Study On The Post-processing Technology Of The High Speed Warp Knitting Needle

The yarn guide needle is one kind of knitting needle.It directly participates in yarn knitting.It is an essential part of warp knitting machine.Due to the performance and surface quality of domestic yarn guide needle are generally not ideal,and high-grade yarn guide needle also depends on import.In order to realize the localization of high-grade yarn guide needle and reduce the dependence on foreign countries,it is a great practical significance to improve performance and surface quality of the domestic guide needle.In order to improve the performance and surface quality of domestic yarn guide needle,the post-processing technology of yarn guide needle was studied in this paper.The heat treatment technology is used to improve the performance of the yarn guide needle,and the surface roughness of the yarn guide needle is reduced by the finishing process,and the performance and surface quality of the yarn guide needle are improved by electroplating technology.The research mainly includes the following subjects:1.Study on the heat treatment process of the yarn guide needle.In view of the mechanical performance requirements of yarn guide needle.,the effect of quenching and tempering process parameters on the performance of SWP-B steel yarn guide needle was studied.The research results show that the quality of SWP-B steel needle after heat treatment is stable and the performance is good,so as to meet the requirements of material selection.At the same time,the SWP-B steel guide needle blank has good mechanical properties at quenching temperature of 800 ~oC,holding10min,tempering temperature of 180~200 ~oC,and holding 120min.2.Study on the mechanical polishing process of the yarn guide needle.Aiming at the surface roughness and finish requirement of guide needle,the mechanical polishing is used to polish the needle blank.The study shows that when the polishing agent SC20 is mixed with water with 1:20~30,the overall mechanical polishing process has obvious effect on removing burr,chamfering angle,refining surface roughness.3.Study on the electrochemical polishing of the hole of the yarn guide needle.In view of the quality requirements of the hole of the yarn guide needle,the electrochemical polishing is applied.The research shows that the inner blanking defect of the hole is solved when the electrolyte temperature is 70 ~oC~80 ~oC,the anode current density 70~80 A/dm~2,the electrode gap is 0.13mm and the polishing time 1~2min.4.Study on the electroplating process of the guide needle.In view of the requirements of high performance and surface quality of the yarn guide needle,hard chromium plating is done to the yarn guide needle.The influence of different technological parameters on the quality of hard chromium plating of the guide needle was investigated.The research shows that the designed fixture is suitable for electroplating of guide needle.When the bath temperature is 40 ~oC and the current density is 50A/dm~2,the chromium plating layer has better surface quality and bonding strength.In this paper,the post-processing of the guide needle is put forward.The optimization processing of heat treatment,finishing and electroplating of the guide needle is determined,and the yarn guide needle with good performance and surface quality is obtained.A complete post-processing technology has been developed for the actual production of guide needle.