How Thermal Insulation Profiles Improve Aluminum Window Performance

At Kronos, we make the thermal insulation profiles that sit between the inner and outer aluminum sections of a window, a door or a curtain wall. The profile is the thermal break: it separates the two metal parts so heat does not travel straight through the frame. Our range covers more than 200 standard shapes, including hollow chamber designs, insert fins and spacers for sliding doors and curtain walls, and it is made for compatibility with mainstream aluminum systems.

Why a Thermal Break Matters

Aluminum is a good conductor, which is useful for a structural frame and a problem for an insulated envelope. Without a break, the inner surface of a frame can be cold in winter and warm in summer, and condensation can form on the metal. A polyamide profile interrupts that path. The result is a higher surface temperature on the inside, less condensation and a lower overall U value for the window. The break also reduces the heat loss at the frame, which can be a significant part of the total window area.

Material: PA66 GF25

The standard material is polyamide 66 reinforced with 25 percent glass fibre, often written as PA66 GF25. The glass fibre raises the strength and the dimensional stability, while the polyamide gives a low thermal conductivity and a good resistance to the temperatures a window frame can reach in the sun. The material also has to bond with the aluminum and resist the expansion and contraction of daily temperature cycles. A profile made from a lower grade material may look the same but perform differently over a long service life.

Profile Types

The range includes hollow chamber profiles for a higher insulation value, insert fins for a specific aluminum system, and spacers for a curtain wall. Some profiles are anti-bi-metal, which means they are designed to avoid a galvanic reaction between dissimilar metals. Others are aluminum reinforced for a higher structural load, or include an adhesive foam component to close a small gap. The correct type follows the aluminum system, the climate and the structural requirement, so the profile should be selected with the window fabricator.

Where the Profiles Are Used

The profiles are used in residential windows and doors, commercial facades and curtain walls, sliding systems and passive house projects. A larger window with a narrow frame needs a profile that fits the available width; a curtain wall may need a spacer with a specific depth. A cold climate may call for a deeper chamber, while a mild climate may use a simpler shape. The same building can use several profile types, so a system schedule is a practical way to keep the order clear.

Extrusion and Quality

The profiles are produced by thermoplastic extrusion, a process that pushes the melted material through a die to form a continuous shape. The tolerance on the profile is important because it has to fit the aluminum groove and hold the assembly together. A profile that is slightly out of tolerance can be hard to insert or can leave a gap. Quality control covers the dimensions, the glass fibre content, the surface and the mechanical properties. A buyer should ask for the inspection data with the batch.

Working With Kronos

Our product range covers standard thermal insulation profiles, special solutions for aluminum doors, windows and curtain walls, optimized thermal solutions for high performance systems, customized profiles, Ultimate-K alu-wire strips, steel window strips and automotive POM and PA parts. Buyers who need thermal insulation profiles can send the aluminum system, the profile drawing, the required U value and the quantity. Our team will confirm the shape, the material and the packing before quoting. A sample helps the fabricator check the fit before a production order.

Send us the window system and the performance target, and we will reply with the recommended profile, the quotation and the next steps. A clear brief on the climate and the frame at the start helps avoid a profile that fits the groove but not the thermal requirement.