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Journal articles on the topic 'Molding materials Testing'
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1
Kuzmin, Anton M., Vladimir N. Vodyakov, Alexandr V. Kotin, Vyacheslav V. Kuznetsov, and Mariya I. Murneva. "Study of the Influence of the Forming Method on the Physical and Mechanical Characteristics of Thermoplastic Polymeric Materials." Key Engineering Materials 869 (October 2020): 342–47. http://dx.doi.org/10.4028/www.scientific.net/kem.869.342.
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This paper presents the results of the study of the effect of polymer materials compression and injection methods of molding on the physical and mechanical properties of the resulting samples. Widely used polymers such as poly-amide, thermoplastic elastomer and polyketone were taken as the objects of study. Granite composites based on polyamide were produced by PolyLab Rheomex RTW 16 twin-screw extruder, then modified with fine powders of schungite, graphite and silicon dioxide. Samples for testing in the form of double-sided blades were obtained by injection molding on a Babyplast 6/10V machine and compression molding on a Gibitre hydraulic press. Elastic-strength tests of the obtained samples were carried out on a tensile testing machine UAI-7000 M.
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Skrobak, Adam, Michal Stanek, David Manas, Martin Ovsik, Vojtech Senkerik, and Martin Reznicek. "The Influence of the Production Process on Mechanical Properties of Rubber Testing Samples." Advanced Materials Research 1025-1026 (September 2014): 37–41. http://dx.doi.org/10.4028/www.scientific.net/amr.1025-1026.37.
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The article deals with the influence of production technology on mechanical properties of rubber testing samples. In practice, rubber testing samples are cut out from a compression molded sheet, also in case of testing of rubber compounds appointed for injection molding. However, the different way of the preparation of testing samples and the production itself may have a negative effect on the mechanical properties of the final product. Thus the article judges, to what extent the mechanical properties (tensile strength, extension, tear strength and microhardness) of testing samples from selected rubber materials are influenced by injection molding, and evaluates the possible divergence.
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Geng, Baoqun, Haifu Wang, Qingbo Yu, Yuanfeng Zheng, and Chao Ge. "Bulk Density Homogenization and Impact Initiation Characteristics of Porous PTFE/Al/W Reactive Materials." Materials 13, no. 10 (May 15, 2020): 2271. http://dx.doi.org/10.3390/ma13102271.
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In this research, the bulk density homogenization and impact initiation characteristics of porous PTFE/Al/W reactive materials were investigated. Cold isostatic pressed (CIPed) and hot temperature sintered (HTSed) PTFE/Al/W reactive materials of five different theoretical maximum densities were fabricated via the mixing/pressing/sintering process. Mesoscale structure characteristics of the materials fabricated under different molding pressures were compared while the effect of molding pressures on material bulk densities was analyzed as well. By using the drop weight testing system, effects of the theoretical maximum densities (TMDs), drop heights and molding pressures on the impact initiation characteristics were studied. Quantitatively, characteristic drop heights (H50) for different types of materials were obtained. The two most significant findings of this research are the density homogenization zone and the sensitivity transition zone, which would provide meaningful guides for further design and fabrication of reactive materials.
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Doerffel, Christoph, Gábor Jüttner, and Roland Dietze. "Micro Test Specimens for Compound Engineering with Minimum Material Needs." Materials Science Forum 825-826 (July 2015): 928–35. http://dx.doi.org/10.4028/www.scientific.net/msf.825-826.928.
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The use of micro test specimens is a good way to characterize micro injection molding processes and the resulting material properties. The material properties of microparts may differ from standard injection molding parts, due to an overrepresentation of the surface layers with high fiber orientation and divergent morphology. In order to characterize the distribution and agglomeration of fibers and particles for the manufacturing of micro injection molding parts of functionalized polymer compounds, it is essential to manufacture the test specimens and the part using the same process. The distribution and size of these particles e.g. Carbon-Nano-Tubes (CNT) or piezo ceramic particles is dependent on the polymer plastication process during injection molding. Therefore the use of micro test specimens is a requirement for precise material selection and engineering.Due to the minimum material needs, micro test specimens are also useful for the comparison of the material properties of new polymers and compounds, which were produced in amounts of 20 g to 100 g. Another application is the testing of highly elastic and ductile materials with strains over 100%. By using micro test specimens it is possible to test high strains with low elongations in a short time.A new innovative micro test specimen has been developed at the Technische Universität Chemnitz in cooperation with the Kunststoff-Zentrum in Leipzig, that is especially designed for the testing and dimensioning of plastic microparts with weights less than 0.1 g. The main feature of the new specimen and testing process is the combined positive and force-fitted locking, which enables a precise positioning of the micro specimen and an even application of the clamping force. In order to achieve reproducible clamping, testing and handling of the sample, the clamping and testing process are spatially separated. The shape of the test specimen enables a parameter optimization for the micro injection molding process.
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Koreniugin, S. V., and S. L. Rovin. "Laboratory methods for the study of rod mixtures at high temperatures." Litiyo i Metallurgiya (FOUNDRY PRODUCTION AND METALLURGY), no. 4 (December 20, 2021): 24–27. http://dx.doi.org/10.21122/1683-6065-2021-4-24-27.
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The article presents an analysis of laboratory methods for studying temperature and phase expansions and changes in the properties of molding and core mixtures during heating. The analysis of laboratory equipment offered on the Belarusian market for high‑temperature testing of molding materials and mixtures is carried out, the methodology for conducting such tests using devices from leading world manufacturers is described. The results of high‑temperature test tests of mixtures based on furan binders are presented.
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Jiang, J., W. J. Meng, G. B. Sinclair, and E. Lara-Curzio. "Further experiments and modeling for microscale compression molding of metals at elevated temperatures." Journal of Materials Research 22, no. 7 (July 2007): 1839–48. http://dx.doi.org/10.1557/jmr.2007.0252.
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Replication of metallic high-aspect-ratio microscale structures (HARMS) by compression molding has been demonstrated recently. Molding replication of metallic HARMS can potentially lead to low-cost fabrication of a wide variety of metal-based microdevices. Understanding the mechanics of metal micromolding is critical for assessing the capabilities and limitations of this replication technique. This paper presents results of instrumented micromolding of Al. Measured molding response was rationalized with companion high-temperature tensile testing of Al using a simple mechanics model of the micromolding process. The present results suggest that resisting pressure on the mold insert during micromolding is governed primarily by the yield stress of the molded metal at the molding temperature and a frictional traction on the sides of the insert. The influence of strain rate is also considered.
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Jia, Hongxin, Jingfu Wang, and Yasong Ma. "Experimental study on preparation of fuel by low-temperature pyrolysis of plastic waste combined with desiccated sludge after preforming." MATEC Web of Conferences 355 (2022): 01028. http://dx.doi.org/10.1051/matecconf/202235501028.
