In April, Kornit launched the Avalanche Poly Pro system, the first DTG system to be specifically developed for printing onto polyester fabrics. The brand’s product marketing manager for Europe, Sharon Donovich, explains how the need for the new machine evolved and what it brings to the market

It all started in the gym. Activewear that had previously been worn solely during workouts and on those early morning jogs started being worn to coffee shops as consumers realised that yoga pants and other gymwear styles were fashionable enough to be worn outside of sports and fitness activities, with the help of a little styling. This adaptation of sportswear for everyday wear, (the athleisure trend), has continued to gain in popularity. Sportswear brands are crossing over into casualwear and fashion, leading to sports apparel becoming much more fashion-sensitive in terms of colours and design.

Meanwhile, all the major fashion retailers and brands have been adopting activewear in their collections, introducing apparel products that are increasingly influenced by sports in terms of style, colours, fabrics and comfort. This trend has been particularly ‘sticky’ for numerous reasons: the tastes of the millennial population, the increasing spend per capita on apparel, the continuing influence of social media and micro-influencers, people’s growing inclination towards ‘wellness’ via health and fitness, and an increasing preference for comfortable, easy-to-wear, convenient, stylish and functional clothes.

Analogue solutions

The most commonly used fabrics in the sportswear and athleisure markets are breathable synthetic materials such as polyester and nylon. Knitted fabrics are more popular than woven fabrics; Lycra, elastane and mesh fabrics are also common. Polyester is the second largest category in the overall T-shirt market. It is key in the sports segment, and is growing in athleisure and functional apparel. In 2019, the global polyester T-shirt market was valued at $29 billion, with 2 billion T-shirts being produced. The market is expected to reach revenues of $33 billion by 2025, with 2.5 billion T-shirts being created. The revenue of the global polyester T-shirt market is growing at a compound annual growth rate of 5.5%.

Activewear is continuing to increase in popularity

Given the popularity of polyester sports and athleisurewear, an industrial solution to printing on polyester fabrics that offers low prices, speedy delivery, design versatility, personalisation and sustainability is needed to serve this growing market. Until now, polyester has been printed predominantly by analogue solutions, and the main challenge has been to create a high quality print with no design limits on multiple polyester fabric types and colours with no dye migration. Dye migration, or bleeding, occurs when a polyester fabric is exposed to high temperatures, causing the dye that has been used to colour the fabric to migrate from the garment into the printed ink.

Techniques for decorating polyester fabrics include the use of heat transfer vinyls (HTV) or film. This process requires the file to be prepared and printed. The design is then cut and any excess vinyl weeded, before the design is heat pressed onto the fabric. This technique produces high-quality embellishment, enhanced abrasion resistance and durability. It also inhibits dye migration and is a best fit for creating names and numbers with fine-cut edges. It does, however, require a sometimes long and labour-intensive process with multiple steps: the result is a compromise on productivity and design limitations.

Kornit’s NeoPoly Technology allows printing on polyester fabrics

Screen printing is also used for printing onto polyester. The process is similar to printing on cotton, in that it involves separating the colours in the design, mixing the colours, creating the screens, setting up the press, printing and then curing. But with polyester, there is a bit more to do: you may be required to use a special mesh with a thinner thread; an additional separation and screen may be needed to block the dye migration; the nature of the polyester fabric can cause it to shift during printing; and in some cases, there is a need to use a catalyst to reduce the curing temperature of the screen ink. 

With this technique it is easy to produce long runs at lower prices, but it is more difficult to use as it requires expertise to achieve high quality prints, time to market is long and short runs are expensive. The sublimation process is also widely used for printing onto polyester fabrics. Easier to master, it involves printing the design onto paper and then heat transferring it to the fabric. This produces beautiful, unlimited designs, but is restricted to prints on white or light coloured polyester fabrics, which, in many instances, is not what the market wants.

The introduction of NeoPoly Technology

Dye migration on polyester has also been an issue with decorators who use direct-to-garment printers; the need to cure the prints at high temperatures results in dye contaminated prints that are not acceptable in this market. In April, Kornit introduced Kornit NeoPoly Technology, which allows industrial polyester printing without dye migration and without compromising on design, run size, substrate or labour. This technological innovation is achieved by an innovative ink set, and a process that is specifically developed for low temperature curing and provides polyester-enhancing functionalities to maintain fabric characteristics and provide superior fastness. This unique process prevents dye migration on polyester, and the inks are Oeko-Tex and Eco-Passport- certified and do not contain PVCs or other harmful ingredients.

The first system equipped with the Kornit NeoPoly Technology is the new Kornit Avalanche Poly Pro, a member of Kornit’s highly productive industrial platforms. The single-step Poly Pro enables easy and cost-effective short runs and on- demand printing on polyester garments. Alternatively, Image Armor has produced a pre- treatment that is said to also make it possible to DTG print onto polyester garments: I am not familiar with Image Armor so cannot comment, but I can tell you that Kornit Avalanche PolyPro solution offers a single-step process meaning that there is no need for external pre-treatment and that it is based on Kornit’s NeoPoly technology, which completely prevents dye migration and preserves original fabric properties.

A sustainable process

Kornit NeoPoly Technology not only allows printing on 100% polyester, but also solves the challenge of printing on fabric blends and different polyester textures such as knitted and woven, and produces high quality prints on all these fabrics. It meets the sports industry’s highest requirements such as fastness to light, wash and perspiration, flexible prints for maximum fabric stretch and the preservation of the fabric’s properties.

Retail brands are adding sportswear-influenced designs to collections

Kornit NeoPoly Technology is a sustainable process that does not waste water or paper, does not use harmful substances, does not pollute water, is low in power consumption and energy and is a completely dry process, which makes it attractive in multiple areas including cost per print, total cost of ownership and environmental regulations. On the cost front, printing a polyester T-shirt on the Avalanche Poly Pro is slightly more expensive than printing a cotton T-shirt using a Kornit system, but gives the same profitability as printing on cotton with Kornit systems compared to traditional analogue print.

The new system has created a solution for the sportswear and athleisure markets as well as for the promotional and work uniforms markets, and brings polyester to the print-on- demand and ecommerce sectors. As Omer Kulka, Kornit’s VP of marketing and product strategy, commented, “Kornit is on a mission to reinvent the garment and textile printing industry with game-changing technologies for growing market segments. We continually work to break technology boundaries so that our customers can innovate and open new markets and new business opportunities while being more operationally efficient. The new NeoPoly Technology is further proof of this innovation and reinvention mission.”