Analysis of Orange Peel Effect in Powder Coating

The choice of powder coating with a high resin content, which offers good weather resistance, can contribute to the appearance of the orange peel effect. The higher viscosity of the melted powder during leveling makes it difficult for the powder to flow smoothly, leading to the orange peel texture.

A significant proportion of powder particles with a diameter larger than 75 µm can result in poor leveling performance of the coating, making it more prone to the orange peel effect.

Leveling agents are essential additives used in powder coating production to improve the leveling and uniformity of the coating, enhance film smoothness, and reduce the occurrence of the orange peel effect.

Uneven application of powder from the spray gun can lead to variations in powder thickness adhering to the surface of the workpiece. This can result in difficulties in leveling and increase the likelihood of the orange peel effect.

If the leveling time is too short, and the powder does not have sufficient time to level properly, the resin molecules in the powder may undergo agglomeration and addition reactions with the curing agent, forming a large molecular network structure. This inhibits the powder's ability to level, resulting in poor leveling and the appearance of the orange peel effect.

During curing, the rising flow of hot air and direct infrared radiation often create more vertical surface ripples than horizontal ones. If the heating rate is too fast, it can increase the number of vertical ripples, hinder proper leveling, and lead to the occurrence of the orange peel effect.

The condition of the workpiece's surface plays a crucial role in the powder coating process. An uneven or non-smooth workpiece surface can negatively impact the leveling of the powder coating, making it more susceptible to the orange peel effect.

An uneven or discontinuous phosphating layer on the workpiece can lead to the appearance of the orange peel effect after powder coating.

Addressing these factors through proper powder coating procedures, adjustments, and quality control can help minimize the occurrence of the orange peel effect and achieve smoother, more even coatings.