解决368.8 dtex/36 f粗旦少孔聚酯预取向丝条干不匀率偏大的方案

Solution to yarn unevenness of 368.8 dtex/36 f polyester POY with coarse denier and few holes

采用熔体直纺侧吹风冷却系统生产368.8 dtex/36 f粗旦少孔聚酯预取向丝(POY),通过理论计算和生产实践自主设计了侧吹风冷却系统,整套侧吹风装置由调风装置、带过滤装置的进风管、扩散室、整流吹风装置、上油装置、导丝装置、左右侧板、顶板、吹风室门、基础板等组成。生产实践中,测试出风面同一水平线上的风速差异≤3%。理论和实践相结合,优选了油嘴、网络器,同时对影响该品种的最重要工艺条件进行组合试验。试验结果表明:当组件的上机压力在13.5~14.5 MPa时,条干均匀度良好,组件的上机成功率、使用周期都满足生产需求;当侧吹风速在0.6~0.65 m/s时,油架高度130 mm、上油率0.35%、网络压力0.1 MPa,可以获得良好的条干均匀度,满足假捻的加工需求。侧吹风、上油系统、网络器长期使用会被污染,随着清洁度的下降而造成产品的条干不匀率变差,生产状况异常,因此根据生产实际需要制定合理的清洗周期。

With the increasing demand of the public for the comfort and beauty of clothing,coarse denier polyester fibers with few pores are widely commended from consumers due to their special optical effect,crisp hand feel,and satisfactory woolen effect.But as the fineness of single fibers increases,the unevenness of the yarn deteriorates,and affects the processing performance and dyeing performance of false twist directly.At present,many manufacturers are unable to solve the problem of unevenness in the production of coarse denier and less porous fiber.This article takes 368.8 dtex/36 f polyester pre-oriented yarn(POY)with coarse denier and few holes as an example to discuss the unevenness problem from fiber products with coarse denier and few holes.During the spinning process of polyester fibers,the melt flows through the components through a process of dispersion,filtration,tearing and mixing,which often has a significant effect on the short wavelength unevenness of the fibers.The wave spectrum of yarn evenness shows that when the spin pack pressure is 13.5 MPa,there is basically no unusual wave pattern in the short wave band.When the spin pack pressure is 10.8 MPa and 12.5 MPa,the spectral analysis shows that there are obvious red columnar peaks in the short wave band;however,the test result of finished fibers under the spin pack pressures of 14.5 MPa is basically consistent with those under 13.5 MPa,and there is a poor peak pattern in the spectrogram when the spin pack pressure reaches 16 MPa.This means that the yarn evenness is preferable when the spin pack pressure is between 13.5 MPa and 14.5 MPa.According to the characteristics of the product,the side blowing system is designed independently through theoretical calculation and production practice,including the whole side blowing device,which is composed of wind adjusting device,wind inlet pipe with filtering device,diffusion room,rectifier blowing device,oiling device,fiber guide device,left and right side plates,roof,blowing room door,base plate,etc.The diffusion room stabilizes and turns the cooling wind from the bottom part of the air conditioner to distribute evenly,so that the cooling wind can be evenly and stably blown out of the vertical rectification frame,and at the same time,the wind window diffusion room is enlarged,and the wind pressure in the diffusion room is reasonably designed from top to bottom,so that the wind pressure before rectification can reach a reasonable state.The vertical rectifier frame is designed as a unique five-section test wind speed rectification cooling mode,and when the wind speed blows out,a stable D-type distribution is formed.The vertical rectification frame is composed of two layers of porous plates,two layers of steel wire cloth and one layer of honeycomb plate.The cooling wind is fully stabilized through the static pressure room,porous plate,honeycomb plate,steel wire cloth,etc.,and the uniform and stable blowing effect is obtained on the blowing surface.The wind speed difference on the same horizontal line of the wind outlet surface is not more than 3%.Through integration of theory and practice,the oil nozzle and network device are optimized,and the most important process conditions affecting this kind of fiber are tested in combination.The test results show that when the pressure of spin pack is in the 13.5 MPa-14.5 MPa range,the yarn evenness is good,the success rate and working time of the spin pack meet the production requirements;when the side blowing speed is between 0.6 m/s and 0.65 m/s,the oil rack height is 130 mm,the oiling rate is 0.35%,and the network pressure is 0.1 MPa,good yarn evenness can be obtained to meet the processing requirements of twisting;the side blowing,oiling system and network device will be polluted after long-term use,and with the decline of cleanliness,the product will have poor yarn evenness and abnormal production conditions.Therefore,a reasonable cleaning cycle must be formulated according to the test data and production data accumulated in the production for a long time to ensure the long time stability of product quality.