overly conservative knock-down factors, more of the performance of composite bonded joints can be accessed. While complex damage modelling techniques are available, the additional material data and analysis time required renders them not suitable for the vast majority of time-sensitive industrial applications. Initially, the work presented in this thesis experimentally studied the effect of the substrate material, substrate layup, adhesive material and adhesive thickness on several laminated composite bonded joint configurations. The corresponding failure surfaces were extensively analysed and failure modes identified. Following this, detailed FE models were developed to identify the trends associated with altering joint parameters. Finally, the stresses and strains within the adhesive and substrate were analysed at each joint’s respective failure loads to identify critical parameters, which would later be used to develop a Critical Parameter Method for evaluating joint performance. Once these parameters were consolidated, they were validated against a unique set of joints. The critical parameter approach was able to predict joint strength with an average error of 26% compared experimental strength. Traditional FE criterions presented an average error of 61% compared to experimental strength. After further consolidation, joint strength prediction reduced to within 3% of experimental strength using the Critical Parameter Method, representing a substantial improvement in predictive capabilities.

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13

Manngård, Johanna. „Evaluation of surface treatment techniques for polypropylene andimplementation of a method for testing ink adhesion“. Thesis, Högskolan Dalarna, Grafisk teknik, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:du-3524.

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If a plastic material is used as a print bearer there are a need of a special surface treatment to get agod and durable printing. The most used surface treatment technique for the moment is coronatreatment. This kind of treatment has unfortunately showed not to be so durable in the long term.Plasma treatment which in this case uses different kind of gases in the treatment of polypropyleneis shown as a more effective treatment in this project. When the plasma treated surface has beenprinted is the good quality last much longer and the adhesion between the ink and the surface isremained. To test this adhesion is for the moment a standard used (ASTM D3359). This standardhas appeared unstable and dependent at many different factors, which gives a big variation in thetest results. Because of this has new test methods been carried out to give a more even and morereliable result in the test of the adhesion.

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14

Yáñez-Pacios, Andrés Jesús. „Tratamiento superficial de materiales compuestos de madera y plástico (WPCs) para mejorar sus propiedades de adhesión“. Doctoral thesis, Universidad de Alicante, 2016. http://hdl.handle.net/10045/66611.

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15

Shoaib, Muhammad. „Discrete element simulation of elasto-plastic shock waves in high-velocity compaction“. Doctoral thesis, KTH, MWL Marcus Wallenberg Laboratoriet, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-31144.

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Elasto-plastic shock waves in high-velocity compaction of spherical metal particles are the focus of this thesis which consists of four papers (A-D). The compaction process is modeled by a discrete element method while using elastic and plastic loading, elastic unloading and adhesion at contacts. Paper A investigates the dynamic compaction of a one-dimensional chain of homogenous particles. The development of the elasto-plastic shock waves, its propagation and influence on the compaction process are examined. Simulations yield information on the contact behavior, velocity of the particle and its deformation during dynamic compaction. Effects of changing loading parameters on the compaction process are also discussed. Paper B addresses the non-homogeneity in a chain having; particles of different sizes and materials, voids between the particles and particles with/without adhesion between them. Simulations show transmission and reflection of elasto-plastic shock wave during compaction process. The particle deformation during incident and reflected shocks and particle velocity fluctuations due to voids between particles are simulated. The effects of adhesion on particles separation during unloading stage are also discussed. Paper C develops a simulation model for a high-velocity compaction process with auxiliary pistons, known as relaxation assists, in a compaction assembly. The simulation results reveals that the relaxation assists offer; smooth compaction during loading stage, prevention of the particle separation during unloading stage and conversion of higher kinetic energy of hammer into particles deformation. Furthermore, the influence of various loading elements on compaction process is investigates. These results support the findings of experimental work. Paper D further extends the one-dimensional case of Paper A and B into two-dimensional assembly of particles while adding friction between particles and between particles and container walls. Three particular cases are investigated including closely packed hexagonal, loosely packed random and a non-homogenous assembly of particles of various sizes and materials. Consistent with the one-dimensional case, primary interest is the linking of particle deformation with the elasto-plastic shock wave propagation. Simulations yield information on particle deformation during shock propagation and change in overall particles compaction with the velocity of the hammer. The force exerted by particles on the container walls and rearrangement of the loosely packed particles during dynamic loading are also investigated. Finally, the effects of presence of friction and adhesion on both overall particles deformation and compaction process are simulated.
QC 20110311

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KORICHO, ERMIAS GEBREKIDAN. „Implementation of Composites and Plastics Materials for Vehicle Lightweight“. Doctoral thesis, Politecnico di Torino, 2012. http://hdl.handle.net/11583/2497432.

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Due to ever more severe environmental regulations, safety standards and rise of fuel cost, design of lightweight vehicle is becoming a challenging task in automotive industry. For these reasons, multidisciplinary design approaches are becoming mandatory that takes into account all parties’ interests. The thesis addresses the potential use of composites, nanomodified composites, thermoplastic and smart hot melts adhesives materials in selected automotive applications to achieve lightweight vehicle. Special attention was paid to specific parts of vehicle structures that are directly related to occupant and pedestrian safety concerns such as B-pillar, frontal bumper subsystem, and engine subframe. Two approaches were implemented to design composites and thermoplastic intensive vehicle components: experimental test and numerical simulation approaches. In experimental approach, experimental method was developed to establish reliable test procedure to characterize composite materials. Then, selected materials were manufactured and characterized under quasi-static and dynamic loading conditions. Furthermore, selected nano-modified composite materials were characterized to understand effect of presence of nano-clays into the matrix on the mechanical behavior of base material. On the other hand, thermoplastic material was modified with short glass fibers to improve its mechanical behavior for frontal vehicle system application. Besides, in this thesis adhesive joint was considered as alternative solution to achieve vehicle lightweight targets. Detailed material characterization and parametric study of hot melt adhesive (HMA) single lap joint were performed for bumper subsystem application. Accelerated ageing were also performed on selected HMA to represent the worst environmental condition in which the bumper subsystem could be exposed. Also, selected hot-melt adhesive was modified by nano-metal particles to obtain smart adhesive that allows bonded vehicle components to be easily detached during disassembly process. Particularly, simplified form of composite B-pillar (T-joint) was manufactured and quasi- static experimental tests were performed to validate the results obtained from numerical simulations. In numerical approach, composite and thermoplastic vehicle components were modeled, they are presented in chapters from seven to nine. Commercially available software have been used for these simulations. Structural analysis and optimizations were performed to obtain a competitive performance in terms of strength, stiffness and crash worthiness against conventional material solutions. The results found from experimental and numerical simulation works revealed that composites and thermoplastics materials can deliver better performances under static and crashing load conditions. Using those materials, considerable amount of vehicle weight reduction was also achieved by keeping the desired design performance criteria. It is also worth to underline that manufacturing process and joining techniques are some of the main factors that should be taken into consideration during design of composite and thermoplastic components for vehicle applications.

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Annapragada, Sriram Kiran. „Mechanism of Foaming on Polymer-Paperboard Composites“. Diss., Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19790.

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This thesis addresses a new technique of foaming on polymer-paperboard composites which combines the advantages of traditional polymeric foam with the environmental benefits of paperboard. Paperboard is sandwiched between two extruded polymeric layers of different densities. On application of heat, one face is foamed by the evaporating moisture in the board; the other face serves as a barrier. This work is directed at gaining a better understanding of the fundamental processes in foaming polymers on paperboard. The ultimate goal is to be able to produce uniform bubbles of a predetermined size on the surface so as to give optimum heat insulation and good tactile properties. Bubble growth was studied as a function of paperboard properties, polymer melt index, extrusion speed, polymer thickness, temperature and moisture content. The foam quality (thickness) is also related to the cell size distribution and various factors affecting it are identified. A combination of experimental techniques such as high speed imaging, infrared thermography and scanning electron microscopy is used for this purpose. Foaming on paper-polymer composites is caused by water vapor escaping through the pores present in the paperboard substrate and then foaming the polymer. The vapor driving force which dominates foaming and overcomes the less significant viscoelastic and surface tension opposition forces depends on the paperboard properties as well as on the ability of the polymer to bond with the paperboard. It was found that the bubble size distribution directly relates to the pore size distribution on the paperboard. The bubble size was also controlled by the thickness of the polymer layer and its ability to bond with the paperboard. Coalescence subsequently led to thicker foams due to the formation of larger sized bubbles.

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Kluge, Axel, Johannes Henneberg, Chokri Cherif und Andreas Nocke. „Methods for adhesion/friction reduction of novel wire-shaped actuators, based on shape memory alloys, for use in adaptive fiber-reinforced plastic composites“. Sage, 2015. https://tud.qucosa.de/id/qucosa%3A35612.

