Our strength--- Inside Feature of Our Die Head 1. Water cooling through mandril can cool the inner cavity thoroughly, the inner cavity could be smooth and regular, and there will be no swelling taking place. The section view of profile is very regular and good looking. (Air cooling or natural cooling will make the inner cavity liable to swell and make the inner rib uneven) 2. The water flow in the mandril can be controlled by valve, and make the products' inner cavity and outer wall cool synchronously, thus improve the inherent quality such as anti impact strength, meanwhile improve the stability of products' quality in the production 3. The cooling efficiency outperforms air cooling and natural cooling countpart so the product extrusion speed can be improved greatly.