How to check the quality of powder paint

Quality coating can only be obtained if you carefully adhere to the coating technology and use only high quality powder paints.

Therefore, choosing a supplier of products first, you need to ask if he has all the necessary certificates that confirm the quality. And even if everything is OK with the documents, it is worth checking every batch of powder that comes in the warehouse. And what are the methods of testing powder paints, we will explain below.

1. Flowability

The first thing to check is the flowability. If it is normal, the powder is easily poured and transported by air. Checking the flow rate is quite simple thing. It is necessary to pass the powder through a funnel with different nozzles. So you can relatively evaluate the flowability of paint. You can also determine the flowability using the angle of natural slope of the freely poured powder.

2. Gelling time

The time at which the powder becomes fluid is the time in seconds for the powder to melt and harden the coating. Measurements of this indicator are made at regular intervals. This indicator shows how stable the paint is and whether it can remain in the stock for some time without losing its properties. You can measure this with a “polymerization plate” and a second timer.

3. Spreading

This is a visual characteristic of the powder, which of course affects the decorative properties of the coating. The spread must remain constant throughout. This means that the paint retains its characteristics for a long time, that is, the coating has consistently high quality. This indicator is directly influenced by the composition of the powder paint. The better the powder spreads, the smoother the coating will be. And if it is worse, then the coating will have an “orange peel” effect.

Powder paints make it possible to create coatings of different thickness. As a rule, the greater the thickness, the better the spread of paint. And products with a not very thick coating may be uneven.

The spreading time is also affected by the curing time and temperature. The higher the temperature, the better the figure.

Contamination on the painted surface also affect the spreading. In the worst case, craters can form because of this.

Large and heavy parts heat up more slowly than thin and light ones. This should be taken into account when adjusting the temperature in the polymerization furnace.

Dyeing conditions also affect spreading. Reverse ionization may occur, which has a bad effect on this indicator.

To check the spillage angle the glass plate and heat it, put a powder tablet on top.
It drains, and then you need to measure the footprint of its drain. In order to carry out such a check, you must have a tablet press and a tilting device.

If this figure decreases over time, it means that the powder has already deteriorated.

4. Particle size

The powder particles affect the flowability and the characteristics of the coating. Check it by passing the powder through sieves of different sizes. The number of particles that have not passed through them is measured.

5. Density

This indicator is measured by a liquid or gas pycnometer. You need to know this figure in order to calculate the cost of powder.

6. Volatiles

Inks may include volatile components. Typically, they are released during the stay of the painted workpiece in the polymerization furnace. They are necessary for the paint to harden. But if there are too many, membrane formation may deteriorate. You can check how many of these compounds are in the powder by weighing before and after exposure of temperature.

In order to protect yourself from the purchase of low-quality paint, it is imperative to ask the supplier for the necessary documents and check every batch of paint that goes into production.