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For fiber-reinforced plastic composites, fiber-matrix adhesion is a significant aspect of composite properties. While conventional lightweight structures are always aiming for high fiber-matrix adhesion, innovative and unconventional functional constructions require different concepts. The research work treating adaptive fiber-reinforced plastic composites with shape memory alloy wires presented here uses the approach of actuators freely movable within the composite. This is supposed to prevent mechanical tensions in the interfaces of actuator and composite structure, which would otherwise cause damages of the composite. This work examines hybrid yarns based on friction spinning technology, with shape memory alloy wires as their core component as well as glass fibers, and partly polypropylene, as their sheath component. Additionally, the surface properties of the shape memory alloy wires being used are modified by sanding and coating. The results of a characterization by pull-out testing clearly show that a coating of the shape memory alloy wires with an abherent causes considerable decrease in adhesion and friction in the interface and leads to the mobility of the shape memory alloy wires in the later composite. An even greater effect is attained by sheathing the hybrid yarns in an additional layer of polypropylene, compacting the yarn cross-section. Thus, the pull-out force could be reduced to 35–40% of the reference structure.

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Cai, Shaobiao. „3D numerical modeling of dry/wet contact mechanics for rough, multilayered elastic-plastic solid surfaces and effects of hydrophilicity/hydrophobicity during separation with applications“. Columbus, Ohio : Ohio State University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1205118488.

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20

Wallin, Harald. „An investigation of friction graphs ranking ability regarding the galling phenomenon in dry SOFS contact : (Adhesive material transfere and friction)“. Thesis, Karlstad University, Faculty of Technology and Science, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-2790.

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The main purpose of this project is to investigate different tool steels in terms of their ability to withstand material transfer buildup, so-called galling, occurring in SMF (sheet metal forming) operations. The ability to withstand galling is vital to optimize cost-effectiveness and increase the work tool’s effective operational time. This investigation studies four different tool steels, including a TiN-coating, with the intention of evaluating the microstructures, chemical composition and hardness effect on galling resistance in dry conditions using a slider-on-flatsurface (SOFS) tribo-tester which measures the coefficient of friction during sliding.

An OP (optical profilometer) was used to measure the size and geometry of lump growth on the tool and damage on the work sheet. A scanning electron microscope (SEM) was used to identify the interacting tribological mechanisms exhibited at different stages during the slide. The SEM figures confirmed three different types of characteristic patterns exhibited in the tracks after tribo- testing which were categorized as mild adhesive, abrasive and severe adhesive damage.

A SEM figure that illustrates a ragged contact surface and an obvious change in the sheet materials plastic behavior is in this report regarded as a sign of severe adhesive contact, the characteristics could possibly be explained by local high temperature and high pressure followed by a sudden pressure drop and creation of hardened welds or solders between the two surfaces which increase the frictional input needed for further advancement. Friction coefficients observed in the initial 100% mild adhesive stage were, μ=0,22-0,26 succeeded by abrasive SEM characteristics often in association with mild adhesive contact and friction values between μ=0,25-0,4 which where sometimes followed by severe adhesive SEM characteristics in 100% of the contact zone with friction values between μ=0,34- 0,9 respectively. The tool material that performed best according to the friction detection criteria was Sv21 closely followed by Sleipner (TiN coated) and Va40 (HRC 63.3). Unfortunately was the friction criteria, a significant raise in friction for defining a sliding length to galling, not adequate for dry conditions due to immediate material transfer succeeded by cyclic changes between partial or 100% abrasive+mild adhesive and severe adhesive contact. The mechanism that change abrasive wear in association with mild adhesive contact, (moderate friction input), to sever adhesive wear, (higher friction input), is dependent on lump shape (lump geometry) and can appear at comparably low speeds 0,04-0,08 [m/s] and low friction energy input (μ=0,34), the magnitude of the change in friction is therefore not always significant and hardly detectable on the friction graph. This was quite unexpected but could be explained by concentration of friction energy rater than the absolute amount. The problem with using friction graphs for galling evaluation was increased even further when a very small lump size and low corresponding rate of material transfer to the tool surface caused a sustainable high raise in friction (μ≈0,3→0,6) on a TiN-coated tool steel called Sleipner.

A hardly detectable or similar friction raise for Sv21 and Va40 showed much larger corresponding lump size and rate of material transfer. This means that friction graphs demonstrate a clear problem with quantifying lump size [m3] and rate of material transfer [m3/s]. Another phenomenon called stick slip behavior, material transfer and lump growth followed by a sudden decrease in lump size and transfer of material back to the work sheet, is also not possible to detect on a friction graph. Because a drop in friction can easily be a change in contact temperature and lump attack angle due to a growing lump and not a decreasing lump.

The conclusion, a friction graph is not suited for galling evaluation and ranking in dry SOFS conditions. A ranking should primarily be based on dimensional OP measurements of the cross section of formed tracks and scratches or preferably by repeated OP measurements of the tool surface during a single test, the last revel the exact lump growth history and true lump growth even in the sliding direction.

civilingenjörsexamen

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Schönström, Linus, Anna Nordh, Anton Strignert, Frida Lemel, Jakob Ekengard, Sofie Wallin und Zargham Jabri. „A process recipe for bonding a silicone membrane to a plastic substrate“. Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-201008.

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A spin-cast silicone membrane has been successfully bonded between two injection-molded microstructured plastic discs. This sandwich structure creates a useful platform for mass production of microfluidic systems, provided that the bonds are leakproof. The bonds were achieved by a silicon dioxide coating deposited on the plastic discs by evaporation. This investigation is concerned with the process and the result only, no theory is discussed.

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Liang, Fenglin. „Caractérisation et modélisation du comportement rhéologique des boues résiduaires urbaines concentrées“. Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2016. http://www.theses.fr/2016EMAC0014/document.

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Les grandes quantités d’eaux usées générées par l’activité humaine doivent être traitées pour minimiser le risque sanitaire et l’impact sur les milieux récepteurs. Les boues résiduaires sont le principal coproduit de ce traitement. Afin de les valoriser, des transformations sont mises en œuvre dans les stations d’épuration pour réduire leur volume et améliorer leur qualité sanitaire. Des problèmes d’écoulement et de mottage sont fréquemment rencontrés par les opérateurs. La caractérisation du comportement rhéologique de ce mélange hétérogène d’eau, microorganismes, fibres, particules colloïdales et non colloïdales, polymères organiques, etc., représente encore de nos jours un challenge scientifique et technique, en particulier lorsque la concentration massique en solides excède 20%. Dans ce travail, une méthodologie complète, associant mesures et modélisation, a été développée afin de caractériser les propriétés rhéologiques, l’adhérence et la cohésion des boues résiduaires. Elle s’adresse à des boues dont le comportement, évalué par un test d’affaissement, s’apparente à celui d’un solide mou et elle peut être mise en œuvre tant que le matériau n’a pas dépassé la limite de plasticité mesurée selon la norme ASTM D 4318, relative aux sols. Dans cette étude, elle a été appliquée à des boues centrifugées, dont la teneur massique en solides était proche de 20%. La méthode expérimentale inclut des essais mécaniques en compression uniaxiale (à très grande déformation, à petite déformation avec un ou plusieurs cycles de charge/décharge) sur un texturomètre de Lloyd Instruments et des essais en cisaillement réalisés sur un dispositif spécialement conçu au laboratoire pour quantifier les propriétés adhésive et cohésive des boues. Ces essais permettent d’identifier le seuil de fracturation du matériau, les ordres de grandeur du module élastique, de la viscosité et du seuil de plasticité, la résilience, les contraintes maximales d’adhésion et de cohésion et, enfin, les énergies d’adhésion. Un modèle mécanique analogique a ensuite été établi. Le comportement viscoélastique et visco-élasto-plastique des boues sous une sollicitation uniaxiale de charge-décharge a pu être simulé par un modèle conceptuel, dit ‘Burgers-Ludwik’, à 7 paramètres rhéologiques. Ce modèle est basé sur les lois mécaniques fondamentales de Hooke, de Newton et sur l'équation de Ludwik pour décrire le comportement plastique d'écrouissage. L’optimisation des paramètres du modèle avec Matlab® a été réalisée avec une méthode de régression multiple non linéaire à plusieurs étapes, ainsi que les calculs des bassins d'attraction et des intervalles de confiance. La sensibilité de la méthodologie à mettre en évidence des changements de propriétés induits par des procédés ou par un stockage a ensuite été évaluée. Il s'est ainsi avéré qu"un malaxage rend le matériau plus adhésif et plus facile à déformer, avec une diminution du seuil et de la rigidité du matériau, et qu’un stockage rend les boues moins cohésives et aussi plus faciles à déformer
Human daily activities generate a large quantity of wastewater that should be treated in order to minimise the sanitary risk and impacts on the environment. Sewage sludge is the main co-product of the wastewater treatment. Specific processes are implemented to reduce its volume and improve its sanitary quality before valorisation. As dewatered sludge is a mixture of water, microorganisms, fibres, colloidal and non-colloidal particles, organic polymers, etc., with the increase of its solid content, difficulties in pumping, conveying or discharging handling are frequently encountered during these treatments. The rheological characterisation of this heterogeneous material still remains a scientific and technical challenge, especially when solid mass content exceeds 20%. In this work, an entire methodology linking experimental measurements and modelling has been developed to characterise the rheological properties and the stickiness of sewage sludge. This methodology is suitable for sludge behaving as a soft solid (evaluated by slumping test) and as long as the material stays below its plastic limit (by the ASTM D 4318 initially standardized for soils). In this dissertation, the methodology is applied to dewatered sludge of total solid content around 20% by weight. This method includes uniaxial compression tests (from very large deformation to small one with single or two cycles of loading-unloading) using a universal materials testing machine of Lloyd Instrument and shearing tests using a device designed and fabricated in our laboratory for quantifying the sticky properties of sludge. These tests can identify the bioyield of the material, the orders of magnitude of the elastic modulus, viscosity, yield stress and resilience, the maximum adhesive and cohesive stresses, and finally the energy of adhesion. An analogical mechanical model is then established. The viscoelastic and visco-elasto-plastic behaviours under uniaxial cyclic compression can thus be simulated with this conceptual model of 7 parameters, named “Burgers-Ludwik”. This model is based on the fundamental mechanical laws of Hooke, Newton and the equation of Ludwik for simulating plastic hardening of material. A multi-step program based on non-linear multiple regressions is coded to optimize the model parameters with Matlab®. The sensibility of this methodology is highlighted by testing the changes in rheological properties of sewage sludge induced by processing or storage. Mixing makes the sludge more adhesive while storage makes it less cohesive. Both make the sludge easier to deform

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23

Jasevičius, Raimondas. „The Numerical Modelling of Normal Interaction of Ultrafine Particles“. Doctoral thesis, Lithuanian Academic Libraries Network (LABT), 2011. http://vddb.laba.lt/obj/LT-eLABa-0001:E.02~2010~D_20110224_161120-06365.

