a method and mechanism for continuously making a plastic film with shaped profiles on the surface including extruding a continuous length of interlocking profiles from a die shaped with a precise shape for interlockingly engaging with another profile and directing a flow of coolant on the profile from a stationary coolant means and adjusting the direction of flow of coolant relative to the direction of movement of the profile or controlling the pressure and temperature of the flow of coolant to control the cooling rate and the shape of the profile .