Study On Processes And Properties Of Polyamide 6 POY/Spandex Covered Yarn By One-step Method

Polyamide/spandex covered yarn has good elasticity and loftiness. It can be used as the preferred material in preparing top elastic fabric. Its application field covers garments, auto interior decoration and health care, and it has a broad market prospect. But most domestic manufacturers still produce polyamide/spandex covered yarn by two-step method now. There is hardly any study on processes, properties and structures of polyamide 6 POY/spandex covered yarn by one-step method. Based on two-step method, polyamide 6 pre-oriented yarns and spandex are used as material in this paper; polyamide 6 POY/spandex covered yarn can be achieved. From the point of technological design and equipment transformation, spinning and combining process parameters are elaborated. Effects of spinning and combining process on structures and properties of yarns are investigated. This paper lays theoretical foundation for industrial exploitation of polyamide 6 POY/spandex covered yarn by one-step method.The major work of paper is listed as follows:(1) Spinning winding equipment is upgraded, and spinning process parameters are determined. Polyamide 6 pre-oriented yarns are produced by different spinning speed while pump delivery remains constant. Effect of spinning speed on orientation structure and properties is discussed. The experimental result shows that linear density decreases, and orientation structure changes with the rise of spinning speed. When spinning speed is 4350m/min, polyamide 6 pre-oriented yarns have excellent evenness and post-finishing property.(2) Polyamide 6 pre-oriented yarns produced by different spinning speed are drew and deformed. Stretch ratio is determined according to false twisting tension fluctuation. Two-step process route is replaced. Godet and spandex unwing device are installed, and it makes stretching, deforming, combing processes are finished on one equipment. So one-step method improves productivity effectively.(3) Process parameters of one-step method are determined though experiment. Polyamide 6 pre-oriented yarns produced by different spinning speed are combined with spandex fibers. Properties of polyamide 6 POY/spandex covered yarns are tested. The result shows that oil concentration and breaking strength decreases but breaking elongation increases successively with spinning speed increase. Hot shrinkage rate of covered yarns are irregularly.(4) Polyamide 6 pre-oriented yarns produced by 4350m/min are combined with spandex fiber with one-step method. Chose the factors which influence combining result mostly, carry out orthogonal test.The optimizing process is as follows: orifice size is 1.6mm, air pressure is 0.3MPa, and processing speed is 650 m/min. The surface morphology is observed. The result demonstrates that polyamide 6 POY/spandex covered yarn has good mechanical property, its intertwining knots have uniform spacing, and loops have the same height. It can meet the demand of high-clothes fabrics.