In order to let the customer can buy the real product, ZUNPIN casters introduced a simple identification methods. 

This method is called "burning". We can identify castor materials based on the flame, smoke smell, and ash after burning: 

Polypropylene (PP) : Flammable, with a slight plastic odor. When burned, the surface melts evenly and has a viscous filament. 

Nylon (PA) : does not burn easily. The smell of burnt hair. After combustion, the surface is foam and the silk body is sticky. 

High temperature nylon PA: Burning conditions are the same as PA, but there is white powder on the surface after burning. 

Polyurethane (PU) : flammable, white smoke when burning, easy to melt, no pungent odor, silk sticky. 

Polyvinyl chloride (PVC) : flammable, burning when strong black smoke, irritating odor, non-stick silk, burning surface is black toner.

There are many ways to verify castor material, we just provide a simple method.

 If it is necessary to know the specific ingredients, sophisticated tests such as RoHS, SDS, and Reach are required, and these tests are provided by third party companies.