Stab resistance of flexible composite reinforced with warp-knitted fabric like scale structure at quasi-static loading

The stab-resistant fabric like scale structure has a promising application prospect for areas of stab prevention owing to its great flexibility and excellent stab-resistance performance. In this paper, a kind of novel stab-resistant fabric has been designed by coating with epoxy resin (ER) and silicon carbide (SiC) particles, which was based on the warp-knitted fabric like scale structure (WKFS). The uniformity of dispersion has been investigated with different diameter and mass fraction of SiC, and polymerization degree of polyglycols (PEG); the flexibility and quasi-static properties of different kinds of WKFS treated with different coating solution has been studied, and the coating solution was prepared by mixing SiC particles and ER at different ratios. The results showed that the dispersion uniformity of the dispersion was the best when the diameter of SiC is 1 μm, the content is 50%, and the polymerization degree of PEG is 600. The longitudinal flexibility of the stab-resistant fabric is greater than that of transverse due to the gap between the longitudinal scales, and the addition of SiC particles can increase the transverse and longitudinal flexibility of stab-resistant fabric, and the flexible properties were the greatest when SiC:ER = 50:30. In addition, the WKFS treated with SiC of 16.7% has fatigue resistance; the damage mechanism of the fabric treated with pure ER is thankful to the brittleness of the resin; the added SiC particles hinder the further crack propagation of the resin, and the failure mode is mainly in stretch.

The Structure and Compression of Medical Compression Stockings

This paper lays out standards of compression stockings and their classification into classes. The analysis of knitted fabric structure parameters, elongation and compression of moderate- and high-compression stockings was conducted. Stocking compression on specific parts of the stocking leg was measured on three sizes of a wooden leg model. For moderate-compression stockings, compression above the ankle was 32 hPa. For high-compression stockings, compression above the ankle was 60 hPa. Both groups of the analyzed compression stockings were made on modern one-cylinder hosiery automats. The legs of the stockings were made in single inlaid jersey 1 + 1. Both yarns were elastane covered. The finer yarn formed loops and its knitting into a course was significantly larger than in the other yarn, which was much coarser and does not form loops but “lay the weft in a bent way”. The smallest elongation of knitted fabric was above the ankle, where the highest compression was achieved, while the largest elongation was under the crotch, where the stocking leg exerted the smallest compression on the surface. The leg of the compression stocking acted as a casing that imposed compression on the leg and often reinforced it to be able to sustain compression loads.

КАРКАСНА МОДЕЛЬ РОЗТЯГУВАННЯ КУЛІРНОГО ТРИКОТАЖУ ВЗДОВЖ ПЕТЕЛЬНИХ РЯДІВ

Purpose. The purpose of this study is to develop a mathematical description of the transformation of the frame model of weft-knits under the action of tensile forces in the courswise direction for further three-dimensional modeling of the knited structure.Methodology. Methods of theoretical analysis and synthesis, basics of knitting theory, methods of geometric modeling and parameterization were used in the research process.Findings. Considering the knitwear stretching during the use of the clothing is one of the determining factors of the quality of design decisions. When stretching the weft-knitted fabrics in the coursewise direction, the configuration of its individual stitches’ changes, as well as the thread’s cross-section due to the force interaction between the adjacent structure elements. To simulate the physical and mechanical behavior of knitwear under the stretching, it is suggested using a complex model of knitwear deformation, that includes the suggested frame model of uniaxial coursewise stretching of knitted fabrics. An algorithm for constructing a frame model of stretching a sample of knitted fabric in the coursewise direction is described in the paper. The algorithm is based on the structure parameters, including the wale spacing and course spacing in a dry relaxed state, the relative elongation of the sample at the time of modeling, number of wales and courses in the sample, the coefficient of courses narrowing. Scientific novelty. The paper investigates the features of the transformation of the knitting structure during stretching in the coursewise direction and offers algorithmic and mathematical support for the automated generation of the mesh frame in the context of three-dimensional modeling, which provides for the possibility of considering the dynamics of deformation of knitted fabric undergoing tensile deformations.Practical value. Frame model of the weft-knits deformation and algorithm of mesh-frame construction suggested in the paper, form the basis for determination of coordinates of characteristic points of the structural elements of the knit in a state of uniaxial tension for construction of a three-dimensional model of thread a deformed knitted fabric.

