Covestro has developed special lens-quality grades of its Makrolon polycarbonate, characterised by excellent optical properties, high mechanical strength, toughness and comfort.
When original equipment manufacturer Jiangsu Sigo Optical decided to upgrade the polycarbonate material used for its corrective and sunglass lenses, it turned to Covestro Makrolon polycarbonate resins for improved optical purity and production yield.
Jiangsu Sigo Optical already uses Makrolon DP1-1821 polycarbonate in its spectacles which is formulated specifically for the ophthalmic market. Available in clear tints, the material offers a number of advantages for corrective lenses including high optical purity, transmission and scatter resistance and UV stabilisation. In processing, the material is distinguished by its high viscosity and easy release from the mould.
For outdoor activities, sunglasses provide UV protection, impact-resistance and good-lookin’ style. Makrolon LQ2887 polycarbonate, a new optical grade, is used for high-performance sunglass lenses from Jiangsu Sigo Optical.
Lenses from Covestro Makrolon for sunglasses.
Importantly, Makrolon LQ2887 polycarbonate provides UV protection from wavelengths up to 400 nanometers (nm), which blocks both energy-rich UVA and UVB rays. The product offers thin and fashionable, yet impact resistant lenses, and is appropriate for outdoor sports such as mountain biking and beach volleyball. UV protection is especially effective in beach and snow environments where water and snow strongly reflect harmful UV rays.
Owing to its medium viscosity and easy release from the mould, the product is easy to process. In addition to supplying the materials, Covestro also offers valuable technical assistance.
Liu Jianzhong, General Manager of Jiangsu Sigo Optical, said: “Our ophthalmic lens branded as Sigo+ meets the global market’s quality requirements with stable growth in export sales, thanks to the high productivity and low impurity quality of Makrolon polycarbonate from Covestro.”
Attendees at the 32nd International Exhibition on Plastics and Rubber Industries (CHINAPLAS 2018), April 24-27, in Shanghai, China, will receive more information about Covestro´s medical applications and materials in Hall 7.2, Booth no. D41.