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Journal articles on the topic 'Rubber Testing Standards'
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1
Kang, Wei, Jiefu Liu, Wei Xiong, Tianyu You, Xinxin Wang, Kexin Zeng, Yingao Deng, Zichao Guo, and Ke Yuan. "Basic mechanical and fatigue properties of rubber materials and components for railway vehicles: A literature survey." REVIEWS ON ADVANCED MATERIALS SCIENCE 61, no. 1 (January 1, 2022): 587–610. http://dx.doi.org/10.1515/rams-2022-0054.
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Abstract Rubber material is widely used in railway vehicles due to its superior damping performance. The testing methods, fatigue, and aging theories of rubber materials are of great significance to improve the design, manufacture, and application of rubber components for railway vehicles. This work systematically introduces the constitutive theory, mechanical testing standards, and testing methods of rubber materials. Then, the aging mechanism is described and the research progress of rubber fatigue properties is reviewed from the perspectives of fatigue crack initiation and fatigue crack propagation. Moreover, the reinforcement methods of rubber materials are presented. Finally, according to the working conditions of rubber components in railway vehicle, the technical difficulties and future research trends of fatigue characteristics analysis of rubber materials and components are pointed out.
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Karmanova, O. V., S. G. Tikhomirov, E. V. Lintsova, and L. V. Popova. "Research of the properties of rubber-cord composites in the presence of new adhesion promoters." Proceedings of the Voronezh State University of Engineering Technologies 82, no. 3 (October 19, 2020): 221–26. http://dx.doi.org/10.20914/2310-1202-2020-3-221-226.
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Studies of experimental adhesion modifiers based on a mixture of fatty acids from the production of light vegetable oils. The properties of rubber compounds and their vulcanizates obtained using experimental adhesion promoters KK with cobalt content from 7.5 to 16.5% are investigated. The plastic-elastic and vulcanization properties of the properties of breaker rubber compounds based on polyisoprene, the physical and mechanical properties of breaker rubbers and the bond strength in the “rubber-brass-plated steel cord system” were studied. When testing belt rubbers containing experienced adhesion promoters or an imported analog of Manobond 680C, the following features were revealed. The plasticity of the prototypes was in the range of 0.2-0.4. This indicates satisfactory processing properties. The Mooney viscosity of the prototypes was lower than that of the production sample. The use of experienced adhesion promoters instead of the analogue (Manobond 680C) increases the resistance to scorching. On the basis of the analysis of elastic-strength properties, it was found that in terms of the conditional tensile strength, the prototypes were inferior to the serial ones. However, rubbers containing the KK-12, KK-13.5, KK-15 promoters met the control standards. The tensile elongation at break of the experimental rubbers is higher than that of the serial sample. This may indicate the formation of a more uniform cure network in the presence of the test products. When testing rubber-metal-hard composites, it was noted that, under normal conditions, the experienced adhesion promoters have advantages over Manobond 680C. However, at elevated temperatures, under conditions of salt and steam-air aging, they are slightly inferior to Manobond 680C. It has been established that the experimental adhesion promoters provide the required set of technical properties of belt rubbers with a CO2 + content of 12–16.5% wt. Thus, it is possible to recommend the adhesion promoters KK 12, KK-13.5, KK 15 for practical use in the composition of belt rubber compounds. This will allow replacing a foreign-made product and reducing the cost of production.
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Dardas, Agnes Z., Viviana M. Serra Lopez, Lauren M. Boden, Daniel J. Gittings, Kevin Heym, Emily Koerber, Taras Grosh, and Jaimo Ahn. "A simple surgical mask modification to pass N95 respirator-equivalent fit testing standards during the COVID-19 pandemic." PLOS ONE 17, no. 8 (August 24, 2022): e0272834. http://dx.doi.org/10.1371/journal.pone.0272834.
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Background The COVID-19 pandemic has infected hundreds of millions of people resulting in millions of deaths worldwide. While N95 respirators remain the gold standard as personal protective equipment, they are resource-intensive to produce and obtain. Surgical masks, easier to produce and obtain, filter ≥95% submicron particles but are less protective due to a lack of seal around a user’s face. This study tested the ability of a simple surgical mask modification using rubber bands to create a seal against particle exposure that would pass N95 standards. Methods and findings Forty healthcare workers underwent TSI PortaCount mask fit testing using an ASTM Level 1 surgical mask modified with rubber bands. Fit Factor was determined after testing four standard OSHA N95 fit testing scenarios. Performance of the properly-modified surgical mask was compared to that of a poorly-modified surgical mask, an unmodified standard surgical mask, and an N95 respirator. Thirty-one of forty (78%) healthcare workers passed Fit Factor testing using a properly-modified mask. The Fit Factor success rate significantly improved by subsequent test date (p = 0.043), but was not associated with any other participant characteristics. The average Fit Factor score for the properly-modified mask was 151 (SD 65.2), a significantly better fit than the unmodified mask score of 3.8 (SD 3.1, p<0.001) and the poorly-modified mask score of 24.6 (SD 48.4, p<0.001) but significantly lower than a properly fitted N95 score of 199 (SD 4.5, p<0.001).do. Conclusions Rubber bands, a low-cost and easily-accessible modification, can improve the seal and protective ability of a standard surgical mask to the level of an N95 respirator. This could mitigate N95 respirator shortages worldwide and provide individuals in under-resourced regions a practical means for increased personal respiratory protection.
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Rahartri, Rahartri. "ANALISIS KEBUTUHAN INFORMASI STANDAR DI KAWASAN PUSPIPTEK SERPONG: BERDASARKAN JENIS DAN KLASIFIKASINYA." BACA: JURNAL DOKUMENTASI DAN INFORMASI 40, no. 2 (May 16, 2019): 181. http://dx.doi.org/10.14203/j.baca.v40i2.436.
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This study aims to find out the standard information needs in the Puspiptek Region. While the specific objective of this study is to know the types of standard and standard classification required. The study was carried out descriptively. The data were collected by inventorying standard information needs during the 2011-2017 period. The results of this study concluded: 1) the type of standard information needed in Puspiptek Serpong Area are ASTM, JIS, ISO, BS, SNI, DIN, IEC, UIC; 2) based on the classification, the standards needed in the Puspiptek Serpong area are: a) ASTM, miscellaneous material classification; miscellaneous subjects; cementious, ceramic, concrete, and masonry material; b) JIS, railway engineering classification; chemical engineering; mechanical engineering; c) ISO, rubber and plastic industries classification; metallurgy; road vehicles engineering; d) British standard, agriculture classification; construction materials and building; chemical technology; e) SNI, metallurgy classification; food technology; construction materials and building; f) DIN standard, rubber and plastic industries classification; paint and colour industries; g) IEC standard, electrical engineering classification; testing/ environmental testing. The results of this study can be the recommendations for decision makers in the context of procurement/provision of documents, especially standard documents in the Puspiptek Serpong, for the development of science and technology.
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Lai, Mun Kou, Hiu Hong Teo, and Jien Ye Lee. "Recycled Cigarette Filter as Reinforcing Filler for Natural Rubber." Applied Mechanics and Materials 705 (December 2014): 39–43. http://dx.doi.org/10.4028/www.scientific.net/amm.705.39.
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Natural rubber is highly resilient and possesses many outstanding characteristics but inferior in aspects like modulus and hardness. This however can be improved by reinforcement, forming a composite. The rubber compound in this study was prepared according to the ASTM D3184 standards and reinforced using cellulose acetate (CA) from recycled cigarette filter, partly as an effort to reduce the amount of waste. Moreover, cigarette filter is highly toxic due to the nicotine content thus requires care when is recycled. From the rheological and mechanical testing conducted i.e. scorch and cure time, torque, tensile test and tear strength, it seems to indicate a small amount of up 4 phr (parts per hundred rubber) of CA, is beneficial in improving the properties of the rubber compound.
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Ramirez-Vazquez, Isaias, Fermin Pascual Espino-Cortes, and Carlos Gómez-Yáñez. "Direct Current Inclined Plane Testing on Silicone Rubber Composites Reinforced with Silica Nano Particles." Journal of Nano Research 71 (January 25, 2022): 135–49. http://dx.doi.org/10.4028/www.scientific.net/jnanor.71.135.
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Polymer insulators traditionally used in HVAC (High Voltage Alternating Current) are used in HVDC (High Voltage Direct Current) transmission lines. For these polymer insulators, silicone insulating rubber, based on Polydimethylsiloxane (PDMS), is used in industry to manufacture high voltage insulators for power lines. Silicone rubber material ages due to pollution and environmental factors such as UV (ultraviolet light), rain, and temperature. Moreover, no international standard is available to standardize its functional characteristics to ensure its best performance in HVDC regime. Standards usually define the testing procedures to measure the resistance of the materials to these conditions. One of the tests used to evaluate the performance in AC (alternating current) of the housing material of polymeric insulators is the inclined plane test (IPT). This test has the purpose of assessing the tracking and erosion resistance of housing materials. However, for the IPT, no consensus is reached yet for this testing in Direct Current (DC) voltage. In addition, there are no indications whether the formulations that have been successfully used for HVAC work fine; also, in HVDC regime, or not. In this paper, an investigation of the tracking and erosion resistance under positive DC IPT is presented. In this way, the study was carried out on skirts of an HVAC commercial insulator and samples of a new outstanding composite silicone rubber formulation filled with micro and nano particles. The results show that HVAC silicone rubber formulations could not be suitable for HVDC applications under highly polluted conditions. In the case of the new enhanced composite, it is shown how nano particles used in this material significantly enhance the performance during DC tracking and erosion testing well above other materials tested in previous works. Also, thermogravimetric analysis (TGA) of the composites is used to correlate thermal stability with the DC IPT performance.
