Staining tests nylon

To make cut pile carpets, two strands of BCF yarns are twisted together and heat-set with steam using a Superba heat setting machine at 135-145 °C or at 175-195 °C when heat-set with super-heated steam in a Suessen. An experimental design experiment [94] showed the higher the heat set temperature, then the lower is the bulk of the final carpet, but there is an increase in the tip definition and walk performance. The tufted carpets are then dyed with disperse dyes at atmospheric boil [95] in a continuous or a batch process. PTT carpets showed excellent resiliency in walk test experiments, equivalent to a nylon and much better than both PET and polypropylene, had lower static charge of <3.5 kV, and were resistant to coffee, mustard, betadine, red acid dyes and other stains [96],... 

Perspiration tests similarly indicated the presence of two dyestuffs. In the alkali solution, the yellow color seemed to be removed almost completely, leaving a pink-colored fabric. In the acidic solution, the yellow dye migrated to the wool, silk, and nylon sections of the multifiber test strips, staining these fibers a bright yellow shade. The pink color seemed to bleed minimally a small amount of color was transferred in the alkali solution tests, but generally this pink color remained comparatively very fast. 

In much the same way, natural polymeric fibers like wool, cotton, silk, etc., are often touted as superior to anything that is man-made or synthetic. But is this fair There is no doubt that natural fibers have a unique set of properties that have withstood the test of time (e.g., it is difficult, but not impossible, to match silk s feel or cotton s ability to breathe ). On the other hand, consider Lycra , a completely synthetic fiber produced by DuPont (Figure 1-12) that has a truly amazing set of properties and is the major component of Spandex (a material that keeps string bikinis on ). Or consider the wrinkle-free polyester fibers used in clothing and the stain proof nylon and polyacrylonitrile polymers used in carpets. The point here is that polymers, be they natural" or synthetic, are all macromolecules but with different chemical structures. The challenge is to design polymers that have specific properties that can benefit mankind. 

We embarked on a large program five years ago to demonstrate that we can use our technical innovation power, coupled with a partner s capability in engineering enzymes, to make bulk chemicals and fibers cost effectively. Our goal was to produce a specialty fiber we call Sorona (Figure 6), which incorporates the attractive properties of nylon, Dacron and Lycra, resulting in superior softness, vibrant color, UV and chlorine resistance, and stain resistance coupled with stretch and recovery. Market test development shows that consumers find this combination of functionalities very attractive. 

Carpets. The process of making PTT BCF carpets has been described in detail (57). The extruded yarn is drawn between sets of heated godets to a draw ratio 2.8-3.5 (58,59). It is then textured with hot air at 160-220°C and at a pressure of 0.6-1.0 MPa (87-145 psi) (60). Heat-setting with steam is at 135-145°C or at 175-195°C (61) when heat-set with the less effective heat conducting superheated steam. Tufted carpets are dyed with disperse dyes at atmospheric boil (62) in a continuous or a batch process. PTT carpets show excellent resiliency equivalent to a nylon in walk tests, have lower static charge of <3.5 kV, and are resistant to coffee, mustard, betadine, red acid dyes, and other stains (63). 

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