Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper...Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.展开更多
Knitted structures are progressively built up from row after row of knitted intermeshed loops known as knitted loops. Apart from this knitted loops, tuck or miss loops may be produced by varying the timing of the inte...Knitted structures are progressively built up from row after row of knitted intermeshed loops known as knitted loops. Apart from this knitted loops, tuck or miss loops may be produced by varying the timing of the intermeshing sequence of the old loop and new loops. These loops are main and prominent part of the design of the weft knitted structures. Structures having float or miss loop exhibits many noticeable characteristics. The fabrics renders better surface appearance or color pattern. Dimensional stability is significantly improved. Fabric width is reduced and areal density is also increased considerably due to the presence of float loops in the structure. Therefore, the dimensional and physical features of different knitted structures having knit-miss loops may be studied carefully to find the influence of float stitch or loop on fabric width and areal density. In this project work, such an attempt has been made to specify some specific single jersey structures, which will be ensured as an effective tool for product research and development as well as for meeting up customer’s quality requirements of high class products.展开更多
In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the...In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the yarn is cubic B-spline curve,is proposed in this paper.With this model,the 3D simulation of the loop and of the basic structures of the knitted fabric is realized by using Virtual Reality Modeling Language(VRML).The virtual simulation scene is suitable for network transmission with freely available VRML browsers and can be translated,scaled and rotated quite arbitrarily.By using Java and External Authoring Interface(EAI)technology,the web-based interactive simulation platform of weft knitted fabric is established.The user can input type of structures,basic fabric parameters,and yarn colors interactively to obtain a more realistic simulation result in real-time.A new approach is provided to imitate the knitted fabric 3D appearance on network.展开更多
This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is estab...This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is established for the first time according to its unique construction. Two kinds of locking angles are considered under different restraint conditions: the locking angle θ1 controlled by the inserting yarns and the locking angle θ2 controlled by the stitch yarns. It is concluded that the ultimate value of the locking angle θ is the larger one of the two angles.展开更多
It is essential to measure the stitch length of weft knitted fabric in a static environment for economy and improving productivity. The image inputted was dealt with the digital image processing techniques： the paper...It is essential to measure the stitch length of weft knitted fabric in a static environment for economy and improving productivity. The image inputted was dealt with the digital image processing techniques： the paper carried out the transformation of grey scale; then removed impurities with filtering; the characteristic of the stitch structure was abstracted by using the Fourier transform technique. To obtain the stitch length more accurately, we should establish ageometric medal of the stitch lined on the digital image processing, which provides a way to transform the stitch length in the two-dimenslon space into a three-dimension space. This study provides a new methed for measuring the stitch length without damaging the fabric.展开更多
The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE univer...The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE universal material testing machine and Aramis V6 digital image correlation( DIC) technique.More specifically,the composite samples own four hybrid ratios(Na∶ Nc= 12∶ 0,8 ∶ 4,6 ∶ 6 and 4 ∶ 8). The results showed that the aramid/carbon hybrid MBWK fabric reinforced composites showed nearly linear response until reaching the maximum load and the inserting yarns distribution on the surface of MBWK fabrics reinforced composites had a great influence on the strain pattern distribution. Besides,the tensile strength,the tensile modulus and the elongation at breakage of 0° samples and 90° samples increased with the decreasing of aramid/carbon hybrid ratio. In a word,the changes of tensile strength, tensile modulus and elongation at breakage have a lot to do with the difference of aramid/carbon hybrid ratio.展开更多
Endoluminal stents for reinforcement and regeneration of human trachea have been developed by weft-knitting method on a small-diameter circular knitting machine. The constituent materials of the stent are Polyglactin,...Endoluminal stents for reinforcement and regeneration of human trachea have been developed by weft-knitting method on a small-diameter circular knitting machine. The constituent materials of the stent are Polyglactin, Polypropylene and Chitosan with Polyglactin and Polypropylene plate-stitched fabric acting as backbone while chitosan as matrix, respectively. The fabrication procedures including knitting and coating are described in this paper. Mechanical and animal tests have been carried out to evaluate the mechanical properties of the stents.展开更多
