Broken bridge thermal insulation aluminum alloy is based on the traditional aluminum alloy, the original integrated profile is divided into two parts, and then two heat insulation strips are mechanically combined to connect the two parts together.
1： Function of heat insulation strip
The use of heat insulation strip determines that it is necessary to have high strength and low conduction function at the same time. Otherwise, it will form thermal insulation aluminum alloy doors and windows, curtain wall, and there will be serious quality risks (lack of strength will lead to the cracking of thermal insulation aluminum profiles from the joint of heat insulation strips), or lose the meaning of heat insulation (high conductivity means that the heat insulation effect cannot be guaranteed). Therefore, the raw material selection and production technology of heat insulation strip are discussed It seems very crucial.
2： Types of insulation strips
There are two kinds of heat insulation strips used in the market, one is PA66GF25 heat insulation strip, the other is PVC raw material heat insulation strip.
1. PA66GF25 heat insulation strip: PA66 is a series of modified engineering plastic alloy, which has high melting point, excellent heat resistance and self extinguishing property. However, the tensile strength and linear expansion coefficient of PA66 without modification do not match with that of aluminum alloy. After testing, it is the best to add 25% glass fiber into PA66 to make engineering plastics as the basic data of heat insulation strips. At present, there is no more reasonable and economical new data of thermal insulation strips in the world.
2. PVC insulation strip: the main raw material is PVC resin powder and 25% calcium carbonate.
The differences between them are as follows
1: Tensile strength
PA66GF25 insulation strip ＞ 126n / mm
PVC heat insulation strip 70N / mm pendulum
2: Thermal deformation temperature:
PA66GF25 insulation strip 240 degrees
PVC insulation strip 90 degrees
3: Aging resistance:
PA66GF25 heat insulation strip is durable and not easy to aging
Simple aging of PVC insulation strip
4: Expansion coefficient:
PA66GF25 insulation strip and aluminum alloy linear expansion coefficient are common
There is a great difference in the coefficient of linear expansion between PVC insulation strip and aluminum alloy
3： How to identify
1. According to the gloss, the PA66GF25 heat insulation strip of the broken bridge aluminum window has a frosted texture, and the color is anti black; however, the PVC heat insulation strip looks very smooth, smooth and white in color. The contrast between the two can clearly distinguish.
2. Another point is that PA66GF25 heat insulation strip does not burn. PVC insulation strip will be burned in a moment when it is ignited. Small flames will be seen, and there is usually a smell of plastic.
3. PA66GF25 thermal insulation strip will break once or twice, while PVC insulation strip will break after more than ten folds.
4. When PA66GF25 insulation strip is broken, the sound is loud, the fracture surface is regular without deformation, and can be restored by butt joint. The fracture surface of PVC insulation strip is white and deformed after fracture.
In the purchase of broken bridge aluminum alloy doors and windows, in addition to pay attention to the wall thickness of door and window profiles, glass, hardware accessories and technology, we must also pay attention to the raw materials of heat strip. If the defective heat insulation strip is used, no matter how good your other equipment is, the service life will be greatly reduced. It's like a luxury car you bought for one million yuan. It's equipped with a tractor engine. Do you think your luxury car has any meaning?