Aluminum die-cast painting was all about pinholes in quality.
The true cause of pinhole formation is not the paint, but insufficient gas release. This explains how it can occur even with heating at 60 degrees.
Pinhole defects are tiny holes that form in countless numbers on the surface of the paint film. In automotive parts, they are considered aesthetic defects and can lead to complaints, with cases where delivery delays and re-manufacturing costs increase by an average of 200,000 to 300,000 yen. The importance of the degassing process: Many sites tend to think that "the quality of the paint is low," but in reality, gases remaining in aluminum die-cast or pressed parts expand at a curing temperature of 180 degrees and form holes when released from the surface of the paint film. Humidity management is crucial: In environments with humidity above 60 percent, moisture absorbed by the material vaporizes, increasing the pinhole occurrence rate by 40 to 50 percent. By simply heating to 100 degrees for 5 to 10 minutes in the pre-curing process, the occurrence rate can be reduced by 70 percent. The effect of pre-degreasing: By setting the temperature of the degreasing solution to 55 degrees just before painting and ensuring a soaking time of 3 to 5 minutes, the amount of gas inside the material can be reduced by up to 80 percent. Addressing pinholes is not about changing the paint but optimizing pre-treatment and environmental management. Our company optimizes the degassing conditions for each material in small lots, achieving high-quality painting.
basic information
Gas release management, empty roasting process, humidity control, pre-degreasing.
Price range
Delivery Time
Applications/Examples of results
Pinhole reduction, quality improvement
Related Videos
catalog（1）
Download All Catalogs
Distributors
We are not just a "subcontracted painting factory." Established in 1958, our company has a foundation of painting technology and also specializes in chemical treatment, stripping, and cleaning, functioning as the "external surface treatment department" in your organizational chart. Based on our philosophy of "preparation is eight-tenths of the work," we emphasize participation from the "upstream process" before the drawings are finalized. We conduct test painting on a wide range of metals and difficult materials, and we produce the entire process from assembly, packaging, to delivery, thereby reducing your management workload. Additionally, by being able to perform zinc phosphate treatment in-house, we achieve stable painting quality. Furthermore, our micro-heating stripping technology, which does not use chemicals, maintains the electrical state of the "jigs (hangers)" that influence painting quality. Our approach of "pre-treatment determines painting quality" ensures the stability of the paint film during mass production. Rather than simply "applying specified standards," we work backwards to achieve optimal painting specifications and prevent scratches during transportation, sparing no effort in thorough discussions from the outset. This diligent preparation is the shortest path to preventing rework and minimizing total costs. From the development stage, please utilize the expertise of our specialists as part of your production line.