PC for LED lights in extreme environments

LED light sources have proven to be energy-saving and long-lasting which makes them economical light sources and are widely used in buildings, vehicles and street lighting. Light guides, reflectors, diffusers and lenses must be designed to ensure optimum use of LED light.

Covestro has spent years developing a customised portfolio of transparent, translucent, reflective, as well as thermally conductive and flame-retardant grades of polycarbonate plastic to meet these needs.  In that way, the company is supporting more sustainable lighting technologies, to which the International Day of Light on May 16, 2021, was dedicated.

LED lighting in swimming pools

Operating LED lamps under water puts special demands on the materials involved. In cooperation with Brazilian swimming pool equipment supplier Ecopyre Lighting, Covestro developed an integrated solution using the thermally conductive polycarbonate Makrolon® TC. It features high dimensional stability during manufacture and operation of the lights, thereby preventing water ingress (ingress protection or IP).

The letters "TC" in the type designation stand for "thermally conductive" and indicate that the plastic also has good thermal conductivity. This makes it ideal – like the other types in the TC portfolio – for efficient thermal management in which the heat generated by the LEDs is well dissipated. In addition, the plastic complies with the chemical resistance required for use in swimming pool water.

Lenses for explosion-proof LED lamps

The highly transparent product Makrolon® is even suitable for lenses in explosion-proof lamps, as demonstrated by a recent case study with safety technology supplier R. Stahl. The lights comply with Categories 2 and 3 (for Zones 1 and 21, or 2 and 22) of the EU ATEX directives1 for industrial environments where highly explosive dust and gas atmospheres may occur during normal operation. These include oil platforms, refineries, and also certain chemical plants.

R. Stahl AG, a German trendsetter for safety technology in potentially explosive atmospheres, was looking for an optical material solution for LED safety lighting that could be used worldwide. The decision was made in favour of the transparent plastic Makrolon®, which enables light-focusing optics and is applicable at elevated temperatures of 60 to 85 degrees Celsius.

Polycarbonate is a thermoplastic that allows efficient development and production of optical parts for LED-powered lights. The various Makrolon® types can be used for injection moulding and extrusion. Stronger and lighter than glass, polycarbonate also facilitates savings in energy and CO2 emissions.