In construction, “thermal break” systems prevent heat from entering or escaping buildings, significantly improving insulation performance and enabling energy-efficient structures with a reduced carbon footprint. This feature is particularly important in geographic regions with large temperature fluctuations, very cold winters, and/or hot summers.
Aluminum window systems, in particular, benefit from specialized design due to the high thermal conductivity of the metal. Thermal breaks interrupt heat transmission, which otherwise would lead to very cold frames in winter and very hot ones in summer—conditions that require more energy to maintain a comfortable indoor temperature.
Polyamide thermal break profiles are used to separate the internal and external components of the frame. Glass fiber-reinforced polyamides are typically used to ensure mechanical stability, as window frames must withstand considerable forces. A polyamide with 25% glass fiber has a thermal conductivity (lambda) of 0.40 W/(m·K), which is over 400 times more insulating than aluminum, which has a lambda value of approximately 160 W/(m·K).
While a standard thermal break profile is sufficient to reduce heat transfer, further enhancing its insulating properties directly improves the energy efficiency of the window system. This solution is now available at an industrial scale, enabling the production of a new generation of thermal break profiles with significantly reduced lambda values. Using the same raw material selection, profiles extruded with this technology have a microcellular foam structure composed of atmospheric gases such as nitrogen or carbon dioxide.
The density of polyamide profiles produced with this method is reduced from 1.31 kg/dm³ to 1.0 ± 0.1 kg/dm³, and the resulting lambda value is approximately 0.20 W/(m·K).
Thanks to their microcellular structure, these profiles retain mechanical properties comparable to solid profiles while significantly improving insulation performance—setting a new benchmark in the thermal break profile industry. This advancement is essential to meet increasingly strict building insulation regulations and the growing demand for sustainable and cost-effective construction solutions.
With its Microcell technology, Promix is the pioneering supplier enabling such density reductions, offering both hot and cold extrusion lines. More than 40 extrusion lines are already operating with this technology, and the number of installations continues to grow.