scholarly journals Influence of Sampling Location on Physical and Mechanical Properties of Full Grain Leather

2021 ◽  
Vol 69 (2) ◽  
pp. 4-11
Author(s):  
Antoneta Tomljenović ◽  
Juro Živičnjak ◽  
Andrijana Barišić ◽  
Jadranka Akalović

Full grain leather refers to the strongest and most durable part of the cattle hide, consisting of the grain layer and the part of the underlying corium, and has not been sanded or buffed to remove any imperfections, that means it displays the more natural characteristics of leather. Leather quality changes with sampling location, depending on variation present in the leather fibrous structure. Leather properties were also affected by tanning and finishing processes utilized during production. Full grain leather, instead finishing, sometimes go only through an ironing process for the desired sheen is obtained. Therefore, with the purpose of analysing the influence of the leather processing level, and sampling location on their quality, in this paper, the physical and mechanical properties of differently (synthetic and chromium) tanned finished and non-finished cattle full grain leathers, sampled from the bend, shoulder and belly of side leather cuts were evaluated. Their applicability for footwear uppers were assessed by measuring leather thickness, mass per unit area, apparent density, tensile strength and percentage elongation at break, all according to the standardised test methods.

2012 ◽  
Vol 3 (1) ◽  
pp. 13-26
Author(s):  
Myrtha Karina ◽  
Lucia Indrarti ◽  
Rike Yudianti ◽  
Indriyati

The effect of castor oil on the physical and mechanical properties of bacterial cellulose is described. Bacterial cellulose (BC) was impregnated with 0.5–2% (w/v) castor oil (CO) in acetone–water, providing BCCO films. Scanning electron micrographs revealed that the castor oil penetrated the pores of the bacterial cellulose, resulting in a smoother morphology and enhanced hydrophilicity. Castor oil caused a slight change in crystallinity indices and resulted in reduced tensile strength and Young's modulus but increased elongation at break. A significant reduction in tensile strength and Young's modulus was achieved in BCCO films with 2% castor oil, and there was an improvement in elongation at break and hydrophilicity. Impregnation with castor oil, a biodegradable and safe plasticiser, resulted in less rigid and more ductile composites.


2021 ◽  
Vol 12 (2) ◽  
pp. 39
Author(s):  
Tuba Bahtli ◽  
Nesibe Sevde Ozbay

Studies in the literature show that the physical and mechanical properties of concrete could be improved by the incorporation of different kinds of industrial waste, including waste tire rubber and tire steel. Recycling of waste is important for economic gain and to curb environmental problems. In this study, finely ground CuAl10Ni bronze is used to improve the physical and mechanical properties, and freeze-thaw resistances of C30 concrete. The density, cold crushing strength, 3-point bending strength, elastic modulus, toughness, and freeze-thaw resistances of concrete are determined. In addition, the Schmidt Rebound Hammer (SRH) and the ultrasonic pulse velocity (UPV) tests, which are non-destructive test methods, are applied. SEM/EDX analyses are also carried out. It is noted that a more compacted structure of concrete is achieved with the addition of bronze sawdust. Then higher density and strength values are obtained for concretes that are produced by bronze addition. In addition, concretes including bronze sawdust generally show higher toughness due to high plastic energy capacities than pure concrete.


2021 ◽  
Vol 20 (4) ◽  
pp. 329-337
Author(s):  
E. I. Batyanovskiy ◽  
A. I. Bondarovich ◽  
N. N. Kalinovskaya ◽  
P. V. Ryabchikov

. The paper presents the results of the development and implementation of the technology of self-compacting heavy structural concrete and the technology of concreting with its use of the largest foundation slab in Belarus (concrete volume ~9100 m3) of a high-rise building at the facility “Construction of a multifunctional complex in Minsk within the boundaries of Filimonova Street – Avenue Nezavisimosty – Makayonka Street”. The results of research are shown, which ensured the production of self-compacting concrete of class C35/45 with water resistance up to W20 (with the required W12 according to the project) from concrete mixtures of the maximum cone expansion of the PK6 (RK6) grade for three zones of the foundation slab different in degree of reinforcement: lower, middle and upper, with a total structure height of 3.5 m and plan dimensions ~(83´34) m. The technology of continuous (seamless) concreting has been developed and implemented, which made it possible to lay ~9100 m3 of concrete into the structure without defects within 42 hours of continuous operation, and a system of technological measures that prevented temperature cracking in concrete. The homogeneity of the physical and mechanical properties of concrete, confirmed by control tests, is ensured due to the uniform supply of the concrete mixture (from six  concrete pumps at the same time) in layers 200–300 mm high with a distance between the supply points of about 5–6 m and the vertical arrangement of the “trunks” of the concrete pipes during delivery of concrete to each point, as well as the fact that the time for feeding the next volume of concrete was significantly less than the setting time of the previously laid concrete (with a total concreting speed £0.1 m/h). Standardized and original test methods for concrete mixtures, hardening kinetics and properties of hardened concrete have been used during the development, research and implementation of the project. Control tests of physical and mechanical properties and characteristics of concrete, carried out at BNTU together with authorized  organizations controlling the progress of construction, as well as in independent (third-party) organizations, have confirmed their compliance with the design requirements.


2017 ◽  
Author(s):  
Arham Rusli

Appropriate concentration of base material and plasticizer is required to obtain good physical and mechanical properties of edible film for food packaging and preservation functions. The aim of this study was to obtain the best combination of the base material and plasticizer in the manufacture of agar films based on physical and mechanical properties. Results showed that the physical and mechanical properties of the agar edible film were affected by the agar and glycerol concentrations. Increasing agar concentrations resulted in the increase in the film thickness, tensile strength (TS), and elongation at break (EAB), but decreased the filmsolubility. While increasing glycerol concentration tended to increase the film thickness and solubility, but decrease the TS of the film. The best concentration combination of agar and glycerol in this study was 3 and 10%, respectively.


