Influence Of Different Additives On The Spinning Speed Of PET POY Products

Due to the increasing competition in polyethylene terephthalate(PET)fiber industry,enterprises need to improve their competitiveness by promoting technology advantages constantly.Improving the spinning speed can reduce the cost of unit product and bring enterprises the promotion of production efficiency,which has practical significance.We cooperate with Zhenhui Chemical Fiber Limited Company,Taicang,Jiangsu province,on this project.Our porpose is to raise the crystallization rate and improve the rheological properties of the melt.So crystalline properties and rheological properties of modified PET were studied to achieve the purpose of increasing polyester spinning speed.It turns out that the modified polyester POY met post-processing requirements.Two kinds of additives were introduced to research the crystallization properties.One additive is CAO,made from acrylic acid and hexylene copolymer.It was then neutralized by two different ways,and CA1 and CA2 were obtained,which contain n-butyl group and carboxylate composition.It's found that CAO has no effect on crystallization properties of PET and CA1 can't be blent with PET well,while CA2 can significantly improve the cooling crystallization temperature of the system,thus reduces the super-cooling degree and has a greater influence on the crystallization properties of PET.But it was not good for spinnability.Another additive is carboxylate nucleation agent CB.DSC test results show that the CB can reduce the supercooling degree of composite system,and have significant effects on the crystallization of PET.The simulation spinning test also show that CB is good for spinnability.In order to study the influence of rheological properties.We introduced nanosilica(RA1),RA2,RA3 and hyperbranched polyester RB for analysis.Through surface treatment by coupling agent of RA1,we got RA2 to improve its dispersibility in polyester.Meanwhile,in order to improve the compatibility with polyester,PMMA was grafted to RA2 and RA3 was obtained.The simulation spinning and capillary rheological test results show that the addition of RA3 and RB to polyester melt can decrease the apparent viscosity,makeing the system more close to the Newtonian fluid.At the same time,It was found that the RA3 also has a positive influence on the crystallization properties of PET.Then we take the experiment scheme into practice.After the parameters were optimized by persistent trying,we used blend and in-situ polymerization to modify PET successfully.In addition,we also optimized the additive amount and verified the modification scheme to make it into industrialized production stage.After all the alternative additives were determined,we compared the spinnability and filament drawn ratio of each system.At last,CB,RA3,RB and CB/RB were selected to do scale-up expriment with PET after the comprehensive analysis of crystallization properties and rheological properties analysis.Judging from the results of amplification spinning experiment,CB is the best for improvement of polyester POY spinning speed,when the spinning speed was increased from 3000 m/min to 3300 m/min,POY elongation remained above 120%,satisfying later process requirement.It's proved that CB is the best modifier,and the optimum additive amount is 500 ppm.