RESEARCH OF THE PROPERTIES OF TECHNOLOGICAL PARAMETERS AND PHYSICAL-MECHANICAL PROPERTIES OF KNITTED WEAVES FROM COTTON AND BAMBOO

ABSTRACT

This study investigates the technological parameters and physico-mechanical properties of newly structured double-layer knitted fabrics produced from cotton and bamboo yarns. The main purpose of the research is to create an innovative knitted structure suitable for lightweight upper knitwear that combines comfort, breathability, and balanced thermal regulation. Four types of double-layer fabrics were developed, differing in raw material composition and yarn linear density, while maintaining identical structural design parameters.

АННОТАЦИЯ

В данной статье исследуются технологические параметры и физико-механические свойства новых структур двухслойных трикотажных полотен, полученных из хлопчатобумажных и бамбуковых нитей. Основной целью исследования является в создании новой структуры трикотажа, совмещающей комфорт, воздухопроницаемость и сбалансированную терморегуляцию, подходящей для легкого верхнего трикотажа. Разработаны четыре вида двухслойных трикотажных полотен полотен, различающихся по составу сырья и линейной плотности пряжи, при сохранении одинаковых конструктивных параметров.

Keywords: knitted fabrics, physical, mechanical, double-layer, cotton, bamboo, air permeability.

Ключевые слова: трикотажное полотно, физический, механический, двухслойных, хлопок, бамбук, воздухопроницаемость.

Introduction

Knitted fabrics have long held a significant place in the textile industry due to their unique looped structure, which imparts exceptional elasticity, comfort, and versatility compared to woven fabrics. The history of knitting dates back several centuries, yet in modern times, the sector has undergone rapid technological transformation, driven by advancements in machinery, fiber engineering, and consumer demand for functional and sustainable textiles. From fashion garments to technical applications, knitted fabrics continue to evolve, meeting both aesthetic and performance requirements.

In order to study the influence of the type of raw material on the technological dimensions and physical and mechanical properties of double-layer knitted fabric and to expand the range of knitted fabrics, the technological indicators and physical and mechanical properties of double-layer knitted fabric obtained using different raw materials were analyzed on a 14-class PROTTI-242 flat-needle knitting machine [1].

In this work, in order to determine the physical and mechanical properties of combined knitted fabrics, three variants of knitted fabrics were obtained, their properties were determined, and the best sample was recommended for production [2]. The influence of knitting structure on the technological performance of double-layer cotton-silk knitted fabrics, 5 variants of double-layer cotton-silk knitted fabrics were developed on a flat knitting machine, using silk and cotton yarns as raw materials [3].

In this comparative study, bamboo viscose fibre was studied as an eco-friendly alternative to cotton fibre in polyester-cellulosic blends. Conventional cotton is not considered eco-friendly because it requires large quantities of water and pesticides during its production. The ecofriendly nature of bamboo viscose is subject to the employed production method. Polyester-bamboo and polyester-cotton blended yarns were prepared by employing open-end spinning technique and the said yarns were single jersey weft knitted. The yarn tensile strength, fabric bursting strength, bending length, thermal resistance and moisture management properties were studied [4].

This research explores conventional wet-finishing techniques for fabrics incorporating recycled cotton fibers. Knitted fabrics were manufactured from open-end and compact yarns, with up to 80% of the cotton content derived from mechanically recycled pre-consumer textile waste. The study assessed how different finishing processes influence the fabrics’ physical properties, considering variables such as recycled fiber proportion, yarn type, and yarn count [5].

The physical behavior of weft-knitted fabrics can be tailored by altering their structural design and the types of fibers used in their production. This study explores how different fiber compositions and fabric structures affect selected physical parameters such as bursting strength, wicking performance, pilling tendency, and abrasion resistance. For experimental comparison, cotton (natural fiber), viscose (regenerated fiber), and polyester (synthetic fiber) were utilized. To minimize the influence of external manufacturing variables, parameters such as the number of feeders, machine diameter, needle gauge, and stitch length were kept constant throughout the knitting process. [6].

Materials

In order to expand the range of knitted fabrics and fully utilize the technological capabilities of the flat-needle knitting machine, 4 variants of double-layer knitted fabrics were knitted. Cotton and bamboo yarns with a linear density of 20 tex were used as raw materials.

The technological parameters and physico-mechanical properties of the double-layer knitted fabric were experimentally determined in the "Uz-Kor Textile Technopark", and the measurement results are presented in Table 1 and table 2.

Experimental work

Table 1.

