Sustainable and cleaner production of elastic core-spun yarns for stretch denim with maximal utilization of recycled cotton extracted from pre-consumer fabric waste.

Stretch denim is an exclusive and stylish textile made with elastic core-spun yarns. It has gained substantial traction for offering essential elasticity and resilience to the garments while retaining a snug fit and comfort when worn. Denim is produced from coarser cotton yarns necessitating a significant quantity of cotton fiber. Owing to the escalating costs of cotton and the harmful environmental impacts associated with its cultivation, it is imperative to explore alternative fibers for denim. Herein, for the very first time, an expedient technique of manufacturing elastic core-spun denim yarns utilizing recycled cotton is investigated. Recycled cotton fibers, in the range of 10-60 %, extracted from pre-consumer fabric waste were blended with virgin cotton and spun into 16 Ne (36.9 Tex) elastic core-spun yarns. To address the challenges posed by the lower spinnability of recycled fibers, attributed to lower fiber length, uniformity index, and higher short fiber content, a compact spinning system featuring a novel pin spacer was used. This combination effectively improved the fiber control within the drafting zone, enabling maximum incorporation of recycled cotton, up to 60 %, into the yarn. The produced yarns exhibited significantly lower unevenness, imperfections, and hairiness along with higher strength and elongation that fell within the top 5 %-50 % ranking of Uster Statistics 2023. The elastic core yarn, even containing 60 % recycled fiber, demonstrated its suitability for use as a weft yarn in a commercial high-speed air-jet loom operating at 950 rpm (equivalent to weft speed 94 km/h or 1577 m/min). The production of denim yarn incorporating 60 % recycled cotton represents an innovative concept to advance sustainable development goal (SDG) 12. This initiative aims to reduce the proportional demand for cotton cultivation and its subsequent processing, thereby making significant contributions to environmental preservation on various fronts. Moreover, this approach offers potential cost savings in the production of denim clothing.

Low-bagging (growth) stretch denim yarn production by spinning optimization of cotton-wrapped dual-core elastane and T400 multifilament.

Cotton-wrapped elastane core yarns have been widely used in producing stretch denim fabrics due to their comfortable stretching and recovery, but they suffer from undesirable fabric growth under prolonged or repeated stress. To reduce that problem, an additional semi-elastic multifilament has been incorporated with the elastane core, called dual-core yarn. Herein, it was intended to produce well-engineered dual-core yarns possessing high elasticity with low bagging. Twenty types of cotton-wrapped elastane/T400 multifilament dual-core yarns with different combinations of elastane and T400 tension draft were produced on industrial scale in a spinning mill. Structural parameters, tensile properties and elastic recovery behavior under cyclic loading of the yarns were thoroughly studied. For an optimum combination of elastane/T400 draft, the dual-core yarn attained excellent tenacity and elongation with significantly low evenness, imperfections and hairiness values. More importantly, the results of the cyclic loading study explicitly revealed a remarkable reduction in plastic deformation and stress decay indicating low growth and high resilience of yarn after deformation. The dual-core yarn containing high strength, high elongation and low growth obtained here can have durable stretch jeans with high body movement comfort and long-lasting shape retention.

Potentiality of sustainable corn starch-based biocomposites reinforced with cotton filter waste of spinning mill.

The textile sector is among the leading industries globally in terms of releasing pollutants and producing waste. Despite being reusable, many wastes are squandered by disposing to landfills or incineration, creating a serious environmental threat. Because the cost of raw materials makes up a significant portion of the total product cost, manufacturers can obtain significant profits by exploiting waste generated during the manufacturing process. Herein, an attempt has been taken to utilize cotton filter waste (CFW) (collected from the humidification plant of the spinning mill) as reinforcement in manufacturing biocomposites with the corn starch (CS) matrix. Starch was considered to be the most suitable matrix as it is sustainable, abundant, natural, biodegradable, and, more importantly, capable of showing thermoplastic behavior under high temperatures. Sheets of corn starch composites reinforced with different wt% of cleaned cotton filter waste were fabricated using hand layup and compression molding techniques. The 50 wt% cotton waste was found to be optimum loading in terms of tensile strength, Young's modulus, bending strength, toughness, impact strength, and thermal Conductivity of the biocomposites. SEM micrographs revealed good interfacial adhesion (bonding) in matrix and filler interfaces, with the most substantial bonding for composites containing 50% fibers that concomitantly enhanced the mechanical properties of composites. The obtained biocomposites are deemed to be a sustainable alternative to non-degradable synthetic polymeric materials like Styrofoam for packaging and insulation applications.

Recycled fibers from pre- and post-consumer textile waste as blend constituents in manufacturing 100% cotton yarns in ring spinning: A sustainable and eco-friendly approach.

The usage of recycled fibers has achieved enormous importance in the textile sector due to growing environmental awareness, legal requirements for more sustainability and the cost of raw materials. Recycled cotton fibers derived from mechanical shredding of textile waste possess lower quality values and therefore they are spun through blending with other fibers in rotor spinning system for the production of coarse yarns (10-20 Ne) to make denim, towel and home furnishing. Owing to low fiber migration, rotor yarns require high twist during spinning which makes them stiffer and poorly moisture absorbent. Rotor yarns also feel harsh in skin contact due to the presence of wrapper fibers in the yarn surface. Intending to make knit top garments like T-shirts and polo shirts, apparel manufacturers nowadays demand recycled fiber-contained soft and high moisture absorbent yarn that can be produced in ring spinning system. In the current endeavor, cotton fibers reclaimed from pre- and post-consumer textile waste were blended with virgin cotton and soft-twisted 30 Ne yarns were manufactured in ring spinning frame on an industrial scale in a spinning mill. A thorough analysis of the structure and properties of the yarns revealed that up to 25% recycled cotton fibers can be used as an alternative to virgin cotton to manufacture medium count (30 Ne) yarn in ring spinning suitable to produce knit top garments.

