New polyester replaces PU

In recent years, demand for greater comfort in sportswear, outdoor apparel and everyday clothing has continued to rise. To achieve the required levels of stretch, polyurethane-based elastic fibres are widely combined with polyester. However, the differing material properties of these two fibres, particularly their heat-setting characteristics, present ongoing challenges in processing and performance consistency.

To address this issue, Tokyo-headquartered Teijin Frontier has developed a new polyester filament yarn designed to deliver the stretch and recovery typically associated with polyurethane, while enabling the production of fully polyester fabrics.

Unlike conventional stretch technologies that rely on yarn structure, such as conjugate yarns combining polymers with different heat-shrinkage properties or highly crimped yarns, the elasticity of this new development is derived from a unique polymer design combined with precise control during spinning.

Despite being a polyester filament, the yarn provides a soft stretch handle and excellent shape stability. It also offers a high degree of recovery comparable to that of polyurethane-based elastic fibres, making it suitable for applications where both comfort and durability are essential.

The strong compatibility of the new stretch polyester with high-performance polyester fibres allows the development of 100% polyester textiles that retain the advanced functional properties typically associated with polyester and polyurethane blends. These include moisture absorption, quick drying, durable water repellency and reliable stretch performance.

An additional benefit of the innovation is improved recyclability. By enabling monomaterial fabric construction, the new fibre simplifies recycling processes and supports more sustainable textile production.