The influence of water absorption of heat insulation strip on the processing process of heat insulation aluminum alloy profile
The base resin of nylon 66 (PA66) heat insulation strip is nylon 66, namely polyamide 66. It is one of the important varieties of engineering plastics. It has high mechanical strength and excellent wear resistance, aging resistance and self-lubrication. And heat resistance. Its low temperature performance is excellent, self-extinguishing, acid and alkali resistance and most inorganic salt solutions, oil and organic solvents. After being reinforced with glass fiber, its mechanical properties, heat resistance, dimensional stability and chemical resistance will be greatly improved. As a heat insulation strip applied to energy-saving doors and windows, it can resist wind pressure and salt spray. Corrosion, and more importantly, the linear expansion coefficient of the glass fiber reinforced nylon 66 insulation strip is very close to that of aluminum alloy, and the overall performance after being compounded with the profile is good. Practice has proved that this is an ideal insulation profile that has been successfully developed so far and has been used in Europe for many years.

The strength of nylon 66 comes from the chemical bonds of the main chain and the interaction between molecules. The characteristic functional groups in the molecular structure of nylon 66 resin-the carbonamide groups are always arranged relative to each other, so that each functional group can be without molecular deformation. Hydrogen bond is formed, and the carbonamide group -NHCO- has polarity, so water absorption is the characteristic of nylon 66. The absorbed water can weaken the force between molecular chains, have a plasticizing effect on the material, reduce the glass transition temperature, and increase the product size And other phenomena. However, water absorption is a two-way process, through some control methods to intervene the impact of water absorption on the product, so as not to affect the use of our heat insulation products.