Spin draw ratio

Benzobisthiazole random copolymers (X) [38] were also prepared using 2-methyl terephthalic acid and terephthalic acid with l,4-dimercapto-2,5-diamino-1,4-benzene dihydrochloride. Various copolymers provided materials with a wide range of crosslink densities. High quality fibers with spin draw ratios as high as 50 to 1 were obtained by dry-jet wet spinning of anisotropic polymerization mixtures. Heat treatment of the fibers was carried out in a tube oven... 

Another effect of the variation of the extensional viscosity is the maximum extend-ibility. For polymers like high-density polyethylene, the rapid increase of the extensional viscosity during the spinning process limits the obtainable spin-draw ratio that is the ratio between the winding velocity and the velocity in the orifice. Examples can be found in an article of Han and Lamonte (1972). 

Tensile Properties. Tensile properties of nylon-6 and nylon-6,6 yams shown in Table 1 are a function of polymer molecular weight, fiber spinning speed, quenching rate, and draw ratio. The degree of crystallinity and crystal and amorphous orientation obtained by modifying elements of the melt-spinning process have been related to the tenacity of nylon fiber (23,27). 

In the coupled process (Fig. 7c), the draw ratio, which affects the tenacity and elongation, lowers with increasing spinning speed. As draw ratio is increased, tenacity and initial modulus increase and elongation decreases. 

Application. In the past, the break strength of a synthetic yarn has averaged 34.6 lb. The first-stage draw ratio of the spinning machines has been increased. Production management wants to determine whether the break strength has changed under the new condition. 

These FOY (Fully Oriented Yam) products therefore eliminated the need for separate spinning and drawing stages, although not for all uses. In particular, the highest tenacity and modulus are best approached by a LOY plus high draw ratio route. 

Filaments about 0.12 mm in diameter were obtained from unfractionated high-density polyethylene (Mi] = 8.0 x 104) by a melt-spinning at 220 ° C with a draft ratio of about 17. They were next stretched at 100 °C in polyethylene glycol with a molecular weight of 380—400 to different draw ratios, which are defined as the ratios of the drawn length to the original. NMR spectroscopy was carried out for the drawn filaments randomly packed into a glass tube 18 mm diameter. The three-component analysis of the spectrum at different temperatures was performed the results are discussed in relation to the phase structure of samples. 

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