Thermal Insulator Made from Solid Natural Rubber: Part 1 - Formulation of Rubber Compounding, Appropriate Forming Condition and Basic Properties

2017 ◽  
Vol 737 ◽  
pp. 567-571
Author(s):  
Teeratat Sopakitiboon ◽  
Apaipan Rattanapan ◽  
Surakit Tuampoemsab
Keyword(s):  
Natural Rubber ◽  
Testing Machine ◽  
Optical Microscope ◽  
Hot Press ◽  
Tensile Testing Machine ◽  
Thermal Insulator ◽  
Closed Cell ◽  
Roll Mill ◽  
Average Maximum ◽  
Rubber Part

Closed cell rubber sponge applied as thermal insulator made from solid natural rubber (NR) was prepared by using Supercell DPT as a blowing agent. Rubber chemicals and STR 20, solid NR, were mixed on a two roll mill prior to prepare the specimen by hot press machine. Curing behaviors of the compounded solid NR with various types of sulfur and peroxide vulcanizations were characterized with moving die rheometer (MDR) at 150 and 170°C. Tensile and compressive strengths of the rubber insulator were measured by universal tensile testing machine followed by ASTM D412 and ASTM D395, respectively. Bubble size of the blown up rubber was inspected by an average maximum length of the bubble by using optical microscope. It should be notice from the experimental that all rubber formula both of sulfur and peroxide systems showed loading percentages to completely expand in a mold by about 38 to 48. Rubber insulator blown up with Supercell DPT used by semi-efficient vulcanization (semi-E.V.) unconcealed predominant results among all curing systems so that further investigations of the formulation as heat stuff will be discussed in next paper

Study on Utilization of Palm Oil Fly Ash as a Filler for Thermoset Natural Rubber

2013 ◽  
Vol 844 ◽  
pp. 280-284
Author(s):  
Bahruddin ◽  
Zuchra Helwani ◽  
Lili Saktiani ◽  
Yanuar ◽  
Rahmat Satoto
Keyword(s):  
Fly Ash ◽  
Natural Rubber ◽  
Tensile Properties ◽  
Palm Oil ◽  
Testing Machine ◽  
Hot Press ◽  
Elongation At Break ◽  
Roll Mill ◽  
Oil Fly Ash ◽  
Vulcanization Process

Palm oil fly ash (POFA) as solid waste produced from crude palm oil industries consist of quite high of silica (more than 50% w/w). This study aimed to compare the properties and morphology of thermoset natural rubber (TNR) with POFA, silica, carbon black (CB), and mixture of POFA-CB fillers. The filler content used is 30 phr (per hundred rubbers). The process of making the compound was conducted by using a roll mill at room temperature and a maximum roll rotational speed of 20 rpm. Zinc oxide 5 phr, stearic acid 2 phr, mercaptodibenzothiazyldisulfide (MBTS) 0.6 phr, and Sulfur of 3 phr were used as curative agents. Trimethylquinone (TMQ) 1 phr was used as an antioxidant. Commercial minarex 2.5 phr was used as a plasticizer. Vulcanization process was carried out at a temperature of 150 °C and a pressure of 50 kg/cm2 using a hot press. Morphology was observed using a scanning electron microscope (SEM). Measurement of tensile properties was carried out using universal testing machine (UTM) according to ASTM D412-06a standard. The results indicated that the use of POFA as a filler could potentially produce TNR with quite good morphology, tensile properties and water absorption properties. A mixture of POFA-CB with a mass ratio of 50/50 (w/w) produced the thermoset with the value of 18.5 MPa of tensile strength, 1600% of elongation at break, and 1.2 MPa of elastic modulus.

A model study on the impact of metal ions on pre-vulcanization of concentrated natural rubber latex and dipped-products

2021 ◽  
pp. 147776062110629
Author(s):  
Porntip Rojruthai ◽  
Narueporn Payungwong ◽  
Jitladda T Sakdapipanich
Keyword(s):  
Natural Rubber ◽  
Metal Ions ◽  
Colloidal Stability ◽  
Mechanical Stability ◽  
Testing Machine ◽  
Natural Rubber Latex ◽  
Tensile Testing Machine ◽  
Model Study ◽  
Stability Time ◽  
The Impact