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Recently, powders of the size d (0.1 μm < d < 10 μm) have been referred to ultrafine particles. The particle shape considered is assumed to be a sphere of the diameter d. The handling of powders is of great importance for processing of pharmaceuticals, cement, chemicals and other products. Most of these technological processes involve powder compaction, storage, transportation, mixing, etc, therefore, understanding of the fundamentals of particles interaction behaviour is very essential in the design of machines and equipment as well as in powder technology, cleaning of environment and other areas. The dynamic behaviour of particulate systems is very complicated due to the complex interactions between individual particles and their interaction with the surroundings. Understanding the underlying mechanisms can be effectively achieved via particle scale research. The problem of a normal contact may be resolved in a number of ways. In spite of huge progress in experimental techniques, direct lab tests with individual particles are still rather time-consuming and expensive. The interaction of particles as solid bodies is actually a classical problem of contact mechanics. In the case of ultrafine particles, the reduction of the particle size shifts the contact zones into the nanoscale or subnanoscale. Thus, steadily increasing contribution of adhesion has to be considered in the development of the physically correct constitutive models and numerical tools. Consequently, it may... [to full text]
Ultrasmulkios dalelės yra šiuolaikinės chemijos, farmacijos, maisto ir kitų pramonės šakų produktų sudėtinė dalis. Tiriant pramoninius technologinius procesus, neišvengiamai reikalingos teorinės žinios apie ultrasmulkių dalelių elgseną. Išsamus supratimas įmanomas tik atlikus įvairius tyrimus. Pastaruoju metu milteliai, klasifikuojami kaip ultrasmulkios (0,1 < d < 10 μm) dalelės, imti plačiai naudoti pramoniniuose procesuose, todėl suprasti ultrasmulkių dalelių elgsenos fundamentalumą miltelių technologijoje yra labai svarbu. Ultrasmulki dalelė yra itin maža, todėl su ja atlikti fizinį eksperimentą, kuris reikalauja specialios įrangos bei žinių, labai sunku. Tokiu atveju dažniausiai naudojamas skaitinis eksperimentas, kurį galima atlikti virtualiai. Skaitinio eksperimento metu yra tiriamos dinaminės ultrasmulkios dalelės savybės bei sprendžiamas dinaminis uždavinys. Taikant skaitinius modelius bei dalelės judėjimą aprašančias jėgų lygtis, naudojami sąveikos modeliai, apimantys adhezinę, klampią, tamprią bei tampriai plastinę sąveikas. Mikroskopinis adhezinės sąveikos modeliavimas – aktualus mechanikos mokslo uždavinys. Taikant sąveikos modelius, svarbu pritaikyti ir diskrečiųjų elementų metodą, kadangi, norint aprašyti dalelių elgseną, visų pirma reikia su-vokti ir aprašyti dalelės modelį. Dalelės elgsenos skaitiniam modeliavimui siūlomi teoriniai modeliai leidžia tirti dalelės sąveiką su dalele ar tampria puserdve bei sąveikos dinamiką. Šie modeliai galėtų būti pritaikyti... [toliau žr. visą tekstą]

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24

Huang, Wei-Jou, und 黃瑋柔. „Investigation of Adhesion between Silicone Adhesives and Plastic Materials“. Thesis, 2014. http://ndltd.ncl.edu.tw/handle/a22h92.

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碩士
國立臺北科技大學
有機高分子研究所
102
This study examines the characteristics of adhesion for silicone adhesives to plastics. Two different types of plastics are used as test samples. They are polyethylene terephthalate (PET) film with a thickness of 0.05 mm and polypropylene (PP) sheet with a thickness of 0.7 mm. After corona discharge treatment (CDT) for PET films and PP sheets, those films and sheets are immediately coated with three different silicone adhesives, namely A, B, and C. The coated samples are placed by 5, 10, 20, and 30 minutes in the environment which is room temperature and relative humidity of 50 ~ 60%. The samples of the same plastics and adhesives are pressed together with 10 kg force and by 24 hrs in the previous environment. Those samples are used for the test of peel strength after 24 hrs. The pH values for silicone adhesives A, B, and C are 10, 5, and 3, respectively. Experimental results indicate that among three silicone adhesives, adhesive A shows the best of adhesion for PET film and PP sheet treated by corona and adhesive C gives the worst of adhesion for PET film and PP sheet. The peel strength of PP sheets without CDT coated the three silicone adhesives is near zero. That means very poor adhesion for the three silicone adhesives to PP sheets without CDT. When a sample has a high peel strength, the place of peel for the sample normally occurs in adhesives. However, when a sample shows a low peel strength, a poor adhesion always happen at the interface between plastics and adhesives.

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25

Vijaya, Kumar R. L. „Some Experimental and Numerical Studies on Evaluation of Adhesive Bond Integrity of Composites Lap Shear Joints“. Thesis, 2014. http://etd.iisc.ac.in/handle/2005/3220.

