A Study On New Material And Heat Treatment Technique Of Knitting Needles

As a key part in the warp knitting machine,warp knitted grooved needle plays an important role in the knitting process.The quality of the knitting products is greatly influenced by the properties of the warp knitted grooved needles.The demand of warp knitted grooved needle is increasing dramatically in recent years.However,there has been little research on the high-quality warp knitted grooved needles because of the low manufacturing level of needles in China.The material and heat treatment of warp knitted grooved needlehas been researched in this paper.According to the actual working condition of textile machinery,warp knitted grooved needle not only has a certain hardness,strength,wear resistance,and also it must ensure that it has certain elasticity and toughness,that preventing the occurrence of brittle fracture and plastic deformation failure.The propertiesof the warp knitted grooved needleis determined by material and heat treatment technique.This thesis mainly contains following subjects:1.Knitting machinery speed of needle,through the analysis of the failure of commonneedle knitting needle performance forms and influence factors,from the material selection a German import ed alloy spring steel GT as knitting raw material.2.Part of the knitting needle related standards domestically no longer fit for today and basied on the fact this study has come up with new necessary property of knitting needle that is the good elastic of the needle hook.3.This study came up with a new method to evaluate the elastic of the needle hook and designed a device to test this property.4.This study has focused on the different performances presented by the knitting needles under different quanching parameters.The results showed that:The quenching temperature has a dramatically influence on the hardness of knitting needles.With the increase of quenching temperature from 800?,the surface hardness of parts firstly increased and then decreased.The highest point is at 840?.The elastic of knitting needles also complies with the same rules.It firstly increased and then decreased.The highest point of elastic is at 820?.The temper techine could adjust and improved the performance of knitting needles.The results showed that the elastic of knitting needles is at the best when the quenching temperature is 820? and the tempering temperature is 240?.The hardness at this time is between 680HV-700HV.When the hardness is harder than this range,the knitting needles have higher fragility.When the temperature is below this range,the knitting needle has lower fragility and higher plasticity due to which the elasity is worse.5.Comparing the knitting needles produced from GT the Germany exported spring steel stripto the demestic technology producing knitting needles:The GT knitting needles have a better elastic than the SK5 knitting needles,and a more stable temper resistance.A proper craftwork of tempering is very important for the attaining of good combination properties of thin small parts such as knitting needles.