Study On The Initial Twisting Process Of E-Glassfiber Yarn

E-Glassfiber yarn is formed by continuous glass filament through twisting,and is woven to form electronic cloth.After being made into Copper Clad Laminate,it is used to make PCB(Printed circuit board).Due to the rapid development of the electronic industry market,China’s production of glass fiber yarn has continued to grow rapidly in recent years,and now it has become the world’s largest producer.However,high-end research and development of E-Glassfiber yarn products and the highest manufacturing technologies are mainly located in Europe,America,Japan and other countries.The initial twisting stage of E-Glassfiber yarn is an important part in the production of glass fiber products.At present,in the domestic production,the tension fluctuation in the initial twisting stage is large and the breakage rate is high,which lead to unstable product quality and much economically.In this paper,the technology of the initial twisting phase of the glass fiber electronic yarn is studied,and two schemes are designed :(1)the rapid calculation of the machine process of the initial twisting phase of the E-Glassfiber yarn;(2)the first twisting process of E-Glassfiber yarn with small decrease of spindle speed.Based on the analysis of the winding principle of E-Glassfiber yarn,in the first scheme,the E-Glassfiber yarn is unwound to obtain the forming parameters of different layers of E-Glassfiber yarn,such as winding diameter of the bobbin yarn and circle distance.According to the winding forming principle,the processing parameters of EGlassfiber yarn are deduced,and the lifting speed limit of the specific type of steel collar plate can be used to derive the spindle speed and steel of the glass fiber in the production process.According to this process,the initial twisting process of D900 electronic yarn is rapidly calculated.By comparing the experimental yarn with the target yarn,it can be seen that the mean difference rate of rising circle distance between the experimental yarn and the sample yarn is-0.63%.The mean difference rate of falling circle distance is-0.29%.Within the error range,the circle distance of the corresponding layers of the experimental yarn are basically the same as that of the sample yarn,which proves the feasibility of the calculation method.Since the friction between the nylon hook and the glass fiber yarn directly affects the winding tension of the glass fiber yarn,the winding tension of the initial stage can be effectively stabilized by ensuring the constant rotation speed of the travler.In practice,the higher the spindle speed,the greater the winding tension.In order to avoid breakage,the winding tension is set at 3%~5% of the yarn breaking strength.In the second scheme,the relation formula between travler speed and spindle speed,twist and yarn diameter are derived,and then the travler speed,maximum spindle speed and minimum spindle speed are calculated through the derivation formula,ultimately the key parameters of initial twisting stage of spindle speed down process are determined.Through the on-machine experiments of G75 and D450 E-Glassfiber yarn spindle speed reduction process,it is found that the tension of the spinning section in the initial stage of the spindle speed reduction process is smaller than that of the current procedure,and the tension unevenness rate is significantly reduced.The tension unevenness rate of G75 is reduced to 5.03%,which is 68.1% lower than the current procedure,and the unevenness of D450 tension is reduced to 3.38%,which is 54.39% lower than the current procedure;the breakage rate of the initial spinning of the D450 spindle reduction procedure is reduced to 2.14%,which is 33.39% lower than the current procedure.By comparing the appearance and unwinding of the fiberglass tube yarn of the D450 spindle with that of the current procedure,it is found that the volume density and hardness of the fiberglass tube yarn of the spindle in the deceleration procedure are smaller,the unwinding is smoother,and the unwinding tension is smaller and more stable.The breakage rate of warping is reduced to 2.6%,which is 9.85% lower than the current procedure.The hairiness ratio is 22.71% lower than that of the current procedure.