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Adhesive bonding which has been in use for long as a traditional joining method has gained ground in the last couple of decades due to the introduction of advanced composite materials into the aerospace industry. Bonded structures have advantages such as high corrosion and fatigue resistance, ability to join dissimilar materials, reduced stress concentration, uniform stress distribution, good damping characteristics etc. They also have certain limitations like environmental degradation, existence of defects like pores, voids and disbonds, difficulty in maintenance and repair etc. A serious drawback in the use of adhesively bonded structures has been that there are no established comprehensive non-destructive testing (NDT) techniques for their evaluation. Further, a reliable evaluation of the effect of the existing defects on strength and durability of adhesive joints is yet to be achieved. This has been a challenge for the research and development community over several decades and hence, been the motivation behind this piece of research work. Under the scope of the work carried out in the thesis, some of the primary factors such as the existence of defects, degradation of the adhesive, stress and strain distribution in the bonded region etc., have been considered to study the bond integrity in composite to composite lap shear joints. The problem becomes complex if all the parameters affecting the adhesive joint are varied simultaneously. Taking this into consideration, one of the key parameters affecting the bond quality, viz., the adhesive layer degradation was chosen to study its effect on the bonded joint. The epoxy layer was added with different, definite amount of Poly vinyl alcohol (PVA) to arrive at sets of bonded joint specimens with varied adhesive layer properties. A thorough review of different non destructive testing methods applied to this particular problem showed that ultrasonic wave based techniques could be the right choice. To start with, preliminary experimental investigations were carried on unidirectional glass fiber reinforced plastic (GFRP-epoxy) lap joints. The adhesive joints were subjected to non destructive evaluation (NDE) using ultrasonic through transmission and pulse echo techniques as also low energy digital X-ray techniques. The results obtained showed a variation in reflected and transmitted ultrasonic pulse amplitude with bond quality. Digital X-Ray radiography technique showed a variation in the intensity of transmitted x-rays due to variation in the density of adhesive. Standard mechanical tests revealed that the addition of PVA decreased the bond strength. A plot of coefficient of reflection from the first interface and the bond strength showed a linear correlation between them. After obtaining a cursory feel and understanding of the parameters involved with the preliminary experiments on GFRP adhesive joints which yielded interesting and encouraging results, further work was carried on specimens made out of autoclave cured carbon fiber reinforced plastic (CFRP)-epoxy bonded joints. Normal incidence ultrasound showed a similar trend. Analyses of the Acoustic Emission (AE) signals generated indicate early AE activity for degraded joints compared to healthy joints. Literary evidences suggest that the ultrasonic shear waves are more sensitive to interfacial degradation. An attempt was made to use oblique incidence ultrasonic interrogation using shear waves. The amplitude of reflected shear waves from the interface increased with an increase in degradation. Further, a signal analysis approach in the frequency domain revealed a shift in the frequency minimum towards lower range in degraded samples. This phenomenon was verified using analytical models. An inversion algorithm was used to determine the interfacial transverse stiffness which decreased significantly due to increase in degradation. Conventional ultrasonic evaluation methods are rendered ineffective when a direct access to the test region is not possible; a different approach with guided wave techniques can be explored in this scenario. Investigations on CFRP-epoxy adhesive joints using Lamb waves showed a decrease in the amplitude of ‘So’ mode in degraded samples. Theoretical dispersion curves exhibited a similar trend. Frequency domain studies on the received modes using Gabor wavelet transform showed a negative shift in frequency with increased degradation. It was also observed that the maximum transmission loss for the most degraded sample with 40 percent PVA occurred in the range of 650 – 800 kHz. Non linear ultrasonic (NLU) evaluation revealed that the nonlinearity parameter (β) increased with increased degradation. Kissing bonds are most commonly occurring type of defects in adhesive joints and are very difficult to characterize. A recent non-contact imaging technique called digital image correlation (DIC) was tried to evaluate composite adhesive joints with varied percentage of inserted kissing bond defects. The results obtained indicate that DIC can detect the kissing bonds even at 50 percent of the failure load. In addition, to different experimental approaches to evaluate the bonded joint discussed above, the effect of degradation on the stresses in the bond line region was studied using analytical and numerical approach. A linear adhesive beam model based on Euler beam theory and a nonlinear adhesive beam model based on Timoshenko beam theory were used to determine the adhesive peel and shear stress in the joint. Digital image correlation technique was used to experimentally obtain the bond line strains and corresponding stresses were computed assuming a plane strain condition. It was found that the experimental stresses followed a similar trend to that predicted by the two analytical models. A maximum peel stress failure criterion was used to predict failure loads. A failure mechanism was proposed based on the observations made during the experimental work. It was further shown that the critical strain energy release rate for crack initiation in a healthy joint is much higher compared to a degraded joint. The analytical models become cumbersome if a larger number of factors have to be taken into account. Numerical methods like finite element analysis are found to be promising in overcoming these hurdles. Numerical investigation using 3D finite element analysis was carried out on CFRP-epoxy adhesive joints. The adherend – adhesive interface was modeled using connector elements whose stiffness properties as well as the bulk adhesive properties for joints with different amounts of PVA were determined using ultrasonic inspection method. The peel and shear stress variation along the adhesive bond line showed a similar trend as observed with the experimental stress distribution (DIC) but with a lesser magnitude. A parametric study using finite element based Monte-Carlo simulation was carried out to assess the effect of variation in various joint parameters like adhesive modulus, bondline thickness, adherend geometrical and material properties on peel and shear stress in the joint. It was found that the adhesive modulus and bond line thickness had a significant influence on the magnitude of stresses developed in the bond line. Thus, to summarize, an attempt has been made to study the bond line integrity of a composite epoxy adhesive lap joint using experimental, analytical and numerical approaches. Advanced NDE tools like oblique incidence ultrasound, non linear ultrasound, Lamb wave inspection and digital image correlation have been used to extract parameters which can be used to evaluate composite bonded joints. The results obtained and reported in the thesis have been encouraging and indicate that in specific cases where the bond line thickness and other relevant parameters if can be maintained or presumed reasonably non variant, it is possible to effectively evaluate the integrity of a composite bonded joint.

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26

Chang, Reiyuan, und 張瑞元. „The study of adhesive performance between fiber reinforcement plastic and concrete“. Thesis, 1997. http://ndltd.ncl.edu.tw/handle/80042273161198200924.

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碩士
國立中央大學
土木工程學系
85
ABSTACT Application of epoxy bonded fiber reinforcement plastic (FRP) to the surface of concrete structure combines two different materials into acomposite one and the integrity of the structure can be improved. Since this is a new method and information on the durability of the materials is lacking. Performance of the bonding between concrete and FRP under different scenarios is considered essential to the success of the method. Since fiber reinforcement plastic bonded to reinforced concrete beam tends to shear and normal stress concentration at the end of FRP under loads. This study investigates the bonding efficiency of epoxybonded FRP experimentally with emphasis on the durability of the bonding. The performance of two epoxy adhesives applied for bonding concrete and FRP has been studied, with specimens subject to 3 different loading conditions. Specimens were then exposed to thermal fluctuation, wet-dry cycling and ultraviolet light irradiating. Results obtained from these tests indicated that the treatment of concrete surface is very important to the bonding efficiency. The best adhesive effect occurs when coarse aggregates in concrete are exposed to bonding. The alternate heating and cooling has a detrimental effect on the bond between concrete and FRP. The adhesive strength of specimens in a saturated situation is less than that in an air-dry situation. There was no marked difference in the performance of specimens after immersion of specimens in water for 2 months.

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27

Vijaya, Kumar R. L. „Some Experimental and Numerical Studies on Evaluation of Adhesive Bond Integrity of Composites Lap Shear Joints“. Thesis, 2014. http://hdl.handle.net/2005/3220.

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Adhesive bonding which has been in use for long as a traditional joining method has gained ground in the last couple of decades due to the introduction of advanced composite materials into the aerospace industry. Bonded structures have advantages such as high corrosion and fatigue resistance, ability to join dissimilar materials, reduced stress concentration, uniform stress distribution, good damping characteristics etc. They also have certain limitations like environmental degradation, existence of defects like pores, voids and disbonds, difficulty in maintenance and repair etc. A serious drawback in the use of adhesively bonded structures has been that there are no established comprehensive non-destructive testing (NDT) techniques for their evaluation. Further, a reliable evaluation of the effect of the existing defects on strength and durability of adhesive joints is yet to be achieved. This has been a challenge for the research and development community over several decades and hence, been the motivation behind this piece of research work. Under the scope of the work carried out in the thesis, some of the primary factors such as the existence of defects, degradation of the adhesive, stress and strain distribution in the bonded region etc., have been considered to study the bond integrity in composite to composite lap shear joints. The problem becomes complex if all the parameters affecting the adhesive joint are varied simultaneously. Taking this into consideration, one of the key parameters affecting the bond quality, viz., the adhesive layer degradation was chosen to study its effect on the bonded joint. The epoxy layer was added with different, definite amount of Poly vinyl alcohol (PVA) to arrive at sets of bonded joint specimens with varied adhesive layer properties. A thorough review of different non destructive testing methods applied to this particular problem showed that ultrasonic wave based techniques could be the right choice. To start with, preliminary experimental investigations were carried on unidirectional glass fiber reinforced plastic (GFRP-epoxy) lap joints. The adhesive joints were subjected to non destructive evaluation (NDE) using ultrasonic through transmission and pulse echo techniques as also low energy digital X-ray techniques. The results obtained showed a variation in reflected and transmitted ultrasonic pulse amplitude with bond quality. Digital X-Ray radiography technique showed a variation in the intensity of transmitted x-rays due to variation in the density of adhesive. Standard mechanical tests revealed that the addition of PVA decreased the bond strength. A plot of coefficient of reflection from the first interface and the bond strength showed a linear correlation between them. After obtaining a cursory feel and understanding of the parameters involved with the preliminary experiments on GFRP adhesive joints which yielded interesting and encouraging results, further work was carried on specimens made out of autoclave cured carbon fiber reinforced plastic (CFRP)-epoxy bonded joints. Normal incidence ultrasound showed a similar trend. Analyses of the Acoustic Emission (AE) signals generated indicate early AE activity for degraded joints compared to healthy joints. Literary evidences suggest that the ultrasonic shear waves are more sensitive to interfacial degradation. An attempt was made to use oblique incidence ultrasonic interrogation using shear waves. The amplitude of reflected shear waves from the interface increased with an increase in degradation. Further, a signal analysis approach in the frequency domain revealed a shift in the frequency minimum towards lower range in degraded samples. This phenomenon was verified using analytical models. An inversion algorithm was used to determine the interfacial transverse stiffness which decreased significantly due to increase in degradation. Conventional ultrasonic evaluation methods are rendered ineffective when a direct access to the test region is not possible; a different approach with guided wave techniques can be explored in this scenario. Investigations on CFRP-epoxy adhesive joints using Lamb waves showed a decrease in the amplitude of ‘So’ mode in degraded samples. Theoretical dispersion curves exhibited a similar trend. Frequency domain studies on the received modes using Gabor wavelet transform showed a negative shift in frequency with increased degradation. It was also observed that the maximum transmission loss for the most degraded sample with 40 percent PVA occurred in the range of 650 – 800 kHz. Non linear ultrasonic (NLU) evaluation revealed that the nonlinearity parameter (β) increased with increased degradation. Kissing bonds are most commonly occurring type of defects in adhesive joints and are very difficult to characterize. A recent non-contact imaging technique called digital image correlation (DIC) was tried to evaluate composite adhesive joints with varied percentage of inserted kissing bond defects. The results obtained indicate that DIC can detect the kissing bonds even at 50 percent of the failure load. In addition, to different experimental approaches to evaluate the bonded joint discussed above, the effect of degradation on the stresses in the bond line region was studied using analytical and numerical approach. A linear adhesive beam model based on Euler beam theory and a nonlinear adhesive beam model based on Timoshenko beam theory were used to determine the adhesive peel and shear stress in the joint. Digital image correlation technique was used to experimentally obtain the bond line strains and corresponding stresses were computed assuming a plane strain condition. It was found that the experimental stresses followed a similar trend to that predicted by the two analytical models. A maximum peel stress failure criterion was used to predict failure loads. A failure mechanism was proposed based on the observations made during the experimental work. It was further shown that the critical strain energy release rate for crack initiation in a healthy joint is much higher compared to a degraded joint. The analytical models become cumbersome if a larger number of factors have to be taken into account. Numerical methods like finite element analysis are found to be promising in overcoming these hurdles. Numerical investigation using 3D finite element analysis was carried out on CFRP-epoxy adhesive joints. The adherend – adhesive interface was modeled using connector elements whose stiffness properties as well as the bulk adhesive properties for joints with different amounts of PVA were determined using ultrasonic inspection method. The peel and shear stress variation along the adhesive bond line showed a similar trend as observed with the experimental stress distribution (DIC) but with a lesser magnitude. A parametric study using finite element based Monte-Carlo simulation was carried out to assess the effect of variation in various joint parameters like adhesive modulus, bondline thickness, adherend geometrical and material properties on peel and shear stress in the joint. It was found that the adhesive modulus and bond line thickness had a significant influence on the magnitude of stresses developed in the bond line. Thus, to summarize, an attempt has been made to study the bond line integrity of a composite epoxy adhesive lap joint using experimental, analytical and numerical approaches. Advanced NDE tools like oblique incidence ultrasound, non linear ultrasound, Lamb wave inspection and digital image correlation have been used to extract parameters which can be used to evaluate composite bonded joints. The results obtained and reported in the thesis have been encouraging and indicate that in specific cases where the bond line thickness and other relevant parameters if can be maintained or presumed reasonably non variant, it is possible to effectively evaluate the integrity of a composite bonded joint.