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S.Pd., M.Kom., Rahmad Fauzi. "IMPLEMENTASI JARINGAN SARAF TIRUAN DENGAN METODE BACKPROPAGATION TERHADAP BIBIT TANAMAN KARET." JURNAL EDUCATION AND DEVELOPMENT 1, no. 1 (October 25, 2018): 1. http://dx.doi.org/10.37081/ed.v1i1.104.
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Availability of seeds is one of the critical success factors of increasing the productivity of rubber plantations, the empirical use of seeds as one component technology has made a great contribution in increasing the productivity of rubber plantations. To obtain plant materials of good quality, it is worth noting the procurement process as well as the quality standards of seeds produced, if all quality standards at every election seedlings to be planted, it is certain that the results will be planted in accordance with what had been planned as long as it is balanced with proper maintenance based technical. Artificial Neural Networks can be used to obtain information about the quality of rubber seedlings by using Backpropagation, observations and measurements of rubber seed 51 seeds were used as a sample, of 50 rubber seed of the 35 samples used as training data and 16 samples as test data, observations done by looking at the characteristics of rubber seed color, reflectivity, results marinade, long beans, broad beans and thick seeds. From the results of the training conducted by Artificial Neural Networks as many as 35 sample data by using architecture patterns 6 15 1 obtained accuracy rate of 94.29%, which means that the artificial neural network has been able to identify the quality of the rubber plant seeds, to prove the results of the training testing using a sample of 16 pieces of new data that has not been trained before, the test results showed the accuracy rate of 100%, of the test results can be concluded that the application of Artificial Neural Networks to identify quality rubber seedlings with architectural 6 15 1 more accurate compared to other architectures
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Liu, Jing Hui. "Laboratory Investigation of Moisture Damage in Asphalt Rubber Hot Mixes Using Warm Mix Technology." Advanced Materials Research 598 (November 2012): 438–43. http://dx.doi.org/10.4028/www.scientific.net/amr.598.438.
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The advantages of using asphalt rubber pavement strategies have been validated by many research efforts. However, the most obvious disadvantage of asphalt rubber hot mix is requiring a higher mix and placement temperature in order to obtain adequate workability, which results in higher energy requirements and asphalt easy ageing. By utilizing Warm Mix Asphalt(WMA) technology the temperature requirements of the asphalt rubber hot mix can be reduced significantly. Warm mix asphalt (WMA) is the name given to certain technologies that reduce the production and placement temperatures of asphalt mixes. Asphalt Rubber Hot Mix of containing Warm Mix technology is a very promising technology whether in energy saving or improving pavement performance. One of the main concentrations of crumb rubber mix is now on the moisture damage evaluation due to WMA additives. In this study, the objective was to conduct a laboratory investigation of moisture damage in Warm Rubber Mix Asphalt(WRMA). Currently, there are no standards or laboratory test data to support the knowledge area on the susceptibility of asphalt rubber mixtures to moisture damage. The widely accepted testing procedures i.e. indirect tensile strength (ITS) and tensile strength ratio (TSR) were performed to determine the moisture susceptibility of the mixtures.
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Gros, X. E. "Technical Note: Detection of delamination in tyres using eddy currents." Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering 211, no. 1 (January 1, 1997): 79–82. http://dx.doi.org/10.1243/0954407971526236.
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Non-destructive testing (NDT) is a useful tool to assess the structural integrity of components in order to maintain quality and safety standards. A low-cost electromagnetic technique based on eddy currents induced into a material appeared promising for the inspection of composite materials. Experiments were carried out in order to assess the potential of eddy currents in detecting delamination in rubber tyres. Infrared thermography was used to verify inspection results achieved with eddy currents. Non-destructive examination results are presented in this paper; these confirm that eddy current testing is an economically viable alternative for the inspection of steel reinforced truck tyres.
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John, Reji, and Shiv Kumar. "D evelopment and Testing of a Closed Loop Feedback Controlled Magnetorheological Fluid Anti-vibration Mount for Onboard Naval Applications." Defence Science Journal 66, no. 4 (June 28, 2016): 374. http://dx.doi.org/10.14429/dsj.66.10211.
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An intelligent semi-active anti-vibration mount using a magnetorheological (MR) fluid is designed and developed for onboard applications. The mount consists of a load bearing elastomer, MR fluid chamber; MEMS based vibration sensor and a controller for closed loop feedback mechanism. The controller regulates the solenoid current in the MR fluid chamber, which in turn regulates the flow of MR fluid through the valve. Comparison of the performance of MR mount with a passive resilient rubber mount shows that the former provides 7 dB extra damping at resonance compared to the later and the isolation of MR mount starts at 10 Hz compared to 50 Hz by rubber mount. This mount can operate in real time, passive and active modes by using a closed loop feedback control mechanism. The efficacy of the mount for outdoor applications is evaluated by characterizing the mechanical, environmental, electrical and electromagnetic properties as per MIL-17185, JSS-55555 and IEC 61000 standards and found to be superior compared to passive mounts. The mount is being evaluated for onboard applications in INS Ranvijay.
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Kokalis, Christos-Christodoulos A., Vassiliki T. Kontargyri, and Ioannis F. Gonos. "A Proposal for the Evaluation of HTV Silicone Rubber Composite Insulators." Polymers 13, no. 21 (October 20, 2021): 3610. http://dx.doi.org/10.3390/polym13213610.
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This paper describes in detail a step-by-step methodology for obtaining specimens from the housing material (high temperature vulcanized (HTV) silicone rubber with aluminum trihydrate (ATH) filler) of composite insulators (finished products), for five well known and commonly used tests. The aim of the paper is to render practical clarifications and additions to the instructions for five tests on composite insulators provided by international standards. Additionally, the ranges of the results of these tests are presented. More specifically, shore A hardness measurement, tensile strength and elongation at break test, tear strength test, density measurement and inclined plane test were conducted on the housing material of ten, new, unaged medium voltage composite insulators made by six different manufacturers. The results of these tests are presented as a contribution to the existing knowledge and a comparative study of corresponding results of previous investigations is performed. The presented procedures for specimens’ preparation, as well as the results (arithmetical ranges), could be used as guidelines for future testing on the housing material (HTV silicone rubber with ATH filler) of composite insulators, either by researchers and manufacturers, during laboratory testing and material development processes, or by customers (distribution and transmission networks owners), during batch acceptance tests.
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Kastein, Benjamin. "People Make the Difference." Rubber Chemistry and Technology 63, no. 5 (November 1, 1990): 81–95. http://dx.doi.org/10.5254/1.3538291.
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Abstract The Las Vegas meeting of the Rubber Division, ACS, provided attendees the opportunity to hear the interview of Mr. Arnold H. Smith, by Mr. Herbert A. Endres, recorded April 7, 1966. Mr. Smith, as Secretary-Treasurer of the Division from 1919 to 1928, and as Chairman in 1929, was the person most responsible for laying the foundation which supported the growth of the Division to its present status. The India Rubber Section was sanctioned by the American Chemical Society on December 30, 1909. The 28 chemists from the rubber industry who were the organizing members, had the objective of meeting together to solve mutual problems. The major problem for everyone in 1909 was the variable quality of the 36 varieties of wild rubber from the jungles of Central and South America and Africa. Para rubber from the Hevea Brasiliensis tree was considered to be the best type available, but there were at least 13 variations, identified by source of the Para rubber. Charles C. Goodrich, as first chairman of the India Rubber Section, moved immediately to resolve the problem and appointed a committee, chaired by Dr. Charles Knight of Buchtel College, to develop standard methods of testing and evaluation. The committee diligently addressed the subject and reported to the Section at each meeting for 10 years, but progress was slow. Members attending had been instructed by their superiors, “Listen—but don't talk!” Not a very satisfactory format for conducting a meeting. Several key individuals helping to organize the India Rubber Section were W. C. Geer, Chief Chemist at the B. F. Goodrich Co. and George Oenslager, of the Diamond Rubber Co. Geer invented the air oven used to accelerate heat aging of rubber samples, and Oenslager is famous for discovering the effect on vulcanization of organic accelerators in 1906 and for the use of carbon blacks in treads in 1911. Although the sharing of technical information was tantalizing slow during the early years, the American Chemical Society, at their meeting in Buffalo, April 7, 1919, approved the formation of the Division of Rubber Chemistry. John B. Tuttle, first chairman of the Division in 1919, with Arnold H. Smith as secretary-treasurer, determined to bring to the members technical information less restricted in content, and from their neutral position of employment at the National Bureau of Standards, thought results could be obtained.
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SZUHAN, NATASHA. "Sex in the laboratory: the Family Planning Association and contraceptive science in Britain, 1929–1959." British Journal for the History of Science 51, no. 3 (June 28, 2018): 487–510. http://dx.doi.org/10.1017/s0007087418000481.
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AbstractScientific and medical contraceptive standards are commonly believed to have begun with the advent of the oral contraceptive pill in the late 1950s. This article explains that in Britain contraceptive standards were imagined and implemented at least two decades earlier by the Family Planning Association, which sought to legitimize contraceptive methods, practice and provision through the foundation of the field of contraceptive science. This article charts the origins of the field, investigating the three methods the association devised and employed to achieve its goal of effecting contraceptive regulation. This was through the development of standardized methods to assess spermicidal efficacy; the establishment of quality, strength and manufacturing standards for rubber prophylactics; and the institution of animal trials to ensure the safety of specific contraceptives. The association publicized the results of its scientific testing on proprietary contraceptives in its annual Approved List of contraceptives. This provided doctors and chemists with a definitive register of safe and effective methods to prescribe.
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Susanto, T., Rahmaniar, V. G. V Putra, T. I. Sari, Farida, K. A. Roni, and G. Puspitasari. "Effect carbon black and modified kaolin hybrid filler on the curing and physic-mechanical properties of natural rubber-styrene butadiene rubber blends." IOP Conference Series: Earth and Environmental Science 963, no. 1 (January 1, 2022): 012029. http://dx.doi.org/10.1088/1755-1315/963/1/012029.
