Conception Of The Tufting Machine And Research On The Procedure Of Braiding And Stitching Composite

This report introduces the internship executed by Lingshan LIU,on 2013,which is carried out in the laboratory.The subject of this project is "Research on the procedure of braiding and stitching composite preform".This project is a part of the European project IMS&CPS.It works for the group of WP5 on the subject of development of the preform.From the nineteenth century,people started to conduct research on the braiding process.The small bending and distortion of the fiber,the high conservation of the performance,good performance in the whole structure,which make two-dimensional braided composite particularly suitable for the manufacturing of tubular,I-beams and other special cross-section.Its high productivity,high level of automation.high-yield and low manufacturing costs make it becomes a domestic and foreign research priority.Stitching technique refers to the technology of using a yarn of stitching to make a two-dimensional fabric becomes a quasi-three-dimensional fabric,or to combine several pieces of fabric into the overall structure.Tufting,as a kind of new technique of stitching process,has attracted the attention of scientists with its simple principle,low damage to the material and imterlaminar mechanical performances.In this project,we have combined these two technologies,and did a research on the procedure of braiding and stitching composite preform and also developed a machine of stitching.This paper is divided into three parts,first of all,we have produced 2D tubular fabric with glass fibers,and then we designed and assembled the stitching machine,at last,we stitched the braided pieces with the stitching machine.We have injected the preform with epoxy resin and observed the form of the stitching yarn,and optimized the procedure of stitching.During this project the mainly procedure is to design the tufting machine.The first step is to consider and list the influence factors,including 3D orientation of fabric and yam,fabric layers,yarn characteristics,tufting density,tufting depth,yarn tension,pressure of the presser foot,needle shape.Next step is to think about the functions of the machine.To realize these different functions,I have designed different systems including needle system,presser foot device,yarn feeding system and the framework.Each system has its own functions.With the needle system we can stitch the fabric and adjust its tufting depth;using the yarn feeding system,we store the yam and feed constant pre-tension yarn;using the presser foot to adjust the pressure and to prevent the yarn slip from the fabric;using the machine frame to mounted all the pieces,to support the fabric,and to achieve the displacement of the tufting device,in order to achieve the density measurement and controlment.This paper is the basic research of the following PhD thesis.