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28

Johnson, Rachel. „Expanding the possibilities adhesives and coatings for the theatrical application of plastic foams /“. 2005. http://catalog.hathitrust.org/api/volumes/oclc/61134673.html.

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Thesis (M.F.A.)--University of Wisconsin--Madison, 2005.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 170-175)

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29

Shih, Jin-Yu, und 石晉羽. „Improving the adhesion of plastic substrate by surface-activated functional groups“. Thesis, 2019. http://ndltd.ncl.edu.tw/handle/74s5kw.

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碩士
國立中央大學
光電科學與工程學系
107
In recent years, with the development of smart automotive electronics, the use of plastic as a substrate for automotive display has a unique product value of low cost, good optical properties, and corrosion resistance. However, compared with glass, the adhesion for plastic between the substrate and the film is worst due to it low surface energy. Moreover, it is easily absorb some water contents on its surface, causing the out-gassing during the deposition process. In order to solve the above problem of plastic coating, the study performs a baking treatment for plastic substrate before thin film deposition, and establishes an experimental method for removing the water contents in a short time. The surface of the plastic is modified by an ion source to increase the number of surface functional groups, greatly improve the adhesion of the substrate surface to the film. The functional groups are measured by FTIR. We also deposited an oxygen-deficient thin film as an interlayer between substrate and anti-reflective(AR) coating. Finally, the plastic substrate treated by baking, surface activation, and adhesion layer deposition can pass the high temperature/humidity environmental test for 1000 hours without thin films peeling.

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30

Yeh, Ren-Yu, und 葉人瑜. „Influence of Micro-mechanical Interlocking on Bonding Strength of Plastic/Metal Direct Adhesion“. Thesis, 2015. http://ndltd.ncl.edu.tw/handle/44437022855560275719.

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博士
國立交通大學
機械工程系所
104
Every material has its unique material properties, which can bring benefits or shortcomings. As advances of technologies, use of only one particular material very often cannot meet the demand of products. Thus, joining of dissimilar materials, especially between metal and plastic, has become a key issue in many industries. Industrial joining of dissimilar materials is generally performed by using adhesive bonds. Nevertheless the usage of adhesives is not environmentally friendly and takes long curing time. Several direct adhesion technologies have been developed, such as insert injection molding, hot pressing, laser welding, ultrasonic welding, and friction lap welding. These technologies were achieved by several different joining mechanisms, however, micro mechanical interlocking is considered as one of the major factor of the direct adhesion. The direct adhesion technologies based on micro mechanical interlocking were studied and developed in this thesis. In the first part, ABS and PBT+30%GF parts were formed and joined on micro-structured A5052 parts by injection molding method. An in-mold heating device was used to heat the metal insert independently. The PBT+30%GF could be joined onto the anodized, PEO, laser treated metal insert when the metal insert heated over 130°C. However, the ABS part could only joined onto laser specimen. In the second part, a low energy demand ultrasonic direct adhesion technology was carried out by the laser micro structure on the metal surface. The ABS parts were joined onto A5052 laser specimens by weld energy lower than 100J in 1sec. A method to predict the shear bond strength of micro-mechanical interlocking was established, and the shear bond strength of ABS/A5052 laser structured specimens were near the theoretical strength. The highest shear bond strength of injection molding was 14MPa, which was 36% of the plastic tensile strength. The highest shear bond strength of ultrasonic direct adhesion was 11MPa, which was 28% of the plastic tensile strength.

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LIN, KUEI-JU, und 林桂如. „High-Density Plasma Treatment for Plastic Substrates and Its Effect on Adhesion Properties“. Thesis, 2004. http://ndltd.ncl.edu.tw/handle/93320269227890856163.

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碩士
國立中興大學
材料工程學研究所
92
Thin-film coatings on flexible substrates have played an important role in future flexible-panel-display applications. Plastic substrates [polyethersulfone (PES), polycarbonate (PC) and polyethylene terephthalate (PET)] have many advantages, such as high shock-resistant, flexible and excellent mechanical properties. They are presently widely used as substrates for flexible organic light-emitting displays. A problem frequently encountered in utilizing the polymeric substrates is the poor adhesion property between the deposited film and substrate. Generally, plasma surface treatment of polymeric substrate is an essential method to improve the interface bonding. In this thesis, the adhesion properties of the SiOX barrier layer on polymer substrates were investigated by high-density plasma. From the experimental analysis, it is confirmed that the plasma pretreatment can provide hydrophilic surfaces for the PES and PC substrates. Under the same plasma treatment condition, the etch rate of the PES substrate is always smaller than that of the PC substrate. For the PES substrate, the bond interlocking between the SiOX and rough polymer surface was formed by the oxygen plasma and improved the adhesion. The Ar plasma pretreatment can enhance adhesive strength to a level of 16.5 N/mm2. The formation of C-S-Si or C-S-O-Si bonds between SiOX and PES interface examined by the x-ray photoemission spectroscopy could contribute the present results. On the other hand, the Ar plasma pretreatment of the PC substrate attributes to the O=C-Si bond formation and improves the adhesion to a level of 13.4 N/mm2; the Ar plasma pretreatment of the PET substrate attributes to the C-C-Si bond formation and improves the adhesion to a level of 4.77 N/mm2 .Based on these results, the high-density-plasma treatment has demonstrated as an efficient method to enhance the interface adhesion of the barrier coatings on plastic substrates.

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32

Lu, Kuan-Wei, und 盧冠為. „Improvement of Adhesion between Optical Film and Plastic Substrate by Using Plasma Polymerization Film“. Thesis, 2018. http://ndltd.ncl.edu.tw/handle/wrrk64.

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碩士
國立中央大學
能源工程研究所
106
Optical components are used in many electronic products in daily life. The demand for lightweight and portable electronic products is increasing, therefore, the use of plastic substrates becomes important. However, the insufficient adhesion on plastic substrates has been a serious problem of the production of optical components. In this experiment, a material with high surface free energy is introduced to deposit a polymer film by using plasma polymerization technique. The optical thin film material silicon dioxide (SiO2) was coated to investigate the improvement of the adhesion between the substrate and the optical film in each process step. In the research, four plastic material, PMMA, 330R, 480R and PC, are used as substrates. The etching process has been adopted to increase the contact area. The surface roughness can be increased up to 61.9 nm. After plasma pretreatment on the substrate surface, the hydroxyl group are activated. The water contact angle can be measured less than 10 degrees, indicating that the surface free energy has been improved. Due to the poor persistent of the hydroxyl group, the polymer film with nitrogen-containing function groups is coated, which can improve the surface free energy more effectively. The increasing of the percentage of nitrogen can be observed by XPS. After the above steps, the optical films are coated. Although etching process cannot improve the adhesion of all the substrates, the four substrates achieve completely adhesion after depositing the polymer film. Besides, the optical property of the substrates is well maintained.

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„Thermo-Mechanical Analysis of Temporary Bonding Systems for Flexible Microelectronics Fabrication Applications“. Doctoral diss., 2011. http://hdl.handle.net/2286/R.I.9038.

