These masterbatches have an activation temperature, which helps toggle the end product’s colour. This property is often utilised in the coding of fabrics, adding a security feature to the original branding.
Ashwin Agarwal, managing director, Kandui Industries, explained, “When a top textile customer asked our R&D team for a counterfeiting solution, after substantial deliberation, we came with the idea of producing the selvedge of the fabric in such a manner that on the application of heat (ironing), its colour would change. The original colour would reappear at room temperature.”
The company took about a year to create the masterbatch. It faced a twofold challenge in the product’s creation – tackling the heat sensitivity of pigments and achieving a smaller pigment particle size.
“As the thermochromic pigments available in the market are extremely heat-sensitive, the molecules get destroyed in the extrusion process. Hence, we thought of applying a heat-resistant coating on the pigments. This enables the preservation of the pigment properties up to a temperature of 260-degree Celcius. The pigment supplier helped us tackle the second challenge, making the particle size small enough to run in low denier applications,” said Agarwal.
Besides textile, the other application segment of the product includes moulded items such as toys. “This technology has become more popular in children’s bottles, wherein refrigeration, the product changes its colour, creating a playful experience for kids,” he added.