Technological parameters of cotton and bamboo double-layer knitted fabrics

Scientific and practical research demonstrates that the structure, physical and mechanical properties, and appearance of knitted fabrics are among the primary factors determining their quality level. The criteria expressing the physical and mechanical characteristics of knitted fabrics include indicators such as air permeability, tensile strength and elongation at break, friction resistance, as well as shrinkage that occurs during heat and moisture treatment processes (Table 2.) [7].

Table 2.

Physical and mechanical properties of cotton and bamboo double-layer knitted fabrics

Results and methods

Based on a comparison of the bulk density of two-layer knitted fabrics, the following conclusions can be drawn: In the first variant of the two-layer knitted fabric, with a surface density of 325.9 g/m² and a thickness of 1.4 mm, the bulk density was 232.7 mg/cm³. In the second variant, with a surface density of 349.1 g/m² and a thickness of 1.3 mm, the bulk density was 268.5 mg/cm³. The third variant, having a surface density of 357.6 g/m² and a thickness of 1.4 mm, yielded a bulk density of 255.4 mg/cm³. Finally, the fourth variant, with a surface density of 480.8 g/m² and a thickness of 1.7 mm, resulted in a bulk density of 282.8 mg/cm³ (table 1).

Air permeability is regarded as a key property of textile materials and plays a significant role in determining fabric comfort. It can be defined as the capacity of a fabric to allow air to pass through it under specific controlled conditions. This property is strongly influenced by the fabric’s structural parameters, with porosity being one of the most critical factors.

The change in the raw material in the fabric led to a change in the physical and mechanical properties of the two-layer knitted fabric. The air permeability of the experimental samples of the double-layer knitted fabric varies from 148.3 to 197.6 cm3/cm2*sec (Fig 1.).

Figure 1. Air permeability

Tensile strength is a mechanical parameter that expresses how much force a fabric can withstand under the influence of elastic tension.

The tensile strength along the length of a double-layer knitted fabric varies from 205 to 279 N. The tensile strength along the width varies from 378 to 482 N (Fig 2.).

Figure 2. Tensile strength

The elongation at break along the length of the knitted fabric varies from 121.6% to 138.2%. The second variant, made from 100% bamboo, had the lowest elongation at break, which was 121.6%.

The elongation at break along the width of the knitted fabric in variant I was 100.5%, variant II was 90.8%, variant III was 106.1%, variant IV was 101.3%, ranging from 90.8% to 106.1%. The second variant, made from 100% bamboo, had the lowest elongation at break, which was 90.8% (Fig 3).

Figure 3. Elongation

Shrinkage of knitted fabrics is an important physical and mechanical indicator, characterized by a certain decrease in the initial geometric dimensions of the fabric during washing, drying, or heat-air treatment.

The phenomenon of shrinkage occurs mainly due to the number of twists of the yarn, the structure of the fabric, the composition of the yarn (natural, chemical or mixed fibers), as well as the rearrangement of fibers and the compaction of the rings as a result of the influence of moisture and heat.

By length shrinkage of cotton-bamboo blended two-layer knitted fabrics showed that sample II, made from 100% bamboo, exhibited less shrinkage at 8% compared to the other two samples.

The width shrinkage of sample III, made from a cotton and bamboo blend, showed lower shrinkage at 5% compared to the other two samples.

Figure 4. Shrinkage

Conclusion. In this study, newly structured double-layer knitted fabrics were developed using cotton and bamboo yarns, and their technological and physico-mechanical characteristics were thoroughly investigated. The main objective was to design a knitted material suitable for lightweight upper knitwear that ensures comfort, breathability, and thermal balance. Through careful selection of yarns and machine settings, a stable double-layer structure was achieved using a Long Xing LXA–252 double-needle flat knitting machine. The experimental results confirmed that the combination of cotton and bamboo fibers provides a unique synergy between mechanical strength and functional comfort. The outer cotton layer contributes to the fabric’s durability, dimensional stability, and resistance to deformation, while the inner bamboo layer significantly enhances hygroscopicity, air permeability, and overall softness. These properties make the fabric highly suitable for warm-season knitwear applications, where moisture regulation and comfort are essential. The obtained data on surface density, thickness, elongation, and air permeability revealed consistent relationships with the yarn type and linear density. It was observed that variations in the yarn fineness and loop length influenced the geometrical and structural parameters of the fabric, thus affecting its performance characteristics. Overall, this research emphasizes that the use of bamboo yarn in the inner layer of double-knit fabrics improves functional and hygienic properties without compromising the mechanical performance provided by cotton yarns. Hence, the developed double-layer knitted structure can be effectively applied to produce eco-friendly, lightweight, and comfortable knitwear. The findings also serve as a foundation for optimizing knitting technology parameters in future studies aimed at sustainable textile manufacturing and functional fabric design.

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