Production Of Knitted Fabrics Research Articles

Research of physical and mechanical properties of knitted fabrics of plush interlooping with reduced material consumption

The article discusses methods for manufacturing lined weave plush knitwear and ways to reduce the material intensity of knitted fabrics. The purpose of the study is to reduce the material consumption of products while maintaining operational, hygienic and aesthetic properties in the production of knitted fabrics. As a result of experimental work, the technological capabilities of the KН-323D flat knitting machine were studied and new types of lined weave plush knitwear were developed. Comparing the bulk density of plush knitwear with elongated lining broaches with the main base weave, it is clear that the presence of elongated lining broaches in the knitwear structure increases the thickness of the knitwear and reduces the bulk density. The breathability of a lined weave plush jersey is significantly less than that of a basic weave. It has been established that air permeability coefficients can be reduced to 33.1% (46.3-66.9 cm3/cm2∙sec) by adjusting the length of the threads of the lining broaches of plush knitted fabric of lined weave. Regression equations are derived to determine the dependence of bulk density, breaking load (along the length and width) and the air permeability index of knitted fabric on technological factors. Mathematical models were built in Excel using regression equations. The research results make it possible to improve the quality and consumer properties of knitted products, and to select advanced production technologies for their production.

Economic efficiency of production of knitted fabrics per unit of time

Economic efficiency of production of knitted fabrics per unit of time

Influence of tuck stitches on the physical and mechanical properties of knitted fabrics

This article discusses ways to develop combined knitwear based on elastic weave. The purpose of the dissertation work is to improve the technology for the production of knitted fabrics with reduced material consumption, which will provide and satisfy the demand of the population with high-quality knitted products that have high performance, hygienic and consumer properties. As a result of the experimental work, the technological capabilities of the modern LIBRA 3.130 flat knitting machine were studied and new types of combined knitwear based on elastic interlock weave were obtained. Regularities of the influence of elements of the structure of knitwear on the parameters and physical and mechanical properties of the fabric of knitwear are established. Comparing the volumetric density of the combined knitwear of different structures, one can be convinced that the presence of rows of satin stitch and a derivative surface in the structure of elastic knitwear not only reduces extensibility and increases dimensional stability, but in some cases reduces the bulk density of knitwear. It has been established that the air permeability coefficients can be reduced to 40% (168.6 - 236.6 cm3/cm2∙sec) for combined knitwear by reducing the length of the thread in the loop. It has been established that a decrease in the surface density of combined knitwear based on elastic and interlock weave can also be achieved by skipping stitches, since this reduces the length of the thread spent on the formation of one loop row. On the basis of a comprehensive comparison, optimal options for new models of knitwear structures with improved physical, mechanical and consumer properties are proposed. Regression equations are derived to determine the dependence of the bulk density of the knitted fabric and the air permeability index on technological factors. The results of the study make it possible to expand the range of knitted products, re-duce the consumption of raw materials per unit of production, as well as improve the quality and consumer proper-ties of the range produced, choose high-quality samples and technologies for their production.

The method of obtaining patterned plush knitwear

The paper presents new ways of pattern formation in the development of plush knitwear on two-contour machines.The purpose of the research work is to improve the technology for the production of knitted fabrics. As a result of the experimental work, the technological capabilities of the modern LIBRA 3.130 flat knitting machine were studied and new types of combined knitwear based on plush weave were obtained. It has been found that air permeability coefficients can be reduced by up to 30% (46.3-66.9 cm3 /cm2 ∙sec) for combined plush knitwear by reducing the length of the thread in the loop. Based on the analysis of the parameters of the produced fabrics of plush knitwear, it was found that a decrease in the surface density of plush knitwear can be achieved in various ways. The most effective are the ways in which the decrease in the surface density of knitwear is achieved by changing the base weave and combining weaves. The use of these methods makes it possible to reduce the surface density of knitwear by 1.5-2 times, and the bulk density by 15-20% compared to full plush. At the same time, knitwear retains its marketable appearance and high quality indicators.