2014 ◽  
Vol 881-883 ◽  
pp. 1153-1156 ◽  
Author(s):  
Yun Bin Zhang ◽  
Jing Wen Wang ◽  
Ping Ping Jiang ◽  
Yue Xia Li ◽  
Xiao Yu Liu

Florida mandarin oil-chitosan composite films were prepared with chitosan (CS), Florida mandarin oil (FMO) by casting-evaporation-alkali leaching method. Influences of FMO to mechanical properties, water contact angle, water-solubility of films were evaluated. The results demonstrated that decrease of film tensile strength was caused by addition of FMO. When FMO content was 4%, elongation at break reached the maximum (2.81±0.01%). Water contact angle and solubility of film increased with increase of FMO content, maximums were 81.80±0.09° and 1.51±0.02 mg/100 g H2O, respectively.


2019 ◽  
Vol 57 (2) ◽  
pp. 68-73
Author(s):  
Evgeny N. Egorov ◽  
◽  
Nikolay F. Ushmarin ◽  
Sergey I. Sandalov ◽  
Ivan S. Spiridonov ◽  
...  

The article investigated the effect of caoutchoucs, sevilen 11808-340, vulcanizing groups, fillers, plasticizers, ingredients of directional actions on the physical and mechanical properties (conditional tensile strength, elongation at break, hardness, rebound elasticity, tear resistance) and operational properties (changes of conditional tensile strength of rubbers after exposure to oil, weight changes after aging of rubbers in a solution of citric and hydrochloric acids, changes in the volume of rubbers after exposure to a mixture of oil and water) of two rubbers. These rubbers are developed for the manufacture of the outer and inner layers of water-oil-swellable sealing elements (WSOE) for the oil and gas industry. It has been established that rubber for the outer layer of WSOE based on butadiene-nitrile BNKS-18AMN, isoprene SKI-3 and butadiene CKD caoutchoucs, as well as rubber for the inner layer of UEN based on butadiene-nitrile BNKS-18AMN, butadiene methylstyrene SKMS-30ARK and butadiene CKD caoutchoucs possess the required physicomechanical and operational properties. It was shown that these rubbers containing a vulcanizing group sulfur + thiazole 2 MBS, sevilen 11808-340, a combination of carbon black T 900 with rosil 175, talc and chalk, petroleum resin “Sibplast”, vermiculite and igloprobivnoe cloth, are characterized by improved physical-mechanical and operational properties. These rubber can be recommended as the basis for the manufacture of outer and inner layers of water-oil-swelling sealing elements.


Author(s):  
V. A. Sedykh ◽  
O. V. Karmanova ◽  
E. V. Koroleva

Search for additives that increase the wear resistance of rubbers is relevant. It is known that the introduction of hollow corundum microspheres (NCM) into rubber reduces the wear of rubber products. The uniform distribution of small amounts of microspheres in rubber by traditional "dry" mixing in a rubber mixer or on rollers is difficult. Microspheres were introduced into rubber at the stage of its separation from latex. The work consisted in the selection of thickeners capable of holding the NSM in rubber latex SCN-18SNT at the stage of its coagulation, and evaluation of physical and mechanical properties of rubbers in the presence of NCM. The retention capacity of thickeners of polyacrylamide (PAA), carboxymethylcellulose (CMC) and polyvinyl alcohol (PVA) was determined. Thickened latex was coagulated in the presence of microspheres with polymeric coagulant and sulfuric acid. When filling the polymer with microspheres, it is preferable to use a PAA thickener. The yield of microspheres in rubber using thickeners PAA, CMC and PVA was 71.1, 66.5 and 38.7% , respectively. The physico-mechanical characteristics of rubbers based on SKN-18SNT in the presence of microspheres introduced both as a "dry" method in rubber and at the stage of its isolation from latex are determined. The presence of microspheres in an amount of 4.4-4.7% by weight. on rubber, did not affect the hardness and elasticity of rebound rubbers. It has been confirmed that the presence of microspheres, especially those introduced from the latex rubber release stage, provides an increase in abrasion resistance. In turn, the presence of microspheres in rubber with traces of polyacrylamide provided an increase in the resistance of rubbers to tearing, the modulus at 100 and 200% elongation with a decrease in the elongation at break.


2015 ◽  
Vol 4 (3) ◽  
pp. 23-28
Author(s):  
Fadhilla Asyri ◽  
Kartini Noor Hafni ◽  
A. Haris Simamora

This study aims was to determine the effect of palm oil fuel ash (POFA) composite as filler on the physical and mechanical properties of high impact polystyrene (HIPS) composites. The research methodology included preparation of raw materials, treatment POFA (hydration process of POFA), mixing using tumbler and then extruder, molding composite specimens, and testing. The variables used were weight ratio of HIPS with 140 mesh POFA at 95/5; 92.5/7.5; 90/10. The composites were tested by Fourier Transform Infrared (FTIR), ash content, specific gravity, tensile strength, elongation at break, impact strength, hardness test, and Scanning Electron Microscopy (SEM). The results of FTIR characterization shows the formation of –OH bonding that was suspected as Si-OH or Si-hydrat. Results of physical and mechanical properties of the composites shows that increase of the filler composition in HIPS-POFA composites until the ratio of 90/10, increase the specific gravity to 7.2% of the original, tensile strength did not change significantly to 28.4 MPa, elongation at break decreased to 2.7%, impact strength decreased to 3.183 KJ/m2, and the hardness increased to 110.5, and Scanning Electron Microscopy (SEM) test show the transformation of POFA structure on treated POFA and intercalation between the matrix and POFA.


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