ANALYSIS OF THE PHYSICAL AND MECHANICAL PROPERTIES OF INLAY INTERLOCK KNITTED FABRIC

ABSTRACT

Currently, effective efforts are underway in our Republic to develop the textile and knitting industries, expand the types and assortment of products being produced, and facilitate the export of finished products. In the ongoing scientific research, knitted fabric based on interlock using cotton yarn has been developed, and its physical and mechanical properties have been analyzed. The production of new structured fabrics based on interlock has allowed for the diversification of yarn types used, the expansion of product assortments based on the produced fabrics and the improvement of their physical and mechanical properties. The interlock fabric with a worp was knitting on a flat double ned knitting machine of type LXA-252 produced by the Chinese company "LONG XING." The analysis of the physical and mechanical properties of knitted fabrics showed that the inclusion of worp yarns between the fabric loops resulted in enhanced physical and mechanical properties of the interlock knitted fabrics. By implementing interlock knitted fabrics into practice, the competitiveness of the produced products has been increased, and the manufacturing of products that meet global standards has enabled knitted products to enter the world market.

АННОТАЦИЯ

В нашей республике на сегодняшний день выполняется большая работа по развитию текстильной, швейно-трикотажной отраслей легкой промышленности, по расширению видов и ассортимента выпускаемой готовой продукции, а также оказания всесторонней поддержки инвестиционной и экспортной деятельности предприятий отрасли. В данной научно-исследовательской работе исследованы и проанализированы физико-механические свойства интерлочного трикотажного полотна из хлопчатобумажной пряжи, при эффективном использовании сырья. Производство новых видов трикотажных структур с использованием хлопчатобумажной пряжи расширяет область использования данного вида сырья, увеличивает ассортимент выпускаемых трикотажных полотен и позволяет повысить их качественные показатели. Интерлочные уточные трикотажные переплетения выработаны на двухфонтурной плосковязальной машине производства китайской фирмы «LONGXING» типа LXA-252. Результаты анализа физико-механических свойств, трикотажных переплетений показывает, что добавление дополнительных элементов петли, входящие в состав трикотажа, положительно влияет на прочностные и физико-механические свойства, а также на её технологические параметры. Внедрение полученных результатов на практике способствует повышению конкурентоспособности выпускаемой продукции, пополнит внутренний рынок высококачественными трикотажными продукциями, позволит получить трикотажные изделия отечественного производства на международном рынке.

Keywords. Flat, double bed, knitting machine, knitting, interlock, worp, needle, loop, fabric, strength.

Ключевые слова. Плосковязалъная двухфонтурная машина, трикотаж, интерлок, уток, игла, петля, полотно, прочность.

Introduction. Currently, effective efforts are being made in our Republic to develop the textile and knitting industries, expand the types and assortment of products being produced, and provide comprehensive support for the investment and export activities of enterprises. The high level of competition for knitted products in the global market necessitates the implementation of advanced technologies that allow for rapid changes in the quality and quantity of fabric types.

The need to obtain high-quality and competitive products, as well as the importance of further improving the quality of knitted goods, is significant. Scientific research is being directed toward developing new scientific and technical solutions for resource-saving technologies and technical tools to create complex knitted fabric structures. Expanding the assortment of knitted fabrics, utilizing the technological capabilities of knitting machines, saving raw material consumption, and improving the quality indicators of knitted fabrics are currently among the pressing issues facing textile industry scientists. Interlock-based knitted fabrics have been produced using local raw materials efficiently, featuring low raw material consumption, as well as high air permeability, hygroscopicity, wash ability, and excellent shape retention properties [1].

As a result, a method for producing interlock-based knitted fabrics with backing has been developed, leading to an increase in the variety of these fabrics.

Theoretical Research: Interlock-based knitted fabrics were produced on a flat double needle LXA-252 knitting machine manufactured by the Chinese company "LONG XING." For the samples of interlock-based knitted fabrics, cotton yarn with a linear density of 20 tex was used as the raw material. The relationship between the report of interlock-based knitted fabrics and the variation in the amount of backing yarn in the fabric, as well as its impact on physical and mechanical properties was studied [2-3].

Experimental Research: Knitted fabrics must possess an attractive appearance, high shape retention, strong physical and mechanical properties, low raw material consumption, and overall quality. In the scientific research, six variants of interlock-based knitted fabrics were produced on the LXA-252 12-class flat double needle machine. The physical and mechanical properties of the obtained fabrics were tested at the “Centex UZ” testing laboratory at TITLI, equipped with modern instruments. The results are presented in Table 1. The physical and mechanical properties of the interlock-based knitted fabric samples, produced from 100% cotton yarn, were compared to those of the base fabric [4]. One of the key requirements for knitted products is air permeability, which refers to the ability of materials to allow air to pass through them.

Using cotton yarn, the study of air permeability properties of interlock-based knitted fabrics with backing is of great importance.

