Why Is The Strength Of The Insulation Strip Different?

PA66 nylon insulation strip is the core component of threaded insulation aluminum alloy profiles. It not only has insulation and insulation functions in bridge broken aluminum alloy doors and windows, but also connects the aluminum profiles on both sides of the insulation profile, playing a structural role. The crystallinity of PA66 is about 30% -40%, and there are still a large number of acyl groups in the amorphous region. During the moisture absorption process of PA66, water molecules bind to the acyl groups in the amorphous region, causing the hydrogen bonds between PA66 molecules to be destroyed, leading to looseness between molecular chains and a decrease in strength.

The polyamide molecular chains in nylon insulation strips contain highly polar amide groups (- NHCO -), which can reduce their strength and dimensional stability due to external environmental factors such as water, heat, and oxygen, further affecting the later threading and long-term use of the insulation strip.

Therefore, the decrease in high-temperature transverse tensile strength and the increase in moisture absorption weight gain rate of imported insulation strips using high-quality PA66 are smaller than those of domestically produced insulation strips using recycled PA66. However, different treatment methods in recycled PA66 can also cause differences in the strength of domestically produced insulation strips.