Bubble problem in waterborne metal paint film formation
- 2018-07-18-

Water-repellent metallic paint Bubble problem during film formation

With the advancement of the times, people's environmental awareness progress, water-based paint as an environmentally friendly paint, the future can not be limited. Tianmai Waterborne Metallic Paint is a wide range of environmentally friendly coatings with decorative functions for the appearance of various metal products. This series of coatings can be divided into: water-based metal baking varnish, water-based self-drying metal lacquer , water-based rust-proof lacquer and so on. It can be customized according to the customer's needs. The advantages of water-dilutable metal coatings are clear to us, but water as a solvent also brings some difficulties in application. This is a strong reaction with water, high polarity, high surface tension, large heat capacity, and slow evaporation. Evaporation is associated with problems such as the effects of air pressure and airflow. These problems require some construction techniques to be noted during preparation and painting. Regarding the bubble problem in the process of water-based metallic paint film formation , Tianmai engineers made the following analysis.

When the water-dilutable coating is dried to form a film, the bubble problem is quite serious. Especially when the coating is thick, the reason is quite complicated. Generally, the viscosity of the upper part of the coating evaporates rapidly, the glass transition temperature is advanced, and the water of the base layer is not easily evaporated. And stay in the lower part, once the temperature rises again, it can suddenly vaporize and form a bubble and be stabilized and intercepted on the outside. Even if the bubble rushes out of the surface, it will leave shortcomings because it cannot be leveled. There are ways to improve this problem:

  1. a boring moment before the oven is extended;

2. The drying tunnel in the oven is lengthened and divided into different temperature zones;

3. Control the thickness of the paint film, not too thick;

4. Control the evaporation rate of the amine, keep the coating alkaline before the water escapes a lot, and make the cross-linking reaction slower, so the glass transition temperature does not rise too fast, dimethylaminoethanol is an amine commonly used, but Its anti-bubble effect is not good, triethanolamine is better;

5. Avoid trapping gas in the guessing, and let it stand before applying the paint;

6. Use an amino resin for high temperature curing;

7. The glass transition temperature of the resin should not be too high;

8. Pick a cosolvent that evaporates slowly.

The company adhering to the "people-oriented, customer first" business philosophy, to provide customers with comprehensive after-sales service, to solve a series of process or technical problems encountered in the customer's use. Guangdong Water-based metal paint manufacturers, Guangzhou Tianmai water paint, to provide you with a full set of metal water-based coating application technology solutions. For technical advice on water-based metallic paint coating, technical advice on “oil to water”, welcome your call!