Polyester staple fibre is the most widely used chemical fibre and has the highest volume of consumption compared to other fibres such as acrylic, nylon, and rayon. Fibre is produced at lower costs due to its petrochemical sources. Its significant features, including strength, ease of dyeing, wrinkle resistance, and lightweight, make it a great option across various industries. Polyester staple fibre can be customized to meet specific industry needs, making it a popular choice.

What is Polyester Staple Fibre?

Chemically, polyester is a monomer containing the ester functional group. Polyester staple fibre (PSF) is produced by continuous polymerization involving purified terephthalic acid (PTA) and monoethylene glycol (MEG), with the use of catalysts to control the reaction process. Some notable properties of polyester fibre include:

• Melting point: 260-270°C
• High resistance to rot
• Excellent resistance to acids and weathering
• Resistant to natural chemicals
• High strength
• Crease and shrink-free fibre
• Quick-drying
• Retains folds and pleats set using heat
• Dye-able textile, making it a popular choice

Applications of Polyester Staple Fibre

Considering the properties of the fibre, manufacturers prefer to use it in their products. Here are some significant uses of fibre:

• Apparel and garment industry: Polyester staple fibre is widely used in all types of clothing such as sportswear, dresses, lining, shirts, suits, neckties, underwear, and more.
• Furnishing: Cushion and pillow covers, curtains, bed sheets, rugs.
• Fabric: Nets, floor coverings, ropes, and more.
• Automotive: Seat filling and covers, floor mats, speaker felts.
• Filling material in mattresses, pillows, polyfill wadding, and cushions.

Manufacturers of polyester staple fibre in India employ state-of-the-art technology and equipment to produce high-quality fibres. The process involves specific steps, and standardization allows companies to maintain quality consistently. The following are the steps involved:

Polymerization: PTA, a white powder, is fed into a hot MEG container by a screw conveyor to dissolve it. Drivers and TiO2 are added, and esterification and polymerization occur at high temperatures ranging from 290-300 degrees Celsius. The resulting material at this stage is a thick viscous liquid called polymer melt.

Melt spinning: The polymer melt obtained in the polymerization section passes through different purification media to remove impurities. A pump called a melt pump then releases small amounts of polymer per spin to spinnerets, which have very fine holes through which the polymer melt is released and immediately solidified using dry cooling air. The process of cooling is called quenching. The released and cooled filaments are then passed onto a spinning wheel, creating ribbons called tows, which are collected in large containers in coiled form.

Drawing of polymer: The next section is the draw section, which collects tows from multiple containers and passes them through a hot water trough. Here, the polymer undergoes a glass transition and can be quickly drawn. The required density is achieved by drawing the polymer. The filaments are strengthened by passing them through several high-tension heated cylinders called annealer rollers. The temperature of the annealer rollers is maintained at 180-220 degrees Celsius using steam.

Crimping: In this step, the tow obtained from the previous phase is introduced into a heated chamber at 100 degrees Celsius. This allows for smooth folding and crimping of the fibre in the glutton box. During this crimping process, the polymer gains stability. Once this process is complete, the crimped fibres undergo textile spin finishing. Finally, the tow is dried completely on a frame with hot air.

Cutting: The tow is moved to a cutter, where it is separated into bales in the final stage of production. The cutter is equipped with a reel that has slots at equal intervals, corresponding to the desired size. Each slot contains sharp blades made of tungsten carbide or steel, which begin cutting the tow as it is rolled onto the reel. The resulting fibre is then baled according to the required weight settings, allowing manufacturers to obtain packages of the same weight that are ready for transport to storage facilities.

There are two broad types of polyester fibre: virgin and recycled. Virgin polyester is produced by polymerizing MEG and PTA, while recycled PET polyester is derived from plastic waste and re-spun into new, reusable fibres. In recent years, recycled polyester has gained popularity as governments promote plastic waste recycling through policies like Extended Producer Responsibility (EPR), which requires plastic manufacturers to reclaim and reuse plastic that they introduce into the environment. Recycled PET polyester is made using plastic bottles, waste containers, and other sources of plastic waste.

Polyethylene terephthalate is recyclable, and manufacturers are taking advantage of this property by obtaining regenerated polyester staple fibre, which finds wide application across industries. Promoting regenerated polyester is a key benefit of reducing environmental damage caused by plastic waste, which can contaminate water sources, soil, and air, and harm wildlife. Customers are becoming aware of the advantages of recycled polyester fibre and are now demanding products made from the material. Recycled PSF has all the properties of virgin polyester fibre, but it consumes fewer resources during production. This sustainable practice must continue in the coming years to help divert waste from landfills and transform it into useful products.

Recycled polyester staple fibre has brought much-needed change to help with better plastic waste management. Polyester, whether virgin or recycled, has applications in almost every industry. Manufacturers of these fibres ensure that they produce high-quality fibre to meet customers’ needs. The clothing industry is the largest consumer of polyester, and with the introduction of recycled PSF, brands are making high-quality garments and offering them at reasonable prices to customers. This new trend will contribute to a cleaner environment and help maintain the ecological balance.