МULTI-LAYER FIBROUS MATERIAL BASED ON TEXTILE WASTE

At the textile and sewing and knitting enterprises of the Republic of Uzbekistan, the number of which increases every year, a sufficient amount of technological waste is accumulated, which formed in the processes of sizing yarn, starting and setting up equipment, designing and sewing products. Meanwhile, there is a shortage of warm, comfortable, light, soft lining materials for clothes and shoes based on natural raw materials. With the purpose of rational use of textile waste - shredded, disheveled scraps of fabric and knitwear, a multilayer nonwoven material for details of clothing and footwear has been obtained. The material formed by adhesive bonding on one or both sides of the knitted fabric of the main, voluminous nonwoven layer, consisting of shredded textile waste. The bonding of the layers takes place as a result of their passing between heated rolls. The microstructure of the material studied by Fourier-IR spectroscopy and

An intelligent defect detection system for warp-knitted fabric

In textile factories, the most typical warp-knitted fabric defects include point defects, holes, and color differences. Traditional manual inspection methods are inefficient for detecting these defects. Existing intelligent inspection systems often have a single function. Factories require a real-time inspection system that can detect common defects and color difference. The YOLO (you only look once) neural network is faster than the two-stage neural network and has lower hardware requirements. The system’s color difference detection algorithm compares the color difference between the standard image and the image to be measured and records where the color difference value is exceeded. Finally, the comparison of the factory application proves that the designed system has good real-time performance and accuracy and can meet the fabric inspection requirements of warp-knitted fabric factories.

Effects of Composite Coatings Functionalized with Material Additives Applied on Textile Materials for Cut Resistant Protective Gloves

The objective of the present work was to evaluate the effects of different types of particles added to a polymer paste applied onto a textile carrier on the cut resistance of the resulting material. Knitted aramid textile samples were coated in laboratory conditions using a polymer paste that was functionalized with 12 types of reinforcing particles of different chemical compositions and size fractions. Cut resistance was tested in accordance with the standard EN ISO 13997:1999 and the results were subjected to statistical analysis. The effects of additive particles on the microstructure of the polymeric layer were assessed by means of scanning electron microscopy. The type and size of the particles affected the cut resistance of the functionalized knitted fabric. They were also found to change the morphology of the porous structure. Composite coatings containing the smallest additive particles exhibited the best cut resistance properties.

Possibility of Using Cotton Knitted Fabric Waste in Concrete

The use of waste and recycled materials in the construction industry, especially in concrete production, is becoming increasingly popular. The production of cotton underwear generates a certain amount of knitted fabric waste. This study was conducted to investigate the possibility of using cotton knitted fabric waste (CKFW) in concrete and to explore its potential application in the construction industry. The aim of the study is not only to reduce the waste but also to add positive properties to the concrete. A total of 4 mixes were prepared for testing purposes. CKFW were cut into small pieces of size about 6-8 cm x 2 cm. The addition of CKFW was a substitute for aggregates and replaced 0, 2.5, 5 and 10% of the total volume of aggregates in the concrete mix to make the concrete lighter. All mixes have the same amount of cement, water and superplasticizer. The knitted waste was saturated in water before mixing with other concrete components. The properties of the fresh mix were determined by slump method. The dynamic modulus of elasticity, flexural strength and compressive strength were tested on 28 days old concrete specimens. The σ-δ diagram is also presented. It was found that specimens with CKFW have better flexural strength and higher ductility but lower compressive strength than the reference concrete mix. The mix with the highest percentage of CKFW reduced the compressive strength by 28%, while the specimens with lower percentage of CKFW increased the flexural strength by 20% compared to the reference mix. The capillary water absorption capacity of concrete is closely related to its durability. The water absorption by capillarity was measured after 2, 4, 8, 15, 30, 45, 60 min, and 4 and 24 h. The increase in the amount of water absorbed was found to be higher than that of the reference mix. It was related to the percentage increase in the knitted waste and the values obtained ranged from 3.3 to 5.6% of the mass of the dry sample. The largest reduction in concrete density was 3.8% compared to the reference mix. Based on the obtained results, recommendations for further tests are given.