Film prepative method

In order to make the test results of the coating film accurate and reliable, it is necessary to prepare a standard coating film that meets the requirements. According to the provisions of the product standard , a uniform coating film with a certain thickness is prepared on the specified substrate, which is the basis for coating film testing. The prepared coating film should be able to truly reflect the essence of the coating film, even if there are defects, it must be reflected, but the essence of the coating film cannot be changed due to external reasons, such as the environment of the preparation.

In order to obtain a uniform coating film model, attention should be paid to the selection and treatment of the bottom plate, the preparation method and conditions, etc. The material of the bottom plate is selected according to the product standard, and the surface treatment must meet the requirements. When preparing a coating film, the viscosity of the coating, preparation method, ambient temperature and humidity, drying conditions and time, etc. must strictly abide by the specified requirements.

All countries have established standard methods for coating film preparation. CHINA's national standard GB/1727-92 "General Preparation Method for Paint Films" stipulates the materials for preparing general coating films, the surface treatment of the bottom plate, the method of making plates, and the drying and state of the coating film. Conditioning , constant temperature and humidity conditions, and coating thickness. The plate making method lists brushing method, spraying method, dipping method, knife coating method, uniform paint film preparation method (rotator painting method) and pouring method. Among them, Spin Coater and paint film preparer (or scraper ) are commonly used preparation instruments.

1. Spin coating method

CHINA's national standard GB/T 6741-86 "Preparation Method of Uniform Paint Film (Rotary Painter Method)" stipulates that a rotary painter prepare a sample for measuring the general properties of the paint film. As shown in Figure 4-1, the rotary paint applicator consists of a speed regulating motor, a time limit switch, a sample fixing frame and a disc container for collecting excess samples.

2. Scratch coater method

The instrument used in the scraper method is called a scraper or a paint Film Applicator, as shown in Figure 4-2. Later, a groove-rod scraper was developed. In order to make the operation of the scraper smooth and uniform, and to eliminate human operation errors, it has now developed into an automatic paint Film Applicator driven by a motor The paint film is more even and consistent.