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abstract: Temporary bonding-debonding of flexible plastic substrates to rigid carriers may facilitate effective substrate handling by automated tools for manufacture of flexible microelectronics. The primary challenges in implementing practical temporary bond-debond technology originate from the stress that is developed during high temperature processing predominately through thermal-mechanical property mismatches between carrier, adhesive and substrate. These stresses are relaxed through bowing of the bonded system (substrate-adhesive-carrier), which causes wafer handling problems, or through delamination of substrate from rigid carrier. Another challenge inherent to flexible plastic substrates and linked to stress is their dimensional instability, which may manifest itself in irreversible deformation upon heating and cooling cycles. Dimensional stability is critical to ensure precise registration of different layers during photolithography. The global objective of this work is to determine comprehensive experimental characterization and develop underlying fundamental engineering concept that could enable widespread adoption and scale-up of temporary bonding processing protocols for flexible microelectronics manufacturing. A series of carriers with different coefficient of thermal expansion (CTE), modulus and thickness were investigated to correlate the thermo-mechanical properties of carrier with deformation behavior of bonded systems. The observed magnitude of system bow scaled with properties of carriers according to well-established Stoney's equation. In addition, rheology of adhesive impacted the deformation of bonded system. In particular, distortion-bowing behavior correlated directly with the relative loss factor of adhesive and flexible plastic substrate. Higher loss factor of adhesive compared to that of substrate allowed the stress to be relaxed with less bow, but led to significantly greater dimensional distortion. Conversely, lower loss factor of adhesive allowed less distortion but led to larger wafer bow. A finite element model using ANSYS was developed to predict the trend in bow-distortion of bonded systems as a function of the viscoelastic properties of adhesive. Inclusion of the viscoelasticity of flexible plastic substrate itself was critical to achieving good agreement between simulation and experiment. Simulation results showed that there is a limited range within which tuning the rheology of adhesive can control the stress-distortion. Therefore, this model can aid in design of new adhesive formulations compatible with different processing requirements of various flexible microelectronics applications.
Dissertation/Thesis
Ph.D. Chemical Engineering 2011

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Chen, Shuh-Heng, und 陳述亨. „A Study on The Improvement of Interfacial Adhesion Strength of Glass Fiber / Thermal Plastic Composites“. Thesis, 2000. http://ndltd.ncl.edu.tw/handle/61037654354600728203.

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博士
國立臺灣科技大學
纖維及高分子工程研究所
88
Through the plasma polymerization, monomers; styrene (ST)、acrylonitrile (AN)、tetramethylsilane (TMS)、hexamethyldisiloxane (HMDSO) 、2，2，4，4，6，6，-hexamrthylcyclotrisilazane (HMCTSN)、1，1，1，3，3，3，-hexamethyldisilazane (HMDSN)were polymerized onto the surface of glass fiber. The surface chemistry deposition were measurement by XPS, the surface free energy by static & dynamic contact angle, and surface morphology after plasma treated by SEM. Through the formation of a transcrystalline layer on the surface of glass fibre, the interfacial adhesion strength between resins and glass fibre was improved. After the glass fibre was treated with coupling agent, six different monomers were used to polymerize on the surface of glass fibre by plasma. The plasma polymers on glass fibre surface changed the surface morphology and surface free energy. The experimental results indicate that the particle-like surface would induce a transcrystalline layer to form on fibre surface improve polypropylene, polyetheretherketone and Nylon 6.6 /glass fibre interfacial shear strength rather than the glass fibre treated with coupling agent only. The glass fibre treated coupling agent than treated with acrylonitrile and styrene increased the interfacial adhesion strength between polypropylene and glass fibre by 65% and 81%. The glass fibre surface treated with particle-like organosilicon, plasma polymerized hexamethyldisilazane (ppHMDSN), ppTMS and ppHMDSO, would induce a transcrystalline layer to form and increased the interfacial shear strength of glass fiber/polypropylene by 196%, the interfacial shear strength of glass fiber/Nylon 66 and glass fiber/poltetherehterketone by 147%and 152% respectively.

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Lin, Michael Wayne 1980. „Simulation and design of planarizing materials and interfacial adhesion studies for step and flash imprint lithography“. 2008. http://hdl.handle.net/2152/17933.

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Step and flash imprint lithography (SFIL) was developed in 1999 at The University of Texas at Austin as a high resolution, cost-effective alternative to photolithography for nanoscale patterning. Unlike current projection steppers, which are resolution limited by diffraction phenomena, SFIL tools have demonstrated patterning capability down to 20 nm, a resolution currently unattainable using traditional lithographic techniques. The combination of high resolution and low cost of ownership make SFIL a strong candidate for future semiconductor integrated circuit manufacturing. For SFIL to be viable as a high volume process, there are numerous technical issues that need to be resolved. Reverse-tone step and flash imprint lithography (SFIL-R) is a reverse tone variant of SFIL that requires the successful application of a planarizing topcoat over topography through spincoating. Photopolymerizable nonvolatile fluids are ideal topcoat materials because they planarize better than volatile fluids during spincoating and can continue to level after spincoating. Fluid mechanics analyses indicate that complete planarization using capillary force is slow. Therefore, defining the acceptable or critical degree of planarization (DOP[subscript crit]) becomes necessary. Finite difference simulation of the spincoat and post-spin leveling processes was used to determine the planarization time for various topographic and material property combinations. A new material, Si-14, was designed to have ideal planarization characteristics and satisfy SFIL-R processing requirements and was used to validate the models through profilometry and interferometry experiments. During spincoating, minimizing the spin speed generates more planar films, however, this increases the spin time. To rectify this problem, a 2-stage spincoating process -- a first step with high spin speeds to achieve the target thickness quickly and a second step with low spin speeds to improve planarization -- was proposed and experimentally demonstrated. An alternative planarization technique is to generate a reverse-conformal film coating through Marangoni-driven flow. The SFIL process requires the clean separation of a quartz template from a polymer, and the force required to create this separation must be minimized to prevent the generation of defects. Fracture mechanics analyses show that control of the polymer modulus and interfacial fracture energy is the key to minimizing the separation force. Adjusting the crosslinker concentration in the imprint formulation reduces the modulus but has no significant impact on the fracture energy. On the other hand, adding surfactants to the imprint formulation reduces both the modulus and fracture energy. The fracture energy is further decreased by using a nonreactive, liquid surfactant versus a surfactant that reacts with the polymer matrix. Angleresolved X-ray photoelectron spectroscopy (XPS) results indicate that surfactant migration is more effective with a fluorinated surface treatment compared to an untreated quartz or organic surface. However, the fluorinated surface treatment that drives the migration process degrades over multiple imprints. Based on these results, it was concluded that the use of fluorinated surfactants must be accompanied by a surface treatment that is both stable and of a similar energy or polarity to induce migration and to lower the adhesive strength. Mixed-mode fracture affects the separation force, especially if shear stresses are present. Overfilling the templatesubstrate gap causes large amounts of shear stresses during separation; however, this phenomenon can be prevented by controlling the surface energies of the imprint template and substrate.
text

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何志成. „Effect of Molecular Adhesion on the Elastic-Plastic Contact Between the Fractal Rough Surface and a Plane“. Thesis, 2000. http://ndltd.ncl.edu.tw/handle/91410958607133802944.

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碩士
國立中興大學
機械工程學系
88
Abstract In the present paper , a rough surface against a flat plane are investigated. The smoothly rough surface is generated by the two-variable W-M function derived from fractal theory. The relationship of actual contact area versus the contact loading and the effect of molecular adhesion on the contact loading are analyzed numerically using Hertzian theory and JKR model. The numerical analysis is performed by considering the volume conservation of plastically deformed asperities for the contact of a rough surface and a plane. The numerical analysis are performed to calculate the functional relationship of the real contact area and real contact pressure versus the approaching ratio and surface adhesion. The results obtained from the numerical analysis are shown as follows: (1)For a given approaching ratio, the contact number of the plastically deformed asperities become larger when the rougher surface is encounted. (2)A power law relationship Ac~Lcn is proposed in this paper, and its exponent n approaches to unity. (3)For a given approaching ratio, the effect of surface adhesion is significant for a smooth surface having low surface roughness. (4)Under a given load applied on the plane, the contact load and the contact area are greater when the rough surface is smoother. In other words, the effect of surface adhesion should not be neglected for smooth and clean surfaces. Keyword: fractal rough surface, elastic-plastic contact, surface adhesion

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Brückner, Julian Karl. „Adhäsionskräfte von Artikulationsgipsen an Typ 3 und 4 Modellgips. Eine in vitro Studie: Adhäsionskräfte von Artikulationsgipsen an Typ 3 und 4 Modellgips.Eine in vitro Studie“. Doctoral thesis, 2014. https://ul.qucosa.de/id/qucosa%3A13310.

