First, the dimensional accuracy of the heat insulation strip
The inaccurate dimensional accuracy of the heat insulation strip not only affects the quality of the profile composite, but also more easily causes the dimensional deviation of the thermal insulation profile after composite and the generation of internal stress, which will directly affect the "three characteristics" (water tightness, air tightness, wind pressure resistance) of the thermal insulation doors and Windows. Nylon extrusion to obtain precision size, it is necessary to have a high-precision mold and the addition of a stabilizer of nylon high-quality materials.
Second, the internal glass fiber structure of the heat insulation strip
The internal structural quality of the heat insulation strip is the principle guarantee of the strength and stability of the profile.
1, The selection of glass fiber reinforced reasons
Because nylon 66 has creep characteristics. That is, under the action of a certain external stress, its deformation increases with the increase of time. In order to suppress the creep of nylon 66, it has been proved that the strength, rigidity and thermal deformation temperature of nylon 66 reinforced by glass fiber are equivalent to that of aluminum alloy. Avoid the danger of heat insulation strip falling off between profiles due to thermal expansion and cold contraction.
Now a number of manufacturers on the market in the sale of nylon 66 heat insulation strip, the test found that: some completely use cheap minerals (such as calcium carbonate, talc powder, etc.) to fill, some use most minerals and a small amount of glass fiber (less than 10wt%) mixed filling method to enhance; There are even nylon 66 to add some non-engineering plastics such as polypropylene, polyvinyl acetate and so on!
2, Glass fiber arrangement
The glass fiber is arranged horizontally + vertically in the heat insulation strip, which can improve the longitudinal tensile strength and also improve the transverse tensile strength. However, in order for the glass fiber to achieve horizontal and vertical alignment, it is necessary to have a suitable mold, a propulsion screw and a special hexagonal clamp, and these technologies are only mastered by Germany.