A model study on the influence of some heavy metal ions on the stability and vulcanization efficiency of uncompounded and compounded high-ammonia natural rubber (HANR) latex was carried out by an exogenous addition and then determined by Brookfield viscometer, mechanical stability time (MST) tester, and tensile testing machine. The case of pre-vulcanized HANR latex with different aging times was determined by the change in the volatile fatty acid (VFA) number, MST, and viscosity. The compounded HANR latex was coagulated by adding Mn2+and Mg2+ while it was unaltered by adding Zn2+, Fe2+, and Cu2+ ions, leading to their colloidal stability. Therefore, these metal ions were chosen further to study the pre-vulcanization of compounded HANR latex. The presence of Zn2+, Fe2+, and Cu2+ in the latex is responsible for the delay in the vulcanization process and changes the appearance of compounded latex. Before compounding, the addition of such metal ions led to the reduction in tensile strength of the obtained gloves. At the same time, there was no effect on the tensile properties of the gloves made from the compounded HANR latex containing the metal ions.

Effect of Iron Content on the Strength and Conductivity of Cu-Fe In Situ Composite

2014 ◽  
Vol 633-634 ◽  
pp. 63-67
Author(s):  
Ke Ming Liu ◽  
Z.Y. Jiang ◽  
Yong Hua Wang ◽  
Z.B. Chen ◽  
Jing Wei Zhao ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Tensile Strength ◽  
Cold Deformation ◽  
Testing Machine ◽  
Optical Microscope ◽  
Good Combination ◽  
Mechanical Processing ◽  
Tensile Testing Machine ◽  
In Situ Composite

Cu-14Fe and Cu-17Fe alloys were produced by casting and processed into in situ composites by hot and cold deformation, and intermediate heat treatment. The microstructures were investigated by using a scanning electron microscope and an optical microscope. The electrical conductivity was evaluated by using a digital micro-ohmmeter. The tensile strength was measured by using an electronic tensile-testing machine. The results show that there are similar cast and deformation microstructures in Cu-14Fe and Cu-17Fe. The tensile strength of deformation-processed Cu-17Fe in situ composite is much higher than that of Cu-14Fe, while the conductivity of deformation-processed Cu-17Fe in situ composite is slightly lower than that of Cu-14Fe at the same cold deformation strain. The Cu-17Fe in situ composite produced by using proper thermo-mechanical processing possesses a good combination of tensile strength and electrical conductivity.

Effect of silver nanoparticle (AgNp) mixed with calcium carbonate on impact, hardness and tensile strength properties of aluminium 6063

2020 ◽  
pp. 002199832092314
Author(s):  
Adefemi Adeodu ◽  
Lateef Mudashiru ◽  
Ilesanmi Daniyan ◽  
Abdulmalik Awodoyin
Keyword(s):  
Tensile Strength ◽  
Calcium Carbonate ◽  
Aluminium Alloy ◽  
Testing Machine ◽  
Charpy Impact ◽  
Stir Casting ◽  
Optical Microscope ◽  
Tensile Testing Machine ◽  
Casting Technique ◽  
The Impact

Mechanical properties (impact, hardness and tensile strength) characterization of samples containing homogenous mixtures of Al 6063 matrix and varying amount of silver nanoparticles mixed with calcium carbonate at 2, 4, 6% weight fractions, respectively, produced by method of stir casting were carried out. Measurement of impact energy, hardness and tensile strength of the produced samples at 24℃ (ambient) temperature was done by Charpy impact, Brinell hardness and universal tensile testing machine in accordance to ASTM E23, E384 and E8/E8M-13M, respectively. The magnitude of impact and hardness increased evidently with increase in percentage weight fraction of the AgNPs. The refined samples were examined under an optical microscope. The fracture surfaces of the impact test samples were further examined by scanning electron microscopy. There is an increase in tensile strength, elongation and modulus of elasticity of Al-AgNP composites compared to as-cast aluminium alloy. The use of stir-casting technique influences the homogeneity and microstructure of the composites positively. It is concluded that Al-silver nanocomposites possess better qualities in hardness and strength and can replace conventional aluminium alloy in terms of performance and longer life in industrial application.

