Safety is a top priority at Bayer MaterialScience, and not just internally. The company is also working intensively to develop new plastic products that help in a variety of applications to reduce the risk of accidents in the workplace, while participating in sports and leisure activities, and in the home.The latest example of this are new, gray-tinted modifications of the polycarbonate Makrolon LQ3187, which was developed in collaboration with Uvex Arbeitschutz. Uvex uses the material to manufacture a new generation of welding goggles that ensure welders can clearly recognize signal colors such as yellow, red or blue despite the gray tinting of the lenses.
“With protective goggles made of other materials, tinting generally changes color perception so that the welder cannot clearly distinguish between different colors, such as in the case of markings, warning lamps or safety notices. In the worst case, the welder is forced to take off the goggles,” explains Matthias Rothe, an expert for polycarbonate eyewear applications at Bayer MaterialScience. Thanks to the special gray tint, the new goggles fulfill the color perception requirements defined in the standard EN 172 for personal eye protection with sunglare filters for industrial use. They also provide reliable protection against UV and IR radiation. With thicknesses between 2 and 3 millimeters, they correspond to Protection Stages 1.2 to 7.0 and satisfy the transmission requirements defined in the standard DIN EN 169 for filters for welding and related techniques.
Another advantage of the goggles is their resistance to mechanical loads such as impacts and metal particles flying around. This is because Makrolon LQ3187 has greater impact strength and breaking resistance than standard polycarbonates. The low weight of the plastics means that the goggles are lightweight for a high level of wearing comfort. A special anti-fog coating prevents the lenses from fogging on the inside. Furthermore, an extremely scratch-resistant hardcoat on the outside minimizes damage due to welding sparks. According to Rothe, “Reliable color recognition together with high wearing comfort and mechanical protection ensures that the goggles will be worn at all times while working, thus offering optimal protection.”
Uvex collaborated intensively with Bayer MaterialScience's Color Competence & Design Center (CCDC) in Filago, Italy, on the development of the color modifications. “With the detailed specifications from Uvex, the new formulations were ready for production in a very short time. The vast expertise of our CCDC with the development of special colors and effects really paid off here,” say Michael Erkelenz, product development manager for polycarbonate compounds at Bayer MaterialScience.
Previously, it was common practice for welding goggle manufacturers to add additives and colorants to the plastics required themselves. In the case of tinting, this required working with solvents, which in turn required elaborate occupational safety measures. The services of a compounder were also frequently engaged. Uvex, on the other hand, can process the fully additivated polycarbonate color variants directly using the injection molding process. “This simplifies the logistical workflows. It also produces less scrap and improves the efficiency and profitability of production,” adds Erkelenz.
Uvex – the renowned supplier of innovative services for the safety and protection of people at work, sport and leisure headquartered in Fürth (www.uvex-safety.com) – markets the new welding goggles under the names “uvex i-vo,” “uvex super fit,” “uvex super f OTG” and “uvex ultrasonic flip-up.”
