涂装施工过程中, 漆膜的收缩问题可能会导致涂层的质量和外观, 所以有必要深入了解缩孔的产生原因及解决办法. 本文将讨论油漆收缩的原因以及如何有效应对这一挑战.

1. 缩孔产生的原因
缩孔通常是由低表面张力的小颗粒或液滴引起的. 这些低表面张力物质可以存在于基材表面, 在油漆中, 或在湿膜刚涂完后从空中掉落. 造成缩水的主要原因有以下几种:

A. 表面张力梯度: 当油漆或基材表面存在低表面张力物质时, 将产生表面张力梯度. The low surface tension part of the paint will try to flow to cover the surrounding high surface tension part, but the volatilization of the solvent will cause the viscosity to increase, and eventually hinder the flow, forming a shrinkage hole.

油漆缩孔的原因及解决方法

乙. Thick edge phenomenon: When spraying the plate, the paint film is usually thicker at the edge and thinner slightly away from the edge. This is because the air flow is strongest at the edge, and the solvent volatilizes the fastest, resulting in an increase in the resin concentration at the edge and an increase in the surface tension, so that the paint at the edge flows to the center.

C. Airborne effects: airborne particles may fall on the wet paint film during the spraying process. If the surface tension of the flying material is low, shrinkage holes will be created. 反过来, if the surface tension of the flying object is high, it will lead to the orange peel effect.

2. Solutions for shrinkage holes
In order to avoid or reduce the shrinkage problem of the paint film, the following measures can be taken:

A. Increase the thickness of wet paint film: Increase the thickness of wet paint film can reduce the formation of shrinkage holes. Thicker wet paint films are less susceptible to impurity particles, so shrinkage is less likely.

油漆缩孔的原因及解决方法

乙. Increase the viscosity of wet paint film: by adding thixotropic agents, ETC。, you can increase the viscosity of wet paint film, thereby preventing paint flow, even if there is the possibility of shrinkage can also reduce its occurrence.

C. Reasonable choice of paint: The choice of paint has an important impact on the shrinkage problem. Solubility between the different components in the paint should be considered to avoid indissolution or precipitation during the drying process.

d. Control coating formulation: The formulation of the coating should be reasonably designed to reduce factors that may cause shrinkage. 尤其, attention should be paid to controlling the formation of impurity particles and droplets in the coating.

油漆缩孔的原因及解决方法

e. Use leveling agents: For coatings prone to shrinkage, leveling agents can be added to reduce surface tension while promoting the leveling of the paint. Levelling agents can also be used to prevent the orange peel effect.

F. Curtain coating: Curtain coating is an effective coating method that can reduce shrinkage problems. Under this method, 漆面需要保持完好无损, 确保没有低表面张力的颗粒或液滴落在漆网上.

缩孔是涂料施工中可能出现的常见问题, 但通过合理的控制和预防措施, 这个问题可以有效减少或避免. 适用于需要高质量涂层的应用, 需要特别注意收缩问题，以确保最终涂层的质量和外观符合要求.