1. Polyurethane is applied to air filters in the form of hot melt adhesive
1. Assemble the filter element according to the process;
2. Clean the surface of the filter cover, remove oil and dust, and dry it thoroughly. There should be no foreign matter such as oil, water, etc. on the surface to avoid affecting the bonding strength;
3. Inject an appropriate amount of adhesive into the rotating filter cover, so that the adhesive surface is evenly applied to various parts of the filter cover;
4. Insert the filter element into the filter cover, check the surfaces of the two adhesive parts, and after ensuring that they are fully in contact, apply a little pressure on the top and let it stand;
5. After curing for about 2 hours, turn it over and glue it to the other end cover. It can be packaged only after it is completely dried for 24 hours, and it will be shipped after curing for 3 days;
6. Some filter elements need to add a strip on the upper end cover, which can be added in the 5th procedure.
2. Polyurethane is applied to air filters in the form of filter elements
Wet air filter elements are generally used in engineering machinery and heavy trucks. The manufacturing material is soft, porous sponge-like polyurethane.
3. Polyurethane is used in air filters in the form of shells
The shell is produced by pouring PU elastomer, which can save the iron end cover and rubber seal of the air filter element, and it is also the most ideal product for producing wedge-type air filter elements. The shell is divided into end covers and frames, each with different production processes.
1. End cover type: by pouring the mixed AB material onto a rotating iron or plastic disc, and then placing the filter element under pressure, the disc can be detached after a few minutes to obtain the air filter.
2. Through closed mold production, the upper mold is placed with the prepared filter paper, the lower mold is wiped or sprayed with a special release agent in advance, and then the AB material is poured, and then the upper and lower molds are closed. After a few minutes, the mold can be opened to take out the molded air filter.