Study On Hollow & Cavernous Yarns And Theirs Properties For The Use Of Thermal Products

The thermal underwear is the traditional product of costume industry of knitting;they always choose cotton material and are endowed with the properties of softness and comfort when wearing next to the skin.They must be bulky and keep more air for warm, always be used of the interlock rib.The thermal underwear is changing with the material and yarn and fabric construction,which were developed as the technics and market requires expand.We want to get a new fabric for warm through changing the yam construction.The fabric can keep more heat if it has a low coefficient of thermal conductivity,and will be good at warm keeping.At the same time,the coefficient of thermal conductivity of still air is lower than any other textile materials,so it has been used frequently that changing the fiber and fabric construction to increasing more still air for obtaining a well warm of fabric.We want to get more gap and voids of yarn through changing its construction to increase content of still air for developing the warm keeping.The tests include the test of yarn constructions and the test of fabric constructions,and force on the feasibility of yarn spinning, fabric weaving and the parameters choosing.The test process planning of spinning that base on the Spinning method,choose the PVA yarn as the core,and use the core yarn technology and sirofil technology,to be the parameters of production.We obtain the appropriate technology of dissolving away the PVA by comparing different methods.The knitting fabrics dissolve away the PVA to get the hollow yarn fabric and the cavernous yarn fabric,and compare with the spinning yarn knitting fabric to get the feasibility of productions of the hollow yarn fabric and the cavernous yarn fabric. In the other side,we chose different PVA contents,PVA fineness and fiber materials to spin 34 kind yarns of 8 varieties in the same condition,and then did series of comparisons after testing theirs properties such as strength,heat retention,air permeability,stiffness and so on.Afterwards,test the properties of hollow-yarn fabric and cavernous-yarn fabric under different proportions and compositions of heat yarn to analyze how it influences fabrics performance so as to establish reasonable select range of proportion and fineness of PVA.Meanwhile,compare the diversification of heat insulating ability and Air permeability of the acquired fabrics which is made by adopting different knitting structures but the same technological parameter to obtain the relationship between property and structure, which will supply credible select basis and strengthen the warmth retention advantages of hollow-yarn fabric and cavernous-yarn fabric.The data after comparative analysis indicated that knitting fabrics of pure yarn could arrive at a superior level in all aspects of its properties when PVA is selected with certain proportion ranging from 20%to 25%and a fineness of 45D.The PVA fineness and its property could influence the ultimate fabrics' performances in all fields.To get the demanded result,yarn structures,PVA proportions, PVA fineness along with yarn's varieties should be established according to different needs of fabrics performance.