Studying the Effect of Different Combinations of Salt Modifier on the Mechanical Properties and Microstructure of A356 Al-Si Alloy

2013 ◽  
Vol 344 ◽  
pp. 27-36
Author(s):  
Rafiq Ahmad ◽  
Saima Mumtaz ◽  
Tahir Ahmad
Keyword(s):  
Mechanical Properties ◽  
Testing Machine ◽  
Optical Microscope ◽  
Tensile Testing Machine ◽  
Purity Aluminium ◽  
High Purity Aluminium ◽  
Casting Sand ◽  
Metallurgical Evaluation ◽  
Mould Casting ◽  
Prepared Alloy

The present study aims to develop A356 Al-Si alloy using high purity aluminium and various master alloy in gas fired pit furnace. Three different ratio of salt modifier (1:1, 1:2 & 1:3) was used to prepare the casting. Sand casting and permanent mould casting techniques were used to prepare the alloys. Optical microscope and universal tensile testing machine were used for the metallurgical evaluation of the prepared alloy. It was observed that the addition of modifier improved the mechanical properties and microstructure of the alloy. It was also observed that modifying agent NaF with CaCl2in 1:1 ratio has shown the best results in terms of microstructure and the mechanical properties.

Heat Treatment, Mechanical Properties and Microstructure of T-Joint Steel Arc Welded

2018 ◽  
Vol 876 ◽  
pp. 36-40
Author(s):  
Yustiasih Purwaningrum ◽  
Dwi Darmawan ◽  
Panji Lukman Tirta Kusuma
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Weld Metal ◽  
Testing Machine ◽  
Optical Microscope ◽  
Heat Treatments ◽  
Tensile Testing Machine ◽  
Weld Metals ◽  
Quenching Process

Heat treatment of T-Joint’s steel arc welded are performed are investigated in this research. The heat treatment process that used were annealing and quenching. The microstructure was investigated by optical microscope. The mechanical behavior of the samples was investigated using universal tensile testing machine for tensile test and Microvickers hardness method for hardness testing. The microstructure of welding zone of welding metals with various heat treatments is grain boundary ferrite, Widmanstatten ferrite and acicular ferrite. The weld metal with quenching treatment has a highest tensile strength with tensile strength 197.97 Mpa. The quenching process increases the tensile strength by 49.58 %. The distortion value in weld metal without heat treatment, quenching and annealing is 0.11mm; 0.04 mm and 0.08 mm respectively. The hardness number of weld metals with quenching process have a highest number base metal, HAZ and weld metals. Results showed that the mechanical properties of T-joints steel arc welded can be improved by various heat treatments.

Effect of B Refinement on Structure and Fracture Morphology of Al-7 wt.% Si Alloy

2014 ◽  
Vol 590 ◽  
pp. 181-186
Author(s):  
Xiao Song Li ◽  
An Hui Cai ◽  
Ji Jie Zeng
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Tensile Testing ◽  
Testing Machine ◽  
Fracture Morphology ◽  
Optical Microscope ◽  
Tensile Testing Machine ◽  
Alloy Microstructure ◽  
Scanning Electron

Using optical microscope, electronic tensile testing machine, scanning electron microscopy methods, such as detailed treatment of the B hypoeutectic Al-Si alloy microstructure, mechanical properties and fracture morphology were studied. The results showed that after treatment by the B refinement, α-Al dendrite phase was refined, resulting in mechanical properties of Al-Si alloy significantly improved. Which, B content 0.036wt.%, the alloy the best, the σb, δ, respectively, than the non-thinning increased 67.8% and 15.2%. From the fracture surface, the fracture morphology of the specimen showed a quasi-cleavage fracture. Which, B content 0.036wt.% at the time of fracture is more deep dimples, and a good plastic toughness.

Influence of Processing Procedure on Mechanical Properties of A319 by Comparison between Casting and Powder Metallurgy

2016 ◽  
Vol 850 ◽  
pp. 841-845
Author(s):  
Feng Gao ◽  
Cong Xu ◽  
Guo Fu Ji ◽  
Ming Ju Yang ◽  
Chao Li Ma
Keyword(s):  
Powder Metallurgy ◽  
Testing Machine ◽  
Optical Microscope ◽  
Hot Press ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cu Alloy ◽  
Universal Testing ◽  
Processing Procedure ◽  
Hot Press Sintering

Al-6wt.%Si-3.5wt.%Cu alloy (A319) were prepared by casting and powder metallurgy (PM) methods to investigate the influence of processing procedure on properties. The casting samples were cast into a horizontal mold after degassing by argon. The PM samples were extruded after hot-press sintering before which Al-11wt.%Si master alloy powder, pure Al powder and 48 h ball-milled Al-40wt.%Cu powder were blended for 12 h at rotation speed of 250rpm. The samples underwent a T6 temper, i.e. solution, water quenching and artificial aging. Microstructures were observed by optical microscope (OM) and scanning electron microscope (SEM), and phases were determined by X-ray diffraction (XRD). The tensile testing was carried out on universal testing machine. The results showed that heat treatment could greatly improve the tensile strength of the samples, especially for the casting counterpart. Discussion was made to analyze the reason that the properties differed.