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Take plastic waste and dried sludge as raw materials, use pressure testing machine and high temperature hot pressing mold to test under different parameters. The effect of raw material ratio, low-temperature pyrolysis temperature, molding pressure and heating time on the physical properties of the molded fuel after low-temperature pyrolysis, such as relaxation density, fall strength, compressive strength and water permeability, are studied. Single factor tests show that the general range of mixed molding parameters is: mixture ratio (dry sludge: composite plastics) 85:15~75:25, temperature 150~250°C, heating time 20~40min, compaction pressure 2~6MPa. Orthogonal test is designed on the basis of single factor test. The results show that the most important factor affecting the relaxation density of molding fuel is molding pressure, the most important factor affecting compressive strength is the ratio of raw materials, and the most important factor affecting water permeability is heating time. The fall strength is less affected by various factors. It is due to the stickiness of the molded plastic after softening, which strengthens the “cohesion” between the raw materials, and will not be explored in the orthogonal experiment. The optimal combination of relaxation density molding parameters is the ratio (dry sludge: composite plastics) 80:20, temperature 250°C, heating time 30min, compaction pressure 6MPa; the optimal combination of compressive strength molding parameters is 75:25, 250°C, 30min, 6MPa; the optimal combination of anti-moisture absorption performance molding parameters is 85:15, 150°C, 30min, 2MPa.
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Selvaraj, Senthil Kumaran, Aditya Raj, R. Rishikesh Mahadevan, Utkarsh Chadha, and Velmurugan Paramasivam. "A Review on Machine Learning Models in Injection Molding Machines." Advances in Materials Science and Engineering 2022 (January 5, 2022): 1–28. http://dx.doi.org/10.1155/2022/1949061.
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One of the most suitable methods for the mass production of complicated shapes is injection molding due to its superior production rate and quality. The key to producing higher quality products in injection molding is proper injection speed, pressure, and mold design. Conventional methods relying on the operator’s expertise and defect detection techniques are ineffective in reducing defects. Hence, there is a need for more close control over these operating parameters using various machine learning techniques. Neural networks have considerable applications in the injection molding process consisting of optimization, prediction, identification, classification, controlling, modeling, and monitoring, particularly in manufacturing. In recent research, many critical issues in applying machine learning and neural network in injection molding in practical have been addressed. Some problems include data division, collection, and preprocessing steps, such as considering the inputs, networks, and outputs, algorithms used, models utilized for testing and training, and performance criteria set during validation and verification. This review briefly explains working on machine learning and artificial neural network and optimizing injection molding in industries.
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Golmakani, Mohammad E., Tomasz Wiczenbach, Mohammad Malikan, Reza Aliakbari, and Victor A. Eremeyev. "Investigation of Wood Flour Size, Aspect Ratios, and Injection Molding Temperature on Mechanical Properties of Wood Flour/Polyethylene Composites." Materials 14, no. 12 (June 20, 2021): 3406. http://dx.doi.org/10.3390/ma14123406.
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In the present research, wood flour reinforced polyethylene polymer composites with a coupling agent were prepared by injection molding. The effects of wood flour size, aspect ratios, and mold injection temperature on the composites’ mechanical properties were investigated. For the preparation of the polymer composites, five different formulations were created. The mechanical properties including tensile strength and the modulus, flexural strength and the modulus, and impact energy were measured. To investigate the changes in the properties resulting from different compositions, mechanical static and impact testing was performed. The obtained results indicate that by reducing the flour size, the tensile strength and modulus, flexural strength, and impact energy were reduced. In contrast, the flexural modulus increased. Furthermore, with the increment of injection molding temperature, the tensile strength and the modulus and the impact energy of the specimens were reduced. On the other hand, the flexural strength and the modulus increased. Thus, an optimized amount of injection molding temperature can provide improvements in the mechanical properties of the composite.
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Shan, Ning, and Guo Heng. "New Technology Research of Nondestructive Testing for Aero Aircraft Composite Materials." Advanced Materials Research 279 (July 2011): 142–46. http://dx.doi.org/10.4028/www.scientific.net/amr.279.142.
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Composite materials have many advantages such as big specific strength, high specific stiffness, good disrepair safety characteristic, large area molding conveniently and easy to forming complex shape. It becomes important structural materials of aero aircraft equipment necessarily and is used widely in aviation industry. Composite materials components of aero aircraft with complex and delicate structure chronically work in harsh environment. Early testing of its key component’s minute defects has been an urgent and necessary task. In this paper, its damage model and characteristic are analyzed and studied. Considering the limitation of composite materials structure’s detection methods at present, a number of existing problems are presented and development directions are pointed out. Laser ultrasound detection technique, continuous distribution sensing technique and optical fiber sensing technique are studied. The method of damage detection of aero aircraft’s composite materials components is put forward based on the organic combination of the three techniques. The results show that the system can be used to detect multi-ultrasound signals of large composite materials structure. Its structure is simple. It has small bulk and low cost. It is characterized by easy realization.
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Tuo, Xiaohang, Yue Yu, Yabo Zhao, Yumei Gong, and Jing Guo. "Validation study on the theory of composites by using three-dimensional printing technology." Journal of Reinforced Plastics and Composites 37, no. 15 (May 24, 2018): 1004–10. http://dx.doi.org/10.1177/0731684418775820.
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RoM, as a reinforcement theory of composite materials, has been widely used. With the advent of new materials and molding processes, this theory is constantly being refined and validated. In this paper, four high-tech fibers as continuous reinforcing materials and carbon nanotubes as non-continuous reinforcing materials were evaluated, and two ideal composite samples were designed using three-dimensional printing technology. The reliability of RoM was verified by tensile testing. Also, a fiber tensile fixture was designed. The fiber bundle strength was inversely proportional to the length and the number of roots of fiber. In verifying the RoM, three-dimensional printing was employed, showing the diversity and complexity of the testing samples.
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Lou, Bai Yang, Qiong Tong Ma, Shui Long Kong, Bin Xu, and Fang Liang Dong. "Study on Temperature Sensibility of Nano-Copper/Paraffin Materials." Advanced Materials Research 502 (April 2012): 91–95. http://dx.doi.org/10.4028/www.scientific.net/amr.502.91.
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In this paper, nano-copper/paraffin thermosensitive composite materials were prepared by high-energy ball milling, and pressed into the glass cylindrical tube by hot press molding. The micro-morphology and particle shape and microstructure of composite particles were observed by SEM, FI-IR, etc, the temperature sensibility of thermosensitive composite materials were tested by self-manufactured thermosensitive testing device. It shows that the way by which high-energy ball milling are prepared, the composite particle coated with good results, dense arrangement of particles, copper particles on the paraffin structure does not produce damage. With copper mass ratio increasing, the thermal conductivity of temperature sensitive composite is improved.
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LEANDRO, Lisliane Nara Rossi, Rui Barbosa de BRITO JÚNIOR, Marcelo Lucchesi TEIXEIRA, Luiz Martins TURANO, and Luciana Jardini da CUNHA. "Different materials and techniques for accurate molding for adaptation in angled implants." RGO - Revista Gaúcha de Odontologia 62, no. 2 (June 2014): 149–52. http://dx.doi.org/10.1590/1981-8637201400020000072608.
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OBJECTIVE: To evaluate the marginal misfit between intermediate and micro-unitmetal cylinder, by varying the angle of the implants, using two different types of material and different molding techniques. METHODS: A model was made with three implants (one perpendicular to the horizontal plane and two inclined) using micro-unit intermediates. A rod attached to the master model served as a control condition to evaluate the suitability of the twenty specimens, carried out with the help of an optical stereomicroscope (Pantec, Brazil; Materials Testing Laboratory, São Leopoldo Mandic, Campinas, São Paulo). RESULTS: Evaluator reliability was assessed using theIntraclass Correlation Coefficient, obtaining 99.6% (excellent). There were significant differences between groups, and the Mann-Whitney test compared groups in pairs for a more accurate result. CONCLUSION: The group which presented the best behavior was open tray and condensation silicone and the worst result, that needed to be cast several times, was closed tray and condensation silicone.
