Classification of precision coating methods

Classification of precision coating methods

Traditional coating methods, such as comma coating or roller coating, are simple and easy to operate, but can only produce low value products with a unit price of less than 10 yuan/square meter. Moreover, this coating method belongs to the open operation mode, which will cause the problem of solvent volatilization and affect the health of operators. Nowadays, the awareness of environmental protection is becoming more and more important, and it is necessary to make appropriate adjustments.
The establishment of precision coating technology can be used in the development of various products, including our food packaging field, with the development of various high-performance coatings. In order to pursue high-quality and high-precision coating products, each stage of the production process needs to be completed through high-quality design.
There are many coating technologies, mainly divided into two categories: one is called dry precision coating, such as vacuum deposition or chemical vapor deposition. The other is called wet precision coating, that is, the liquid coating material is coated on the substrate, dried and solidified into a film.
Precision coating can be divided into post test method and prediction method according to different hydrodynamic characteristics.
Precision coating: The common feature of these coatings is that the film thickness is affected by the rheological properties of the film solution and the film conditions. Among them, dip coating is commonly used. The coating thickness increases with the increase of coating speed, but not in direct proportion. With the increase of film speed, the thickness will tend to a fixed value or decrease. Others such as scraper plate and roller coating are such coatings.
Thickness coating: the thickness of precision coating is only set by the perfusion system and does not change with the rheological property of the coating solution or the coating speed. The principle of this type is to pump a self stabilizing coating into a precisely designed extrusion die to form a wide and uniform film, and then apply it on the substrate. This coating method includes groove coating, sliding coating, curtain coating and intaglio coating. Because most electronic products are developing in the direction of light, thin, short and small, and the requirements for precision and uniformity of coating products are gradually improving, domestic coating manufacturers have also set off an investment boom in research and development of precision coating related technologies in recent years, among which precision mold coating is more popular.
The metering pumps commonly used for precision coating include screw pump (screw pump) and gear pump (gear pump). Their common characteristics are as follows: continuous delivery without pulsation. It can be quantitatively transported from aqueous liquid to high viscosity of several hundred thousand centigrade difference (CPS). Roast metering accuracy is high and reliability is high, and roast metering accuracy is within ± 1%; Variable speed motor is used to change the flow range; The structural design of the valve is not adopted, which will not block; Strong self suction capacity, high suction and discharge pressure; Stable operation without vibration and noise; The disassembly and maintenance shall be as simple as possible.