Why do the plastic profiles crack?

The main reason is that THE PC molecular chain structure is damaged. Molecular chain is disconnected while resulting in product cracking or surface cracks. 

There are several factors that affect the molecular chain structure:  

 1. Repeated use of materials.  Some PC profile manufacturers will add some or even secondary recycling materials in raw materialsin order to reduce costs. PC materials are repeatedly used, under the action of constant high temperature, themolecules will occur fission andmolecular chain will occur fracture, cracking.  It can change high polymer materialinto low molecular material,thenthe materials become brittle.   

2. Excessive stress. First of all, the stress fromthe shape of the product, the size of the mold design andtheproduced by demoulding.  Secondly, the external stress onto the product.   

3. Environmental factors.  The main component of PC is polycarbonate. It is easy to react with the gas produced by glue, washing board water or other components in the LED lamp tube, resulting in brittle and cracked.  In addition, PCprofile in acid alkaline, strong ultraviolet, high and low temperature under the use of the environment, also easy to be affected and reduce the service life.