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Lawrence, Jeffrey M., Mathieu Devillard, and Suresh G. Advani. "Design and Testing of a New Injection Approach for Liquid Composite Molding." Journal of Reinforced Plastics and Composites 23, no. 15 (October 2004): 1625–38. http://dx.doi.org/10.1177/0731684404039780.
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Stanek, Michal, David Manas, Miroslav Manas, Vojtech Senkerik, Adam Skrobak, and Jan Navratil. "Influence of Technological Parameters on Material Flow." Advanced Materials Research 1120-1121 (July 2015): 1194–97. http://dx.doi.org/10.4028/www.scientific.net/amr.1120-1121.1194.
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Injection molding is one of the most extended polymer processing technologies. It enables the manufacture of final products, which do not require any further operations. The tools used for their production – the injection molds – are very complicated assemblies that are made using several technologies and materials. Delivery of polymer melts into the mold cavity is the most important stage of the injection molding process. The fluidity of polymers is affected by many parameters Inc. mold design. Evaluation of set of data obtained by experiments in which the testing conditions were widely changed shows that the quality of cavity surface and technological parameters (injection rate, injection pressure and gate size) has substantial influence on the length of flow.
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Alantali, A., RA Alia, R. Umer, and WJ Cantwell. "Scaling effects in the manufacture and testing of grid-stiffened composite structures." Journal of Composite Materials 52, no. 17 (November 29, 2017): 2351–63. http://dx.doi.org/10.1177/0021998317744871.
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Scaling effects in the manufacture and testing of glass fiber-reinforced epoxy grid-stiffened structures have been investigated in this study. Four nominally identical scaled sizes of mold have been manufactured, in which the length, width, height, and internal channel sizes were varied to achieve ¼, ½, ¾ and full-scale stiffened structures. The panels were manufactured on a glass mold using the vacuum-assisted resin transfer molding technique, enabling the flow front to be monitored throughout the filling process. Grid-stiffened beams were removed from the cured panels and tested in flexure on scaled bending fixtures. The vacuum-assisted resin transfer molding manufacturing study on the four scaled sizes indicated that resin infusion incurred more rapidly in the smallest mold, possibly due to difficulties in accurately cutting the glass fabric, which in turn reduced the effective areal density of the fabric, thereby modifying its effective permeability. The flow rates and velocities of the resin fronts in the larger mold sizes were similar, suggesting that an appropriately scaled mold can be used to successfully predict the infusion process in more representative structures. Flexural tests on the grid-stiffened samples highlighted a similar response in the three largest samples, with the smallest sample again offering a modified response. Similar failure mechanisms, including fracture of the grid structure, debonding at the skin-core interface, and flexural failure in the center of the sample, were observed in all of the samples.
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Tarasovskii, V. P., A. A. Avgustov, A. Yu Omarov, V. V. Rybalchenko, A. A. Vasin, A. V. Smirnov, and A. D. Shlyapin. "Properties of different aluminum oxide powders and ceramics made of them." NOVYE OGNEUPORY (NEW REFRACTORIES), no. 2 (April 26, 2019): 40–43. http://dx.doi.org/10.17073/1683-4518-2019-2-40-43.
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Different aluminum oxide powders CL370, CT1200 SG and CT3000SG of Almatis GmbH (Germany) were studied to determine their service ability for obtaining dense-sintered products by hot injection molding. The manufacturing technology parameters for given powders were experimentally determined and properties of ceramic materials thus obtained were investigated. The products manufactured according to the selected technology were transferred to real customers for their further testing. Ill. 3. Ref. 7. Tab. 9.
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Liu, Mingrui, Lidong Wang, and Xiongqi Peng. "Testing, characterizing, and forming of glass twill fabric/polypropylene prepregs." Journal of Composite Materials 53, no. 28-30 (May 24, 2019): 3939–50. http://dx.doi.org/10.1177/0021998319851215.
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This paper investigates the mechanical behaviors of thermoplastic woven prepregs via testing and forming experiments. Glass twill fabric/polypropylene prepregs are produced by chemical treatment on fabric surface and a hot pressure molding approach. Then, mechanical tests including uniaxial tensile and bias extension of the glass twill fabric and its prepregs are carried out to provide basic data set for material modelling. An anisotropic hyperelastic model based on strain energy decomposition is proposed. And its material parameters are obtained by fitting these experimental data. Hemispherical thermo-stamping experiments are implemented for model verification. Very good agreements between forming simulation results and experimental data including boundary profiles, local shear angles, and forming force magnitude are obtained. The present work provides a complete data set for the model development and verification of thermoplastic woven fabric prepregs.
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Wang, Fei Fei. "Study on the Application of Carbon Fiber Composite Materials in High-Speed Trains." Materials Science Forum 893 (March 2017): 31–34. http://dx.doi.org/10.4028/www.scientific.net/msf.893.31.
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The new carbon fiber composite materials trains hood is designed with vacuum infusion molding process characteristics and performance of existing trains hood according to the characteristics of the high specific strength and stiffness of the carbon fiber composite materials. According to the requirements of referring to the IEC61373-1999[Railway Rolling Stock Equipment Shock and Vibration Testing Standards] and GB/T3317-2006[Electric Locomotive General Technical Conditions], the strength and deformation of the trains hood is calculated and analyzed on the conditions of the impaction, air movement load case and the end compression. The test result shows that the mechanical properties of the structure meets the requirements in the 500km/h high-speed test train.
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Wang, Ju Wei. "Cellulose-Based Biodegradable Packaging Materials of Antimicrobial." Advanced Materials Research 811 (September 2013): 280–83. http://dx.doi.org/10.4028/www.scientific.net/amr.811.280.
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In recent years, with the requirements of environmental protection of packaging materials improve, biodegradable antibacterial materials more and more attention to. This paper to can hair sex polystyrene as main raw materials, and by the synthesis of biodegradable bacteriostasis of study on the properties of packaging materials. The results shows that can hair sex polystyrene as the main raw material made by injection molding process thickness of 0.25 mm plate, and influence factors of sheet material performance, get the film material performance is the ideal process parameters. According to People's Republic of China national standard GB/T1040-92"plastic tensile properties test method" and GB/T20197-2006"degradable plastics the definition, classification, signs and degrade the performance requirements," as determined by the experimental method for testing. The orthogonal experiment results show that can hair sex polystyrene usage: 6 g; Microcrystalline cellulose usage: 0.2g; The antibacterial agent type: silver nanotio2 in the system performance and degrade the performance of the material mechanics and antibacterial good performance.
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Ernst, L. J., G. Q. Zhang, K. M. B. Jansen, and H. J. L. Bressers. "Time- and Temperature-Dependent Thermo-Mechanical Modeling of a Packaging Molding Compound and its Effect on Packaging Process Stresses." Journal of Electronic Packaging 125, no. 4 (December 1, 2003): 539–48. http://dx.doi.org/10.1115/1.1604156.