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Abstract Carbon black is known as an excellent reinforced filler for rubber compounding, this petroleum based product needs to be substituted using renewable or mineral filler due to some negative adverse. In this paper, natural rubber (NR) – styrene-butadiene rubber (SBR) (50/50) phr binary blends based on polyethylene glycol-modified kaolin (PEG-K) and carbon black CB hybrid filler were synthesized. The rubber formulation was designed for idler roller for charcoal conveyor in open peat mining application. The present study investigates the effect of PEG-K and CB composition on curing, physical, tensile and oil, and acid resistance of the binary blends. The effect was examined by varying the composition of PEG-K/CB as follows: 50/0; 40/10; 30/20; 20/30; 10/40; 0/50 phr/phr of the hybrid filler. The rubber compounding was conducted in accordance with the ASTM D3142, and the testing procedures were analyzed based on international standards. The vulcanizates were prepared by heating press at 140 °C for about 25 minutes. The results showed that the processing-ability of a single filler is easier than the higher hybrid filler. The rheological analysis showed that the higher PEG-K may increase the cure rate index, but the lower PEG-K might improve cross-linking density. The higher loading CB improved the specific gravity and hardness, tensile strength slightly, while there is less significant effect on decreasing compression set, abrasion resistance, and elongation at break. Meanwhile, the higher number CB of binary blends has better oil and acid resistance than the PEG-K. Compared to idler roller specification in the market, the vulcanizates in this research have better quality.
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Suriyavongpongsa, Bundit, and Cumnueng Watyotha. "Design and Performance Evaluation of Hot Air-Microwave Continuous Belt Dryer for Drying Block Rubber STR 20." Advanced Materials Research 1044-1045 (October 2014): 280–86. http://dx.doi.org/10.4028/www.scientific.net/amr.1044-1045.280.
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This aim of this research study was to examine the design and construction, as well as to test the performance of hot air-microwave continuous belt dryer machines for drying block rubber STR 20. This industrial type of machine is divided into three major systems: 1) the hot air system, 2) the microwave heating system, and 3) the drying room and conveyor systems. The experiments in this study have shown that the machine can produce heat in the temperature range covered to dry block rubber and the temperature is precise enough within a range of 100 to 130°C (±0.5°C). Security experiments on the microwave leakage have shown that it does not exceed the standards of the HHS (no more than 5 mill watts per square centimeter). Performance experiments have indicated the heat distribution was 83.46 percent which is over 65% of what is considered normal, and the power of the microwave was measured by testing was the value of 24.42 percent of the magnetron wattage used.
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Huang, Jiandong, and Yuantian Sun. "Viscoelastic Analysis of the Damping Asphalt Mixtures (DAMs) Made with a High Content of Asphalt Rubber (AR)." Advances in Civil Engineering 2020 (October 27, 2020): 1–12. http://dx.doi.org/10.1155/2020/8826926.
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Damping asphalt mixtures (DAMs) have been developed to resist vibration and noise caused by traffic loads, and the ultimate design goal in this process is to increase damping. However, while optimizing its damping characteristics, the viscoelastic properties are not yet clear. In the present study, two DAMs are designed based on the open-graded (OG) aggregate structure, and the viscoelastic properties are evaluated subsequently by the dynamic mechanical testing. The results show that the proposed mix-design method for DAMs can meet the mechanical requirements specified in the standards; DAMs are detected to have higher phase angle and lower stiffness modulus compared with traditional mixtures, and the antifatigue performance is excellent but resistance to rutting may face challenges.
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Krawiec, Piotr, Łukasz Warguła, Daniel Małozięć, Piotr Kaczmarzyk, Anna Dziechciarz, and Dorota Czarnecka-Komorowska. "The Toxicological Testing and Thermal Decomposition of Drive and Transport Belts Made of Thermoplastic Multilayer Polymer Materials." Polymers 12, no. 10 (September 28, 2020): 2232. http://dx.doi.org/10.3390/polym12102232.
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The article presents the potential impact of flat drive and transport belts on people’s safety during a fire. The analysis distinguished belts made of classically used fabric–rubber composite materials reinforced with cord and currently used multilayer polymer composites. Moreover, the products’ multilayers during the thermal decomposition and combustion can be a source of emissions for unpredictable and toxic substances with different concentrations and compositions. In the evaluation of the compared belts, a testing methodology was used to determine the toxicometric indicators (WLC50SM) on the basis of which it was possible to determine the toxicity of thermal decomposition and combustion products in agreement with the standards in force in several countries of the EU and Russia. The analysis was carried out on the basis of the registration of emissions of chemical compounds during the thermal decomposition and combustion of polymer materials at three different temperatures. Moreover, the degradation kinetics of the polymeric belts by using the thermogravimetric (TGA) technique was evaluated. Test results have shown that products of thermal decomposition resulting from the neoprene (NE22), leder leder (LL2), thermoplastic connection (TC), and extra high top cower (XH) belts can be characterized as moderately toxic or toxic. Their toxicity significantly increases with the increasing temperature of thermal decomposition or combustion, especially above 450 °C. The results showed that the belts made of several layers of polyamide can be considered the least toxic in fire conditions. The TGA results showed that NBR/PA/PA/NBR belt made with two layers of polyamide and the acrylonitrile–butadiene rubber has the highest thermal stability in comparison to other belts.
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Saputra, A. E., A. Setiawan, S. Bakri, Tugiyono, I. Zulkarnain, and M. Wisman. "Utilization of Natural Rubber (Latex) as Raw Material for Flexible Pavement Industry." IOP Conference Series: Earth and Environmental Science 1012, no. 1 (April 1, 2022): 012082. http://dx.doi.org/10.1088/1755-1315/1012/1/012082.
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Abstract The rapid development of structures so far needs to be balanced with road construction, but there are many road damages that use asphalt flexible pavements are damaged and changes or deformations in the pavement, this can be caused by the influence of heat, radiation, rainfall, volume or high traffic loads and will be overcome with the addition of natural rubber to reduce the bad things above. The research implemented.at the Road and Bridge Laboratory and the Lampung State Polytechnic Analysis Laboratory for 6 months. The treatment that will be applied in this research is the manufacture of additives with the creaming method in the Analysis Laboratory which finally concentrates latex with variations of 3%, 5% 7 and 9% of the weight of pure asphalt which will be applied with asphalt and aggregate materials. pavement to form a denser bond. Variations in making samples using the FCR (Design Mixed Formula) method or DMF design mix formula, using concentrated latex as an additive and testing using the Marshall Test testing method in road and bridge laboratories so that from the research results obtained for asphalt and latex the treatment has an effect on the value MQ (Marshall Quotient), but the interaction results show that the ANOVA table shows that asphalt, latex and the interaction between asphalt and latex show significant values. Duncan’s analysis with an alpha of 0.05 shows that the additives provide significant added value from the MQ (stability/Fatigue) kg/mm value and it is shown that the asphalt mixture with samples A and E after being mixed with additives gives a value according to the applicable standards in the table. requirement 2 for LL (traffic) Weight The min value of MQ 200 and the maximum of MQ 350 lies in a mixture of Type A 3% asphalt content and Type E with 9% asphalt content after adding latex and according to duncan’s analysis of the relationship between Asphalt Content and MQ Value. and for the best result for Flexible Pavement Industry Type A with 3% content can be recommended to be used
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Wechsler, B. "Floor quality and space allowance in intensive beef production: a review." Animal Welfare 20, no. 4 (November 2011): 497–503. http://dx.doi.org/10.1017/s0962728600003134.
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AbstractIn intensive beef production in Europe, finishing beef cattle are typically reared in pens with fully slatted floors and low space allowances. These housing conditions were questioned in a report published by the Scientific Committee on Animal Health and Animal Welfare in 2001. The report concluded that the welfare of finishing bulls and steers is at risk if they are housed on fully slatted concrete or wooden floors or not provided with adequate floor space. The aim of the present paper is to review and update scientific evidence on the effects of floor quality and space allowance on the welfare of finishing beef cattle. It is shown that the recommendations made by the Scientific Committee on Animal Health and Animal Welfare are still valid, and are well supported by studies published over the last 10 years. Furthermore, results of several recent studies testing fully slatted floors with rubber covering indicate that this type of flooring is an acceptable alternative to concrete slats, with positive effects on animal behaviour and leg lesions. Consequently, a phasing-out of housing systems with fully slatted concrete floors is suggested. With respect to floor space, the studies reviewed here support the notion that it is essential to enforce minimum standards resulting in increased space allowances for intensive beef production systems.
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Salih, Choman, Allan Manalo, Wahid Ferdous, Rajab Abousnina, Peng Yu, Tom Heyer, and Peter Schubel. "Novel Bending Test Method for Polymer Railway Sleeper Materials." Polymers 13, no. 9 (April 21, 2021): 1359. http://dx.doi.org/10.3390/polym13091359.
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Alternative sleeper technologies have been developed to address the significant need for the replacement of deteriorating timber railway sleepers. The review of the literature indicates that the railway sleepers might fail while in service, despite passing the evaluation tests of the current composite sleeper standards which indicated that these tests do not represent in situ sleeper on ballast. In this research, a new five-point bending test is developed to evaluate the flexural behaviour of timber replacement sleeper technologies supported by ballast. Due to the simplicity, acceptance level of evaluation accuracy and the lack of in-service behaviour of alternative sleepers, this new testing method is justified with the bending behaviour according to the Beam on Elastic Foundation theory. Three timber replacement sleeper technologies—plastic, synthetic composites and low-profile prestressed concrete sleepers in addition to timber sleepers—were tested under service loading condition to evaluate the suitability of the new test method. To address the differences in the bending of the sleepers due to their different modulus of elasticities, the most appropriate material for the middle support was also determined. Analytical equations of the bending moments with and without middle support settlement were also developed. The results showed that the five-point static bending test could induce the positive and negative bending moments experienced by railway sleepers under a train wheel load. It was also found that with the proposed testing spans, steel-EPDM rubber is the most suitable configuration for low bending modulus sleepers such as plastic, steel-neoprene for medium modulus polymer sleepers and steel-steel for very high modulus sleepers such as concrete. Finally, the proposed bending moment equations can precisely predict the flexural behaviour of alternative sleepers under the five-point bending test.
