Application of Doctor blade Film Applicator in prepative foam coatings

The coating machine plays a vital role in coating preparation. In the foam coating finishing process, the foam coating finishing aims to evenly and completely coat the prepared foam on the surface of the fabric. After heat treatment and drying , adhere to the surface of the base fabric, thereby improving the performance of the base fabric and obtaining materials with excellent performance. Its main function is to evenly apply paint, solution or other materials on the surface of the base fabric to ensure coating uniformity and quality. After coating is completed, the Film Applicator can also assist in subsequent processing, such as heat treatment or curing, to ensure that the resulting coating has the required performance and characteristics.

In the blade coating method, the Film Applicator plays a key role. It uses a scraper to apply foaming solution on the surface of the base fabric, and uses the downward pressure of the scraper to scrape the foam onto the surface of the base fabric. After the coating is completed, the coated fiberglass cloth must be heat treated immediately to avoid excessive penetration and rupture of the foam and ensure that the intact foam structure is retained. This heat treatment process is usually divided into three stages.

The first stage is low-temperature drying. The drying temperature range is between 120-180°C. The main purpose is to evaporate the water in the foam coating to obtain a dry coating structure, retain the cell structure, and provide the basis for the subsequent formation of microorganisms. The hole coating structure lays the foundation.

The second stage is high temperature sintering, the sintering range is usually between 330-380℃. The coated fiberglass cloth is sintered near the melting point of PTFE to remove all impurities in the foam coating, and PTFE can remain stable at this temperature without decomposing, thus forming a fiberglass fabric with certain mechanical properties and dimensional stability. PTFE microporous structure.

The third stage is slow cooling treatment, with the temperature ranging from 360℃ to 100℃. This stage further optimizes the structure of the coating. According to previous experimental results, after heat treatment of the polytetrafluoroethylene hollow fiber membrane, it is placed in a cooling oven and the heat treatment is continued for a period of time. More features can be obtained. Hollow fiber membrane with better pores and performance. This shows that thermal insulation has a certain positive effect on improving the pore structure.

In the process of preparing PTFE foam-coated glass fiber composite filter materials, the film coating machine also plays an indispensable role. This complex material preparation process requires precise steps and efficient equipment, and the coating machine is one of them, which is related to the uniform coverage of the coating on the fiberglass substrate and the excellence of the coating quality.

First, raw materials such as PTFE emulsion, betaine, Tween, acrylic resin and methylcellulose are accurately distributed through a pipette, and mixed together according to a certain formula ratio to form a prepared PTFE foaming liquid. The accuracy of this step is critical to the subsequent coating process, as the Film Applicator is required to accurately apply this complex coating. Then, the Film Applicator comes into play. The high-speed stirring rod stirs the solution to quickly produce and obtain a foaming solution. When the coating machine is operating, the foaming liquid is applied on the substrate by pushing the scraper at a constant speed to ensure that the foam is evenly coated without damaging its structure. After completing the coating, immediately send the coated fiberglass substrate to the hot air dryer for a short drying process, and then send it to the preset temperature for rapid drying. At this time, the coating effect of the coating machine Critical to the quality of subsequent steps. Next is the sintering process. The coating prepared by the coating machine needs to be sintered briefly under high temperature conditions. After sintering is completed, the coated glass fiber substrate needs to continue to undergo a slow cooling process. This step is a key step to ensure the structural stability and performance consistency of the coating.

After this series of precise and complex steps, the coating machine successfully prepared the PTFE foam-coated glass fiber composite filter material. This Film Applicator plays a key role in the process, ensuring the uniformity and quality of the coating so that the final product has the required filtration performance and stability.