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For reliable virtual thermo-mechanical prototyping of electronic packages appropriate descriptions of the mechanical behavior of the constituent materials are essential. In many packages molding compounds are used for encapsulation and underfill to provide environmental protection and/or to improve the package thermal mechanical reliability. Therefore, among others, the availability of appropriate constitutive models for various epoxy-molding compounds is one of the requirements for computational prototyping. As there is a large variability of available molding compounds, it is essential to be able to experimentally establish the model parameters in an efficient manner. Because of the implied simplicity, linear visco-elastic models combined with the time-temperature superposition theory are mostly used in thermo-mechanical simulations. Among the various experimental possibilities to efficiently establish the model parameter functions, in the present paper the use of unidirectional creep testing is worked out for a chosen molding compound. Here isothermal one-day creep experiments at different temperatures (ranging below and above the glass transition temperature of the compound) are performed. The tensile creep compliance and the time-dependent Poisson’s ratio of the material at different temperatures are successfully used to construct visco-elastic master curves. As the Poisson’s ratio shows a significant change during a creep or relaxation test, its effect in partly constraint situations (as in packages) will be evident. Therefore it is not reliable to approximate this variable using a constant value. Further, the visco-elastic model of the material is implemented in a finite element program and verified by means of a shear stress relaxation experiment and a creep experiment both under nonisothermal conditions. Moreover, the effect of the creep behavior of the molding compound on the packaging process stress field and its evolution is investigated. Substantial cost saving was realized by package design optimization based on the reliable prediction of the packaging process stresses.
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Kharbas, Hrishikesh A., Jason D. McNulty, Thomas Ellingham, Cyrus Thompson, Mihai Manitiu, Guenter Scholz, and Lih-Sheng Turng. "Comparative study of chemical and physical foaming methods for injection-molded thermoplastic polyurethane." Journal of Cellular Plastics 53, no. 4 (June 2, 2016): 373–88. http://dx.doi.org/10.1177/0021955x16652107.
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Thermoplastic polyurethane is one of the most versatile thermoplastic materials being used in a myriad of industrial and commercial applications. Thermoplastic polyurethane foams are finding new applications in various industries including the furniture, automotive, sportswear, and packaging industries because of their easy processability and desirable customizable properties. In this study, three methods of manufacturing injection molded low density foams were investigated and compared: (1) using chemical blowing agents, (2) using microcellular injection molding with N2 as the blowing agent, and (3) using a combination of supercritical gas-laden pellets injection molding foaming technology and microcellular injection molding processes using co-blowing agents CO2 and N2. Thermal, rheological, microscopic imaging, and mechanical testing were carried out on the molded samples with increasing amounts of blowing agents. The results showed that the use of physical blowing agents yielded softer foams, while the use of CO2 and N2 as co-blowing agents helped to manufacture foams with lower bulk densities, better microstructures, and lower hysteresis loss ratios. Chemical blowing agent-foamed thermoplastic polyurethane showed an earlier onset of degradation. The average cell size decreased and the cell density increased with the use of co-blowing agents. A further increase in gas saturation levels showed a degradation of microstructure by cell coalescence.
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Wong, Lionel C., and Moir D. Haug. "Cyclical closed-system freeze–thaw permeability testing of soil liner and cover materials." Canadian Geotechnical Journal 28, no. 6 (December 1, 1991): 784–93. http://dx.doi.org/10.1139/t91-095.
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The impact of closed-system freeze–thaw cycles on the permeability of clay, till, and sand–bentonite mixtures was examined in a laboratory test program. The bentonite content of the sand–bentonite mixtures varied from 4.5 to 25%. Test samples were prepared by dry mixing, moisture conditioning, and compacting materials according to ASTM D698, method A specifications. The molding water content of these samples was at or slightly wet of optimum. Trimmed test samples were placed in a triaxial permeameter and their unfrozen or initial permeability was established. These permeability tests were conducted for approximately 10 000 min using low hydraulic gradients and confining stress. Changes in specimen volume were also measured during permeability testing. Once the initial permeability of a specimen was established, the test was halted and the specimen was frozen inside the permeameter with no access to water. After freezing, the specimens were allowed to thaw before a second permeability test was conducted. This process of alternating permeability tests with freeze–thaw cycles was continued until the change in permeability between freeze–thaw cycles became insignificant. The results of this test program show that the permeabilities of both the clay and till specimens increase due to freeze–thaw cycles. In contrast, the sand–bentonite specimens showed no increase in permeability due to freeze–thaw cycles. Key words: closed system, freeze–thaw, permeability, volume change, soil liners, soil covers.
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SHI, XIAOLIANG, GANGQIN SHAO, XINGLONG DUAN, and RUNZHANG YUAN. "RESEARCH ON SHAPING TECHNOLOGY OF NANOCOMPOSITE WC-6Co POWDER AND PROPERTIES OF SINTERED COMPACTS." International Journal of Nanoscience 05, no. 02n03 (April 2006): 233–38. http://dx.doi.org/10.1142/s0219581x06004292.
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The influences of powder extrusion molding (PEM), die pressing and cold isostatic pressing (CIP) on the green compacts and the sintered compacts of nanocrystalline WC-6 Co composite powder produced by spray pyrogenation-continuous reduction and carburization technology were researched. The results showed that the pore volume distribution, density and scanning electron microscopy (SEM) morphologies of fractured surface of powder extrusion molding or die pressing followed by the cold isostatic pressing consolidation green compacts were better than that of powder extrusion molding or die pressing. The green compacts were sintered by using vacuum sintering plus hot isostatic pressing (HIP), the sintered specimens were characterized by testing density, Rockwell A hardness, saturated magnetization, coercivity force, transverse rupture strength (TRS) and atomic force microscope (AFM) images, the results showed that sintered specimen of the green body that prepared by powder extrusion molding or die pressing followed by cold isostatic pressing had excellent properties of high strength and high hardness, transverse rupture strength of sintered specimen was more than 3100 MPa, Rockwell A hardness of sintered body was more than 93. Ultrafine WC-6 Co cemented carbide rods with excellent mechanical properties and fine microstructure were obtained.
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Wiranegara, Haruman, Muhammad Nauval Fauzi, and Shinta Virdhian. "Precision Mold of Prototype Titanium Orthopedic Implant using Metal Injection Molding Approach." Jurnal Rekayasa Mesin 11, no. 3 (December 15, 2020): 487–95. http://dx.doi.org/10.21776/ub.jrm.2020.011.03.21.
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MIDC’s researchers in fulfilling Industry Development Programme have taken a step to develop technology in the design application of orthopedic implants to help suppress the rate of imported medical devices in Indonesia. This research objective was to make a prototype plate for a jawbone connector that meets the geometric specifications with the metal injection molding approach. The jawbone connector plate has a very small size of about 2 mm x 20 mm x 0.5 mm that needs precision mold with certain geometric specifications. MIM approach was used, from the literature reviews that show MIM is the appropriate process for manufacturing implants. The phases of MIM were done according to the standard reference which is making raw materials or feedstock, gatting system design, flow simulation, precision mold producing, mold testing, injection process, debinding, sintering, and mechanical product testing. The results of this study were precision molds with several variants and were test using plastic polypropylene to see the performance of the mold. The researchers then produce the jawbone connector implant using feedstock material. The test result conducted in MIDC successfully shows that the mold can produce shapes that match the required geometry.
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Willberg-Keyriläinen, Pia, Hannes Orelma, and Jarmo Ropponen. "Injection Molding of Thermoplastic Cellulose Esters and Their Compatibility with Poly(Lactic Acid) and Polyethylene." Materials 11, no. 12 (November 23, 2018): 2358. http://dx.doi.org/10.3390/ma11122358.
