The heat insulation strips are combined by some mechanical means and used on the doors and windows, so the nature determines that the insulation strip must have both high strength and low conductivity. Otherwise, it will cause a major safety hazard to the building (insufficiency will cause the insulated aluminum profile to break from the joint of the heat insulation strip), or lose the meaning of heat insulation (the conductivity is high, the insulation effect cannot be guaranteed), so the material of the heat insulation strip Selection and manufacturing processes are critical.
At present, there are two kinds of heat insulation strips for aluminum doors and windows on the market, one is PA66GF25 insulation strip, and the other is PVC insulation strip.
PA66GF25 insulation strip
PA66 is a series of modified engineering plastic alloys with high melting point, excellent heat resistance and self-extinguishing properties. However, the unmodified PA66 material does not match the aluminum alloy in terms of tensile strength and coefficient of linear expansion. Through experiments, 25% of glass fiber is added to PA66 to be converted into engineering plastics as the basic material of the heat insulation strip. It is the best. At present, there is no new material that is more reasonable and economical than this one.
The main raw material is PVC resin powder plus 25% calcium carbonate.
The differences between the two are as follows:
1. Tensile strength
PA66GF25 insulation strip>126N/mm
PVC insulation strip 70N/mm or so
2. Heat distortion temperature:
PA66GF25 insulation strip 240 degrees
PVC insulation strip 90 degrees
3. Aging resistance:
PA66GF25 insulation strip is durable and not easy to age
PVC insulation strips are easy to age
4. Expansion coefficient
PA66GF25 insulation strip is consistent with aluminum alloy linear expansion coefficient
PVC insulation strip and aluminum alloy linear expansion coefficient greatly differ
There are some ways to identify:
1. Look at the gloss. The surface of the PA66GF25 insulation strip of the broken aluminum window is a matte texture, the color is anti-black; but the PVC insulation strip looks smooth, smooth, and the color is reversed. The two can be clearly distinguished.
2. Another point is that the PA66GF25 insulation strip is not burning. The PVC insulation strip will burn for a while and will see a small flame, and there will be a general plastic smell.
3. PA66GF25 insulation strips are broken one or two times, and PVC insulation strips need to be folded more than ten times to break.
4. When the PA66GF25 insulation strip is broken, the sound is crisp. After breaking, the fracture is neat and not deformed, and it can be docked and restored. After the PVC insulation strip is broken, the fracture is white and deformed.