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Einleitung Artikulationsgips dient der sicheren Verankerung von zahnärztlichen Gipsmodellen im Kausimulator. Eine Norm zur Quantifizierung der Haftfähigkeit dieses speziellen Dentalgipses an Gipsmodellen existiert bisher nicht. Ziel der vorliegenden Untersuchung ist es, Unterschiede zwischen Artikulationsgipsen bezüglich ihrer Adhäsion an Modellgipsen festzustellen und die neu entwickelte Methode zu bewerten. Material und Methoden Zur Untersuchung wurden die Artikulationsgipse dentona® arti-base® 60, piccodent® A 50, AmannGirrbach Artifix® und KerrTM Snow White Plaster No.2 an einen Typ 3 (dentona® dento dur® 110) und 4 Gips (dentona® sockel plaster® GT 160) gegossen. Die zylindrischen Prüfkörper enthielten zentrisch eingegossene Retentionen, die zur Verankerung in einer Universalprüfmaschine dienten. Prüfkörper aus Typ 3 und 4 Gips wurden vor dem Angießen des Artikulationsgipses 48 h getrocknet. Die Messung der Adhäsionskraft (in N) erfolgte mittels Zugversuch, 1 h nach der Erstarrung des Artikulationsgipses. Für jede Kombination wurden 10 Versuche durchgeführt. Die Datenauswertung erfolgte mittels t Test bei unabhängigen Stichproben und Dunnett´s T3 Vergleichstest (α=0,05). Ergebnisse Aus den 80 ermittelten Werten konnte ein Ranking der Gipskombinationen erstellt werden (Max. 1950,77 N, Min. 495,97 N). Es zeigten sich signifikante Unterschiede zwischen den einzelnen Kombinationen aus Modell- und Artikulationsgips. Innerhalb der Kombinationen mit Typ 3 Gips ergaben sich signifikante Unterschiede. Die Gruppen mit Typ 4 Modellgipses unterschieden sich hingegen nicht signifikant. Eine weitere Analyse zeigte bei zwei Artikulationsgipsen einen signifikanten Unterschied zwischen der Verwendung von Typ 3 und 4 Modellgips. Schlussfolgerung Es zeigte sich, dass die neu entwickelte Methode für die Untersuchung der Haftfähigkeit von Artikulationsgipsen geeignet ist. Aneinander gegossene Artikulations- und Modellgipse erreichen unterschiedlich hohe Adhäsionskräfte. Ein Vorteil für die Verwendung des Typ 3 gegenüber dem Typ 4 Modellgips ergab sich nicht. Am besten erschien in unserer Untersuchung die Kombination von dentona® dento dur® 110 und dentona® arti-base® 60.

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Solomon, Christopher S. „Estimation and Control of Friction in Bulk Plastic Deformation Process“. Thesis, 2018. http://etd.iisc.ac.in/handle/2005/4194.

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Friction plays a significant role in bulk plastic deformation processes in controlling the tool life, formability of the work piece material and the quality of the finished product such as, surface finish, microstructure and mechanical properties. Friction causes in-homogenous deformations, leading to defects in the finished products.Excessive friction leads to heat generation, wear, pick-up and galling of the tool surface, resulting in premature failure of the tools. Computer simulations based on Finite Element Methods are being extensively used for process planning and tool designing metal working industry for bulk plastic deformation process.Material and friction models used in simulation packages are very important to have accurate process simulations. Hence it is essential to estimate the friction and understand its role on deformation of the work piece to do realistic process simulations. Friction in bulk plastic deformation processes is influenced by many factors such as velocity, temperature, contact pressure and tribological conditions such as surface roughness, lubrication etc. Among the above factors, Surface Roughness and Surface Topography (ST) of the die material are the important parameters that influence the friction between the dies and the work-piece. The abbreviation “ST” is used for surface topography. Transfer layer formation and the coefficient of friction along with its two components, namely, the adhesion and ploughing, are controlled by the ST. Ploughing component is mainly the frictional resistance caused by asperities of hard surface ploughing through soft material. The force required for plastic flow of softer material represents the ploughing friction component. Adhesion component of friction is due to the cold welding/adhesive bond occurring in the real contact area of asperities. The force required to shear the adhesion junctions formed at the interface represents the adhesion component. Though surface characteristics such as roughness were dealt with by many researchers, the influence of surface topography on friction and microstructure evolution in bulk plastic deformation is still to be understood well.Though the work done by Menezes et al. has shown that friction is influenced by the surface roughness, ST and transfer layer, but does not link this ST to the micro structural evolution of the material.Friction influences the strain and strain rates imparted to the deforming material. The strain and strain rate (apart from the temperature) imposed on the deforming material would in turn influence the microstructural evolution of the work-piece. Thus, for application to industrial scale it is important that the influence of friction on the bulk deformation and microstructural evolution, if any, be understood.Further, the techniques used by Menezes et al. for generating the STs are very difficult to be adopted in industrial scale. The present thesis addresses the following three issues on the possible influence of friction in metal forming. • Use of surface generation techniques that can be easily adapted at the industrial scale. • Role of ST on friction during room temperature and high temperature deformation. • Role of this friction on the microstructural evolution during bulk plastic deformation of Aluminium alloys.

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Qualen, Lilly Hélène Jeanne. „Adhäsionskraft von Artikulationsgipsen an Typ-IV-Modellgips in Abhängigkeit makroskopischer Oberflächenvergrößerungselemente“. Doctoral thesis, 2016. https://ul.qucosa.de/id/qucosa%3A16753.

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In der vorliegenden Arbeit galt es, die Adhäsionskraft zweier verschiedener Artikulationsgipse an einem Typ-IV-Modellgips in Abhängigkeit von makroskopischen Oberflächenvergrößerungselementen zu untersuchen und die jeweiligen Gipskombinationen zu vergleichen. Angelehnt an die Idee eines oberflächenvergrößernden Sockelformers für Gipsmodelle wurden fünf in der Adhäsionsfläche variierende Silikonformen erstellt. Untersucht wurden die Artikulationsgipse dentona® ZERO arti® und picodent® A50, die zur Messung der Adhäsionskraft [N] an Typ-IV-Modellgips (dentona® ZERO stone®) gegossen wurden. Eine von Brückner 2015 entwickelte Methode zur normierten Quantifizierung der Adhäsionskraft wurde modifiziert, sodass die Messung der Abzugskräfte bei steigender Oberfläche möglich wurde. Die zum Vergleich herangezogene Grundfläche betrug 39,6 cm². Dem gegenüber gestellt wurden Gipsformen mit um 3, 6, 12 und 30 % ansteigender Oberflächenvergrößerung. Bei der Oberflächenvergrößerung fanden aus Dublisil 20 hergestellte Negativ-Silikonformen Verwendung. Um Unterschnitte bei den makroskopischen Oberflächenvergrößerungselementen zu ver-meiden, wurden um 2° konisch zulaufende Kegelstümpfe für die Herstellung der Grundformen gewählt. Diese wurden aus Messing-Rundstangen mittels Drehmaschine hergestellt, mit runden Aluminiumplatten (Grundfläche 39,6 cm2) verschraubt und an 40 mm Rohrteilen fixiert, sodass daraus die entsprechenden Silikonformen erstellt werden konnten. Als Angriffspunkt für den Zugversuch dienten mittels einer Arretierhilfe, bestehend aus Streckgitter und je einer M8-Schraube, rechtwinklig in den Gips eingelassene Retentionen. Die Prüfkörper aus Typ-IV-Gips wurden vor dem Angießen der zu untersuchenden Artikulationsgipse für 48 h im Wärmeschrank getrocknet. Nach einstündiger Aushärtung der Artikulationsgipse unterlagen die fertigen Prüfkörper dem Zugversuch. Für beide Gipskombinationen wurden in allen fünf gewählten Oberflächen je zehn Versuche durchgeführt und die Ergebnisse mittels t-Test bei unabhängigen Stichproben und Mehrfachvergleichstests (α ≤ 0,05) statistisch ausgewertet. Die insgesamt 100 gewonnenen Versuchsergebnisse zeigen in beiden untersuchten Gipskombinationen eine signifikante Steigerung der zu überwindenden Abzugskräfte bei der Verwendung von makroskopischen Oberflächenvergrößerungselementen. Auch wird ein signifikanter Unterschied der Gipskombination aus dem Typ-IV-Gips dentona® ZERO stone® mit dem Artikulationsgips dentona® ZERO arti® gegenüber derjenigen mit picodent® A50 deutlich; es konnte ein Vorteil bei der Verwendung des Artikulationsgipses dentona® ZERO arti® im Vergleich zu picodent® A50 aufgezeigt werden. Die modifizierte Methode zur Messung der Adhäsionskraft von Typ-IV-Modellgips an Artikulationsgips in Abhängigkeit von makroskopischen Oberflächenvergrößerungselementen stellte sich bis zu einer 30%igen Oberflächenvergrößerung als geeignet dar. Es zeigte sich eine Steigerung der Adhäsionskraft bei allen makroskopischen Oberflächenvergrößerungen gegenüber dem Grundkörper ohne Oberflächenvergrößerungselemente. Die Haftkraft nimmt insbesondere durch die vertikale Flächenvergrößerung bei annähernd senkrechten Mantelflächen der Oberflächenvergrößerungselemente überproportional im Vergleich zur horizontalen Grundfläche zu. Für den zuverlässigen Verbund von Gipsmodellen mit Artikulationsgips im Kausimulator scheint demnach die Nutzung von Sockelformern oder anderweitigen Methoden zur Oberflächenvergrößerung unerlässlich.:Inhaltsverzeichnis Inhaltsverzeichnis I Tabellenverzeichnis III Abbildungsverzeichnis IV Abkürzungsverzeichnis VI 1 Einleitung 1 1.1 Untersuchungsziel 3 1.2 Zum Aufbau der Arbeit 4 2 Literaturübersicht 5 2.1 Definition Gips 5 2.2 Historischer Überblick 6 2.3 Einteilung von Gipsarten und -formen 7 2.3.1 Naturgips und Naturanhydrit 7 2.3.2 Synthetischer Gips 8 2.4 Das System CaSO4-H2O 9 2.5 Herstellung des Halbhydrats 10 2.5.1 Das nasse Brennen – Herstellung des α-Halbhydrats 11 2.5.2 Das trockene Brennen – Herstellung des β-Halbhydrats 12 2.6 Die Abbindereaktion 13 2.7 Dentalgips 14 2.7.1 Einteilung und Eigenschaften von Dentalgipsen 17 2.7.2 Einflussfaktoren auf Gipseigenschaften 20 3 Aufgabenstellung 24 4 Material und Methode 25 4.1 Gipsauswahl 25 4.1.1 dentona® ZERO stone® 25 4.1.2 dentona® ZERO arti® 25 4.1.3 picodent® A50 26 4.1.4 Technische Daten der Gipse 26 4.2 Rohre zur Formherstellung 27 4.3 Oberflächenvergrößerungselemente 27 4.3.1 Vorversuche 28 4.3.2 Kegelstümpfe zur Oberflächenvergrößerung 30 4.4 Herstellung der Silikonformen 32 4.5 Spannex II 34 4.6 Geräte 34 4.6.1 Dreve Dosper evo 34 4.6.2 KERN®-Waage 35 4.6.3 Wassermann Wamix-Classic 35 4.6.4 KaVo-Rüttler 35 4.6.5 MLW®-intermed-Trockenschrank 36 4.6.6 Zwick/Roell-Universaltestmaschine Z010 36 4.7 Gipsverarbeitung 36 4.8 Gipsretention mit Arretierhilfe 37 4.9 Prüfkörperherstellung 38 4.10 Versuchsanordnung 42 5 Versuchsergebnisse 43 6 Statistische Auswertung 50 7 Diskussion 54 7.1 Diskussion der Methode 54 7.1.1 Gipsauswahl 54 7.1.2 Oberflächenvergrößerungselemente 55 7.1.3 Prüfkörperherstellung und Versuchsdurchführung 55 7.2 Diskussion der Ergebnisse und Literaturvergleich 58 8 Schlussfolgerung und praktische Relevanz 62 9 Zusammenfassung 64 10 Literaturverzeichnis 66 11 Anhang 72