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Interest in biobased polymers from renewable resources has grown in recent years due to environmental concerns, but they still have a minimal fraction of the total global market. In this study, the injection molding of thermoplastic cellulose octanate (cellulose C8) and cellulose palmitate (cellulose C16) were studied. The mechanical properties of injection-molded test specimens were analyzed by using tensile testing, and the internal structure of injection-molded objects was studied by using a field emission scanning electron microscopy (FE-SEM). We showed that thermoplastic cellulose C8 and cellulose C16 were completely processable without the addition of a plasticizer, which is very unusual in the case of cellulose esters. The compatibility of cellulose esters with poly(lactic acid) (PLA) and biopolyethylene (bio-PE) was also tested. By compounding the cellulose esters with PLA, the elongation of PLA-based blends could be improved and the density could be reduced. The tested thermoplastic cellulose materials were fully biobased, and have good future potential to be used in injection molding applications.
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Larin, A. A., M. Yu Fedotov, O. N. Budadin, V. A. Aniskovich, S. O. Kozel’skaya, and V. I. Reznichenko. "ON THE EXPERIENCE OF COMPUTED X-RAY TOMOGRAPHY OF REINFORCED THREE-STRINGER PANELS MADE OF POLYMER COMPOSITE MATERIALS." Kontrol'. Diagnostika, no. 274 (April 2021): 40–49. http://dx.doi.org/10.14489/td.2021.04.pp.040-049.
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Experimental studies of the possibility of the MCT method for NC three-stringer panels made of PCM by the method of autoclave molding have been carried out. Based on the results of the experimental studies, it was shown that the MCT method makes it possible with a high reliability to identify defects in composite structures at the stage of final inspection (immediately after production), which is especially important for highly loaded and critical structures made of carbon composite materials based on polymer matrices of various types. On the example of testing a three-stringer (reinforced) panel, it is shown that the presented structure as a whole does not have pronounced macrodefects, however, an accumulation of micro-layers is observed in the zone of transition of layers from the sheathing plane to the stringer, which indicates a slight decrease in the molding pressure in this zone. In the studies carried out, these microdefects are not critical, while the results of the tomogram can be used to slightly refine the shape of the tooling in the zone of transition of layers from the skin to the stringer to provide the required molding pressure. Thus, it has been shown that the SRT method is an effective tool for assessing the structure of reinforced composite panels, taking into account different degrees of damage. The high measurement accuracy and resolution of the MCT method allow realizing high reliability and information content of control and ensuring high reliability of PCM structures due to the following factors: • Structures with defects exceeding the maximum permissible ones are not allowed into operation by the technical control department (QCD); • Structures with defects close to the maximum permissible are taken out of service until their properties are restored; • Positioning of defects reduces the labor intensity of repair.
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Mohd Hasdi, Nur Atheerah, Nurjannah Salim, Rasidi Roslan, and Siti Noorbaini Sarmin. "The Effects of Alkaline Treatment on Physical and Mechanical Properties of Oil Palm Trunk/Polypropylene Blends Composite." Materials Science Forum 1056 (March 14, 2022): 3–9. http://dx.doi.org/10.4028/p-lb9r7o.
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Wood-plastic composites (WPCs) are composites that incorporate plants composed up of wood and non-wood fibres blended with thermosets or thermoplastic polymers to form a composite. Oil palm trunk (OPT) is one of the wastes produced from the oil palm industry known as oil palm biomass (OPB). The OPT was utilized to turn oil palm biomass into a value-added product. In this research, oil palm trunk/polypropylene (OPT/PP) blends composite was produced by extrusion and injection molding techniques. Alkaline treatment was applied to the fibers to improve the interfacial adhesion of fibers. After alkaline treatment, treated OPT (T-OPT) and untreated (UT-OPT) together with PP were blended at 200°C with the speed of 85 rpm in the extruder to form a pellet. Pellets were then injected in injection molding at 200°C to form sample size for mechanical testing; tensile and impact testing. The physical testing conducted was Melt Flow Index (MFI), water absorption test and Thermogravimetric Analysis (TGA). The results show that the mechanical properties of OPT/PP composite were improved by alkaline treatment. In the water absorption test, T-OPT composite demonstrated lower water absorption than that of UT-OPT composite. This indicated that the reduction of water absorption in T-OPT composite is due to alkaline treatment that degraded the lignin and cellulose structure subsequently reducing the OH groups in fibers to absorb water. For TGA, T-OPT composite had slightly higher thermal stability as compared to UT-OPT composite.
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Dobránsky, Jozef, Martin Pollák, Luboš Běhálek, and Jozef Svetlík. "Implementation of a Recycled Polypropylene Homopolymer Material for Use in Additive Manufacturing." Sustainability 13, no. 9 (April 29, 2021): 4990. http://dx.doi.org/10.3390/su13094990.
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The main objective of the presented scientific article is to define the mechanical properties of polypropylene homopolymer with a prescribed percentage ratio of recycled granulate. The chosen material is intended for injection molding and especially for the production of products made by additive technologies. Experimental verification of the mechanical properties was realized by testing samples produced with various concentrations of the recycled material. Experimental samples underwent tests to obtain the mechanical properties of the produced new material. These tests included rheological tests, tensile and flexural tests as well as and Charpy impact toughness tests. These mechanical tests were conducted according to ISO standards valid for the individual testing method. Testing methods were carried out using prescribed numbers of testing samples. The presented scientific article is also focused on changes in microstructures of testing materials in relation to the percentage ratio of recycled granulate. Recycled granulate of thermoplastic was not necessity for additional modifications.
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Wang, You Yan, Hong Bai Bai, and Shu Ai Tao. "The Micro Physical Mechanism Study of Metal Rubber Material on Compressive Performance." Advanced Materials Research 79-82 (August 2009): 27–30. http://dx.doi.org/10.4028/www.scientific.net/amr.79-82.27.
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Metal rubber material is a new type of elastic and porous material which develops from metal materials. The macro-structure of metal rubber is reticular just as high polymer, made up of fine metal wires. In this paper, the testing equipment which can test micro-motion of metal rubber is designed and the compressive force-displacement curve along molding of metal rubber has gain. The cure along molding of metal rubber has three different characteristic stages. In different characteristic stages, the deformation of metal rubber material has different micro physical mechanism. The micro physical mechanism of different deformation periods is summarized by the micro analyses of three different characteristic curve stages and the study of metal rubber molding technology. Based on the manufacture technology and molding process, the spring wires in metal rubber material have contacted adequately after molding. The micro physical mechanism of metal rubber material in this stage is produced by blank tear combination deformation in linear elastic of spring wires. Because of the deformation stage is very little; the stiffness of metal rubber material is represented linear characteristic in this stage. The contacted points of spring wires are slide along with deformation increasing. The stiffness of metal rubber material is reduced after early linear deformation stage. The compressive force-displacement curve represents soft characteristic stage in macro- expression. When the most contacted points of spring wires are slide along with deformation increasing, the stiffness of metal rubber material is rapid rise. The exponential reinforcement stage is caused by the strongly constraints among spring wires. The micro physical mechanism can explain the different characteristic stages of metal rubber material on compressive performance.
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Gajdoš, Ivan, Ján Slota, Ľuboš Kaščák, Oleksandr Grytsenko, and Tomasz Jachowicz. "UTILIZATION OF ANALYTICAL METHODS FOR THE FAILURE ANALYSIS OF INJECTION MOLDED PART." Acta Metallurgica Slovaca 26, no. 3 (September 3, 2020): 122–25. http://dx.doi.org/10.36547/ams.26.3.547.