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Sabri, BAM, NHM Radzi, FZA Hadi, and IH Ismail. "Feasibility of using Latex Examination Gloves as Dental Dam: A Tensile Strength Study." Compendium of Oral Science 2, no. 1 (September 1, 2015): 6–13. http://dx.doi.org/10.24191/cos.v2i0.17521.
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Objective: To evaluate feasibility of hand gloves as a rubber dam isolation alternative, in respect of physical properties. Materials and Methods: A randomized controlled trial study design was used. Three types of gloves were tested with two types of a rubber dam used as the control group. Cut-out pattern of dumb-bell shapes were made from 35 samples for each type of groups and tensile strength were tested using Universal Testing Machine and the Trapezium X software. All tests for physical requirements were performed in accordance with American Society for Testing and Materials D412, Standard Test Methods for Vulcanized Rubber and Thermoplastic Rubbers and Thermoplastic Elastomers-Tension. Findings were analyzed by analysis of variance (ANOVA) and differences were compared using a Tukey-Kramer interval calculated at the 0.05 significance level. Results: Heavy gauge rubber dam has the highest Mean (calculated at the 0.05 significance level) except for maximum stress calculated at entire area. Medium-gauge rubber dam has significantly higher tensile strength (44.5075 N/mm2) when compared to heavy-gauge rubber dam (35.7787 N/mm2) although it was 0.09mm thinner. Discovery 2020 Powder Free Latex Examination Gloves with tensile strength value of 28.5922 N/mm2 (±3.27366) is more than the minimum requirement specified by American Federal Specification ZZ-R90B Rubber Dam (Dental, 1985) (4000 pounds per square inch or 27.6 N/mm2). For all variable tested, all groups are significantly different from each other. The mean square between the groups was quite large. Conclusion: This study shows that there are significant differences between the physical strength of latex gloves when compared to rubber dam. However, the comparison between thickness and tensile strength among various rubber dam, did not correspond proportionately. Only one type of rubber gloves met the minimum requirement but that is just one aspect. In view of these mixed results, more research is needed before we can conclude that it is feasable that we use hand gloves to replace rubber dam.
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Skrobak, Adam, Michal Stanek, David Manas, Martin Ovsik, Vojtech Senkerik, and Martin Reznicek. "Mechanical Properties of Injection Molded Rubber Testing Samples." Applied Mechanics and Materials 752-753 (April 2015): 308–11. http://dx.doi.org/10.4028/www.scientific.net/amm.752-753.308.
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The aim of this article is to demonstrate and asses to what extent there is an impact on the mechanical properties of a standardized testing sample made of rubber compound based on synthetic rubber EPDM and produced by injection molding in comparison with a sample produced by classic preparation (cutting off a compression molded plate) according to the standard ISO 23529.
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Utami, Rima Wahyu, Kartini Kartini, and Aji Ali Akbar. "Pengaruh Keragaman Penggunaan Lahan di Ekosistem Gambut sub DAS Kapuas Kabupaten Kubu Raya." Jurnal Ilmu Lingkungan 19, no. 2 (July 4, 2021): 409–21. http://dx.doi.org/10.14710/jil.19.2.409-421.
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Lahan gambut merupakan komponen ketahanan lingkungan yang diupayakan untuk menjamin keamanan publik dan munculnya bahaya lingkungan yang disebabkan secara alami oleh alam maupun disengaja oleh perbuatan manusia. Lahan gambut di Desa Teluk Empening telah mengalami konversi menjadi lahan usahatani seperti lahan sawit, karet dan jahe, sedangkan lahan sekunder yang ada pada daerah penelitian sebelumnya pernah mengalami kebakaran pada tahun 2017. Penelitian ini dilakukan dengan mengidentifikasi keanekaragaman jenis pada lahan gambut dengan melakukan pengukuran biodiversitas lahan dengan analisis vegetasi. Kemudian menganalisis pengaruh konversi lahan gambut dengan pengukuran sifat fisik tanah, pengukuran Tinggi Muka Air tanah, pengukuran dimensi saluran dan pengujian kualitas air. Perubahan dinamika tutupan lahan yang dipengaruhi oleh kondisi sosial ekonomi masyarakat, data diperoleh dengan menggunakan observasi, wawancara dan kuesioner sebanyak 30 sampel. Hasil analisis menunjukkan lahan jahe, karet dan sawit memiliki nilai indeks keanekaragaman (H’) ±0 dikategorikan biodiversitas rendah. Lahan sekunder memiliki nilai indeks keanekaragaman (H’) 2,001 masuk kategori biodiversitas sedang. Konversi lahan gambut mempengaruhi sifat fisik tanah gambut seperti parameter porositas, permeabilitas, kadar serat dan kadar air. Konversi lahan gambut menjadi lahan karet memengaruhi penurunan muka air tanah yaitu setinggi 68 cm. Pengaruh konversi terhadap kualitas air pada lahan, ditandai dengan parameter pH berkisar 3,3 - 4,6, TSS berkisar 6-440 mg/l dan DO berkisar 0,89-3,4 mg/l yang tidak sesuai dengan baku mutu yang ditetapkan yaitu Kelas 2 PP No.82 Tahun 2001. Konversi lahan gambut semakin meningkat tiap tahun dan mempengaruhi kondisi sosial ekonomi masyarakat dengan fungsi sosial penyerapan tenaga kerja serta fungsi ekonomi pendapatan dari hasil produksi usahatani. Lahan gambut memberikan keunggulan dan kapasitas bagi kawasan lokal untuk kekuatan alam seperti lingkungan, ekonomi dan sosial yang dapat dilakukan sambil tetap menjaga daya tahan lingkungan. AbstractPeatlands are a component of environmental resilience that strives to ensure the safety and security of environmental hazards caused naturally or intentionally by human actions. Peatland in Teluk Empening Village has undergone conversion to agricultural land such as oil palm, rubber and ginger, while the secondary land in the previous study area experienced fires in 2017. This research was conducted by identifying the diversity of species on peatland by measuring biodiversity land with vegetation analysis. Then analyze the effect of peat land conversion with physical measurements of soil, measurement of groundwater level, measurement of channel dimensions and testing of water quality. Changes in land cover dynamics obtained from socio-economic conditions, data obtained using observations, interviews and questionnaires as many as 30 samples. The analysis showed that ginger, rubber and oil palm land had a diversity index value (H ') ± 0 which was categorized as low biodiversity. Secondary land has a diversity index value (H ') of 2,001 in the medium biodiversity category. Peat land conversion affects the physical properties of peat soil such as parameters of porosity, permeability, fiber content and air content. The conversion of peatlands to rubber lands has an effect on the decrease in the water table, which is 68 cm long. The effect of conversion on water quality in land, fear with pH parameters ranging from 3.3 to 4.6, TSS ranging from 6-440 mg / l and DO ranging from 0.89-3.4 mg / l which are not in accordance with the specified quality standards namely Class 2 PP No. 82 Year 2001. Conversion of peatlands is increasing every year and affects the socio-economic conditions of the community with the social function of absorption of labor and the economic function of income from agricultural production. Peatlands provide advantages and capacities for local areas for natural forces such as environment, economy and social that can be done while maintaining environmental resilience.
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Valenta, László, and Attila Bojtos. "Mechanical and Electrical Testing of Electrically Conductive Silicone Rubber." Materials Science Forum 589 (June 2008): 179–84. http://dx.doi.org/10.4028/www.scientific.net/msf.589.179.
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Silicone rubber is an essential construction material in food industry, medicine and in some fields of mechanical engineering, because it has good mechanical, electrical, biological and other special properties. One needs to know these material properties in order to develop silicone sensors. We performed several standard measurements for rubber, like tensile strength, cyclic tensile, bending, fatiguing, stress relaxation tests etc. To investigate the electrical properties, we measured the resistance of silicone during the mechanical tests. The paper summarizes the newest results of our research in connection with mechanical and electrical properties of conductive silicone rubber.
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Rahmaniar, Rahmaniar. "KETAHANAN USANG BARANG JADI KARET PEGANGAN SETANG SEPEDA MOTOR DARI TEPUNG KULIT KERANG." Jurnal Industri Hasil Perkebunan 11, no. 1 (June 15, 2016): 43–50. http://dx.doi.org/10.33104/jihp.v11i1.3409.
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Padding used to strengthen and enlarge rubber volume, can improve the quality of rubbery goods’physical characteristics and vulcanization. The objectives of the research were to obtain the formulation ofrubber compound met SNI standardvaried with particle size of flour clamshell and ratio composition of padding(clamshell flour: carbon black). The experimental design of the research was Completely RandomizedFactorial Design. The first factor was concentration of clamshell flour in particle size (A): A1:30 phr, A2:40 phr, A3: 50 phr. The second was ratio composition of padding (clamshell flour: carbon black N330) (B):B1 = 15:55 phr, B2=25:45 phr and B3=35:35 phr. Testing on quality of rubber compound’s characteristicsincludevisual test, modulus, and ageing resistance including hardness, tensile strength, elongation at break.The result showed that visual test for physical compound characteristics value is no defect for all formula, 55– 104% for modulus, while compound physical test after ageing process shows 56 – 64 shore A for hardness,106 – 129 kg/cm2 for tensile strength, 336 – 579% for elongation at break. Test result for all parametersmeets SNI 06-7031-2004 as the standard for motorcycle grip handle.Keywords: rubber compound, Flour Clamshell, carbon black.