Influence of Cotton Knitted Fabric Waste Addition on Concrete Properties

Manufacturing cotton knitted fabric apparel generates a substantial amount of production (pre-consumer) waste. One of the ways to alleviate the environmental impact of this is to use the cotton knitted fabric production waste (CKFW) in concrete, which had the simultaneous benefit of reducing the use of virgin aggregate. The aim of this research was to examine the influence of CKFW on concrete properties, and to explore the possible application of this novel material in the construction industry for the production of precast building elements based on its characteristics. An additional goal was to enhance certain properties of concrete and determine the shortcomings of CKFW concrete. A total of 10 mixes were made and tested. CKFW was used at rates of 1.7% and 3.5% of the total mix volume. All mixtures had the same amount of cement, with three mixes having the addition of silica fume. Crushed limestone was used as the aggregate with different aggregate size combinations. Two types of polycarboxylic ether-based superplasticizer were used. The properties of the fresh mix were determined by the slump method. The ultrasonic pulse velocity, dynamic modulus of elasticity, flexural strength and compressive strength were tested on 28-day-old concrete specimens. The σ–δ diagram is also presented in this paper. We learned that the flexural strength of specimens with CKFW addition was increased by up to 38% but the compressive strength was reduced by up to 20% compared to the reference concrete mix. The CKFW mixtures had higher ductility and permeability. Additionally, silica fume had a positive effect on the concretes with a higher percentage of textiles. The percentages of textile waste used in this study affected the density of concrete in a range of 0–2%. Based on the obtained results, we offer recommendations for further tests and possible applications.

A feasibility study to analyze the behavior of heat settings on the cleaner production of knitted fabrics

Textile finishing gives textile materials their distinct appearance and aesthetic properties. One of the most critical stages of textile finishing is heat setting. Several factors of textile finishing are depend on heat settings. This study examines the behavior of heat settings and correlates the parameters on single jersey and pique knitted fabrics. In this case, the behavior of single jersey fabric and pique fabric are different in terms of target tumble dry GSM, and the tendency of single jersey cotton & viscose fabric in the grey stage is less width, high GSM, more shrinking characteristics, less bursting strength, and more yellowish than pique fabric. Following the heat setting changes for fabric width and GSM based on light, medium, and dark colors; all heat-dependent finishing parameters, such as fabric weight, pilling, spirality, dimensional stability, bursting strength, and color strength, are systematically analyzed based on industrial applications. The target GSM are set for cotton fabric is 190 and viscose fabric is 210. The result of the GSM are found in the almost in the same range in between 190 and 210. The other properties of fabric after heat settings are pilling 4–5, dimensional stability change (lengthwise 0.86–5.71 and widthwise 0.86–5.43), spirality (−2.5 to +2.1), bursting strength (162.4–450.4 kN/m2), and color strength (increased an average 5%). As a result, analyzing several influential factors based on heat setting provides a clear concept for the cleaner industrial production of knitted fabrics.

THE FEATURES OF PATTERN FORMATION ON FLAT KNITTING MACHINES

The development of the production of knitwear will lead to the further application of new technologies and the expansion of the range of knitwear. In the fields of trade industry, as well as in the service sector, the main requirement is the production of knitwear, which is combined with high manufacturability and wide distribution, which will lead to low cost, with relatively acceptable consumer characteristics and parameters. In this regard, the solution to the above problems in the technological part of the production of knitwear is of particular importance and is necessary. The article explores the features of improving the technology of production of knitted fabrics using knitted elements, the development of practical methods for obtaining knitted knitwear based on scientific generalization, the formation of patterns on flat knitting machines.

STUDY OF PHYSICAL-MECHANICAL INDICATORS OF PATTERN KNITTING FABRICS MADE IN A NEW METHOD

In this article, the physical and mechanical performance of a new structure of knitted fabric production technology has been developed using the capabilities of flat double-needle knitting machines. Three samples of the new structure of knitted fabric were taken, their technological parameters and physical and mechanical properties were studied experimentally, presented in the table and analyzed. Experimental samples of the new structure of knitted fabric were developed graphic notation is given.

