In the construction of passive houses and ultra-low energy residential buildings, door and window openings are the biggest thermal bridge loss points in the building envelope. Traditional steel and wood-plastic composite subframes have high thermal conductivity, which easily leads to heat loss, condensation, and mold growth on the walls. Graphite polystyrene subframes, based on graphite polystyrene modified foam substrate, balance structural strength and ultra-low thermal conductivity, and have now become the designated supporting components for energy-saving buildings in severely cold and cold regions.

The graphite polystyrene subframe is made of high-density graphite-modified polystyrene in one piece, with an apparent density ≥150kg/m³, compressive strength up to 2000kPa, and screw holding force exceeding 1400N. It can stably support multi-layered hollow energy-saving doors and windows and heavy-duty floor-to-ceiling windows, and will not loosen or deform even after long-term use. Its core advantage lies in its thermal bridging capability, with a thermal conductivity ≤0.06W/(m・K), far lower than that of metal subframes. It can cut off the heat conduction path between the wall concrete and the door and window profiles, significantly reducing the linear heat transfer coefficient of the door and window openings, and solving the problems of condensation at the window edge in winter and leakage of air conditioning cooling in summer.

In terms of durability, the product's closed-cell structure has a water absorption rate of ≤1.5%, and its dimensional change rate under high and low temperature cycles is controlled within 0.2%. It withstands repeated temperature changes from -20℃ to 60℃ without cracking or shrinkage. Its fire performance reaches B2 level, and when combined with an external wall insulation system, it enhances overall fire safety. Compared to wood-plastic composite frames, it does not suffer from moisture rot or insect infestation. Compared to steel frames, it requires no rust prevention treatment, and construction does not require an additional heat insulation layer, simplifying procedures and shortening the construction period.

With excellent construction adaptability, standard-sized subframes can be prefabricated and directly embedded in the wall on-site. Gaps are filled with expanding foam sealant and a waterproof vapor barrier membrane to complete the integrated waterproof and thermal insulation structure. It perfectly matches external wall graphite polystyrene insulation board systems, achieving seamless integration between door and window openings and external wall insulation. Currently, ultra-low energy consumption building codes in various regions have explicitly recommended graphite polystyrene subframes, making them an indispensable energy-saving component for achieving 65%+ energy-saving standards and passive house certification.