مدل نمودن تاثير ظرافت الياف بر رفتار منسوجات سوزني طرح دار در يك سيكل فشار

چكيده انگليسي :

Modelling of the Effect of Fibre Fineness on Behavior of Structured Needle Fabric during Compression Cycle Azam Alirezazadeh a alirezazadeh@tx iut ac ir Degree M sc Language Farsi Evaluated and Approved by the Thesis Committee on 16 3 2011 Supervisor M Zarrebini Zarrebini@cc iut ac ir M Ghane Ghane@cc iut ac ir AbstractProduction of nonwoven textiles has expanded tremendously in comparison to conventionaltextiles This is due to both economical and technical advantages of various nonwoven productiontechniques Needled nonwovens comprise a very significant part of total nonwoven productionindustries Needled fabrics have found various end uses such as floor coverings automobiletextiles filtration fabrics sound and thermal isolations and waddings used in bedding items orupholstery Special needles are employed to impart both strength and surface effect in the fabrics In needling operation both fiber variables such as fiber fiber friction and fiber fineness andmachine variables such as type of needle used have profound effect on mechanical and physicalproperties of the needled product Mechanical properties of non woven textiles such as resiliencyand tensile features determine their end use Textile scientists have employed numerous methodssuch as geometrical finite element and image processing to design ideal models capable ofpredicting the above mentioned properties Since textiles are structurally different to othermaterials thus their various tensile behaviors are ascribed in relation to their high elasticity Lackof defined geometry in non woven fabrics structure makes the analysis of their mechanicalproperties rather difficult In the present work the effect of fineness of melt spun polypropylene fibers on behaviour ofstructured needled fabric having cord surface effect during compession cycle was studied Datawere obtained using Delphi program Various fiber fineness were achivied by varying the spinningpump speed Hough transfom was incoporated in the used image processing technique Oreientation of fibers in the exprimental samples was determined using the Hough transformincorporated image processing technique This technique premitted the recovery of more than 95 of the main lines of the images Simple mathematical relationships were used in the developementof a geometrical model It was found that the model yeilds a smaller number of surface loops incomparison to the number of loops counted using image processing technique Application offinite element analysis in Abaqus environment allowed the full compressive behaviour of thefabrics to be defined Results showed that an increase in the fineness of fibers causes the fiberloop density to be reduced This intrurn tended to reduce the force needed to compress the samplesto a pre defined thickness It can be stated that inter fiber frictional force is proportinal to cube offiber fineness provided the coefficient of friction is assumed to be constant Additionally it wasfound that in the case of sample produced using 15 denier fibers inter fiber frictional force is atits maximum value It was concluded that generally in comparison to unfinished samples tensileproperties of the samples impragnated with Latex are significantly improved In this respect theeffect of Latex addition on tensile properties is more in machine direction in comparison to theobserved improvement in cross machine direction Key words non woven textile Polypropylene mechanical properties resiliency fiber friction finite element image processing Hough transformation

عليرضا زاده، اعظم

مدل نمودن تاثير ظرافت الياف بر رفتار منسوجات سوزني طرح دار در يك سيكل فشار

منسوج بي بافت , پلي پروپيلن , خواص مكانيكي , بازگشت پذيري , اصطكاك ليف , پردازش تصوير