To give hungry people a portable option for hot food, one woman has developed a cloth food bag that runs on batteries.

Ayaka Ueda, 41, developed a bag called Willcook that uses electricity to raise the temperature inside of it to heat food and keep it warm.

Willcook is about the size of a standard sheet of paper. Turning on a mobile battery makes packaged dishes inside ready to eat within about 20 minutes.

The product’s foldable design, along with a weight of around 300 grams that includes the battery, makes it easy to carry around.

In pitching Willcook, Ueda, who is responsible for product development at Willtex--a company she founded in 2018 along with someone who has worked in the textile industry--embodied an idea she’s had for sometime. 

COMBATING THE COLD

The inspiration came when Ueda worked at a circuit board designing and manufacturing firm, to which she had moved from a textile trade house.

At the time, Ueda was tasked with creating a new product to display at an exhibition.

While contemplating what to make, Ueda remembered her experiences watching her eldest son’s baseball practices outside, where the midwinter cold was often particularly intense.

“I wanted to combat that shivering cold any way I could,” recalled Ueda.

For her first project at the maker, Ueda committed herself to perfecting a piece of underwear that was to be put on below firefighting uniforms so the wearers’ body temperature and cardiac potential could be measured to prevent them from having heatstroke amid the blazing fires.

One challenge was determining how to apply electronic circuits to the entire surface of the underwear since they needed to be connected to a device to receive the data.

Ueda took advantage of a technology that prints circuits on fabrics, and she incorporated a type of liquid that conducts electricity when solidified at high temperatures.

She carefully chose a fabric that made printing easy, then conducted repeated experiments in an oven at home by baking and hardening the specialized fluid.

Looking back on earlier challenges, Ueda decided to utilize the technique to “print circuits on fabric” again to release heat-generating winter gear marked by electric circuits that keep wearers warm.

Ueda accomplished her goal and showcased the completed winter clothing at a fair in 2018.

This drew attention from an executive of road repairs, Shutoko Maintenance Kanagawa Co., who offered to carry out joint research with her.

MORE FLEXIBLE

Ueda was still not content with the quality of her inventions, however.

She found it especially unacceptable that the products were not stretchable enough.

Ueda sought advice from an industrial heater manufacturer she knew.

The company referred Ueda to air conditioner firm Sanki Consys Co., which they described as an “interesting enterprise.”

Sanki Consys is known as the developer of the highly flexible fabric Hotopia.

The textile woven with conductive yarn, thereby producing heat, was exactly what Ueda was trying to realize.

She quickly contacted Hiroshi Kimura, 58.

Kimura, a former colleague of Ueda at their textile trading company, had once attempted to market conductive fabric jointly with a major business, but he’d had to give up on it.

Hoping to develop an elastic garment for flexible use across a wider range of fields than cables that are vulnerable to bending, Kimura found his finished fabric was characterized by a rough feel resembling that of “washi” traditional paper--something he didn’t want.

Hotopia appeared to be unachievable.

He was therefore “about to fall on my knees” at the sight of the super stretchable material.

During a technical tour of Sanki Consys, Kimura proposed setting up a new enterprise to put out items featuring Hotopia.

Sanki Consys was seeking a way to commercialize it and so agreed.

Kimura and Ueda then established Willtex.

The pair delivered a work uniform using Hotopia to Shutoko Maintenance Kanagawa in 2019.

The same technology was adopted for Willcook.

Whereas conventional heating wires incorporated into clothes stop working if a part of the wire is cut, Hotopia is fashioned from woven cloth that can be freely bent and stretched.

Even holes do not cause Hotopia to lose its ability to conduct electricity. Its temperature can reach a maximum of 280 degrees.

Willcook comprises a combination of five tiers, such as a noncombustible cloth layer and a water-repellent fabric sheet to keep away food-associated messes.

Ueda selected the materials, and she made full use of the connections she had built during her days at the textile trading house to get them.

Arriving on the market in April 2023, Willcook was put on display at the renowned CES trade show in the United States in January this year.

It won the top award in the home appliance division there.

Willtex is now being flooded with a stream of inquiries from companies all over the world.