Introduction to the Simple Process and Process of PVC Liquid Immersion

Liquid immersion coating is a complex physicochemical and colloidal chemical process. The process conditions directly affect the quality of plastic protrusions. To ensure normal production, strict and scientific management of the process conditions is necessary. The following is a brief introduction to the liquid impregnation coating process and process:

1) The preheating temperature of the coated object is generally proportional to the thickness of the plastic coating. A high temperature means a high amount of hot melt, and a higher amount of coating will adhere to the surface of the coated object, resulting in a thicker coating after curing; On the contrary, the coating must be thin, and may not even reach the minimum thickness value.

2) After the preheating temperature is set, the length of the immersion time is generally proportional to the thickness of the plastic coating. The longer the immersion time, the more adhesive the coating will be, and the thicker the coating will be; On the contrary, the thinner it is.

3) The immersion angle of the coated object directly affects the uniformity of the coating thickness. If one end is immersed in the impregnation solution first, its contact time with the coating solution is longer than the other end, the result must be uneven coating thickness. To maintain consistent coating thickness on the entire surface of the coated object, it must be parallel immersed in the impregnation solution, that is, zero angle immersion.

4) When the speed at which the coated material is immersed in the impregnation solution (i.e. the container containing the impregnation solution rises) is too fast, the impregnation layer is prone to air entrapment, resulting in defects such as holes. When it is too slow, due to the high temperature of the area where the coating is first immersed in the impregnation solution and the long contact time with the coating solution, the coating will be thick; On the contrary, if the temperature of the part that is immersed in the impregnation solution is low (during the impregnation process, the temperature of the coated material shows a downward trend), and the contact time with the coating solution is short, the coating will be thin, so if it is too slow, it is easy to produce uneven thickness defects in the impregnation layer. From this, it can be seen that the speed at which the coated material is immersed in the impregnation solution is too fast or too slow, which will affect the appearance quality of the coating layer. Therefore, automatic equipment must be used to strictly control it within the process range.

5) When the speed at which the coated material leaves the impregnation solution (i.e. the container containing the impregnation solution descends) is too fast, the impregnation layer is prone to defects such as flow marks (sagging) and hanging points. When it is too slow, due to the difference in temperature of the coated object and the time of contact with the coating liquid, it is easy to produce uneven thickness defects in the impregnation layer. Both will affect the appearance quality of plastic coatings, so it is necessary to use equipment to control the speed of the coated material leaving the immersion solution within the process range.