Study On PTT "Shape Memory" Fabrics

PTT(Polytrimethylene terephthalate) "shape memory" fabric is a newly developed advanced fabric in recent three years.It has not only the soft texture that the traditional fabrics have,but also easy-shape character and crease recovery that the traditional fabrics do not have. The former can make the fabrics be shaped at your needs by hands,and the latter make wrinkle which was formed in wearing and storing be easily removed.Widely speaking,the fabrics' character belonged to the definition of the shape memory materials,that is,through out shaping and fixed shaping,materials which has initial shape can return to their initial state after stimulating by the environment condition.Owing to the appearance looks like some fabrics made by shape memory metal fibers, so it is also called "shape memory" fabrics in common.The difference between the traditional fabrics and PTT "shape memory" fabrics is that stimulating condition is force rather than heat,light,magnetism, electricity and chemistry,etc.Until now,the systemic research on PTT "shape memory" fabrics have not been presented.In this paper,the PTT filament and PTT "shape memory" fabrics were studied in the following five aspects:(1) The tensile properties,the glass transition(Tg) and the crystal degree of PTT filament were respectively tested by Electronic Single Yarn Strength Tester YG061,Differential Scanning Calorimet(DSC) and X ray Tester.The results of tensile test suggested that the PTT filament's tensile properties produced by different manufactories was different,so it is a suggestion that different filament by different manufactories could not be used in the same fabrics,especially the same direction(warp or weft direction),so as to avoid making bubble on the fabrics in the process of weaving and dyeing &finishing.The test results of DSC and X ray was shown that PTT filament had low glass transition(Tg)(41.7℃) and low crystal degree(17-21%).The glass transition(Tg) is near to the temperature of hands and environment,that is the possible reason why this fabric can be retuned to the flat shape by stroking.And low crystal degree could be one of the reasons why PTT filament has the low glass transition(Tg).(2) In this paper,easy-shape character and crease recovery of PTT "shape memory" fabrics ware confirmed according to the practical value of this kind of fashion in the market.To explore the main stimulating condition which can make the fabrics return to the initial shape,series tests were designed,as a result force was found to be the main stimulating condition,and temperature has little effect on the recovery. The iron force of 100g(5N/cm^-2) combined with 35℃was designed,and the objective evaluation method for crease recovery was built up.(3) As to the characters of PTT "shape memory" fabrics(easy-shape character and crease recovery),the test method was discussed and the definition-Bending curvature for easy-shape character was raised and test results was shown that there was close relation between bending curvature and the evaluation results.The objective test method can reflect the easy-shape character practically.(4) To understand the effect of materials and structure parameters to PTT "shape memory" fabrics,six kinds of fabrics were chosen in category of light,high tight fabrics,they were PTT "shape memory" fabrics whose warp and weft yarn were made of PTT filament,PTT/PET intertexture whose warp yarn was made by PTT filament,while weft yarn was made by PET filament,PET fabric whose warp and weft yarn were both of PET filament,Cotton/PTT mixture,PET/cotton blends and cotton fabrics.The fabrics above were tested by the methods that built up by ourselves,the test results indicated that PTT "shape memory" fabrics and PTT/PET intertexture had excellent easy-shape character and crease recovery,that is better than other kinds of fabrics.(5) According to the fabric structure parameters adopted by manufactories,seven structure parameters were chosen to explore their influence to easy-shape character and crease recovery.Firstly the single-element method was used to hunt for the main parameters which affect the characters of PTT "shape memory" fabrics,then the experimental data affecting the easy-shape character and crease recovery were respectively analyzed by step-regression method to find out the main factors among numerous factors,and their effect on the characters was analyzed.What's more,the influence to the easy-shape character and crease recovery for PTT/PET intertexture and PET fabric was primarily analyzed.