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Kudelin, D. V., and T. N. Nesiolovskaya. "Application of a computational and experimental method of analysis the complexly stressed state of rubber membranes for effective solutions for their production." Proceedings of the Voronezh State University of Engineering Technologies 83, no. 2 (September 27, 2021): 230–36. http://dx.doi.org/10.20914/2310-1202-2021-2-230-236.
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The competitiveness of rubber membranes determined by their durability, quality, reliability, including the time required to create. During operation, the membranes undergo complex deformations, as a result of which a large number of potential destruction zones of a different nature arise, which can lead to the failure of the product. The standard test methods used in the development of formulations for membranes involve testing the material under uniaxial tension conditions in most cases and do not take into account the actual loading conditions of the product during operation, which significantly increases the development time of new formulations for membranes. The paper presents and applies in practice a computational and experimental method of analysis the complexly stressed state of rubber membranes, including carrying out simple laboratory tests in a heterogeneous complexly stressed state, which is realized during the operation of rubber membranes, and analyzing the stress-strain state by the finite element method. An inhomogeneous complexly stressed state was realized by forcing the rubber membrane with a spherical indenter. The application of a computational-experimental method for analyzing the complexly stressed state of rubber membranes is considered on the example of a rubber corrugated membrane of an automatic valve of a bag filter purge system. An assessment of the physical and mechanical properties of rubbers in a heterogeneous complexly stressed state was carried out, as well as an analysis of the stress-strain state of the membrane when it was loaded with a spherical indenter, which made it possible to identify the most dangerous zones of the section. The complex use of this method made it possible to improve the resource of this corrugated membrane by thirty five percent in comparison with the standard, while reducing the creation time.
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Jensen, J. Steen, and Henning B. Treichl. "Mechanical testing of prosthetic feet utilized in low-income countries according to ISO-10328 standard." Prosthetics and Orthotics International 31, no. 2 (June 2007): 177–206. http://dx.doi.org/10.1080/03093640701210986.
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This report summarizes the results from 1132 ISO-10328 standard tests performed on 21 different prosthetic foot models commonly utilized in the developing world. None of the tested feet passed the strictest ISO testing protocol. All but one failed at the initial Static Proof test, which simulates a single momentary overload, due to permanent forefoot deformation. In addition, all tested feet had significant internal failures that were visible when sectioned longitudinally. Static Proof testing revealed average permanent deformation of the forefoot of all feet that exceeded the optional 5 mm ISO requirement. Forefoot deformation for non-Jaipur rubber feet came closest to meeting the standard at 8.3±3.4 mm; deformation of the various types of rubber Jaipur feet was the greatest at 22.5±5.4 mm. Forefoot deformation for polyurethane (PU) feet was 13.6±5.5 mm. Forefoot deformation of the ethyl-vinyl-acetate (EVA) feet was slightly greater than the Jaipur feet at 22.8±5.7 mm. After the Static Strength test, which simulates a higher momentary overload, permanent deformation of the feet increased. The average maximum deformation for rubber SACH forefeet varied from 17 – 30 mm, and 11 – 26 mm for the heel; Jaipur forefeet 47 – 60 mm and heels 13 – 19 mm; PU forefeet 20 – 44 mm and heels 20 – 33 mm; and EVA forefeet 33 – 50 mm and heels 16 – 31 mm. After completion of the Cyclic Test the prosthetic feet were sawn in half and closely examined visually. All feet revealed internal derangements: (i) Deformation of rubber or PU foam under the keel of forefoot and/or heel: HCMC, VI, EB1, BAVI, HI Cambodia, Myanmar, Angola, TATCOT, Kingsley and CR; (ii) Delamination from the keel: Mozambique, PHN, and Pro-cirugia; and (iii) Delamination between foam layers: BMVSS, NISHA, MUKTI, and OM. The influence of the two environmental factors tested was minimal for rubber feet with respect to deformation and inconsistent for the polymer feet; in particular for the forefeet. Creep increased with humidity exposure in some feet of natural rubber. However, creep decreased with ultraviolet (UV) exposure for these natural rubber feet, as was also the case for EVA feet, whereas the creep increased for two PU feet. Comparison of the effect of humidity and UV exposure generally showed less creep with UV exposure. In conclusion, ISO-10328 testing prior to release of a new foot construction for amputee use appears to be useful in the developing countries as well as in the developed world, even though it does not simulate the wear on the plantar surface that is seen clinically in barefoot walking. Inspection of the internal structures after the laboratory testing has been shown to reveal occult failure mechanisms in all tested feet.
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Poh, B. T., and Junidah Lamaming. "Effect of Testing Rate on Adhesion Properties of Acrylonitrile-Butadiene Rubber/Standard Malaysian Rubber Blend-Based Pressure-Sensitive Adhesive." Journal of Coatings 2013 (October 20, 2013): 1–6. http://dx.doi.org/10.1155/2013/519416.
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The dependence of loop tack, peel strength, and shear strength of NBR/SMR L blend-based pressure-sensitive adhesives on the rate of testing was investigated using coumarone-indene resin and toluene as the tackifier and solvent, respectively. A 40% NBR content in the NBR/SMR L blend was used throughout the experiment. The adhesion properties were measured by a Lloyd Adhesion Tester operating at different rates of testing. The result indicates that loop tack, peels strength, and shear strength increase with the rate of testing due to the viscoelastic response of the adhesive. At low testing rate, the failure mode is cohesive in nature whereas adhesion failure mode occurs at higher testing rates. Adhesion properties also increase with the increase in adhesive coating thickness, an observation which is attributed to the wettability of the adhesive and viscoelastic behavior of the rubber blend.
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Faisal Sadique, Muhamed Ismaeel, Migara Liyanage, and Chitral Angammana. "Developing a Rubber basedNanocomposite." Journal of Advances in Engineering and Technology 1, no. 1 (September 30, 2022): 56–64. http://dx.doi.org/10.54389/qebq2494.
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Polymer compounds such as Natural Rubber (NR), which consists of compounds such as isoprene, are capable of being processed for the manufacture of a range of rubber based products for a large variety of applications. The properties of a natural rubber compound are susceptible to enhancements in their properties through the incorporation of nanofillers into its matrix. This study addresses the preparation of a natural rubber based nanocomposite that utilizes graphene as a nanofiller for the facilitation of the required enhancement in the rubber compounds properties. The nanocomposite specimens used in the study were prepared by means of acid-coagulation. The acid-coagulation formulation utilized was adapted from methodologies employed in commercial applications. The enhancement in the rubber properties due to the incorporation of the nanofiller was validated by means of mechanical testing. Prior to the testing, the applicable standard for tensile property testing was identified to be ASTM D412. Through the acclaimed standard, a mould to facilitate the preparation of the required specimens was 3D printed from PETG. The primary aim of the study was to determine the effect of large concentrations of graphene (beyond 2.5wt %).The results from the mechanical testing of the acid-coagulated samples exhibited enhancements in the elongation at break and tensile strength between unfilled NR and the graphene filled NR nanocomposite. With the incorporation of 5wt% of graphene, the elongation at break of the rubber increased to 687%, showing a 25% increase. The tensile strength of the rubber increased to 4.07 MPa, showing an enhancement of 102% in comparison to the pristine rubber compound. KEYWORDS: Natural Rubber, Graphene, Acid-Coagulation, Tensile strength, Elongation at break.
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Ushmarin, N. F., and S. M. Kavun. "New Antiozonants for Rubber Compounds Based on Oxyalkylated Derivatives of 4-Aminodiphenylamine." International Polymer Science and Technology 44, no. 11 (November 2017): 29–36. http://dx.doi.org/10.1177/0307174x1704401107.
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This paper sets out the properties and the results of the testing of new antiozonants 2PPD and 3PPD in place of standard and imported 6PPD and IPPD which are used in the production of mechanical rubber goods and tyres (in the sidewall, tread, and other elements). The proposed method for producing the new antiozonants makes it possible to organise their industrial production by low-cost technology, in contrast to 6PPD and IPPD production technology. The raw materials for the new antiozonants include ethylene and propylene glycols, available in Russia, and 4-aminodiphenylamine, imported for the production in Russia of antioxidant S789, which is widely used in the production of large-tonnage rubbers, in particular synthetic isoprene rubber SKI-3, over 70% of the volume of which is exported. A number of advantages of 3PPD over imported stabilisers have been established. These include a greater effectiveness in protecting rubber compounds against thermal oxidation and ozone cracking by comparison with the stabilisers it is replacing. The shortcomings of the new antiozonant (in terms of the form in which it is produced and in terms of its influence on the vulcanisation kinetics) are considered, and various ways to overcome these shortcomings are presented.
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Tedeschi, Edward. "Booms." Pure and Applied Chemistry 71, no. 1 (January 1, 1999): 17–25. http://dx.doi.org/10.1351/pac199971010017.