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As the use of the thermoplastic materials becomes conventional in numerous parts and various applications, incidence of various types of failure becomes inevitable. Failure of injection molded parts can be a cause of economic and legal problems, as well as causing health damage or death. Public perception of plastics is adversely affected by their failures, such as the bad reputation that early plastics earned with toys that broke too easily. As the injection molding process is very complex, finding the cause of failure is very complicated. In industrial mass scale production, determining the cause of failure is key point in customer-supplier relationship. In the presented study, a type of injection molded product from HDPE affected by occurrence of cracks was investigated by mechanical, thermal testing and spectral analysis. Mechanical properties were evaluated by the uniaxial tensile test and the SHORE hardness test. Thermal properties of the samples were evaluated by DSC/TGA analysis and for the spectral analysis a Raman spectroscopy device was used. Obtained results provided information about fluctuating quality of used material, coupled with non/stable molding conditions and small molding window. All those aspects caused molded in stress, which was released in the form of crack during the installation.
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Norazlini Abd Aziz, Siti, Wan Saiful Sarhan Wan Saidi, Mimi Azlina Abu Bakar, and Muhammad Hussain Ismail. "Rheological Behavior of Zirconia Added Alumina Mixture." International Journal of Engineering & Technology 7, no. 4.26 (November 30, 2018): 251. http://dx.doi.org/10.14419/ijet.v7i4.26.22177.
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Zirconia and alumina are one of the materials that is widely used in medical industry. Zirconia Toughened Alumina (ZTA) have great properties to be apply in the ceramic injection molding such as have high hardness and high strength. The powder used in this research are alumina and zirconia while the binder to be used in this research is using 100% single based binder of palm stearin (PS). Behavior of zirconia blended alumina was investigated by rheological testing at temperature 55°C. Two formulations were used which is 60% (alumina/zirconia) plus 40% PS and 64% (alumina/zirconia) plus 36% PS. The ratio of alumina and zirconia used in this research is fixed at (85:15) for both samples. Four basic process involved which is mixing process, injection molding, thermal debinding and sintering process has been implemented to complete ceramic injection molding (CIM). Sample were performed the thermal debinding at a heating rate 0.5°C/min up to 700°C and sintering at heating rate 3°C/min for temperature 1400°C and 1600°C. The hardness was tested using Rockwell hardness test for both AZ60 and AZ64 sample. Highest hardness was obtained from the sample AZ64 at the temperature 1600 °C which is 109HRR compare to the 1400°C that achieved 95.3HRR.
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Chval, Zdenek, Karel Raz, and Frantisek Sedlacek. "Design of Injection Mold from Plastic Material." Key Engineering Materials 847 (June 2020): 75–80. http://dx.doi.org/10.4028/www.scientific.net/kem.847.75.
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This paper deals with the use of plastics for making injection molds. Mold production times reduced by 90% and costs cut by up to 75% are some of the benefits of prototype molds from plastic materials. Today, materials with melt temperatures above 300 °C are used for plastic molds. They include ABS, PE, PP and PA. In this study, testing of high-temperature resin from Formlabs was performed. Compression and tensile test data are compared with the datasheet values and with virtual simulations. The tests were carried out at different temperatures. Based on their results, one can identify a suitable molding process with molds from this material.
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Olejnik, R., P. Slobodian, P. Riha, and P. Saha. "An Electrically Conductive and Organic Solvent Vapors Detecting Composite Composed of an Entangled Network of Carbon Nanotubes Embedded in Polystyrene." Journal of Nanomaterials 2012 (2012): 1–7. http://dx.doi.org/10.1155/2012/365062.
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A composite composed of electrically conductive entangled carbon nanotubes embedded in a polystyrene base has been prepared by the innovative procedure, when the nonwoven polystyrene filter membrane is enmeshed with carbon nanotubes. Both constituents are then interlocked by compression molding. The mechanical and electrical resistance testing show that the polymer increases nanotube network mechanical integrity, tensile strength, and the reversibility of electrical resistance in deformation cycles. Another obvious effect of the supporting polymer is the reduction of resistance temperature dependence of composite and the reproducibility of methanol vapor sensing.
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Fedotov, M. Yu, O. N. Budadin, S. O. Kozelskaya, I. G. Ovchinnikov, and I. S. Shelemba. "MONITORING BY FIBER OPTICAL SENSORS OF RELIABILITY OF OPERATION OF BUILDING STRUCTURES WITH EXTERNAL COMPOSITE REINFORCEMENT." Kontrol'. Diagnostika, no. 265 (July 2020): 54–64. http://dx.doi.org/10.14489/td.2020.07.pp.054-064.
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This article describes of the actual state of building structures by the example of structures of reinforced concrete and metal bridges. It is shown that a high degree of wear of artificial structures leads to the need for a reliable assessment of their actual condition using modern methods and means of non-destructive testing and diagnostics, as well as strengthening exploited structures with polymer composite materials. The results of researches on fiber-optic monitoring and strengthening of bridge spans with composite materials based on domestic and foreign carbon reinforcing fillers and epoxy polymer matrices are presented. It has been experimentally shown that for reinforced concrete structures it is advisable to use composite strengthening systems using external reinforcement installed directly on the damaged object by contact molding. For metal structures, this approach is not applicable due to a significant difference in the coefficients of linear thermal expansion of composites and metals. In this case, an amplification system based on prefabricated composite truss systems made by autoclave and unautoclave molding can be applied. The obtained research results also indicate the advisability of joint use of monitoring systems and strengthening of damaged bridge structures by composites.
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Fedotov, M. Yu, O. N. Budadin, S. O. Kozelskaya, I. G. Ovchinnikov, and I. S. Shelemba. "MONITORING BY FIBER OPTICAL SENSORS OF RELIABILITY OF OPERATION OF BUILDING STRUCTURES WITH EXTERNAL COMPOSITE REINFORCEMENT." Kontrol'. Diagnostika, no. 265 (July 2020): 54–64. http://dx.doi.org/10.14489/td.2020.07.pp.054-064.
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This article describes of the actual state of building structures by the example of structures of reinforced concrete and metal bridges. It is shown that a high degree of wear of artificial structures leads to the need for a reliable assessment of their actual condition using modern methods and means of non-destructive testing and diagnostics, as well as strengthening exploited structures with polymer composite materials. The results of researches on fiber-optic monitoring and strengthening of bridge spans with composite materials based on domestic and foreign carbon reinforcing fillers and epoxy polymer matrices are presented. It has been experimentally shown that for reinforced concrete structures it is advisable to use composite strengthening systems using external reinforcement installed directly on the damaged object by contact molding. For metal structures, this approach is not applicable due to a significant difference in the coefficients of linear thermal expansion of composites and metals. In this case, an amplification system based on prefabricated composite truss systems made by autoclave and unautoclave molding can be applied. The obtained research results also indicate the advisability of joint use of monitoring systems and strengthening of damaged bridge structures by composites.
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Wang, Ju Wei. "Starch-Based Biodegradable Packaging Materials of Antimicrobial." Applied Mechanics and Materials 457-458 (October 2013): 231–35. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.231.
