If flame intensity is high enough, and residence time of plastic in the flame is increased, modification and realignment of surface molecules creates a stronger plastic surface, which is also smoother and with fewer micro cracks and weak points.

This effect is often called surface polishing. It requires a high intensity burner flame and accurate control of plastic product residence time in the flame. This process is often used in plastic tube manufacturing where tubes can be stretched around 50% after initial extrusion. Surface weak points and micro cracks in the original extrusion significantly reduce the stretching capability if the product is untreated. For more information about our surface modification systems, please contact us.