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Introduction: A "Boom" is a floating mechanical barrier used to control the movement of substances that float according to ASTM F-818 Standard Terminology Relating to Spill Response Barriers. (ASTM, 1994).Since oil has been transported by sea, accidental spills have occurred from time to time, but only since the 1960's has its spillage along coastlines or within harbor areas caused enough public concern to demand that it be removed immediately. Large disasters, such as the grounding of the "Torrey Canyon" and the Santa Barbara drilling platform blowout, put pressure on the oil producing community to prevent spillage and to develop procedures and equipment to recover the spills that did occur. Experimental booms were introduced in the early 1960's but it wasn't until later in the decade that their manufacture became commercially viable. Relatively crude booms to contain or control the spread of spilled oil were developed and some were assembled on site. Logs were tied together with old conveyor belting nailed between the ends; oil drums were strapped to plywood sheets connected with rubber or fabric; canvas was sewn over fishing floats knotted along a line. Although these booms were relatively effective in calm water when a small volume of oil was spilled, most of them were cumbersome to maneuver and they quickly failed when waves or current were present.Spills in the early 1970's, along with growing environmental awareness, prompted legislators, both national and local, to require that the responsible parties clean up their act. Worldwide entrepreneurial spirit spawned several dozen small manufacturing enterprises to meet local and, in some cases, international demand for cheap efficient booms.In the mid 70's, several events happened which shaped the spill response industry and started the evolution leading to the better products and response techniques which we use today. The Arab Oil Embargo of 1973 raised the price of a barrel of oil to the point that the cost of the product lost in a spill became relevant. U.S. governmental agencies, including E.P.A., M.M.S., and Coast Guard developed regulations that fined the spillers of even small amounts of oil. Money was spent by government and the oil industry on research and test facilities to understand the limits and differences of boom designs, resulting in improved performance. Oil terminals in most major harbor areas pooled their resources and formed local and regional oil spill response cooperatives (Etkin, 1991). The U.S. Navy, being a large buyer of booms, contacted the American Society of Testing and Materials (ASTM) to see if they had any people working on the subject of spill response products in general and specifically on standardization of boom connectors. They did not, so they issued an invitation to the industry at-large to form a committee to write standards on that subject. Committee F-20 was born. It took ten years to publish F-962 Standard Specification for Oil Spill Response Boom Connector, but along the way, over 40 consensus Standards (ASTM, 1994) have been published to aid users and manufacturers alike in the selection of spill response products and guidelines for their use.This chapter will discuss the types of booms available today, the problems associated with their use under various environmental conditions, special products for unusual situations, and also thoughts regarding future developments.
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Skrobak, Adam, Michal Stanek, David Manas, Martin Ovsik, Vojtech Senkerik, and Martin Reznicek. "Mechanical Properties of Rubber Samples." Key Engineering Materials 606 (March 2014): 249–52. http://dx.doi.org/10.4028/www.scientific.net/kem.606.249.
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This article demonstrates what influence has a change in production technology on mechanical properties of rubber testing samples. It compares two basic production technologies compression molding and injection molding. The aim of this research is to show and evaluate to what extent the properties (tensile strength, extension, tear strength and microhardness) are influenced by the used production technology and to quantify this potential difference on the basis of standard tests. The mechanical tension test according the standard ISO 37, the test determining tear strength according to the standard ISO 34-1 and the instrumented microhardness test (DSI) according to the standard ISO 6507-1.
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Skrobak, Adam, Vojtech Senkerik, and Vaclav Janostik. "The Effect of Injection Molding on Physical Properties of EPDM Rubber." MATEC Web of Conferences 210 (2018): 02039. http://dx.doi.org/10.1051/matecconf/201821002039.
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The paper a part of research aimed at the alternative of preparing test samples by injection molding. Such an alternative could bring more objective results in the field of testing samples produced in the same technology. The research is aimed at changing the preparation of rubber testing samples - replacing the standard method according to ISO 23529 by the injection method, especially with the use of rubber compounds for injection molding. This article compares and evaluates the selected physical properties (tensile strength and tear strength) of EPDM rubber injection molded samples with samples prepared by the standard method - cutting out of a compression molded plate. The results have shown that using the injection molded samples we will achieve more objective results mainly to determine the tear strength. In the case of tensile strength, the differences are not so significant.
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Ushmarin, Nikolay F., Evgeny N. Egorov, and Nikolay I. Kol'tsov. "INFLUENCE OF MICROSPHERES ON PROPERTIES OF AGGRESSIVE RESISTANT RUBBERS." IZVESTIYA VYSSHIKH UCHEBNYKH ZAVEDENII KHIMIYA KHIMICHESKAYA TEKHNOLOGIYA 64, no. 2 (January 29, 2021): 49–55. http://dx.doi.org/10.6060/ivkkt.20216402.6165.
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The aim of the work is to study the effect of hollow corundum, glass and pomegranate ceramic microspheres on the rheometric characteristics of aggressive resistant rubber mixtures and the physicomechanical parameters of their vulcanizates to determine of the content of fillers of this type, which provides an improvement in the priority properties of products and, as a result, an increase in their durability. The objects of research were two rubber mixtures intended for compression molding and injection molding. The compression molding mixture is based on a combination of nitrile butadiene, isoprene and butadiene-α-methyl styrene caoutchoucs with colloidal silicic acids as the main fillers. And the injection molding mixture is based on a combination of synthetic isoprene and butadiene rubbers filled with chalk, P234 carbon black and carbon 100. We used hollow corundum (HMC-L), glass (MS-V), and pomegranate ceramic (MVMD-170) microspheres. The rheometric properties of the rubber compounds were evaluated by the values of the minimum and maximum torques, the duration of the induction period, the time to reach the technological optimum, and the maximum vulcanization rate. When testing vulcanizates, conditional tensile strength, elongation at break, tear resistance, hardness, abrasion and rebound elasticity were determined. Priority indicators were also determined that correlated to the greatest extent with the durability of the products during operation - relative changes in conditional tensile strength and elongation at break, hardness after heat aging in air and standard liquid SZhR-1, change in mass of samples after swelling in industrial oil I-20A and Nefras S-80/120. For a mixture for compression molding, the effect of the type of microspheres introduced at a dosage of 5 parts by mass per 100 parts by mass caoutchoucs, on the properties of unvulcanized mixtures and vulcanizates was studied. It was found that the rubber mixture with glass microspheres is somewhat below in vulcanization activity, and its vulcanizate in terms of abrasion resistance, heat aging, especially in air, is inferior to two mixtures and rubbers with corundum and pomegranate microspheres. In the second mixture, we tested corundum microspheres with a dosage of 3.0 to 7.0 parts by mass per 100 parts by mass of caoutchoucs while reducing by the appropriate amount of carbon black. It was found that with an increase in the dosage of microspheres, a decrease in the vulcanization activity of the mixture, minimum and maximum torques, and also their difference is observed, which indicates a slight decrease in the degree of crosslinking of rubbers. The consequence is an increase in relative lengtheningof the vulcanizates. To the least extent, this effect manifests itself with the introduction of corundum microspheres in a dosage of 3 parts by mass. Thus, the advantage of rubbers with microspheres is reduced abrasion, higher tear resistance while maintaining resistance to the action of physically and chemically aggressive environments at the level of rubbers that do not contain microspheres.
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Xin, Shu Ying, Yong Cui, Min Xu, and Jian Li. "Technological Properties of Poplar Particle/Waste Rubber Powder Composites." Advanced Materials Research 194-196 (February 2011): 602–5. http://dx.doi.org/10.4028/www.scientific.net/amr.194-196.602.
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The hot-pressing technology for the poplar particle /waste rubber powder composites was studied using the poplar particle and waste rubber powder as raw materials. Effects of waste rubber powder content, hot-pressing time, hot-pressing temperature, resin content and board density were analyzed. The hot-pressing technology was better than molding technology. The optimal technological parameters of hot-pressing technology were obtained as board density0.8g/cm³, resin content3%, hot-pressing temperature160°C, hot-pressing time 7min , waste rubber powder content 30%. The testing results showed that the mechanical performances of the poplar particle /waste rubber powder composites made by the hot-pressing technology could achieve the Chinese National Standard for particle board.
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Andersson, Johan, Ulf H. Nilsson, Susanne Nilsson, Hedvig Pollak, and Nilena Nilsson. "Influence of Field Grading in Setup for Electric Breakdown Testing of Polyethylene Films." Proceedings of the Nordic Insulation Symposium, no. 26 (August 8, 2019): 47–51. http://dx.doi.org/10.5324/nordis.v0i26.3277.
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High dielectric strength of solid electrical insulation materials for high voltage applications is essential for high reliability and long-term performance.The IEC 60243 and ASTM D149 both describe very similar test methods to determine the short-term electric strength of solid insulation materials. A test sample, usually thin plaque, is placed in an electrode system with surrounding insulating oil. The voltage is then steadily increased until an electric breakdown occurs. Despite the relatively simple test setup, testing materials with high electric strength can be difficult. The breakdown channel is often located outside the active testing area of the electrodes and found at the electrode edge at the triple point between the electrode, test object, and surrounding oil.In this study, we have investigated different possibilities to control the electrical field enhancement in the vicinity of the electrode edges using silicone rubber, field grading silicone rubber, and a high permittivity oil. The testing was performed with semi-spherical electrodes and electrodes as recommended in IEC 60243 on polyethylene films. Electrodes covered with the field grading rubber increased the short-term breakdown strength compared to standard testing without modification. The high permittivity oil and silicone rubber seemed to have limited effect on the breakdown strength.
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Leblanc, Jean L. "Nonlinear Viscoelasticity of (Unvulcanized) Natural Rubber, Derived Materials, and Compounds Through LAOS Testing." Rubber Chemistry and Technology 83, no. 1 (March 1, 2010): 65–96. http://dx.doi.org/10.5254/1.3548267.
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Abstract Natural rubber (NR) is by far the most important elastic material but its production specifications remain relatively poor when compared to synthetic elastomers. The so-called technically specified NR grades (i.e., technically specified rubber) are indeed characterized with respect to basic rubber test techniques, such as the Mooney viscosity, the (Wallace) plasticity (P0), and the Plasticity Retention Index, but high elasticity grades like ribbed smoked sheets are classified with respect to visual inspection criteria only. In addition, NR exhibits by nature more variation than synthetic polymers, owing to inevitable production differences from around 50 different clones of Hevea Brasiliensis, which are further enhanced by climate, soil, and other local effects, as well as seasonal effects on tapping. Most rubber processing operations occur at high rates of strain, and therefore it is essentially the nonlinear viscoelastic response of rubber materials that is of interest. This prompted the development of advanced investigation testing, such as large amplitude oscillatory strain (LAOS) experiments, which over the last decade were developed into powerful techniques to document the nonlinear viscoelastic behavior of polymer materials. First, the standard rheological tests for characterizing gum NR grades are briefly reviewed and discussed. Second, the equipment, test protocols, data treatment, and results modeling necessary to apply nonlinear viscoelastic testing are presented. Third, a number of LAOS experimental results obtained on various grades of NR, on a few chemically modified NR materials, and on two carbon black-filled NR compounds are reported and discussed.
