Properties Analysis Of High Strength Nylon 6 Filament And Mathematical Simulation Of Fiber Spinning

The theoretical strength of high-strength nylon 6 is as high as 32.7 cN/dtex,but the actual strength is only 4~9cN/dtex.With the continuous expansion of the application of nylon fiber,its strength requirements have also been continuously improved,and high-strength nylon 6 has become one of the hot spots in market development.In this project,the POY nylon 6 filament,FDY nylon 6 filament and high-strength nylon 6filament were used as the research object to test the tensile properties,heat shrinkage,crystallinity and orientation of the three fibers,compare the difference in structure and performance.Then based on the existing high-strength nylon 6 spinning process,the numerical simulation of the nylon 6 melt spinning and hot roll drawing process provides theoretical guidance for further optimizing the existing high-strength nylon 6 filament preparation process and improving fiber strength.The paper draws the following conclusions:(1)The structure and properties test results of POY nylon 6,FDY nylon 6,high strength nylon 6 filament show that the breaking strength,fracture work,heat shrinkage and orientation of high strength nylon 6 filaments are best in three samples;The crystallinity of high-strength nylon6 filaments is between the crystallinity of POY nylon 6 and FDY nylon 6;the high-strength nylon6 filament has the smallest elongation at break.(2)According to the production process parameters of the cooperative enterprise,the melt spinning process of high strength nylon 6 was simulated.The results show that the spinning tension,filament speed,crystallinity and orientation of the fiber are gradually increased and stabilized during the spinning process.The fiber diameter and the filament temperature are gradually reduced and tend to be stable.The spinning tension,degree of orientation and crystallinity decrease with the increase of pump supply,and the temperature of the yarn,the speed of the yarn and the diameter of the yarn increase with the increase of the pump supply.Spinning tension,degree of orientation and crystallinity increase as the spinning speed increases,the yarn temperature,the yarn speed,and the diameter of the yarn decrease as the spinning speed increases.(3)According to the production process parameters of the cooperative enterprise,the high-strength nylon 6 multi-stage hot roll drafting was simulated.The results show that the stress,strain,velocity,crystallinity and orientation of the fiber are gradually increasing and become stable during the drafting process.The fiber diameter decreases and tends to be stable.The simulated yarn ’ s temperature,winding tension,fiber crystallinity are in accordance with the measured results.Further simulation results show that as the drafting temperature increases,the birefringence of the fiber increases first and then decreases,and the stress decreases.With the increase of the draw ratio,the fiber birefringence and crystallinity The speed,strain and stress of the yarn are increased,and the diameter is reduced.With the increase of the pre-orientation degree of fiber,the variation of the fiber parameters during the drawing process increases,which is likelyto cause breakage.The above simulation results can inspire the producing process of high-strength nylon 6: in terms of the drafting temperature,when the temperature of the drafting roller is too high,the degree of fiber orientation will decrease due to molecular orientation,and the fiber strength does not necessarily increase;In terms of the draw ratio,when the fiber is continuously headed,the drafting multiple can be increased as much as possible;in terms of the degree of orientation of the primary fiber,when the degree of orientation of the primary fiber decreases,the draw ratio in the drawing process can be increased,and a more desirable high-strength nylon 6product can be obtained.