بررسي اثر پارامترهاي نخ و پارچه بر ميزان لول شدن بافت هاي يكروسيلندر حلقوي پودي

چكيده انگليسي :

Investigation into Yarn and Fabric Parameters on Curling of Single Jersey Weft Knitted Shohreh Minapoor s minapoor@tx iut ac ir Department of Textile Engineering September 2011 Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Saeed Ajeli sajeli@cc iut ac irAbstractOne of the most important characteristics of knitted fabrics is edge curling Knitted fabric edges tend to curlto the fabric technical face or back This tendency is due to release of energy that stored in loops by forcesand bending and twisting moments which are applied to changing the straight yarn into a loop during knittedprocessing Thus when the fabric is cut curling at the edges started with the discharging of this energy In adry relaxed state some forces act on the loop in a knitted fabric These forces arise from tension acting onthe structure during knitting from jamming and also from changing the straight yarn into a loop by bendingand twisting Energy on the loop resulting from these forces causes a many problems such as shrinkage andcurling The yarn when bent into a loop during knitting tends by virtue of its elasticity to straighten itself outand if the edge of the fabric is unrestrained these forces in all the loops can be sufficient to lift the fabric andform it into a roll Edge curling is important problems which occur in particular in plain knitted fabrics owing to theunbalanced yarn bending moment existing in the three dimensional nature of the structure The curlingoccurs at the upper and lower edges of a piece of fabric towards the front side and at the left and at the rightedges of the fabric towards the back side In a plain knitted fabric structure the yarns want to adopt a straightform but it is prevented from doing so by neighboring loops Thus curling can start at the edges as there is noneighboring loop on one side to prevent curling The edge curling can create some problems during thecreation of plain knitted clothing goods Edge curling of knitted fabrics is one of their defects and resultsproblems and waste in finishing and sewing so study and measurement of curling is very important Inprevious studies researchers have tried to identify factors affecting curling and measurement curling distanceby calculating moments on the loop that force fabric to curl These moments are functions of fabric and yarnparameters such as yarn diameter and bending rigidity loop length wale course spacing and fabric structurewhich are known before fabric production It will be possible to calculate material loss duo to curling duringgarment preparation with predicting of it before production The aim of this study is investigation into yarn and fabric parameters on curling of single jersey weft knittedfabrics Single jersey weft knitted fabrics were produced on a circular knitting machine Taguchi sexperimental designs were used to examine the effect of different fiber yarn and fabric parameters such asfiber material and blend percent yarn twist and count fabric structure and density relaxation time aftercutting fabric and cut direction on fabric curling The results show that the investigated parameters havesignificant effect on fabric curling in both wale and course cut direction The factors were ranked due to theireffect on the edge curling According to the results of Taguchi method fabric structure shows the strongesteffect on fabric curling and fabric density is second in both wale and course cut direction In wale cutdirection relaxation time after cutting is third yarn twist is fourth blend percent is fifth and is followed byyarn count In course cut direction yarn twist is third yarn count is fourth blend percent is fifth and isfollowed by relaxation time after cutting The optimum conditions were determined through the experimentaldesign In both cut directions the double cross tuck structure the lowest density the lowest yarn twist and50 50 cotton polyester yarn conclude minimum of edge curling Measuring of edge curling

ميناپور، شهره

بررسي اثر پارامترهاي نخ و پارچه بر ميزان لول شدن بافت هاي يكروسيلندر حلقوي پودي

پارچه ي يكروسيلندرحلقوي پودي , روش طراحي آزمايشات تاگوچي , شبيه سازي