Shanghai – China's energy-efficient window market has been boosted after Covestro, Krauss-Maffei and Chinese fibreglass maker Chongqing Polycomp International Corporation (CPIC) signed a memorandum of understanding.
The three parties will combine efforts to advance energy-efficient window and door frames with Covestro’s Baydur polyurethane pultrusion composites.
The frames will use non-alkali fibreglass as reinforcement, and polyurethane resin as the matrix. The profiles will be shaped by closed-injection pultrusion.
Covestro will research more energy-efficient materials, CPIC will develop fibreglass for a high-speed pultrusion process, and Krauss-Maffei will provide machinery specially designed for polyurethane pultrusion.
The project was inspired by China's Technical Standard for Nearly Zero-Energy Buildings. This was published in 2019, and sets national targets on building energy consumption. New standards are also being promulgated on a local level.
Beijing, for exa,ple, is revising its residential building design standards, and setting the whole-window thermal conductivity coefficient at 1.1W/(m2K). The municipal authorities estimate that heat loss through windows and doors accounts for 25% of total building energy consumption in the city.
With Covestro’s Baydur material, it should be possible to produce glass reinforced frames with a coefficient as low as 0.77 W/(m2K), the company said.
Part of the project will study how the profile’s cross-section can be simplified to cut costs. The material combination has good soundproofing performance, and has passed the hour-long fire resistance integrity test under China’s national standards.
Covestro added that polyurethane profiles made using closed injection pultrusion have high fibre content, high modulus and an expansion coefficient similar to that of concrete.
State-owned CPIC was set up in 1991 in Chongqing, and claims to be the world’s fourth-largest fibreglass maker.
