Study On Reducing Shrinkage Rate Of Cotton Single Pique Knitted Fabric

Single pique is a kind of single needle bed knitted fabric,which is made of knitting needles and knitted yarns on a single circular weft machine.It is interlaced with knit loop and tuck loop.Single pique fabric has better air permeability and hygroscopicity than weft plain knitted fabric because of the existence of tuck loop.It is widely used in shirts and sportswear.Although cotton single pique knitted fabric has good wearability,its shrinkage rate is relatively large.Therefore,this paper mainly focuses on reducing the shrinkage rate of cotton single pique knitted fabric and studies the knitting,dyeing and finishing process and the change of its shape under the external force in enterprises and school laboratories condition.In the enterprise,29.2 tex cotton ring spinning yarn is used,and then three kinds of single pique fabrics with different knit loop lengths are woven on two different machines.In the aspect of width,the width of blank cloth and greige cloth increases with the increase of knit loop length before and after washing.in detail,before washing,the width of blank cloth decrease,while after washing,the width remain unchanged.In the aspect of surface density,although the surface density of blank cloth and greige cloth decreases with the increase of knit loop length,after dyeing and finishing,their surface density and difference in surface density before and after washing all decrease.As for density,both transverse density and longitudinal density decrease with the increase of knit loop length.After dyeing and finishing,the transverse density basically does not change,but the longitudinal density decreases.In terms of thickness,the thickness of greige cloth is lower than that of blank fabric,and it also decrease with the increase of knit loop length.Considering the final shrinkage,the overall shrinkage rate has decreased,but the difference between vertical and horizontal shrinkage rate has increased.In addition,the shrinkage of cotton single pique knitted fabric treated with liquid ammonia was also studied and analyzed.It was found that the density and surface density of cotton single bead flooring material treated with liquid ammonia did not change much before and after washing,and the shrinkage rate of both horizontal and vertical fabrics could be controlled within 5%.In school laboratory,18.2 tex cotton ring spinning yarn was used.Ten kinds of cotton single pique knitted fabric with different knit loop lengths were knitted on a single side small diameter circular weft machine.Dry relaxation,wet relaxation,total wet relaxation and conditional equilibrium were carried out on each sample.It can be concluded from the experiment that the shrinkage rate of cotton single bead floor fabric is greatly affected by the different length of knit loop and the different relaxation methods.The density of the fabric decreases with the increase of the length of the knit loop,and the shrinkage of the fabric varies greatly with the increase of the length of the knit loop.In terms of four different relaxation treatments,different relaxationtreatments also have a great influence on fabric shrinkage,in which conditional equilibrium plays the most important role compared to other treatments.The shrinkage of fabrics treated by conditional equilibrium is relatively small and the size of fabrics remains basically unchanged.In the laboratory,the tensile tests of various fabrics in the longitudinal and weft directions were carried out by using the electronic fabric strength tester,and the effects of various external forces on the fabrics under the production process were simulated.The results show that the elastic recovery rate of cotton single pique knitted fabric is inversely proportional to the plastic deformation rate.When knitting,fine gauge should be chosen and the length of knit loop should be controlled at about 2.75 mm,so that the knitted fabric is relatively compact and the dimensional stability is relatively better.Fabrics are prone to deformation when subjected to external forces,so the tension of fabrics should be reduced as much as possible during dyeing.The elastic recovery rate of greige cloth is relatively smaller than that of blank cloth,which indicates that setting treatment plays a decisive role in its dimensional stability.In addition,due to the larger elastic recovery rate of blank cloth,in order to make the setting process more reasonable,some time should be left for the blank cloth to be fully restored after dyeing and shaping.Because the fabric is easily deformed when it is subjected to external forces,the tension should not be too large when it is expanded on the setting machine.If the tension is too large,the fabric will easily shrink when it is washed later.In this paper,the production technology and properties of cotton single pique knitted fabric have been fully studied which can help enterprises to set up reasonable production process in the production of cotton single pique knitted fabric,thereby reducing the shrinkage rate of cotton single pique knitted fabric,and finally laying the foundation for improving the inherent quality of cotton single pique knitted fabric.