Effect of Calcium Stearate Concentration on Tensile Properties of Epoxidized Natural Rubber

2011 ◽  
Vol 117-119 ◽  
pp. 1027-1031
Author(s):  
Yong Yue Luo ◽  
Qing Huang Wang ◽  
Chang Jin Yang ◽  
Can Zhong He ◽  
Yue Qiong Wang ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Natural Rubber ◽  
Ring Opening ◽  
Testing Machine ◽  
Calcium Stearate ◽  
Epoxidized Natural Rubber ◽  
Tensile Testing Machine ◽  
Elongation At Break ◽  
Aging Resistance ◽  
Percentage Retention

The tensile strength and elongation at break of epoxidized natural rubber (ENR) was investigated by adding different concentration of calcium stearate. Two grades of epoxidized natural rubber (ENR), namely, ENR 25 and ENR 40 were used as model materials. Semi-efficient vulcanization (semi-EV) was used throughout the study. The tensile property of unaged and aged ENR vulcanizates was determined by using U-CAN electron tensile testing machine. Results indicate that tensile strength and elongation at break of unaged ENR 25 and ENR40 vulcanizates increase gradually with increasing concentration of calcium stearate up to about 1phr of calcium stearate and after which, the tensile strength and elongation at break drop with a further increase in calcium stearate loading. For a similar alcium stearate concentration, the tensile strength and elongation at break of ENR 40 vulcanizates exhibits a consistently higher value than that of ENR 25 vulcanizates, which is due to the higher crosslink density of ENR40 which contains more epoxide groups than ENR 25. For aged samples, the addition of calcium stearate could enhance the tensile strength and elongation at break of aged samples. Percentage retention of tensile strength and elongation at break also gradually increases with calcium stearate loading. That means that the incorporation of calcium stearate is found to improve the aging resistance of ENR vulcanizates. This is because calcium stearate neutralizes sulfur acids which can catalyze ring-opening of expoxide groups via ether crosslinks.

Influence of Amino Acids on Anti-Oxidative Properties of Green Natural Rubber and Natural Rubber Compound

2013 ◽  
Vol 747 ◽  
pp. 664-667
Author(s):  
Surakit Tuampoemsab
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Natural Rubber ◽  
Hot Press ◽  
Synthetic Antioxidant ◽  
Roll Mill ◽  
Aging Test ◽  
Chain Breaking ◽  
Better Than ◽  
Ozone Resistance

This research was to study the efficiency of amino acids such as alanine, asparagine and cysteine, which were applied as antioxidant both in green and vulcanized natural rubbers (NR) for STR5L and RSS3, comparing with the use of synthetic antioxidant, i.e., N-(1, 3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6-PPD). In the case of green NR, the rubber was mixed with antioxidants on a two-roll mill machine. Then, the specimens were shaped by hydraulic hot press. In the case of cured NR, conventional system of the sulfur vulcanization was carried out at 150°C for t95. Both green and vulcanized NRs specimens were subjected to heat aging test at 100°C for 24, 48, 72 and 96 hours. Another mixed green and cured NR were also tested the plasticity by Wallace plastometer and ozone resistance following ISO 1431/1, respectively. From the experiment, it was found that although plasticity retention index (PRI) of the green NR mixed with each type of amino acids were lower than those mixed with 6-PPD, alanine exhibits the best antioxidative property among all of amino acids. Considering at the reduction in tensile properties, stress at 200% strain of both raw STR5L and RSS3 mixed with 1 phr of 6-PPD after heat aging test were totally lower than those applied with alanine, asparagine, and cysteine. In addition, for the cured NR specimens, the tensile results are agreeable with the PRIs value of the raw NR. However, NR vulcanizates preserved with each amino acid inhibited the crack length under ozone test better than that mixed with 6-PPD. Anti-oxidative mechanism of amino acids as well as 6-PPD is available as chain breaking donors (CB-D) mechanism. This might be concluded that alanine can be applied as a natural antioxidant in the green and vulcanized NR better than other amino acids, but not for 6-PPD. Moreover, three types of amino acid can be used as a good antiozonant for the sulphur vulcanized NR.

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