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Fibres
Published in Ashok R. Khare, Principles of Spinning, 2021
During the manufacture, a product ‘hexamethylene-diamine’ is formed. It has acid at one end and amine at the other end. It is then polymerized to form a chain. Basically, there are two types of nylons – nylon 66 and nylon 6. The properties of nylon 66 include features such as capability to pleat and crease when heat-set at high temperature. Its melting point is 256°C and is resistant to sunlight and weathering effects. It possesses excellent colour fastness and abrasion resistance.
Health, safety, security, and the environment
Published in Andrew Livesey, Motorcycle Engineering, 2021
Protective clothing is worn to protect the worker and his or her clothes from coming into contact with dirt, extremes of temperature, falling objects, and chemical substances. The most common form of protective clothing is the overall, a one-piece boiler suit made from good-quality cotton, preferably flameproof. Nylon and other synthetic materials tend to be highly flammable and therefore pose a hazard in the vicinity of open flames. Worn and torn materials should be avoided, as they can catch in moving machinery. Where it is necessary to protect the skin, closely fitted sleeves should be worn down to the wrist with the cuffs fastened. All overall buttons must be kept fastened, and any loose items such as ties and scarves should not be worn. The coveralls must withstand continuous exposure to a variety of chemicals. They can be of the one-piece variety or can have separate disposable hoods.
Health, safety, security and the environment
Published in Andrew Livesey, Bicycle Engineering and Technology, 2020
It is worn to protect the worker and his/her clothes from coming into contact with dirt, extremes of temperature, falling objects and chemical substances. The most common form of protective clothing is the overall a one-piece boiler suit made from good quality cotton, preferably flame-proof. Nylon and other synthetic materials tend to be highly flammable and therefore pose a hazard in the vicinity of naked flames. Worn and torn materials should be avoided as they can catch in moving machinery. Where it is necessary to protect the skin, closely fitted sleeves should be worn down to the wrist with the cuffs fastened. All overall buttons must be kept fastened, and any loose items such as ties and scarves should not be worn. The coveralls must withstand continuous exposure to a variety of chemicals. They can be of the one-piece variety or can have separate disposable hoods
Powder flowability characterisation at preheating temperature in additive manufacturing
Published in Powder Metallurgy, 2023
Experimental results show that nylon powder has better flowability than that the stainless steel powder at room temperature. The particle size of stainless steel powder is smaller than that of nylon powder as shown in Figure 1. The fine stainless steel powder with a volume-based particle size D (50) of 32.7 μm is a very cohesive powder. The agglomeration of stainless steel powder results in poorer powder flowability than that of nylon powder at room temperature. Figure 10 shows that nylon powder flowability becomes poor in the range from 80°C to 160°C. The elasticity and surface properties of nylon powder will change at high temperatures. The viscous plastic deformation will occur at the contact portion points of the powder, resulting in increased adhesion and friction forces between particles [22]. It leads to an increase in avalanche angles and deterioration of powder flow properties. Comparing the results of the work [23], the effect of temperature on polymer powder flowability shows good agreement. However, the temperature has a small effect on the avalanche angle of stainless steel powder compared with nylon powder. The high temperature will lead to an increase in the contact curvature radius between particles, resulting in an increase in Van der Waals forces and avalanche angles [15]. But the preheating temperature of 200°C relative melting point temperature of stainless steel powder is lower, so the increasing trend of avalanche angle is small.
Dynamic cushion, quasi-static stab resistance, and acoustic absorption analyses of flexible multifunctional inter-/intra-bonded sandwich-structured composites
Published in The Journal of The Textile Institute, 2021
Ting-Ting Li, Zhike Wang, Xiayun Zhang, Liwei Wu, Ching-Wen Lou, Jia-Horng Lin
This study aims to develop the cushioning/sound-absorbent flexible sandwich-structured nonwoven composites and measure their cushion properties using a self-made drop-tower machine. Nylon fiber has low production cost, fineness controllability, high mechanical properties, and wear resistance. It has obvious advantages over natural fibers and uses less aramid fiber or re-knitted aramid cloth to enhance the material. The performance of the composite material is further improved on the premise of ensuring production costs. Moreover, needle punching and aramid combination are used to render the porous-laminated nonwoven composites with high sound absorption at low and high frequencies, cushioning performance, and puncture resistances. Nylon fibers and aramid fibers at different ratios are processed with combing and needle punching to form nylon webs and nylon/aramid nonwoven webs. A nylon/aramid web and five-layered of nylon webs are then laminated and multiple needle-punched to form flexible, cushioning, and sound-absorbing sandwich-structured composites. The laminated nonwoven composites are tested for cushioning performance, bursting strength, puncture resistance, stab resistance, and sound absorption, examining the influence of the content of aramid fibers.
Medical textiles
Published in Textile Progress, 2020
Nylon was the first synthetic-polymer man-made fibre to be produced commercially, and this was achieved rapidly following its discovery in 1935 by Carothers; Dupont brought it into production in late 1939 [119]. Although never a particularly cheap fibre to make, because it was the first synthetic polymer man-made fibre to appear on the textile market, nylon became commercialised very quickly with womens’ stockings made of nylon appearing from 1940 and rapidly replacing silk in this application; the term ‘Nylon’ became synonymous with ladies hosiery providing an indication of its commercial success. Nylon is a polymer made by condensation polymerisation brought about by the reaction of di-functional monomers containing equal numbers of amine and carboxylic acid groups such that amide links can be formed at both ends of each monomer residue [121]. Nylon is therefore a synthetic linear polyamide consisting of repeating lengths of hydrocarbon chains joined together by amide links and this results in the different nylons being classified according to the number of carbon atoms in the sections of hydrocarbon chain between the repeating amide groups [10]; applying this approach, three of the more important members are known as nylon 6.6 and nylon 6 (the most common types used in fibre or filament form) and nylon 11 (which uses castor oil as the starting point and is mainly used in resin form).