Coating leveling and sagging

In the Coating industry, the leveling and sagging properties of Coatings are two key performance parameters that directly affect the performance of Coatings during construction and curing. This article will delve into the leveling and sagging properties of Coatings, including their definitions, testing principles, and impact on construction.

Definition and test principle of levelling

Leveling refers to the ability of the film of Coating to flow from an irregular and uneven surface to a flat and smooth surface after construction. It reflects the self-equilibrating ability of Coating after construction, and is usually used to evaluate the performance of Coating during brushing or lame plating.

The principle of testing levelling is to observe the ability of the Coating to spread itself and eliminate surface irregularities during the drying process after construction. This process is affected by many factors, including Coating composition, performance, surface tension, shear force, and construction method.

Levelling is directly related to the Appearance mass of the film. When brushing, the brush marks on the film should disappear quickly, and when lame plating, the paint mist grain marks should also disappear quickly to ensure that the film surface is smooth and uniform.

Definition and testing principle of sagging

The sag property is the phenomenon that the thickness of the paint film is uneven due to the downward movement of the wet-film during the process of painting to curing. It is a comprehensive manifestation of the flowability and adhesion of Coating under specific conditions.

The sag property is usually observed in the construction of the vertical surface. It may be manifested as the entire vertical surface Coating falls to form a curtain-like sag, or it may be manifested as local cracking, excessive Coating at the nail hole or small hole causing irregular thin strips to fall., called flow column or tear sag.

The principle of testing sag property is to observe whether the Coating is coated on a vertical surface and tends to fall together during the drying process. Usually, coatings of different film thicknesses are used to observe whether sag phenomenon occurs. According to the provisions of GB/T 9264, the thickness of the last coating is the maximum thickness that does not produce sag during construction.

Influence of leveling and sagging on construction

Impact of leveling on construction:

Excellent leveling can reduce the uneven surface of Coating during brushing or lame plating, provide a smooth film, and improve the appearance mass of the film. Good leveling helps reduce the possibility of operational errors, improve the work efficiency of construction personnel, and reduce the waste of Coating. Coating with poor levelling can cause brush marks or paint mist marks on the surface of the film, requiring additional repair work and increasing construction costs and time.

Influence of sagging on construction:

Good sag sexual suggesageeness means that during vertical construction, the Coating will not have uneven sag phenomenon and maintain the uniformity of the film. Coating with poor sag properties may lead to thick edges, curtain sag or flow columns in the lower part of the film, which reduces the construction mass and requires additional repair work.

In Coating engineering, leveling and sag are two crucial performance parameters. Understanding the leveling and sag of Coating helps to select suitable Coating, improve construction efficiency and ensure construction mass. For Coating manufacturers, continuous research and improvement of the leveling and sag of Coating is a key factor to improve product competitiveness. Therefore, the Coating industry should pay attention to the testing and optimization of these two performance parameters to meet the evolving market demand. The good performance of leveling and sag not only helps to improve the market position of Coating, but also helps to achieve the goal of sustainable development.