Research On Properties And Manufacture Process Of Medical Graduated Compression Socks

Varicose vein of lower limb is a kind of common vascular disease, which has ahigh incidence worldwide. Using medical graduated compression socks is the mosteffective and convenient way to treat varicose veins. It is a medical device, dividedinto care levels and treatment levels. Not only can the care level of varicose socksprevent varicose veins to healthy people, but also to make the leg thiner after wearing.Thus it is very popular for fashion-conscious ladies. Different treatment levels ofvaricose socks can cure varicose vein in different disease severity. Medical graduatedcompression socks have a broad market. Research and development on the socks is agood project with high economic efficiency and practicality.The main subject of study is to find how the yarn size, process parameters (suchas yarn feeding speed, sizing motor and stitch cam) affect the size and pressure ofmedical graduated compression socks. The results can be used to guide the productionof varicose veins socks, stockings reduce the amount of waste, reduce productioncosts and improve productivity.Firstly, the research analyzed domestic and foreign medical compressionstockings standards to determine the size and pressure indicators of varicose socks.Researcher tested the breaking force， elongation at break, twist and did electronmicroscopy analysis on lycra/nylon double wrapped yarns, which applyed pressurefor compression socks. The resultes showed that: high denier lycra/nylon doublewrapped yarns have better elongation, flexibility and covering degree, but lessstrength. As laying-in threads, they provide pressure and resiliency for compressionsocks. Ordinary denier lycra/nylon double wrapped yarns have bigger strength, butless elongation, flexibility and covering degree. As ground yarns, they supply strengthand extend the working life of socks.Secondly, the author researched the influence between process parameters ofyarn feeding speed and lateral dimensions of sock. The compression socks have three different pressure levels and different level stockings are knitted with differentlaying-in yarn. In the leg of socks the stitch structure is1:1laying-in stitch. The yarnfeeding speed choice19different parameters from500to1400r/min, knitting fabricand analysising the data, and to get the function equation of lateral dimensions andyarn feeding speed. The results showed that: the most important parameters affectingthe lateral dimensions is yarn feeding speed, the impact of the stitch cam and sizingmotor is very small, negligible. The yarn feeding speed and lateral dimension arelinear correlation. Base on these data, the author established regressive equations. R2value of the regression equations were about99%, that means the fit of equation isvery good.According to pressure level and size, the medical graduated compression socksare divided into nine kinds. In each kind of socks have4important testing point, theyare ankle (point B), the junction of Achilles tendon and calf muscle (points B1), calfwhere circumference is maximum (point C) and point below the knee (points D).The researcher established four orthogonal test in four points, to study how sizingmotor and stitch cam affecting socks pressure. The factors of orthogonal test aresizing motor, stitch cam1,3and stitch cam2,4. Testing conclusion as follow: thethree factors sorted by importance were sizing motor, stitch cam2,4and the stitchcam1,3. The value of sizing motor reduces due to sock pressure increases. With theincrease of stitch cam2,4values, the sock pressure will increase. the impact of thestitch cam1,3is very small, negligible. Based on above conclusions,researcher candetermine parameters value of sizing motor, stitch cam1,3and stitch cam2,4onfour test points.Finaly, using the above conclusions researcher can design and develop ninedifferent kinds of medical graduated compressur socks.