Domestic thermal insulation aluminum profile production lines primarily employ the "roll-press embedded" technology. Whether using imported or domestically produced equipment, the process follows a three-step procedure: toothing, strip insertion, and roll pressing. Some companies are researching a two-step process, performing toothing and strip insertion simultaneously, but the basic principle remains the same, only shortening the process time. The process flow is: profile on operating platform → applying protective film → toothing → strip insertion → roll pressing → filling the insulation cavity with polyurethane foam → packaging.
(⑴) The first step mainly involves inspecting the surface quality and dimensional specifications of the profile. The inner and outer aluminum profiles can be anodized or electrostatically powder-coated. Alternatively, the inner and outer aluminum profiles can be made with different colors, connected by a thermal break strip to form two-tone aluminum alloy doors and windows.
(⑵) The second step is applying a protective film, primarily to protect the surface quality of the profile from damage during processing and handling.
(3) Tooth cutting is a key process, mainly involving rolling to form sawtooth-like grooves on the inner walls of the strip-cutting channels in the thermally insulated aluminum profile. Rigid PVC strips are then embedded and fixed together using a roller press.
While there are no specific regulations regarding the groove depth in China, the industry standard JC/T for thermally insulated aluminum alloy profiles specifies tensile and shear strength values, requiring that the grooves tightly connect the rigid PVC thermal insulation strip to the aluminum alloy profile using a roller press.
(4) Strip insertion and rolling are important processes. Strip insertion involves inserting the rigid PVC thermal insulation strip into the pre-cut grooves in the thermally insulated aluminum profile using a strip insertion device. Then, a roller press is used to roll the thermally insulated aluminum profile and the rigid PVC strip together.
(5) The process of filling the insulation cavity with polyurethane foam applies to foamed insulated aluminum profiles. The profile is placed in a two-component metering mixer, and the foam is injected into the insulation cavity through a mixing nozzle, allowing it to naturally foam.
Polyurethane is short for polyurethane. Polyurethanes are high-molecular-weight compounds containing many repeating groups on their main molecular chain. They have exceptionally low thermal conductivity and excellent acoustic, electrical, and chemical resistance properties. Foamed insulated aluminum profiles provide dual insulation and are suitable for cold regions.
(6) Packaging is the final step. Plastic film or wrapping paper can be used to wrap the profiles, primarily to protect them from damage during transportation and processing.
