To day, we will introduce to you the method of testing the painted surface after the simplest processing of electrostatic painting. Giving you the best view of the quality of powder coating, a new technology in Vietnam.
In the previous section, we also introduced briefly about the ways to check the surface of electrostatic paint for your reference, but in that part, the testing steps are more complicated, requiring complicated machines, but here You can check it now.
Before and after powder coating, we have to consider some problems when using and checking the quality of powder coating surface. In order to ensure uninterrupted powder coating processing, high efficiency is achieved as well as to give the best quality after electrostatic painting products.
Quality control method of powder coating surface
a. Film thickness measurement
Currently on the market there are many paint thickness gauges so the test of this part is also very simple and fast.
Before being put into an industrial drying oven: Check the thickness of the paint film with electronics with a standard plastic film, a rake comb, laser technique or visual inspection.
After drying: Use electronics with standard plastic film.
Testing method of powder coating surface
b. Check the paint color
There are ways to check the color of powder coating:
Use laboratory equipment
Use a portable device
Compare with standard eye color sample
Note: Use a standard light source when adjusting colors.
c. Check the gloss of paint
To test the gloss of the powder coating surface, we use a gloss meter at many different angles:
60-degree angle: The angle most commonly used in the powder coating industry.
20 degree angle: Used when measuring the gloss of powder coated surface with high surface gloss.
85-degree angle: Used when measuring the gloss of powder coated surfaces with low surface gloss.
d. Ability to cover
Use black and white panel to determine the coverage of powder coating
e. Check for errors on painted surfaces
Possible errors on powder coating surfaces:
Specks: Due to other powders, from kilns, dust from the environment, …
Fire hole: The surface is contaminated with substances such as silicone, acrylics, oil or lubricant and some other substances that are not compatible with powder coating.
Needle holes: Due to the exhaust from paint film or painted object, the surface is contaminated, the electrostatic powder powder is moist, …
f. Impact resistance test
Measure the deformation of the coating
Carry out inspections on the front and back of the sample paint panel
Film thickness should be as standard (60-80 microns).
The impact resistance is determined by the weight of the fruit and the maximum height without coating breaking (inches x pounds or Joule).
Checking film viscosity
Test for elasticity / elasticity of Cupping or Erichsen
Determine the plasticity / elasticity of the paint film by slowly deforming the paint film. A marble is pressed into the pattern plate and pushed deep until a crack appears, recording the resulting length.
g. Bending degree
Use a conical measuring device to bend a paint film (Conical) or a cylinder (Mandrel).