Negative-pressure coating method

Abstract

The invention relates to a negative-pressure coating method comprising the steps of a. providing a tool with a coating supporting body, enabling the coated surface of the coating supporting body to face to an open space, and locating the non-coated surface of the coating supporting body in a negative-pressure space communicated with negative-pressure equipment such as a vacuum pump; b. at least arranging the whole coated surface of the coating supporting body in the tool into slurry, and isolating the non-coated surface of the coating supporting body from the slurry; c. enabling the air pressure inside the negative-pressure space to be lower than the pressure in the slurry through the negative-pressure equipment, and attaching powder particles in the slurry onto the coated surface of the coating supporting body under the action of a pressure difference to form a coating; and d. sintering the dry formed coating supporting body with the coating to form a porous film. The negative-pressure coating method disclosed by the invention is very simple and feasible, the efficiency of uniformly and rapidly coating the coating supporting body is greatly increased, meanwhile, the forming quality of the coating is also remarkably improved, and the stability of the filtering effect of the porous metal film is greatly improved.

Description

technical field [0001] The invention relates to a film coating method, in particular to a negative pressure film coating method. Background technique [0002] In many industries including high-temperature filtration, it is necessary to filter gases through filter membranes. A common structure of filter membranes is metal membranes, the base material of which is metal, and the membrane material is metal or metal oxide, and is used for separation Porous membranes for gases and impurities in gases, where the membrane material is composed of powder particles. The separation process is to use the gaps between the powder particles of the membrane material to separate the gas and impurities. The size of the gaps between the powder particles is generally hundreds of nanometers. [0003] According to the cross-sectional structure of the porous metal membrane, it is further divided into a symmetrical porous metal membrane and an asymmetric porous metal membrane. As the thickness of ...

AI Technical Summary

Problems solved by technology

The efficiency of manual painting is low, and the thickness of the film layer is uneven. The main reasons include: 1. The amount of film liquid sprayed by the spray gun is not uniform; 2. The moving speed of the spray gun is not uniform. The larger the amount, the greater the thickness of the spraying, and the moving speed of the spray gun is controlled manually, which cannot guarantee that the spraying amount at each position is consistent; 3. It is difficult to control the number of repeated spraying

When spraying manually, it is generally necessary to repeat the spraying on the spraying object several times. In this process, it is impossible to guarantee that each part is sprayed the same number of times. For example, when spraying a certain part, other sprayed parts around it may also be sprayed.

Although the efficiency of mechanical spraying with tools is high, there are still problems such as uneven spraying of film liquid and repeated spraying, and the thickness of the film layer is still difficult to control.

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