The coating machine extrusion coating is to apply the molten mesh of synthetic resin onto the base material. It is a multi-functional coating technology, which is used for the economic application of various plastics, especially polyethylene, cardboard, corrugated fibreboard, paper, aluminum foil, cellulose, non-woven fabric or plastic film. What are the characteristics of the coating extrusion technology? Today we tell you:
Characteristics of Extrusion Coating Technology of Coating Machine
The monotony of the size after coating by the coater consists of the following two kinds of heat and mass transfer processes
1. Vaporization process of external liquid
The wet coating absorbs the heat of the monotonous air through the heat exchange with the monotonous hot air. The liquid on the surface of the coating continuously evaporates into steam and enters the air, and the steam is taken away by the monotonous air.
When the coating is monotonous until its moisture content reaches the critical moisture content, the external vaporization speed depends on the loose speed of the liquid inside the coating.
2. The internal liquid looseness process, because the vaporization on the surface of the coating reduces the concentration of the liquid on the surface of the coating, and the liquid inside the coating continuously loosens toward the surface.
(1) The coating after coating in the transition stage enters the monotone chamber, and the temperature of the membrane decreases gradually due to the vaporization and heat absorption of solvent or water, resulting in a leveling process.
(2) The monotonous phase of speed reduction, which is characterized by:
A. Monotonic speed is controlled by internal loose speed
B. Monotonic speed decrease
C. The coating temperature increases monotonously for a long time
(3) Constant speed monotone stage, characterized by:
A. There is satisfactory water or solvent on the surface of the coating,
B. The monotonous speed is controlled by the external condition - gasification speed.
C. Monotonic speed and stability
D. Most of the water or solvent is gasified at this stage.
Consulting