The lower strength of friction spun yarns has became a key problem that hinder the develop-ment of friction spinning,especially in high speeds and fine yarns.In this paper a project aimed atincreasing the strength of ...The lower strength of friction spun yarns has became a key problem that hinder the develop-ment of friction spinning,especially in high speeds and fine yarns.In this paper a project aimed atincreasing the strength of friction spun yarns by using a false twist process has been made.In re-ported experiment false twist was inserted into the yarn which has been formed on a friction spin-ning machine,so that it made the yarn untwist at first,then regain the twist.In the meantime draftwas applied to generate more tension than that which had been experienced during yarn formationon the friction spinning machine.It made the yarn reforming and the loosely bound fibres in thefriction spun yarn formed due to extremely low tension on the friction spinning machine becametighter.Results indicate that with the proper draft,tension and false twist the tenacity of processedyarn will increase more than 10%.This project is an attempt to discover whether improvements can be made and whether it isworth pursuing research into modifications of yarn structure.The results imply that if the yarntension can be raised during yarn formation on the friction spinning machine or a chance is offeredto the yarn to reform after the yarn formation the yarn tenacity will be increased obviously.展开更多
A model was deveIoped to investigate impregnation behavior of thermoplastic resin into filament bundle based on Darcy's law. Consolidation processes of unidirectional laminate were performed to evaluate the validi...A model was deveIoped to investigate impregnation behavior of thermoplastic resin into filament bundle based on Darcy's law. Consolidation processes of unidirectional laminate were performed to evaluate the validity of the model. Friction spun core yarns were used in the experiments with polypropylene fiber sheath and glass filament core. The processing conditions, such as temperature and pressure, and filament parameters were taken into consideration. A good agreement was found between theoretical prediction and experiment data.展开更多
Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a me...Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a method to test the anti - stripping property of the core yarn. With a modified Universal Testing Machine, the stripping resistance of friction spun core yarn can be continuously measured. Some factors Influencing the measurements are discussed in detail. The testing results are compared with those from a Y731 Yarn Abrasion Tester and fur - ther confirmed by weaving practice.展开更多
Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the...Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the bundleeffect was affected considerably by processing conditions(applied pressure and processing time).The boundaryof the bundles was disappeared under suitable processingconditions and finally an even fiber/resin distributioncould be attained.In consolidation,filament bundlesgetting close each other and resin flowing into the bundl-es occurred simultaneously,and eventually the bundleswere fully impregnated by the resin.Fiber packing den-sity in UD-laminate was the same as that of frictionspun core yarn(55%-65% in volume)and was not af-fected significantly by processing conditions under thecurrent experimental conditions.展开更多
文摘The lower strength of friction spun yarns has became a key problem that hinder the develop-ment of friction spinning,especially in high speeds and fine yarns.In this paper a project aimed atincreasing the strength of friction spun yarns by using a false twist process has been made.In re-ported experiment false twist was inserted into the yarn which has been formed on a friction spin-ning machine,so that it made the yarn untwist at first,then regain the twist.In the meantime draftwas applied to generate more tension than that which had been experienced during yarn formationon the friction spinning machine.It made the yarn reforming and the loosely bound fibres in thefriction spun yarn formed due to extremely low tension on the friction spinning machine becametighter.Results indicate that with the proper draft,tension and false twist the tenacity of processedyarn will increase more than 10%.This project is an attempt to discover whether improvements can be made and whether it isworth pursuing research into modifications of yarn structure.The results imply that if the yarntension can be raised during yarn formation on the friction spinning machine or a chance is offeredto the yarn to reform after the yarn formation the yarn tenacity will be increased obviously.
基金Funded by the Research Fund for the Doctoral Program of High Education
文摘A model was deveIoped to investigate impregnation behavior of thermoplastic resin into filament bundle based on Darcy's law. Consolidation processes of unidirectional laminate were performed to evaluate the validity of the model. Friction spun core yarns were used in the experiments with polypropylene fiber sheath and glass filament core. The processing conditions, such as temperature and pressure, and filament parameters were taken into consideration. A good agreement was found between theoretical prediction and experiment data.
文摘Friction spun core yarn has two components: filament core and staple fiber sheath. Under axial rubbing action, the failure mode of the core yarn is the stripping of the sheath from the core. This paper introduces a method to test the anti - stripping property of the core yarn. With a modified Universal Testing Machine, the stripping resistance of friction spun core yarn can be continuously measured. Some factors Influencing the measurements are discussed in detail. The testing results are compared with those from a Y731 Yarn Abrasion Tester and fur - ther confirmed by weaving practice.
文摘Consolidation of thermoplastic unidirectional(UD)lami-nate with friction spun core yarns was investigated,espe-cially the characterization of filament bundles in consoli-dation was analyzed.The results showed that the bundleeffect was affected considerably by processing conditions(applied pressure and processing time).The boundaryof the bundles was disappeared under suitable processingconditions and finally an even fiber/resin distributioncould be attained.In consolidation,filament bundlesgetting close each other and resin flowing into the bundl-es occurred simultaneously,and eventually the bundleswere fully impregnated by the resin.Fiber packing den-sity in UD-laminate was the same as that of frictionspun core yarn(55%-65% in volume)and was not af-fected significantly by processing conditions under thecurrent experimental conditions.