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With the gradual increase of the global environmental awareness and environmentally friendly voice rising, the deal with the problem of plastic waste has become the focus of public opinion around the world has also become a hot topic of scientific research. This paper can be made of polystyrene as main raw material, adding starch and antibacterial agents containing silver nanoscale titanium dioxide, and by the synthesis of biodegradable packaging materials performance. The results showed that: 0.25mm sheet of polystyrene made of the thickness of the main raw material by injection molding process, and factors affecting the performance of the sheet, the better the performance of the film material process parameters. According to the definition of the GB/T1040-92 national standards of the People's Republic of China "plastic tensile properties of test methods and GB/T20197-2006 degradable plastics, classification, marking, and degradation of the performance requirements" and GB4789.3-94 "State Microbiological examination of coli form bacteria in the standard of food hygiene as determined by experimental methods for testing. The orthogonal experiment results show that the expandable polystyrene Dosage: 80%; starch dosage: 2%; toluene, acetone and put ratio: 3:2 .The mechanics of materials, degradation, and antimicrobial properties.
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Arias-Nava, Elias H., B. Patrick Sullivan, and Delia J. Valles-Rosales. "Biopolymer Degradation Analysis: Accelerated Life Testing Study to Characterize Polylactic Acid Durability." Materials 14, no. 19 (September 30, 2021): 5730. http://dx.doi.org/10.3390/ma14195730.
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While the degradation of Polylactic Acid (PLA) has been studied for several years, results regarding the mechanism for determining degradation are not completely understood. Through accelerated degradation testing, data can be extrapolated and modeled to test parameters such as temperature, voltage, time, and humidity. Accelerated lifetime testing is used as an alternative to experimentation under normal conditions. The methodology to create this model consisted of fabricating series of ASTM specimens using extrusion and injection molding. These specimens were tested through accelerated degradation; tensile and flexural testing were conducted at different points of time. Nonparametric inference tests for multivariate data are presented. The results indicate that the effect of the independent variable or treatment effect (time) is highly significant. This research intends to provide a better understanding of biopolymer degradation. The findings indicated that the proposed statistical models can be used as a tool for characterization of the material regarding the durability of the biopolymer as an engineering material. Having multiple models, one for each individual accelerating variable, allow deciding which parameter is critical in the characterization of the material.
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Loewenhoff, Th, S. Antusch, G. Pintsuk, M. Rieth, and M. Wirtz. "High pulse number thermal shock testing of tungsten alloys produced by powder injection molding." Nuclear Materials and Energy 20 (August 2019): 100680. http://dx.doi.org/10.1016/j.nme.2019.100680.
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Sujarwadi, Roni, and Tresna Priyana Soemardi. "Mechanical Characteristics Testing of Biodegradable Ramie Fiber Reinforced Polylactic Acid (PLA) Fabricated with Hot-Press Molding." Proceeding International Conference on Science and Engineering 3 (April 30, 2020): 301–6. http://dx.doi.org/10.14421/icse.v3.517.
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In this research, composite material was fabricated from both renewable resources and biodegradable materials: ramie woven fabric as reinforcement and 3D printed polylactic acid (PLA) filament as resin matrix. The laminate composites were produced using a film stacking method and processed using hot-press molding. The mechanical properties of woven ramie fabric, PLA matrix, and laminate composites were investigated. It is shown that the breaking force of the plain woven ramie fabric in the warp direction was greater than in the weft direction. Further, the tensile and impact properties of laminate at warp direction higher than weft direction when ramie fabric reinforcement is used. In addition, scanning electron microscopy examination of laminate composite showed good bonding between ramie fiber and PLA matrix. In summary, laminated composites based on polylactic acid and woven ramie fabric display good performance capability, which can use for the development of engineering applications.
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El-Shekeil, Y. A., S. M. Sapuan, M. D. Azaman, and M. Jawaid. "Optimization of Blending Parameters and Fiber Size of Kenaf-Bast-Fiber-Reinforced the Thermoplastic Polyurethane Composites by Taguchi Method." Advances in Materials Science and Engineering 2013 (2013): 1–5. http://dx.doi.org/10.1155/2013/686452.
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“Kenaf-fibers- (KF-)” reinforced “thermoplastic polyurethane (TPU)” composites were prepared by the melt-blending method followed by compression molding. Composite specimens were cut from the sheets that were prepared by compression molding. The criteria of optimization were testing the specimens by tensile test and comparing the ultimate tensile strength. The aim of this study is to optimize processing parameters (e.g., processing temperature, time, and speed) and fiber size using the Taguchi approach. These four parameters were investigated in three levels each. The L9 orthogonal array was used based on the number of parameters and levels that has been selected. Furthermore, analysis of variance (ANOVA) was used to determine the significance of different parameters. The results showed that the optimum values were 180°C, 50 rpm, 13 min, and 125–300 micron for processing temperature, processing speed, processing time, and fiber size, respectively. Using ANOVA, processing temperature showed the highest significance value followed by fiber size. Processing time and speed did not show any significance on the optimization of TPU/KF.
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Ishanovich, Adilxodjaev Anvar, and Son Dmitry Olegovich. "Some Aspects Of Studying Clays For Producing Ceramic Brick Of Required Properties." American Journal of Applied sciences 03, no. 05 (May 31, 2021): 190–95. http://dx.doi.org/10.37547/tajas/volume03issue05-30.
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This article aims to show what research needs to be carried out not only to understand the nature and establish the potential capabilities of clay raw materials, to guide technologists, what stages of testing should be organized in production and at what stages it is advisable to consult a specialist in order to develop a technically competent and optimal composition of ceramic bricks. A program for testing clay raw materials is described, which should be developed in such a way as to obtain the most complete information about this clay, its composition, properties, behavior during technological processing: molding, drying and firing during research. And also an explanation is given about the measures necessary before the start of the tests, it is advisable to have information about the geological surveys of the field, about the previously conducted studies and, if the plant has already been built and operated, about the problems that do not allow the production of products of the required quality.
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Sazonova, S. A., S. D. Nikolenko, T. V. Zyazina, E. V. Chernyshova, and I. M. Kazbanova. "Strength test of the industrial building’s load-bearing structures." Journal of Physics: Conference Series 2373, no. 2 (December 1, 2022): 022016. http://dx.doi.org/10.1088/1742-6596/2373/2/022016.
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Abstract Experimental studies were carried out in the molding shop. Tests were carried out for brickwork materials of enclosing walls by the shock pulse method. The compressive strength grades of ceramic brick fences and cement-sand mortar were determined experimentally. When testing concrete, a non-destructive strength control method and the necessary devices were used. The concrete class was determined by compressive strength in reinforced concrete columns of the building, in reinforced concrete beams of the coating and in reinforced concrete slabs of the coating. According to the proposed methodology, verification calculations were carried out. The verification calculations showed sufficient bearing capacity of the columns and foundations of the workshop building and the coating beams for the full design load. A calibration calculation of the workshop frame was also performed, which showed sufficient strength of the entire load-bearing structures of an industrial building. The proposed methodology can be used for testing similar building materials and objects.
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Kismet, Yilmaz, and Manfred H. Wagner. "Enhancing the potential of employing thermosetting powder recyclates as filler in LLDPE by structural modifications." Journal of Polymer Engineering 37, no. 3 (March 1, 2017): 287–96. http://dx.doi.org/10.1515/polyeng-2015-0498.
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Abstract Potential of using powder coating recyclates as filler material for polyethylene compounds was investigated. Due to their strong adhesion to the metal surface during compounding at extrusion temperatures higher than 100°C, the coating powder recyclates were chemically modified to facilitate its processing by extrusion and injection molding at higher temperatures. For this purpose, the coating powder recyclates were first hydrolyzed with addition of an alcohol as swelling agent. The deactivated recyclates were mixed at different ratios with the matrix polymer, a linear low-density polyethylene (LLDPE). The mixtures obtained were then compounded by extrusion and subsequently injection molded to plates to produce specimens for testing. The resulting samples were characterized mechanically by tensile, bending, and impact strength tests. In summary, the powder coatings recyclates can be processed as filler for thermoplastic material, without any adhesion problems up to 160°C and 180°C in the extruder and in the injection molding machine, respectively.
