Hong Kong-based brand KnitWarm, launched in 2017, has brought heat-conductive knitting technology developed by The Hong Kong Polytechnic University into wearable and lifestyle products. By combining its patented thermal knitting technology with design, the company has received more than 90 international design and technology awards. The technology behind KnitWarm’s products comes from research at The Hong Kong Polytechnic University.

In the process, continuous polyamide yarn is coated with pure silver through a metallisation process, which gives the yarn electrical conductivity. The silver-coated yarn is then built into the fabric using patented 3D knitting technology. This creates a soft and flexible textile circuit that produces heat when connected to a power source while maintaining the appearance of an ordinary knitted fabric.

The products are powered by connecting a detachable cable between two snap buttons on the textile and the USB port of a 5V2A power bank. After being connected, the fabric can heat up to 45°C in around 30 seconds. Users can select from five temperature settings and choose 15-, 30- or 60-minute timers through a control panel or mobile app. An automatic shut-off feature is also included to improve safety and help reduce the risk of burns caused by prolonged exposure to heat.