1. The external dimension accuracy of the heat insulation strip

The inaccuracy of the outer dimension accuracy of the heat insulation strip not only affects the quality of the composite profile, but also causes the deviation of the outer dimension of the composite heat insulation profile and the generation of internal stress, which will directly affect the "three properties" (water tightness, water tightness, Air tightness and wind pressure resistance) ensure essential impact. To obtain precise dimensions for nylon extrusion, it is necessary to have high-precision molds and high-quality nylon materials with stabilizers.

　　 2. The internal glass fiber structure of the heat insulation strip

　　The internal structural quality of the heat insulation strip is the principle guarantee for the strength and stability of the profile.

　　 1. Reasons for choosing glass fiber reinforcement

　　 Because nylon has creep characteristics. That is, under a certain external stress, its deformation increases with time. In order to suppress the creep of nylon, experiments have proved that nylon 66 reinforced by glass fiber is equivalent to aluminum alloy in terms of strength, rigidity and heat distortion temperature. Avoid the danger of the heat insulation strip falling off between the profiles due to thermal expansion and contraction.

At present, many manufacturers on the market are selling nylon heat insulation strips. After testing, it is found that some are completely filled with cheap minerals (such as calcium carbonate, talc, etc.), and some are filled with most minerals and a small amount of glass fiber (less than 10wt. %) The method of mixing and filling is reinforced; and even nylon 66 must be added with some non-engineering plastics such as polypropylene, polyvinyl acetate, etc.!

　　2, glass fiber arrangement

　　The glass fiber is arranged horizontally + vertically in the heat insulation strip, which can increase the longitudinal tensile strength and the horizontal tensile strength. However, in order to achieve the horizontal and vertical arrangement of the glass fiber, it is necessary to have a suitable mold, a propelling screw and a special hexagonal fixture.