Unusable cotton spinning mill waste: A viable source of raw material in paper making.

Since the reserves of natural renewable resources are being inexorably diminished, the utilization of the recoverable waste in new area is gaining global attention day by day. Besides, as the cost of raw materials constitutes the majority of a production cost, the usage of undesirable but inevitable processing waste in the manufacturing process provides a considerable advantage to the manufacturers. Herein, it has been attempted to exploit unusable cotton spinning mill waste (filter waste derived from humidification plant) to convert it into paper. Handsheets of 70 g/m2 and 80 g/m2 were successfully produced from 100% cotton waste, 100% bleached cotton waste, and blends of bleached cotton waste with bleached hardwood kraft pulp (HWKP) (HWKP is typically used to produce commercial-grade papers). Morphologies and mechanical properties of handsheets were thoroughly investigated by whiteness index, brightness%, breaking length, tear index, bursting index, FTIR spectroscopy, optical microscope, and scanning electron microscope. Based on detailed observations, it is summarized that the produced handsheets, depending on the chemical treatment and blend ratio with HWKP, possess variations in appearances and properties that will have a wide range of potential applications from newsprint, tissue paper to commercial-grade writing and printing papers.

Enhancing the quality of elastane-cotton core yarn by compact spinning.

The quest for highly stretchable fabrics with good aesthetic and functional properties has led researchers to constantly involve in mingling of natural and synthetic fibers. Elastane-cotton core yarns have an increasing demand due to their wear comfort and stretch-to-fit properties; therefore, efforts are still going on to optimize the yarn properties to meet the requirements for diversified applications. With a view to enhancing the appearance and performance characteristics of elastane-cotton core yarns, the present work was undertaken to manufacture them by exploiting the most modern and versatile pneumatic compacting mechanism, namely Suessen's EliTe compact spinning system. Elastane-cotton core yarns of different counts (20 tex, 30 tex and 60 tex) were produced with compact and conventional ring spinning system. The difference in morphology and physical properties of two types of yarns were compared after a thorough investigation by scanning electron microscope, evenness tester and strength tester. The results exhibited a noticeable decrease in hairiness, hairiness variation and neps values, especially seed-coat neps, for elastane-cotton compact core yarn. Unevenness & imperfection of compact core yarns were also found to be decreased that were reflected to the proportional enhancements in tenacity & elongation values. The overall observation reveals the potential of pneumatic compacting mechanism in obtaining elastane-cotton core yarn with superior structure and improved mechanical properties.

Investigation of the performance of okra fiber in woven fabric.

There has been an increase interest in natural plant fibers over the last decades with the intension to identify the ecologically acceptable alternatives to reduce the dependency on synthetic fibers. Naturally extracted okra fiber (Abelmoschus esculentus) was used in this study. Since okra is a stiff fiber, yarns with 100% Okra fiber was not possible to produce and tried to blend with polyester. The maximal ratio of okra was 20% with polyester to spin yarns in traditional ring spinning system. This study explores, for the first time, the possibility of manufacturing woven fabric with polyester-okra (80/20) yarns at weft direction with 100% cotton yarn at warp direction in order to prominent blend effect at weft direction. The properties of produced fabrics were compared with the same produced widely-used polyester-linen (PL) (80/20) counterpart. The both PO and PL woven fabrics were characterized in terms of fabric weight, thickness, abrasion, pilling, fuzzing, air permeability, tensile strength and tear strength. In addition, the morphological aspects of the fiber alignment in the woven fabric structure were observed using optical microscopic images. The performance of PO woven fabric was in acceptable ranges and can be considered as a sustainable blended woven fabric to meet the actual demand in the textile weaving industries.

Outstanding reinforcing effect of highly oriented chitin whiskers in PVA nanocomposites.

To utilize the extreme reinforcing performance of chitin whiskers (ChWs), the current work was undertaken to fabricate nanocomposites embedded with highly uniaxial oriented ChWs into the matrix polymer. Fibers of poly(vinyl alcohol) (PVA)/ChWs were prepared by gel spinning and the fibers were subjected to a hot drawing to their maximal draw ratio. WAXD analysis revealed the very high orientation of ChWs in the PVA matrix. DSC measurements showed that, upon ChWs loadings, crystallinity of PVA increased and non-isothermal cooling crystallization peak of PVA shifted towards lower temperature, indicating the interaction of PVA with ChWs. Measurement of infrared dichroism suggested that the orientation of overall PVA chains increased with the increase in ChWs loading due to the possible dragging of PVA chains attached with ChWs during drawing, which resulted higher PVA crystallinity in the composites. The stress transfer in PVA/ChWs interface quantified by X-ray diffraction evidenced the strong adherence between the two. The stress transfer between PVA and ChWs interface, and higher PVA crystallinity induced by ChWs were reflected to the outstanding enhancement in mechanical- and anti-creep properties of nanocomposite fibers.