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Jhin, Minseok. „Crack Growth Rate and Crack Path in Adhesively Bonded Joints: Comparison of Creep, Fatigue and Fracture“. Thesis, 2012. http://hdl.handle.net/1807/33256.

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The relationship between crack path and test method was examined by comparing the performance of adhesive-adherend combinations (six) in quasi-static fracture, mixed-mode fatigue, and creep crack growth. Crack paths in creep and quasi-static fracture were similar due to similar crack-tip plastic zone sizes in the epoxy adhesive even though the crack growth rates in creep were much smaller. Under condensed moisture and mixed-mode, creep and threshold fatigue tests produced interfacial failure. Under room-temperature dry environment, near threshold mixed-mode fatigue was interfacial, but was not in creep or quasi-static fracture. Smaller plastic zone size and crack path proximity to the interface that followed increased the sensitivity of near threshold, mixed-mode fatigue to surface properties. Therefore, the interfacial or cohesive failure of an adhesive system, which may judge the quality of the bond, can be a function of the test being conducted and may not be an absolute indicator of joint quality.

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Muthukumar, R. „Effect Of Material Non-Linearity Of Adherends On Fracture Behaviour Of Bimaterial Interface Cracks“. Thesis, 2005. https://etd.iisc.ac.in/handle/2005/1470.

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Muthukumar, R. „Effect Of Material Non-Linearity Of Adherends On Fracture Behaviour Of Bimaterial Interface Cracks“. Thesis, 2005. http://etd.iisc.ernet.in/handle/2005/1470.

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Sommer, Guido Sebastian. „Mikromechanische Untersuchungen zur Faser-Matrix-Haftung in Faser-Kunststoff-Verbunden:: Einfluss von Härtungsdauer, Feuchtigkeit und Prüfparametern“. Doctoral thesis, 2017. https://tud.qucosa.de/id/qucosa%3A31135.

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Zur Untersuchung der Faser-Matrix-Haftung in Faser-Kunststoff-Verbunden werden neben makromechanischen Methoden wie dem Querzug und der Drei-Punkt-Biegung mikromechanische Methoden an Einzelfaser-Modellverbunden eingesetzt. Zu letzteren Methoden zählen bspw. der Tropfenabscherversuch, der Einzelfaserauszugversuch (engl. single-fibre pull-out test, SFPO) und der Einzelfaserfragmentierungsversuch (engl. single fibre fragmentation test, SFFT). Bei ihrem Einsatz ist zu beachten, dass sich unterschiedliche Einflussgrößen auf ihre Ergebnisse auswirken können. In der vorliegenden Arbeit wird eine ausführliche Literaturübersicht mit einem detaillierten Überblick zu einer größeren Anzahl verschiedener Einflussgrößen durchgeführt. Daraus werden die Einflussgrößen Härtungsdauer, Feuchtigkeit, freie Faserlänge und Abzugsgeschwindigkeit als Untersuchungsgegenstände dieser Arbeit erarbeitet. Wesentliche aus dieser Arbeit resultierende Ergebnisse und Schlussfolgerungen sind nachstehend zusammengefasst. Härtungsdauer: Bei SFFT-Untersuchungen an Keramikfaser/Epoxidharz-Prüfkörpern wird ein degressiver Anstieg der Faser-Matrix-Haftung über der Härtungsdauer beobachtet. Die Ergebnisse geben Hinweise darauf, dass sich die Härtungsdauer beim SFFT und SFPO prinzipbedingt unterschiedlich auswirkt (aufgrund destruktiver bzw. konstruktiver Überlagerungen von Eigenspannungen und Prüfkraft-induzierten Spannungen). Feuchtigkeit: SFPO-Untersuchungen an Kohlenstoffaser/Epoxidharz-Prüfkörpern nach einmonatiger Konditionierung in feuchtem (50 %rF, 23 °C) bzw. trockenem Klima (0 %rF, 23 °C) belegen eine feuchtebedingt verringerte Haftung. Daraus wird geschlussfolgert, dass eine schwankende Luftfeuchtigkeit auch in diesem eingegrenzten klimatischen Spektrum (bspw. in teilklimatisierten Laboren) als wichtiger potentieller Störfaktor zu beachten ist. Prüfparameter: Auf Basis des Hooke’schen Gesetzes kann für den SFPO gezeigt werden, dass die freie Faserlänge die Maximalkraft beeinflusst und die Einflüsse der freien Faserlänge und der Abzugsgeschwindigkeit auf die Maximalkraft in Zusammenhang stehen. Beides wird anhand von SFPO-Untersuchungen an Glasfaser/Epoxidharz-Prüfkörpern bestätigt. Ferner wird aus den Untersuchungen geschlussfolgert, dass eine Geschwindigkeitserhöhung von 0,01 µm/s auf 0,1 µm/s zur Reduzierung der Versuchsdauer – im vorliegenden Fall von 30 45 min auf 6 8 min – vertretbar ist. Darüber hinaus werden anhand von Fehlerverstärkungsfaktoren differenzierte Aussagen zum Einfluss fehlerhaft bestimmter Eingangsdaten auf die Berechnung der lokalen Grenzflächenscherfestigkeit generiert.
For investigating fibre-matrix adhesion in fibre-polymer composites, macromechanical methods such as transverse tensile and three-point bending tests can be applied as well as micromechanical methods for which single-fibre model composites are used. The latter category of methods includes microbond, single-fibre pull-out (SFPO) and single-fibre fragmentation tests (SFFT). When applying these methods, it needs to be considered that their results can be affected by different influencing factors. In the present thesis, an extensive literature survey with a detailed overview of a larger number of influencing factors is conducted. Based on this overview, the factors curing time, moisture, free fibre length and test speed are acquired as objects of investigation of this thesis. Main results and conclusions of this work are summarised below. Curing time: Results from SFFT investigations on ceramic fibre/epoxy-specimens exhibit a degressive increase of fibre-matrix adhesion with curing time. This indicates that curing time affects SFFT and SFPO results differently due to different underlying principles (based on destructive and, respectively, constructive superposition of internal stresses and load-induced stresses). Moisture: SFPO specimens (carbon fibre/epoxy) are conditioned in humid (50 %rH, 23 °C) and dry climate (0 %rH, 23 °C) for one month prior to testing. The results show lower adhesion due to moisture. It is concluded that uncontrolled humidity, even in this limited climatic spectrum, needs to be considered as an important potential factor of influence (e.g. in partially climatised laboratories). Test parameters: Based on Hooke’s law, it is demonstrated for the SFPO that a) the free fibre length affects the maximum force and b) the effects of the free fibre length and the test speed on the maximum force are interrelated. Both is confirmed with results from SFPO investigations on glass fibre/epoxy-specimens. Furthermore, it is deduced from the above investigations that an increase in test speed from 0.01 µm/s to 0.1 µm/s is legitimate for reducing test duration – in the present case from 30 45 min to 6 8 min. In addition, the effect of erroneously determined input data on the calculation of the local interfacial shear strength is studied using conditions numbers (a measure for the propagation of error). With this, differentiated statements are generated.

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