The air permeability values ​​of the knitted fabric samples obtained on the basis of the manufactured interlock were determined in  unit at 20⁰C 1 atm pressure using the air permeability instrument "AP-360 SM". The air permeability of knitted fabric with a new structure interlock changed from 24.51 to 47.05 . The air permeability index of the IV-variant tissue was the smallest 24.51 , while the air permeability of the I-variant base tissue showed the highest value of 47.05  (Figure 1). As a result, it can be seen that whether the air permeability of the fabrics is low or high is related to the increase in the amount of backing yarn, which leads to the blocking of air passages between the loops.

Analysis of Results: In the conducted scientific research, 6 variants of interlock-based knitted fabrics with backing were analyzed, and their physical and mechanical properties were compared based on air permeability, abrasion resistance, tensile strength, elongation at break, recovery from deformation, and washability. The results of the scientific study indicate that the physical and mechanical properties of the interlock-based fabrics have shown favorable outcomes depending on their application in the field of knitted products (Table 1) [5].

Table 1.

Physical and Mechanical Properties of Interlock-Based Knitted Fabrics with Backing

The air permeability index of the interlock-based knitted fabric samples with backing meets international standards for knitted products. The physical and mechanical indicators for knitted fabrics, including strength, stiffness, elongation at break, abrasion resistance, and shape retention, were acknowledged. The impact of changes in the fabric report and raw material consumption on the tensile strength and elongation at break of interlock-based knitted samples was investigated.

Figure 1. Histogram of air permeability of interlock knitted fabrics

The tensile strength and elongation at break of the presented interlock-based knitted fabric samples were measured using the "AG-1" dynamometer device.

The tensile strength values for the interlock-based knitted samples varied from 433.1 N to 533.03 N lengthwise, and from 830.2 N to 1174.3 N widthwise (Figure 2). Among these, the tensile strength of the V variant was the lowest at 433.1 N, while the highest value was observed in the IV variant at 533.03 N. For the widthwise tensile strength, the smallest value was recorded for the II variant at 830.2 N, while the largest value was found in the IV variant at 1174.3 N.

Figure 2. Histogram of the change in tensile strength of interlock-based knitted fabric samples along the length and width

The horizontal placement of backing yarns between the fabric loops increased its strength properties. As the amount of backing yarns increased, the tensile strength of the knitted fabric also improved. The tensile strength values of the interlock-based knitted fabric samples meet standard requirements. Shape retention properties are crucial for knitted products, and these properties include the elongation at break of the fabric. The increase in fabric length under tensile strength, meaning its elongation, reflects the elongation at break.

The elongation at break values in the samples varied from 121.5% to 184.8% lengthwise and from 62.7% to 97.1% widthwise (Figure 3). The elongation at break indicators of the investigated interlock-based knitted fabrics corresponded well to the shape retention properties required for knitted products.

Figure 3. Elongation at break histogram of lengthwise and widthwise knitted fabric samples obtained on the basis of interlock. Reverse deformation ε_o, (%)

Figure 4. Return deformation histogram of interlock knitted fabric samples

In the scientific research, the effect of varying the linear density of backing yarns in interlock-based knitted fabrics on their recoverable and unrecoverable deformation properties was investigated. The results showed that the recoverable deformation varied from 66.66% to 78.75% lengthwise. Widthwise, the recoverable deformation changed from 88% to 100%. Considering that the samples were obtained under the same conditions, the changes in physical and mechanical properties were related to the fabric structure. The alteration in the shape and structure of the fabrics influenced their deformation properties (Figure 4).

The abrasion resistance properties of interlock-based knitted fabrics with backing were determined (Figure 5). The instrument used to measure the abrasion resistance of knitted fabrics operates based on the number of revolutions. In the tests conducted to assess the abrasion resistance of the knitted fabric samples, the abrasion resistance of the proposed interlock-based knitted fabric varied between 19,500 and 32,000 revolutions. The lowest abrasion resistance was recorded for the I variant, while the IV variant sample exhibited a higher resistance. The difference in the variant samples compared to the base fabric was 39% (Figure 5). One of the reasons for the increase in abrasion resistance is attributed to the increasing linear density of the backing yarn in the fabric, as well as the corresponding increase in the amount of backing yarn, which is related to the fabric structure [6-7].

Figure 5. Histogram of abrasion resistance indicators of knitted fabric samples obtained on the basis of interlock

Conclusion. The analysis of the physical and mechanical properties of interlock-based knitted fabrics with backing, produced on the flat double needle LXA-252 knitting machine by the Chinese company "LONG XING," revealed that using cotton yarn as the base and backing yarns, along with variations in their linear densities and quantities, resulted in improvements in tensile strength, elongation at break, recoverable and unrecoverable deformation, and abrasion resistance compared to the base fabric. The interlock-based knitted fabrics can be utilized to produce a variety of lightweight knitted products for children, women, and men.

References:

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