Joel Chadwick, managing director at Chadwick Textiles, guides you through the different polyester materials found in sportswear, highlighting the latest trends and how best to decorate these performance fabrics
Sportswear designs have never evolved as fast as they are evolving at present, with leading high street and specialist brands continuously seeking new cutting-edge methods to manufacture garments that offer functional performance and innovative features. However, one of the constants in this fast moving market is the use of polyester fabrics.
Polyester, both knitted and woven, remains the staple fibre for sportswear. Gone are the days when polyester was widely regarded as cotton’s cheaper, shinier and altogether nastier little brother. Developments in yarn technology and finishing in recent years mean polyester can be used to produce a huge variety of sumptuous fabrics with numerous technical benefits – high tenacity, quick drying, lightweight and soft, as well as being durable, printable and coatable.
There are, however, a plethora of different factors to consider when working with polyester, depending on the fabric’s intended end use.
Polyester for lightweight inners, next-to-the-skin and fabric panel inserts: running, cycling, training wear… This is probably the area that has seen the most growth in recent years. Things you should expect from your fabric, without necessarily having to pay a premium, would be its quick-dry functionality and adequate snagging performance along with a good next-to-the-skin, soft hand feel. The trend in this area is for lightweight polyester knits with special knit effects and texture, and garments with laser cut features are becoming increasingly important.
Polyester yarns combined with stretch, such as Spandex, for base layer warmth are now worn by sportspeople of all ages at all levels. These fabrics are ideal for embellishment with the use of reflective prints and transfers remaining strong. Such lightweight knit fabrics can, however, be difficult to embroider and will pucker more easily.
Polyesters in both lightweight and heavier outer garments, such as single, two- and three-layer fabrics: workwear,d weatherproof outerwear… Woven polyester shell garments that offer the wearer a barrier to the elements are designed for many end uses, and are not necessarily waterproof and tape seamed. The use of high density, ultra lightweight polyester fabrics is required if the garment is to be packed away quickly and easily, while still offering a degree of breathability.
It’s important for these fabrics to ensure a good level of colourfastness and wet/dry rub if they are likely to be packed away damp after use in the bottom of the bag. A suitable level of water-repellence is vital: be aware that levels of PU coatings and silicone finishes can vary hugely in performance.
These days, two- and three-layer laminated polyester fabrics are more widely used in conjunction with wafer thin membranes, offering high levels of waterproof and breathable performance, without compromising hand feel and weight. Print transfers can still be easily applied when the fabric face is 100% polyester even if the fabric has a water-repellent finish.
Polyester for sublimation: rugby kit, cheerleading outfits… Sublimation printing has revolutionised sportswear garment embellishment and personalisation in the last 10 years and continues to dominate apparel for team sports. Both woven and knitted polyester can be sublimated, but knitted options tend to offer more variety and often produce a more desirable garment. Woven polyester tends to become harsher and more rigid the heavier it is, although many lighter-weight wovens, for running shorts etc, are ideal for the job.
Most warp knitted polyester fabrics (as opposed to weft knit) offer good levels of inherent stretch, which negates the need to add Spandex when stretch characteristics are required. Combining polyester with Spandex or Lycra becomes important for end users who require greater mobility.
However, fabrics with a high stretch content can be more sensitive to high temperatures during printing – that is, the more stretch a fabric has, the more it can be prone to shrinkage during the print process. However, with a reasonable level of knowhow, and the right inks and papers, decorators can easily overcome any issues.
Ultimately, the key to producing fit-for-purpose polyester fabrics for printing comes down to ensuring consistent yarn quality and heat set processes. This enables garment sublimators to avoid unwanted wastage or downtime during production.