Broken bridge thermal insulation aluminum alloy is to divide the original integrated profile into two on the basis of traditional aluminum alloy, and then connect the separated two parts together by means of mechanical compounding by two thermal insulation strips.
One: the role of heat insulation strips
The nature of the heat insulation strip determines that it must have both high strength and low conductivity, otherwise it will cause major quality hazards in insulated aluminum alloy doors, windows and curtain walls (insufficient strength will cause the insulation aluminum profile to break from the joint of the insulation strip) , Or lose the meaning of heat insulation (high conductivity, the heat insulation effect cannot be guaranteed), so the material selection and manufacturing process of the heat insulation strip are very critical.
Two: Types of heat insulation strips
At present, there are mainly two types of thermal insulation strips used in the broken bridge aluminum doors and windows on the market, one is PA66GF25 thermal insulation strip, and the other is PVC thermal insulation strip.
1. PA66GF25 heat insulation strip: PA66 is a series of modified engineering plastic alloys. It has a 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 linear expansion coefficient. Through experiments, adding 25% glass fiber to PA66 is modified into engineering plastic as the basic material of the heat insulation strip. It is good, and there is no new material for insulation strip that is more reasonable and economical than this.
2. PVC heat insulation strip: the main raw material is PVC resin powder plus 25% calcium carbonate.
The difference between the two:
1: Tensile strength
PA66GF25 heat insulation strip＞126N/mm
PVC heat insulation strip around 70N/mm
2: Heat distortion temperature:
PA66GF25 insulation strip 240 degrees
PVC insulation strip 90 degrees
3: Aging resistance:
PA66GF25 heat insulation strip is durable and not easy to age
PVC heat insulation strips are easy to age
4: Expansion coefficient:
PA66GF25 insulation strip has the same linear expansion coefficient as aluminum alloy
The linear expansion coefficient of PVC heat insulation strip and aluminum alloy is very different
Three: How to identify
1. Looking at the gloss, the surface of the PA66GF25 heat insulation strip of the broken bridge aluminum window is a frosted texture, and the color is anti-black; but the PVC heat insulation strip looks smooth, shiny, and the color is white. The two can be clearly distinguished by comparing them together.
2. Another point is that PA66GF25 heat insulation strips are not combustible. PVC heat insulation strips will burn after ignited for a while and you will see a small flame, and there will generally be a smell of plastic.
3. PA66GF25 insulation strip will break once or twice, while PVC insulation strip needs to be folded more than ten times before it breaks.
4. When the PA66GF25 heat insulation strip is broken, the sound is clear and crisp, and the fracture is neat and not deformed after being broken, and it can be restored by butting. After the PVC heat insulation strip is broken, the fracture is white and deformed.
Four: Summary
When buying broken bridge aluminum alloy doors and windows, in addition to paying attention to the wall thickness, glass, hardware accessories and craftsmanship of the door and window profiles, you must also pay attention to distinguishing the material of the heat insulation strips. If you use inferior heat insulation strips, no matter what you have. How good the configuration is, the service life will be greatly reduced. It's like a luxury car you bought for 1 million, with everything in it, but you got a tractor engine. Do you think your luxury car is meaningful?