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Żuk, Daria, Norbert Abramczyk, and Katarzyna Panasiuk. "Analysis of Strength Parameters at Tension of Epoxy-Glass Composites with Rubber Recyclate Addition." Journal of KONBiN 52, no. 1 (March 1, 2022): 131–50. http://dx.doi.org/10.2478/jok-2022-0009.
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Abstract The aim of the research was to analyze the strength parameters of epoxy-glass sandwich composites with the addition of rubber recyclate. Material samples were subjected to a static tensile test performed on a universal testing machine in accordance with the current standard for fiber-reinforced composite materials. The test results showed that the addition of rubber recyclate increases the plastic parameters of the composite, which allows considering the use of the tested material for structures loaded with the vibration and noise scale. The use of rubber recyclate to modify the strength parameters of the composite allows to reduce the amount of rubber waste and ensures the durability of the new material.
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Su, Haolin. "Analysis of Cube Compressive Strength on Concrete with Recycled Aggregate and Rubber Particles." IOP Conference Series: Earth and Environmental Science 1050, no. 1 (July 1, 2022): 012029. http://dx.doi.org/10.1088/1755-1315/1050/1/012029.
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Abstract This paper analyzed the cube compressive strength of concrete containing recycled aggregate as part of coarse aggregates and rubber particles as part of fine aggregate, simultaneously. The effect of content of both aggregates on concrete compressive strength was studied. 25 sets of samples were made with a constant water/cement ratio of 0.39. Cube compressive strength of different samples at age of 28 days were obtained in accordance with relevant standard. Influence of replacement ratio of recycled aggregate and rubber on strength was investigated basing on the analyses of testing data and microstructure inspections, respectively. Results indicate that both recycled aggregate and rubber particles weaken the compressive strength of concrete while rubber particles plays a more important role. Replacement of fine aggregate over 20 vol% by rubber particles should be used carefully.
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Poh, Beng Teik, and Yin Yin Teh. "Effect of zinc oxide and testing rate on the adhesion property of styrene-butadiene rubber/standard Malaysian rubber blend adhesives." Journal of Vinyl and Additive Technology 22, no. 1 (August 4, 2014): 3–7. http://dx.doi.org/10.1002/vnl.21442.
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Magee, R. W. "Evaluation of the External Surface Area of Carbon Black by Nitrogen Adsorption." Rubber Chemistry and Technology 68, no. 4 (September 1, 1995): 590–600. http://dx.doi.org/10.5254/1.3538760.
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Abstract Specific surface area is an important property for carbon black grade classification, production control, and prediction of rubber reinforcement characteristics. Total surface area alone is insufficient for estimating the reinforcing properties of a microporous carbon black because the internal area of the micropores is inaccessible to rubber molecules. The CTAB surface area test, based on adsorption of a molecule too large to enter the micropore, measures the surface area available to rubber. Although widely used, the CTAB method has failed to gain wide popularity due to its labor-intensive nature and poor testing precision. In the present paper, the extent of microporosity on the surface of carbon blacks is investigated. The external surface area derived from the nitrogen adsorption characteristics is compared to CTAB surface area for a number of standard rubber carbon blacks. This study reports the optimum testing conditions to achieve precise external surface area measurements and the ability of this method to overcome the disadvantages of the CTAB method. Other advantages of this technique are discussed.
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Troy, Kenneth, Peter E. Sebaaly, and Jon A. Epps. "Evaluation Systems for Crumb Rubber Modified Binders and Mixtures." Transportation Research Record: Journal of the Transportation Research Board 1530, no. 1 (January 1996): 3–10. http://dx.doi.org/10.1177/0361198196153000101.
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The use of crumb rubber modified (CRM) asphalt mixtures has been increasing steadily. The reasons for this increase in use are twofold: the Intermodal Surface Transportation Efficiency Act of 1991 mandate and the potential of better performance. The technology of testing, design, and evaluation of CRM binders and mixtures has not yet caught up. Therefore, there is a need for establishing standard procedures for the design and evaluation of CRM mixtures. The outcome of a recent research project sponsored by the Nevada Department of Transportation (NDOT) is presented. The binder testing system concentrated on the newly developed Strategic Highway Research Program (SHRP) performance grading system and its applicability to CRM binders. It was concluded that the standard SHRP system will not work for CRM binders containing coarse rubber particles. The plate and cup system will have to be used for such CRM binders. However, the plate and cup system cannot adequately replace the bending beam rheometer for low-temperature testing. In the case of CRM mixtures, a modified Hveem mix design procedure was developed and validated on an actual NDOT project. Temperature susceptibility, moisture sensitivity, rutting resistance, and low-temperature cracking of CRM mixtures also are presented.
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Kahraman, Hasan, and Edmund Haberstroh. "DIRECTION-DEPENDENT AND MULTIAXIAL STRESS-SOFTENING BEHAVIOR OF CARBON BLACK–FILLED RUBBER." Rubber Chemistry and Technology 87, no. 1 (March 1, 2014): 139–51. http://dx.doi.org/10.5254/rct.13.87910.
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ABSTRACT The mechanical behavior of filled rubbers depends on the maximum stretch previously reached and consequently on the induced stress softening. This softening effect is referred to as the Mullins effect. Current investigations point out that the Mullins effect exhibits a significant directional dependence, which calls for an anisotropic material model. But for the formulation and validation of anisotropic material models, there is still a lack of suitable experimental data. For this the purpose, experiments based on chloroprene rubber (CR) are reported. To trace the anisotropic Mullins effect, the standard test method for characterization of the isotropic mechanical behavior must be extended. The appropriate type of specimen enables us to perform multiple load steps with alternating load directions. After repeated stretching in the same direction, a subsequent first uniaxial loading in any other direction is characterized by a stiffer stress–strain behavior compared with the stabilized curve of the previous primary load. Hence, the experimental results confirm the deformation-induced anisotropy. To identify the multiaxial material behavior after the prestretching in one direction, a biaxial tensile-testing machine is developed. A specific property of the biaxial tensile-testing machine is the independent control of both the loading axes. Thus, the rubber material can be subjected to arbitrary loading histories. Therefore, a cross-shaped specimen with four arms is used. Multiple slits parallel to the sides on each arm ensures the homogenous uniaxial load condition in the primary load. In the secondary load step, the loading axis, which was previously inactive, is moved in a uniform manner as the master axis or in any arbitrary defined ratio. The experimental results confirm the deformation-induced anisotropy of the Mullins effect. In summary, the material behavior significantly results from the deformation mode and the loading direction applied in the loading history.
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Cheewapattananuwong, Weeradej, and Pathom Chaloeywares. "The Innovation of Natural Rubber Applied with Concrete Road Barriers in Thailand." Advances in Science and Technology 103 (August 2020): 55–61. http://dx.doi.org/10.4028/www.scientific.net/ast.103.55.
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The Development of Natural Rubber for Traffic Devices in Thailand has been researched in several years. The enormous budgets have also been invested for the increasing of rubber prices. One of Traffic Devices is the application of natural rubber sheets for the protection of motorists - driving motorcycles as crashed through concrete barriers. The number of road side accidents on rural roads in Thailand is about 3 fatality per 10 kilometers. Therefore, the 11.20 MTB per a Fatality of accident cost is evaluated to be 3,360 TB per km. This leads to the mitigation methods to remedy a symptom’s motorist from severity to moderate and mild respectively. The solution is to find the best practice of road barrier which is applied with natural rubber latex glued with concrete barrier. In addition, the composite materials will be calculated of the modulus of elasticity and properties such as, strength and durability. The simulation of crashes, finite element of materials, LRFD and Concrete Technology methods will be taken into consideration. The testing of material in Thailand will be firstly applied for these, for example the road crash testing under the standard of NCHRP – TL3 (100 kph) will be taken into account.
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Smith, Frazer Howard. "Field joint coating of pipelines – effect of soluble salt contamination on 2-layer heat shrink sleeve performance." Anti-Corrosion Methods and Materials 63, no. 2 (March 7, 2016): 105–15. http://dx.doi.org/10.1108/acmm-09-2015-1573.