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Nguyen, L. T. "Reliability of Postmolded IC Packages." Journal of Electronic Packaging 115, no. 4 (December 1, 1993): 346–55. http://dx.doi.org/10.1115/1.2909343.
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This paper discusses the current reliability issues involved with typical postmolded IC packages. Four major topics are presented, namely, stress, moisture permeation and corrosion-related problems, adhesion, and outgassing impurities. As the trend moves toward higher lead count, with increasingly larger dies which require more power dissipation within smaller package outlines, stress reduction will become a main concern. Methods to quantify package stresses in situ are outlined, together with the advantages and drawbacks of various schemes for decoupling the silicon die from the molding compound. Since the typical molding compound is permeable to moisture, the package collects water during stringent qualification tests (autoclave, T/H, and HAST), and even under normal ambient conditions. Any ionic impurities in the molding compound will combine with the absorbed water to form an electrolytic pool. This increases the likelihood of corrosion in the presence of passivation defects or exposed metal lines. Device structures designed to follow moisture permeation and detect water-induced damage are discussed. The integrity of the interface between the molding compound and the device components is crucial to the long term reliability of the package. Delamination at the die interface produces complex stress profiles that can result in various defects ranging from metal line shift, passivation cracking, corner die chipping, to ball bond fatigue. Poor adhesion along the leads also opens potential paths for moisture ingress. The effects of assembly conditions and various adhesion enhancing schemes on the package integrity are evaluated. Finally, outgassing of halogenated (bromine and antimony oxide) byproducts added for flame retardancy during high temperature storage life testing results in ball bond degradation. The interaction yields typically porous intermetallic structures which grow in size with exposure time, leading ultimately to bond lifting. Possible reaction mechanisms are presented.
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Ma, Yuqin, Shuangshuang Li, Jie Wang, Luyan Ju, and Xinmei Liu. "Influence of Defects on Bending Properties of 2D-T700/E44 Composites Prepared by Improved Compression Molding Process." Materials 11, no. 11 (October 30, 2018): 2132. http://dx.doi.org/10.3390/ma11112132.
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2D-T700/E44 composite materials were prepared by improved compression molding process (ICM) then microstructure and properties of the composites were analyzed and summarized by scanning electron microscope (SEM) and electronic universal testing machine. It is found that defects will occur when the process parameters are not controlled properly and the main defects of composite materials include inadequate resin impregnation, weak interlaminar binding force, fiber displacement warping, hole and brittle fracture. Moreover, there are significant differences in the infiltration microstructure, bending properties, and fracture morphology of the composite materials with different defects. When the defects of weak interlaminar binding force and brittle fracture occur, bending properties of composite materials are relatively low, and they are 220 MPa and 245 MPa, respectively, which reach 34.9% and 38.9% of the bending strength of composite material whose defects are effectively controlled. When the process parameters are reasonable and the defects of the composite materials are effectively eliminated, the bending strength can reach 630 MPa. This will lay a foundation for the preparation of 2D-T700/E44 composite materials with ideal microstructures and properties by ICM.
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Tan, Zan Wu, Kong Lian Xu, and Su Yun Hu. "Application of Orthogonal Test in Numerical Simulation of Aluminum Sheet Forming." Advanced Materials Research 503-504 (April 2012): 297–300. http://dx.doi.org/10.4028/www.scientific.net/amr.503-504.297.
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Sheet forming is a high-volume fabrication method for producing lightweight materials components. An important goal in manufacturing research is to determine the optimum method for producing products with less cost. In this paper, combined with the orthogonal test method and finite element method (FEM) simulation, the analysis was carried out to analyze the key process factors such as stamping force, fillet radius, and friction coefficient. Using orthogonal test method can reduce the testing time, learn how the molding parameters influence the total equivalent plastic strain, acquire the best match forming parameters, and give guidance for the better condition
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Sun, Qin, Xi Tao Zheng, Ye Li, Ya Nan Chai, and Zheng Hua Cao. "An Experimental Investigation on Composites Through-The-Thickness Stitched Foam Core Sandwich Panels." Key Engineering Materials 353-358 (September 2007): 1443–46. http://dx.doi.org/10.4028/www.scientific.net/kem.353-358.1443.
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This study explored the feasibility and potential benefits provided by the addition of through-the-thickness reinforcement to foam core sandwich structures. Through-the-thickness stitching is proposed to increase the interlaminar strength and damage tolerance of composite sandwich structures. A low-cost, out-of-autoclave processing method was developed to produce composite sandwich panels with carbon fiber face sheets, a closed-cell foam core, and through-the-thickness Kevlar stitching. The sandwich panels were stitched in a dry preform state, vacuum bagged, and infiltrated using Vacuum Assisted Resin Transfer Molding (VARTM) processing. For comparison purposes, unstitched sandwich panels were produced using the same materials and manufacturing methodology. Five types of mechanical tests were performed: flexural testing, flatwise tensile and compression testing, core shear testing, and edgewise compression testing. Drop-weight impact testing followed by specimen sectioning was performed to characterize the damage resistance of stitched sandwich panels. Compression after impact (CAI) testing was performed to evaluate the damage tolerance of the sandwich panels. Results show significant increases in the flexural stiffness and strength, out-of-plane tensile strength, core shear strength, edgewise compression strength, and compression-after-impact strength of stitched sandwich structures.
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Bahrani, Farideh, Mahroo Vojdani, Anahita Safari, and Ghasem Karampoor. "Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods." World Journal of Dentistry 3, no. 2 (2012): 171–75. http://dx.doi.org/10.5005/jp-journals-10015-1151.
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ABSTRACT Purpose The aim of this study was to evaluate mechanical property hardness and surface roughness (Ra) of different polymerization acrylic resins used for denture bases. Materials and methods A total of 30 specimens were prepared and divided in two groups. A total of 15 samples were processed by the compression molding technique using Meliodent (heatcured). Another 15 samples were processed with cold-cured resin Futura Gen via the injection molding technique. Hardness testing was conducted using a Vickers hardness tester. The Ra test was performed by a profilometer. Data were analyzed using the independent sample t-test and differences were statistically significant at the 0.05 level. Results The Vickers hardness numbers (VHN) were 20.8 ± 2.39 for Meliodent and 21.18 ± 1.42 for FuturaGen, which was not significantly different (p > 0.05). The Ra of Meliodent was 0.92 ± 0.23 µm and for FuturaGen it was 0.84 ± 0.37 µm. There were no significant changes in roughness. Conclusion The hardness and Ra of Meliodent and FuturaGen were not significantly different. Therefore, we recommend the use of FuturaGen for manufacturing denture base materials. How to cite this article Bahrani F, Safari A, Vojdani M, Karampoor G. Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods. World J Dent 2012;3(2):171-175.
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Moneke, Martin, Philipp Seeger, and Ralph Stengler. "Capability of Scratch Testing − A View on the Influence of Injection Molding, Water Absorption, and Blend Systems of Polymeric Materials." Macromolecular Symposia 384, no. 1 (April 2019): 1800176. http://dx.doi.org/10.1002/masy.201800176.
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