Research on dyeing workshop scheduling methods for knitted fabric production based on a multi-objective hybrid genetic algorithm

As the most important core process in the dyeing and finishing workshop of knitting companies, the dyeing process has the characteristics of multi-variety, small-batch, parallel machine processing of multiple types, and high cost in equipment cleaning, which render the dyeing scheduling problem a bottleneck in the production management of a dyeing and finishing workshop. In this paper, the dyeing process scheduling problem in dyeing and finishing workshops is described and abstracted, and an optimized mathematical model of dyeing scheduling is constructed with the goal of minimizing the delay cost and switching cost. Constraints such as multiple types of equipment, equipment capacity, weights of orders and equipment cleaning time are considered. For the sub-problem of equipment scheduling in the dyeing scheduling problem, a heuristic rule that considers equipment utilization and order delay is proposed. For the sub-problem of order sorting of the equipment in the dyeing scheduling problem, a hybrid genetic algorithm with a variable neighbourhood search strategy has been designed to optimize sorting. The algorithm proposed in this paper has been demonstrated via case simulation to be effective in solving the scheduling problem in dyeing and finishing workshops.

Environmentally friendly textile production: continuous pretreatment of knitted cotton fabric with normal temperature plasma and padding

To reduce pollution in cotton knitted fabric production, this study aimed at developing a novel open width and continuous pretreatment process combining plasma, padding, and enzyme washing etc. In this process, plasma destroyed oily and waxy structures, padding provided the same functions of scouring and polishing, and enzyme washing gave deoxidization. Compared with conventional one bath alkali peroxide pretreatment process in pilot experiments, the quality of products from the novel pretreatment process is higher. The superiority was attributed to not generating microfibers on the surfaces of the products, integrity of the fiber microstructure of the products, and effective removal of oils and waxes. Water consumption is only 26.4% of that used in the conventional one-bath pretreatment. Also, pollutant production is reduced; chemical oxygen demand (CODCr), total nitrogen (TN), ammonia nitrogen (NH3–N), and total phosphorus (TP) of the developed process are lower by 73.18%, 87.09%, 60.64% and 60.81% respectively, because high pretreatment efficiency of novel process leads to a lower need for water and auxiliaries.

In situ prepared polyamide 6/DOPO-derivative nanocomposite for melt-spinning of flame retardant textile filaments

A novel flame retardant polyamide 6 (PA6)/bridged 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-derivative (PHED) nanocomposite textile filament yarns were developed. The scalable production approach includes in situ water-catalyzed ring-opening polymerization of ε-caprolactam in the presence of the flame retardant PHED followed by melt-spinning of nanocomposite filament yarns and production of knitted fabrics. The specific chemical structure of the PHED additive enabled its excellent miscibility with molten ε-caprolactam and the uninterrupted polymerization of ε-caprolactam. The produced PA6/PHED nanocomposite was characterized by the preserved molecular structure of the polyamide 6 and uniformly distributed nano-dispersed FR at concentrations of 10 and 15 wt %. The PA6/PHED nanocomposite structure was successfully preserved after the melt-spinning processing. The PA6 nanocomposite filament yarns at the applied 15 wt %. loading of PHED showed (a) increased thermo-oxidative stability compared to neat PA6 up to 500 °C, with a 43% higher residue at 500 °C and (b) self-extinguishment of fiber strand and knitted samples within 1 s in standard vertical flame spread tests (ASTM D6413), followed by the significant reduction of the melt-dripping and the melt-drop flammability. Additionally, 1.2 mm-tick PA6/PHED bar samples achieved a V0 rating in UL94 vertical burning test at the applied 10 wt % concentration of PHED. This innovative and scalable approach could pave the way for the production of new-generation nanocomposite PA6 filament yarns with self-extinguishing properties at the macro-scale, which would be highly beneficial for increasing fire safety, whilst maintaining the use of a DOPO derivative at the minimum level.

