How Ensinger revolutionised the insulation of metal windows, doors and façades worldwide with the first roll-in profile made from modern thermoplastics
Aluminium windows are also very popular in China for new buildings and renovations thanks to their advantages in terms of design variety, ease of maintenance and durability. As the thermal conductivity of aluminium is very high, the frame must be thermally separated. The optimum thermal insulation of windows, doors and facades is a key factor in healthy, environmentally friendly and resource-saving construction. The insulating profiles are already incorporated into the window during production. In order to achieve optimum energy efficiency here, the type, material and processing of the profile are important. Decades of practical use worldwide of roll-in profiles made from glass-fibre reinforced polyamide have shown that these profiles achieve optimum Uf values. The inventor of insulating profiles made from thermoplastics for the thermal separation of metal windows is called Ensinger and comes from Germany.
As far back as 1952, a Swiss company developed roll-in profiles for incorporation into the metal frames of windows. Until then, aluminium frames had been foamed with polyurethane, fitted with long fabric strips hardened with epoxy resin or short pieces of polyamide or polyester. The roll-in profile made it easier for window manufacturers to integrate the processing of the profile into their manufacturing process. However, the profile was made of elastic plastic. The material did not withstand the forces acting during further processing. At the latest during the anodizing or stove enamelling stage, the elements deformed and no longer sat perfectly, which massively interfered with their insulating capabilities.
The idea for optimal insulation of aluminium windows
The solution to this problem came about 20 years later from Germany. For years, the German plastics specialist Ensinger had been conducting intensive research into an insulating profile with good mechanical capabilities and high strength that would retain its structural properties and shear strength when the profile was rolled into the frame, and thus provide reliable insulation. In a specially developed extrusion process, an insulating profile made from glass-fibre reinforced polyamide 66 with low thermal conductivity and high stability, shear strength and temperature resistance was created for the first time: insulbar® was born. With the invention of insulbar®, Ensinger – one of the world’s leading developers and producers of insulating profiles for window, door and façade construction – has significantly optimised the thermal separation of the inner and outer shells of metal frames. This is because the coefficient of thermal expansion of the thermoplastic corresponds to that of aluminium. This minimises stresses during temperature changes, and the aluminium-plastic composite can be coated without problems even under heat treatment up to 200° C.