LUKI children’s eyewear featuring Hytrel® 

Case Study

Plastic sunglasses frames that are cool and tough enough for kids

Children’s sunglasses have a practical function—protecting the eyes against damaging ultraviolet (UV) light. But kids typically regard them as toys. Exuberant youngsters can be tough on the frames, subjecting them to twisting, tossing, and dropping. That’s why the best sunglasses combine durability and resilience with kid-friendly colors and a soft, comfortable feel. 

LUKI kids’ eyewear combines strong, flexible frame material with bold, stylish colors.

To meet these needs and offer high-end children’s sunglasses, the LUKI Kids’ Eyewear brand was created. These sunglasses are designed specifically for children from infants to preteens, while maintaining the brand’s goals of safety and style. 


Getting it right: The initial design challenges
LUKI designers sought a thermoplastic material that was sufficiently soft and flexible but wouldn’t break easily under stress. The material also needed to be stiff enough to secure the lenses. Finally, it was also important that the material be free of bisphenol A (BPA) to allay parental concerns about potential health risks. 

Hytrel® TPC-ET performs well when placed in contact with many everyday chemicals.

Beyond safety, LUKI glasses had to be stylish and fun enough for kids. The frame material needed to provide easy colorability and high-quality surface finish without the need for secondary painting. To avoid lot-to-lot variation, a material with consistent performance was vital, including reliable durometer properties.

Luckily, there was one material that fit the bill.


The solution: Hytrel®, a better TPC-ET

LUKI’s manufacturer turned to DuPont™ Hytrel® thermoplastic polyester elastomer (TPC-ET).  Not only does Hytrel® TPC-ET meet all safety requirements, it also stands up to just about everything kids send their way, from soda to sunscreen to sweat. It also looks good. Hytrel® materials come in a natural color, enabling custom frame colors using masterbatches.

The processing capabilities of Hytrel® are also well suited for this eyewear application. Good flow properties support design freedom and enable easy processing. Fast cycle times help control system costs. The flexibility of TPC-ET even makes it easier and faster to assemble eyewear components such as nosepieces. 

Hytrel® TPC-ET demonstrates the flexibility and toughness ideal for a kids’ product.

A sunny outlook

The LUKI brand has yielded important business benefits for the manufacturer, including access to a younger audience. This represents a new, high-end market sector for the company, with significant global growth opportunities and increased positive visibility. Parents appreciate the safety, protection, and durability of LUKI glasses, while their children love the vivid colors and fun designs.

Thanks to its desirable combination of properties, Hytrel® TPC-ET grades have also become popular choices for sporting goods such as footwear, winter sports binding components, fitness products, protective equipment, and wearable fitness trackers. 


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