Multiple faces of contemporary hand knitting

Knitting and crocheting are traditional textile techniques with great significance both in history and modern times. Similar to other textile techniques, knitting has developed into a diversified industrial sector, comprising the production of knitted fabrics, knitwear, hosiery and fashion accessories. At the same time, contemporary knitting and crocheting became hobbies as well as arts-and-crafts activities, extending to various areas of work and leisure. Historical and traditional ethnic knitting and crocheting patterns keep inspiring designers’ collections and also other industrial products. Not so long ago, knitting was seen as an ordinary and unchanging indoor activity and, in its domestic history, it was the preserve of older women making products of dainty work and taste. Today, knitting deals with urban population of all classes. The popularity of leisure hand knitting is increasing; moreover, hand knitting is becoming more and more widespread among young people. With the emergence of artistic and handicraft markets, hand-knitting and crocheting developed into a profitable market activity. Positive effects of hand knitting have become increasingly important - from generating creativity and innovativeness, through knitting and socializing in groups, to medical and therapeutic effects as well as social and global connections. Yarn bombing, yarn storming or graffiti knitting has been used to describe urban social practices of knitted objects placed, or tagged, in public spaces. Knitting became means of communication, artistic and social expression and statement. The advantage of hand knitting is its mobility. One can knit almost everywhere, and for hand knitting, only a ball of yarn and knitting needles are required. Handknitted products have nice touch, they are custom-made and therefore personalized.

Thermal and mass transport properties of polyester–cotton plated fabrics in relation to back layer fibre profiles and face layer yarn types

Clothing plays an important role in maintaining thermal equilibrium between a human body and the ambient environment by serving as a medium for heat, moisture vapour and liquid moisture transfer. The ability of fabric to maintain this equilibrium is related to thermo-physiological comfort. Plating is an innovative knitted fabric production technique to obtain bi-layered fabrics. An attempt has been made to engineer plated knit structures with such a combination of fibre cross section in the back (inner/next to skin) and the yarn type in the face (outer) layer, so that a rapid liquid transfer from back layer by wicking and quick liquid absorption and evaporation by the face layer can be achieved. Plated fabrics using the combination of triangular polyester fibre in the back and carded cotton yarn in the face layer showed the higher thermal resistance, higher absorbent capacity and would be warmer to the initial touch. However, the combination of combed cotton yarn with triangular polyester fibre resulted in fabrics with the higher air permeability, moisture vapour transmission rate and transplanar wicking.

Automatic Detection and Classification of Defects in Knitted Fabrics

High technological equipments are currently used in the knitted fabric production process. However, repetitive tasks are still being performed by human operators in steps of this process, thus reducing productivity and product quality. The inspection of fabric rolls which occurs after the knitting process corresponds to an example. As this activity is still performed by a human inspector, mistakes are common because of human inability to maintain attention during long working hours. In this work, the development of an automated inspection system for knitted fabric in raw and flat state is presented. In order to automatically inspect the fabric, new methods of detection and classification using computer vision are proposed. The system was evaluated in a series of tests using a large image database created from rolls supplied by the industry. Excellent rates on defect detection and classification were achieved, demonstrating the effectiveness of the proposed approach.

Influence of yarn tension variations before the positive feed on the characteristics of knitted fabrics

In recent years, there has been a substantial increase in the production of knitted fabrics with textured synthetic yarns in circular knitting machines. However, there are few studies for this type of yarn on the effects of variations in tension on circular knitting machines. In this work, we examine the variation in yarn tension before the positive feed and analyze its influence on the properties and quality of knitted fabrics produced with spun yarn and textured synthetic yarn. Knitted fabrics were produced with spun cotton yarn and textured microfiber nylon yarn (polyamide), which were analyzed with respect to loop length. The results demonstrate the importance of controlling the yarn feed tension when working with textured yarns, even with the use of a positive feed, in contrast to what occurs when spun yarn is used.

Special features of treatment of cotton-polypropylene yarn in knitted fabric production

The process of cotton-polypropylene yarn treatment in knitted-fabric production is investigated. Based on analysis of the properties of cotton-polypropylene yarn vis-a-vis the properties of cotton yarn, the major directions of enhancing accuracy and stability of knitting in the process of treatment of yarn with inclusion of polypropylene fibres are established.