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Purpose – During offshore pipe-lay, pipe lengths with anticorrosion coating are welded together, and, to facilitate the welding process, the ends of the pipe remain uncoated. A wide range of field joint coating (FJC) types is available for coating this bare section, functioning in conjunction with the pipeline cathodic protection system to provide an anti-corrosion system or package. This paper aims to relate to two-layer type heat shrink sleeves (2LHSS), which commonly are used for FJC of concrete-weighted offshore pipelines where the sleeve typically is over-coated with a solid or foam type polyurethane “infill”. Similar sleeves also are used sometimes in exposed conditions on lines without concrete over-coating. The maximum allowable soluble salt contamination prior to application of high-performance coating systems can vary, depending upon the coating type, but typically has been set at 20 mg/m2 (de la Fuente et al., 2006). The first layer of three-layer heat shrink sleeve (3LHSS) systems for pipeline FJC, liquid epoxy, falls into this category (ISO_21809-3:2008, 2008). In contrast, the 2LHSS system does not use a liquid epoxy first layer but relies instead on the bonding of a “mastic” layer directly to the pipe metal surface. The maximum acceptable concentration of salt contamination on prepared metal surfaces prior to the application of 2LHSS has been a subject of debate and was the focus of this study. International standards for FJC do not provide a maximum salt level. However, some companies have continued to specify low thresholds for the maximum allowable salt level for 2LHSS, which can result in expensive delays in production during offshore pipe-lay. In this study, salt contamination levels of up to 120 mg/m2 were found to have no effect on peeling performance after accelerated aging by hot water immersion. Furthermore, preparation for welding and the use of potable water during ultrasonic testing procedures prior to FJC, typically reduces the salt contamination level to below 50 mg/m2 providing a strong case for the deletion of salt contamination testing for 2LHSS. Design/methodology/approach – The potential risk of failure of the coating due to poor surface cleanliness/contamination was assessed by testing the adhesion between the coating and the steel substrate to which the coating is adhering, following a period of hot water immersion. Compliance with ISO 21809-3 “Annex I” requires 28 days’ immersion at maximum operating temperature. For this study, to create a severe situation, the test rings were subjected to accelerated aging by water immersion at the HSS upper specified temperature of 65°C for more than twice the specified period (ISO_21809-3:2008, 2008). Two HSS were tested; one was widely used in applications where exposure to moderate mechanical stress is required, having a high shear strength type mastic “hybrid” adhesive containing a significant proportion of amorphous polypropylene blended with tackifiers and ethylene vinyl acetate (EVA), Andrenacci et al. (2009) referred to as “Type A”. The second, referred to as “Type B”, is widely used in applications where it is covered by a layer of “infill”, typically consisting of polyurethane foam or solid polyurethane elastomer, i.e. typical design methodology for concrete coated pipelines. “Type B” HSS had a more moderate strength traditional type mastic than “Type A” containing a significant percentage of butyl rubber with asphalt, activation agents and tackifying resins. To determine how to apply the salt contamination without causing flash rust, a mini-study was completed on the steel substrate. After numerous trials, it was found impossible to not to form visible rust on the pipe surface. The extent of rusting was minimised by heating the pipe immediately after the application of the salt solution. Findings – High levels of sea salt on power tool prepared pipe surfaces were investigated by peel testing of 2LHSS after hot water immersion and compared against peel tests undertaken prior to hot water immersion. The test conditions were considered severe: salt contamination levels of up to 120 mg/m2 applied on power tool cleaned pipe surfaces that had been aged for one year without prior grit blasting. The accelerated ageing procedure had twice the specified (ISO_21809-3:2008, 2008) water immersion duration, and the test samples had exposed edges providing the possibility for moisture to creep under the coating. The test results showed that there were no noticeable deleterious effects on the performance of the two most commonly used FJCs, 2LHSS. Therefore, it was concluded that, as the level of salt contamination on prepared pipe surfaces after wet non-destructive testing typically is much lower than the levels tested in this study, pipe surfaces prepared for the application of 2LHSS type do not require specific additional measures to further reduce salt contamination, provided that care is taken to ensure that these conditions are maintained consistently during pipe laying operations. Practical implications – The frequency of salt contamination testing of power tool cleaned surfaces prior to mastic type heat shrink sleeves can be minimised, and perhaps omitted entirely, provided the above criteria are satisfied. Originality/value – A literature review revealed there was little published information on the testing of 2LHSS and nothing related to hot water immersion testing. Hence, the results of this investigation have provided useful industrial data regarding the effect of hot water ageing and the influence of surface salt contamination on field joint corrosion prevention capabilities.
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Sutanto, Muslich, Nura Bala, Kemal Al Zaro, and Sri Sunarjono. "Properties of Crumb Rubber and Latex Modified Asphalt Binders using Superpave Tests." MATEC Web of Conferences 203 (2018): 05007. http://dx.doi.org/10.1051/matecconf/201820305007.
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Polymer modified binders have been used for long time to improve the quality of asphalt pavement. This study investigates the effect of crumb rubber and latex on the properties of bitumen binders. Crumb rubber and latex were added to the control 60/70 pen grade bitumen. Four different proportions of crumb rubber and latex were considered in this study: 0%, 4%, 6% and 8% by weight of bitumen binder. The effect of crumb rubber and latex were evaluated through standard penetration and softening point tests as well as dynamic shear rheometer (DSR) test. Temperature ranges of 20°C - 40°C were used for the DSR rheological testing. The results showed that the addition of crumb rubber and latex leads to a promising improvement on the binder properties. A reduction in penetration and an increase in softening point temperature were observed with the addition of either crumb rubber or latex, this indicates improvement in stiffness and rutting resistance. The analysis on DSR results also show that the modified binders have good rutting resistance.
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Andreini, G., P. Straffi, S. Cotugno, G. Gallone, and G. Polacco. "COMPARISON OF SINE VERSUS PULSE WAVEFORM EFFECTS ON FATIGUE CRACK GROWTH BEHAVIOR OF NR, SBR, AND BR COMPOUNDS." Rubber Chemistry and Technology 83, no. 4 (December 1, 2010): 391–403. http://dx.doi.org/10.5254/1.3512954.
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Abstract Fatigue crack growth experiments on carbon black-filled rubber compounds have been carried out to evaluate the influence of testing conditions over different compound formulations. Investigations on the influence of waveform, data acquisition, and compound formulation have been performed on strip-tensile specimens reproducing the mode I of crack opening. The response of three different compound formulations (based on either natural rubber, butadiene rubber, or styrene-butadiene rubber) to the application of two different waveforms, pulse and sine, has been analyzed, showing significant differences in fatigue behavior and ranking of the various compounds. Compared to the sinusoidal waveform, the use of a pulse waveform provided an improved correlation of the tearing energy with the crack propagation speed. This difference was particularly evident in the case of natural rubber and butadiene rubber, while it resulted negligible in the case of styrene-butadiene rubber. Such a different behavior could be attributed to differences in macromolecular chains orientation. Fine-tuning of video acquisition parameters provided an accurate observation of the crack growth process, as confirmed by the low standard deviation of the estimated tearing energy and crack growth rate.
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Sambucci, Matteo, Abbas Sibai, Luciano Fattore, Riccardo Martufi, Sabrina Lucibello, and Marco Valente. "Finite Element Multi-Physics Analysis and Experimental Testing for Hollow Brick Solutions with Lightweight and Eco-Sustainable Cement Mix." Journal of Composites Science 6, no. 4 (April 5, 2022): 107. http://dx.doi.org/10.3390/jcs6040107.
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Combining eco-sustainability and technological efficiency is one of the “hot” topics in the current construction and architectural sectors. In this work, recycled tire rubber aggregates and acoustically effective fractal cavities were combined in the design, modeling, and experimental characterization of lightweight concrete hollow bricks. After analyzing the structural and acoustic behavior of the brick models by finite element analysis as a function of the type of constituent concrete material (reference and rubberized cement mixes) and hollow inner geometry (circular- and fractal-shaped hollow designs), compressive tests and sound-absorption measurements were experimentally performed to evaluate the real performance of the developed prototypes. Compared to the traditional circular hollow pattern, fractal cavities improve the mechanical strength of the brick, its structural efficiency (strength-to-weight ratio), and the medium–high frequency noise damping. The use of ground waste tire rubber as a total concrete aggregate represents an eco-friendlier solution than the ordinary cementitious mix design, providing, at the same time, enhanced lightweight properties, mechanical ductility, and better sound attenuation. The near-compliance of rubber-concrete blocks with standard requirements and the value-added properties have demonstrated a good potential for incorporating waste rubber as aggregate for non-structural applications.
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Yu, Yang, Simin Ren, Jie Li, Jiaqian Chang, Song Yu, Chao Sun, and Tingmin Chen. "Calibration and Testing of Discrete Element Modeling Parameters for Fresh Goji Berries." Applied Sciences 12, no. 22 (November 16, 2022): 11629. http://dx.doi.org/10.3390/app122211629.
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This paper aims at the standard grading of fresh goji berries and develops a variable gap-type fresh goji berry grading machine. To establish a complete simulation model, the discrete element parameters of the model were calibrated by a combination of physical experiments and simulation experiments. The outline of the goji berry was extracted by the SFM-CMVS technique, and a goji berry model was obtained using the multi-spherical particle model filling method in the EDEM software. By designing the free-fall, suspension collision, slope slip, and slope rolling experiments, we obtained the discrete element simulation parameters: the inter-particle collision restitution coefficient was 0.158, the collision restitution coefficient of fresh goji berry–silicone rubber material was 0.195, the static friction coefficient of fresh goji berry–silicone rubber material was 0.377, and the rolling friction coefficient of fresh goji berry–silicone rubber material was 0.063. By designing the steepest ascent search and central composite design experiments with the angle of repose (AoR) value obtained from the physical experiment as the target value (31.27°), we determined the inter-particle static friction coefficient to be 0.454 and the inter-particle rolling friction coefficient to be 0.037. Validation tests were conducted on the calibrated discrete element modeling parameters, and the results showed that the established fresh goji berry model and the optimally calibrated parameter combination are effective for discrete element studies on fresh goji berries.
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Setyarini, Putu Hadi, Purnomo, Dwi Hadi Sulistyarini, and Aski Asfia. "The Effect of Addition of Waste Materials on Nitrile Butadiene Rubber to the Mechanical Properties of Roller Rubber." Key Engineering Materials 851 (July 2020): 47–52. http://dx.doi.org/10.4028/www.scientific.net/kem.851.47.
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This research aims to determine the effect of adding filler material in the form of waste material on Nitrile Butadiene Rubber (NBR) in making roller rubber to improve quality in terms of hardness and tensile strength. Each rubber roller compound is made from a mixture of NBR with rice husk, recycled rubber and wood charcoal. The process of making NBR and NBR with the addition of alloys is done with two roll open mixers at a certain temperature and time accompanied by the addition of certain additives. Furthermore, the compound is pressed using Hydrosan and then cut according to the standard test to be performed. The process ends by placing the material in an environment with a certain humidity level for 24 hours. Tests carried out include the test of hardness by using Shore A Durometer and Universal testing machines to test the strength of tensile strength. The test results show that the addition of recycled rubber can increase hardness by 30% when compared to NBR without the addition of filler. While the value of tensile strength for NBR and recycled rubber alloys is much higher.