In order to regenerate myocardium and provide appropriate mechanical support after a heart attack,jersey,tuck and rib stitch structures were knitted from polylactic acid(PLA)yarns to fabricate a cardiac patch,which mi...In order to regenerate myocardium and provide appropriate mechanical support after a heart attack,jersey,tuck and rib stitch structures were knitted from polylactic acid(PLA)yarns to fabricate a cardiac patch,which mimicked the mechanical properties of myocardium in both directions.Cardiosphere-derived cells(CDCs) were seeded on these PLA patch fabrics,and using scanning electron microscopy(SEM) characterization and an MTT assay the cells proliferated and attached successfully to the PLA fabrics.Based on the results,the rib stitch structure is the most promising candidate for fabricating cardiac patches due to its high elasticity and its ability to promote cell proliferation.展开更多
In the knitting industry the measurements of the stitch density and the stitch length are usually done manually, which may lead to lower efficiency and less definition and also bring subjective ideas into the test res...In the knitting industry the measurements of the stitch density and the stitch length are usually done manually, which may lead to lower efficiency and less definition and also bring subjective ideas into the test results. In order to improve the effect we can measure with Digital Image Processing Techniques. A piece of sample is scanned into computer and changed into a digital image, which is processed with media filtering. To acquire the power spectrum, the image in the spatial domain is converted into the frequency domain. Picking up the characteristic points describing the stitch density and the stitch length separately in the power spectra and reconstructing them, the values of the stitch density and the stitch length could be calculated. When measuring the stitch length, we should establish a geometric model of the stitch based en the digital image processing, which provides a method to transform the stitch length in the two-dimensien space into the three-dimensien space and to measure the value of the stitch length more accurately. This method also provides a new way to measure the stitch length without damaging the fabric.展开更多
基金Natural Science Foundation of Tianjin,China( No. 11JCYBJC26400) Tianjin High School Scientific and Technology Fund Planning Project,China( No. 20100310)
文摘Weft knitted fancy fabrics are widely used in knitted garment design. Due to the complexity of the structures, their modeling and simulation needs to be solved in three-dimensional (3D) CAD developments. In this paper, 3D loop geometrical models of weft knitted fancy structures, including tuck stitch, jacquard stitch, transfer stitch and fleecy stitch, were developed based on an improved model of plain loop, and their central axes as some 3D space curves were achieved by using Non-Uniform Rational B-Splines (NURBS). The 3D visual simulation programme was written in C++ programming language using OpenGL, which was a function library of 3D graphics. Some examples of weft knitted fancy fabrics were generated and practical application of 3D simulation was discussed.
文摘Knitted structures are progressively built up from row after row of knitted intermeshed loops known as knitted loops. Apart from this knitted loops, tuck or miss loops may be produced by varying the timing of the intermeshing sequence of the old loop and new loops. These loops are main and prominent part of the design of the weft knitted structures. Structures having float or miss loop exhibits many noticeable characteristics. The fabrics renders better surface appearance or color pattern. Dimensional stability is significantly improved. Fabric width is reduced and areal density is also increased considerably due to the presence of float loops in the structure. Therefore, the dimensional and physical features of different knitted structures having knit-miss loops may be studied carefully to find the influence of float stitch or loop on fabric width and areal density. In this project work, such an attempt has been made to specify some specific single jersey structures, which will be ensured as an effective tool for product research and development as well as for meeting up customer’s quality requirements of high class products.
基金Jiangsu Natural Science Foundation of University,China(No.07KJD540178)Foundation of Nantong Science and Technology of China(No.K2007009)Graduate Innovation Project of Nantong University,China(No.YKC09056)
文摘In order to realize parametric simulation of three-dimensional(3D)fabric structure based on web,a 3D model describing a plain knitted fabric,in which the cross-section of the yarn is circular shape and the path of the yarn is cubic B-spline curve,is proposed in this paper.With this model,the 3D simulation of the loop and of the basic structures of the knitted fabric is realized by using Virtual Reality Modeling Language(VRML).The virtual simulation scene is suitable for network transmission with freely available VRML browsers and can be translated,scaled and rotated quite arbitrarily.By using Java and External Authoring Interface(EAI)technology,the web-based interactive simulation platform of weft knitted fabric is established.The user can input type of structures,basic fabric parameters,and yarn colors interactively to obtain a more realistic simulation result in real-time.A new approach is provided to imitate the knitted fabric 3D appearance on network.
