Pibo Ma, Gaoming Jiang and Zhe Gao
Zhiwen Lu and Gaoming Jiang
In order to create realistic loop primitives suitable for the fast computer-aided design (CAD) of the flat knitted fabric, we have a research on the geometric model of the loop as well as the variation of the loop surface. Establish the texture variation model based on the changing process from the normal yarn to loop that provides the realistic texture of the simulative loop. Then optimize the simulative loop based on illumination variation. This paper develops the computer program with the optimization algorithm and achieves the loop simulation of different yarns to verify the feasibility of the proposed algorithm. Our work provides a fast CAD of the flat knitted fabric with loop simulation, and it is not only more realistic but also material adjustable. Meanwhile it also provides theoretical value for the flat knitted fabric computer simulation.
Qing Chen, Pibo Ma, Haiwen Mao, Xuhong Miao and Gaoming Jiang
This study investigated the elastic elongation and elastic recovery of the elastic warp knittedfabric made of PET( polyethylene terephthalate) and PBT(polybutylene terephthalate) filament. Using 50/24F PET and 50D/24F PBT in two threadingbars, the tricot, locknit and satin warp knitted fabrics were produced on the E28 tricot warpknitting machine. The knitting parameters influencing the elastic elongation under 100N wereanalyzed in terms of fabric structure, yarn run-in speed and drawing density set on machine.Besides, dyeing temperature and heat setting temperature/time were also examined in order toretain proper elastic elongation and elastic recovery. The relationship between elastic elongationand knitting parameter and finishing parameter were analyzed. Finally, the elastic recovery ofPET/PBT warp knitted fabric was examined to demonstrate the elastic property of final finishedfabric. This study could help us to further exploit the use of PET/PBT warp knitted fabric in thedevelopment of elastic garment in future.
Dong Xia, Gaoming Jiang and Pibo Ma
In this paper, a non-subsampled wavelet-based contourlet transform (NWCT) is applied in warp-knitted fabric defect segmentation. Compared with the traditional contourlet transform, wavelet transform takes the place of Laplacian pyramid in NWCT and the directional filter bank is non-subsampled. The wavelet transform with improved wavelet threshold is put to use, and the original fabric image can be decomposed into low-frequency approximate coefficient A and high-frequency detail coefficients V, H, and D. The high-frequency detail coefficients are processed by the non-subsampled directional filter bank to get directional sub-band coefficients. Afterward, the effective sub-band coefficients based on regional energy are chosen to reconstruct V, H, and D. And the reconstructed fabric image will be achieved by inverse non-subsampled wavelet-based contourlet transform. The adaptive threshold method and morphological processing are used to obtain the legible defect profile. The experiment demonstrates that NWCT can achieve the positive segmentation regarding the common defects, such as broken warp, width barrier, and oil, and has excellent performance on these directional defects and regional defects. It is acknowledged that NWCT will provide a new way to detect warp-knitted fabric defects automatically.
Haiwen Mao, Pibo Ma and Gaoming Jiang
In this study, woven fabrics with numerous electrostatic charges and desirable charge stability were investigated. A kind of core–shell monofilaments with different melting points between outer and inner layers were applied to wove the fabrics. These fabrics were hot coated through tourmaline particles as an charge enhancer at 122°C. Benefiting from the anions released by tourmaline particles and optimized content of the particles, the fabrics were endowed with surface potentials from −10 to −160 V and the voids content decreased from 45.4% to 41.2%, which contribute to the improvement in the filtration performance of the fabrics. A filtration mechanism was proposed while incremental surface charges with increasing tourmaline particles content have been confirmed through the noncontact measurement of electrostatic charges. The resultant fabrics exhibited a high filtration efficiency of 64.8% and superior long-term service performance. This study can provide a new application of the screen window for PM 2.5 governance.
Jiajia Peng, Gaoming Jiang and Honglian Cong
To realize 3D garment simulation online and show the wearing effect of different body types, a method for rapid parametric human modeling is proposed in this article. The parameterization consists of two phases. In the first phase, the characteristic parameters of the sample model are extracted according to the different types of feature information. In the second phase, the deformation is realized by combining the axial deformation method and the radial weight. Thus, according to contrasts between the input measurement and the sample sizes, parametric human modeling is realized by deformation of the sample model. In the deformation stage, the axis curve is simplified to the straight-line segment in the axis deformation method, reducing the calculation. Comparative analysis and the results of experiments demonstrate that the better performance can be achieved at a higher speed, and this method realizes real-time parametric human modeling.
Xuan Luo, Gaoming Jiang and Honglian Cong
This paper focuses on the better performance between the garment simulation result and the simulation speed. For simplicity and clarity, a notation “PART” is defined to indicate the areas between the garment and the human body satisfying some constraints. The discrete mechanical model can be achieved by the two-stage process. In the first stage, the garment can be divided into several PARTs constrained by the distance. In the second stage, the mechanical model of each PART is formulated with a mathematical expression. Thus, the mechanical model of the garment can be obtained. Through changing the constrained distance, the simulation result and the simulation speed can be observed. From the variable distance, a desired value can be chosen for an optimal value. The results of simulations and experiments demonstrate that the better performance can be achieved at a higher speed by saving runtime with the acceptable simulation results and the efficiency of the proposed scheme can be verified as well.
Xinxin Li, Gaoming Jiang and Pibo Ma
Based on a further study on knitting and jacquard principles, this paper presents a mathematical design model to make computer-aided design of warp-knitted jacquard spacer fabrics more efficient. The mathematical model with matrix method employs three essential elements of chain notation, threading and Jacquard designing. With this model, the processing to design warp-knitted jacquard spacer fabrics with CAD software is also introduced. In this study, the sports shoes which have separated functional areas according to the feet structure and characteristics of movement are analysed. The results show the different patterns on Jacquard spacer fabrics that are seamlessly stitched with jacquard technics. The computer-aided design method of warp-knitted jacquard spacer fabrics is efficient and simple.
Zhiwen Lu, Gaoming Jiang, Honglian Cong and Xi Yang
To achieve the efficiency and specification of the flat-knitted uppers design, the basic patterns of uppers are made from shoe lasts based on the research on the characteristics of human’s feet and wearability requirements on uppers. The knitting technology for half-shaped and fully shaped uppers was formed after the shear deformation of basic pattern and combination with flat knitting technology. As regards to the functional requirements on key parts of uppers, the structures of flat-knitted shaped uppers were intensively analysed and studied, dividing them into two categories (functional structure and decorative structure), discussing the knitting methods and advantages of different structure, and finally experimentally proving that the planar pattern of flat knitted uppers can apply to the design of flat-knitted uppers and achieve the combination of functionality and artistry of sneakers after combining with structural changes, with a great significance on the achievement of the efficient production of uppers and the enhancement of its commercial value.
Xiaoying Li, Gaoming Jiang, Xiaolin Nie, Pibo Ma and Zhe Gao
This paper introduces a knitting technique for making innovative curved three-dimensional (3D) spacer fabrics by the computer flat-knitting machine. During manufacturing, a number of reinforcement yarns made of aramid fibres are inserted into 3D spacer fabrics along the weft direction to enhance the fabric tensile properties. Curved, flat-knitted 3D spacer fabrics with different angles (in the warp direction) were also developed. Tensile tests were carried out in the weft and warp directions for the two spacer fabrics (with and without reinforcement yarns), and their stress–strain curves were compared. The results showed that the reinforcement yarns can reduce the fabric deformation and improve tensile stress and dimensional stability of 3D spacer fabrics. This research can help the further study of 3D spacer fabric when applied to composites.