Preheating treatment method for heat shrinkable film label

The preheating treatment method of heat shrinkable film label includes preheating of heating plate, preheating of oven, preheating of infrared ray, high frequency electric heating and so on.

Preheating of the heating plate: the plastic is placed on a metal plate which can be rotated horizontally with electricity, gas or steam to the specified temperature, and the surface of the press plate can be preheated.

Preheat the oven device inside the oven with forced air circulation and accurate temperature control, general electric heating resistance wires, using resistance heating wire heating air, then the hot air will be heated to a predetermined temperature of plastic, and the fan forced air circulation. Because of the poor thermal conductivity of plastic, resulting in a larger temperature difference between the inner and outer layers of plastic, so the need to preheat the plastic roll out, and the thinner the better, and every once in a while.

Infrared preheating: the use of infrared radiation to the surface of the plastic into heat energy, heat conduction to the inner layer of plastic. The equipment is equipped with infrared lamp box, the inner wall of the box painted with white paint or chrome plated, external use of asbestos board insulation. The preheating temperature is controlled by adjusting the wattage of the lamp, the number of the plastic, the distance between the plastic surface and the lamp and the irradiation time.