Electrophoretic paint for iron casting parts

Electrophoretic paint is also known as cataphoresis painting, KTL painting or electrophoretic coating, which is a new type of paint with low pollution, energy saving, resource saving and good anti corrosion. Currently, electrophoretic paint is widely used to iron casting parts for automotive, mechanical, and home appliances.

Types of electrophoretic paint

There are two types of electrophoretic paint, one is anodic electrophoresis paint (ED), another is cathodic electrophoretic paint.

Anodic electrophoresis paint is using carboxylate with high acid value to form a potential difference at the two poles. So, there is Electronic precipitation at the anodized surfaces. The positive pole is the iron casting part, so the paint will be covered on its surfaces.

Cathodic electrophoretic paint is using a cation type compounds, after dissolution, they could form potential difference at the two poles, so there is electronic precipitation at the surfaces of cathode surfaces.

Characters of electrophoretic coating

1. Electro Deposition can achieve fully automatic production, so will increase productivity, therefore, it is more suitable for the large volume flow production.

2. ED has high swimming through rate, and low viscosity, so easier to reach the groove shape positions and cracks. Especially suitable for iron casting parts, because its high electrical conductivity.

3. The utilization rate of the paints could reach 95% to 100%, so this process could save materials, and so reduce the painting costs.

4. Electrophoretic paint has good anti-rust ability because of its uniform thickness of coating, and good adhesive force.

5. Electrophoretic paint demand less solvent, so it is better for environmental protection, and higher safety for production.

The advantages compared with electroplate, spray paint and dipping paint

1. Compared with spray painting and dipping paint, the electrophoretic paint can control the thickness of coating more easier and accurate.

2. As for the iron castings with complex inside structures, the ED could form uniform coating.

3. The ED has low moisture content, so the thickness is uniform, and free of ripple and nodule problems.

4. Electrophoretic paint does not use organic solvent, so will not cause fire disaster or heavy metal poisoning, and pollution problems.

The disadvantages of ED

1. The ED requires the electrical conductivity of coated parts, so it is more suitable for metal parts, such as iron and steel castings parts.

2. The coating of cathode electrophoresis paint has higher anti-rust capability, but it is hard and brittle, not very flexile, and worse glossiness. So, it is more suitable for primer painting.

3. The coating of anodic electrophoresis paint has better glossiness, anti ultraviolet radiation resistant aging, better appearance, so suitable for finish coating, but it is has worse heat resistance and abrasive resistance.

In China, most of iron foundries can not perform this coating in-house, but there are some professional coating workshops providing this service. So, iron foundres could entrust them to do the electrophoretic paint for their cast iron and cast steel products.

As for the costs of KTL painting, it is not cheap. It is more costly than electroplating, and almost same price with the hot dip galvanizing.

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