文摘This paper introduces the construction of the multi-layered biaxial weft knitted fabric （MBWK fabric） and studies the locking angle of this kind of fabric. Moreover, a locking angle model of the MBWK fabric is established for the first time according to its unique construction. Two kinds of locking angles are considered under different restraint conditions: the locking angle θ1 controlled by the inserting yarns and the locking angle θ2 controlled by the stitch yarns. It is concluded that the ultimate value of the locking angle θ is the larger one of the two angles.
文摘It is essential to measure the stitch length of weft knitted fabric in a static environment for economy and improving productivity. The image inputted was dealt with the digital image processing techniques： the paper carried out the transformation of grey scale; then removed impurities with filtering; the characteristic of the stitch structure was abstracted by using the Fourier transform technique. To obtain the stitch length more accurately, we should establish ageometric medal of the stitch lined on the digital image processing, which provides a way to transform the stitch length in the two-dimenslon space into a three-dimension space. This study provides a new methed for measuring the stitch length without damaging the fabric.
基金Tianjin Municipal Science and Technology Commission for the Financial Supports,China(No.11ZCKFSF00500)China's General Administration of Quality Supervision,Inspection and Quarantine for the Financial Supports,China(No.201210260)
文摘The effects of aramid/carbon on tensile properties of multilayered biaxial weft knitted( MBWK) fabric reinforced composites are analyzed by experiments. The tensile tests are inducted by the SHIMADZU AG-250 KNE universal material testing machine and Aramis V6 digital image correlation( DIC) technique.More specifically,the composite samples own four hybrid ratios(Na∶ Nc= 12∶ 0,8 ∶ 4,6 ∶ 6 and 4 ∶ 8). The results showed that the aramid/carbon hybrid MBWK fabric reinforced composites showed nearly linear response until reaching the maximum load and the inserting yarns distribution on the surface of MBWK fabrics reinforced composites had a great influence on the strain pattern distribution. Besides,the tensile strength,the tensile modulus and the elongation at breakage of 0° samples and 90° samples increased with the decreasing of aramid/carbon hybrid ratio. In a word,the changes of tensile strength, tensile modulus and elongation at breakage have a lot to do with the difference of aramid/carbon hybrid ratio.
文摘Endoluminal stents for reinforcement and regeneration of human trachea have been developed by weft-knitting method on a small-diameter circular knitting machine. The constituent materials of the stent are Polyglactin, Polypropylene and Chitosan with Polyglactin and Polypropylene plate-stitched fabric acting as backbone while chitosan as matrix, respectively. The fabrication procedures including knitting and coating are described in this paper. Mechanical and animal tests have been carried out to evaluate the mechanical properties of the stents.
基金the College of Textiles,North Carolina State University,Raleigh,USA“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘In order to regenerate myocardium and provide appropriate mechanical support after a heart attack,jersey,tuck and rib stitch structures were knitted from polylactic acid(PLA)yarns to fabricate a cardiac patch,which mimicked the mechanical properties of myocardium in both directions.Cardiosphere-derived cells(CDCs) were seeded on these PLA patch fabrics,and using scanning electron microscopy(SEM) characterization and an MTT assay the cells proliferated and attached successfully to the PLA fabrics.Based on the results,the rib stitch structure is the most promising candidate for fabricating cardiac patches due to its high elasticity and its ability to promote cell proliferation.
文摘In the knitting industry the measurements of the stitch density and the stitch length are usually done manually, which may lead to lower efficiency and less definition and also bring subjective ideas into the test results. In order to improve the effect we can measure with Digital Image Processing Techniques. A piece of sample is scanned into computer and changed into a digital image, which is processed with media filtering. To acquire the power spectrum, the image in the spatial domain is converted into the frequency domain. Picking up the characteristic points describing the stitch density and the stitch length separately in the power spectra and reconstructing them, the values of the stitch density and the stitch length could be calculated. When measuring the stitch length, we should establish a geometric model of the stitch based en the digital image processing, which provides a method to transform the stitch length in the two-dimensien space into the three-dimensien space and to measure the value of the stitch length more accurately. This method also provides a new way to measure the stitch length without damaging the fabric.
