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How can surface cleaning of HEPA filters increase adhesion?

Surface cleaning of HEPA filters increases the adhesion, which in the case of HEPA filters is mainly related to the choice of material for the spraying surface.

Choosing the right spray material and spray surface not only makes gluing easier but also reduces the cost of gluing.

Nowadays, the competition in the high-efficiency filter industry is relatively fierce and the price is a common concern. To reduce the cost of high-efficiency filters, we must consider the choice of various materials from a general point of view to ensure both product quality and cost reduction, and it is incorrect to focus on just one aspect.

The latter two methods are rarely used in the manufacturing process of high-efficiency filters, but others can be a combination of one, two, or several methods, of which surface cleaning is an indispensable method.

Any object will have a layer of oxides, hydroxides, lubricants, anti-rust oils, release agents, dust, and other foreign contaminants which prevent the adhesive from wetting the surface to which it adheres and which need to be properly treated.

In high-efficiency filters, many products have metal frames such as galvanized sheets, stainless steel sheets, aluminum alloys, aluminum sheets, etc. These metal frames are exposed to the air and generally absorb a certain amount of moisture and dust.

These contamination layers and oxide films with low cohesive strength and surface energy will reduce the strength of the glue joint.

Before gluing, the metal surface should be properly treated to ensure that it is free of dust, moisture, and oil.

The method used can be surface cleaning or degreasing, depending on the actual condition of the metal frame.

The outer packaging of the high-efficiency filter is intact and free of stains, without traces of impact and cracking; the inner packaging (plastic bag) should be sealed intact, the foam corner and foam board should be complete, the model, air volume, air flow direction, and other markings should be complete, accurate and complete, with the product factory certificate of conformity, etc.

Frame High-efficiency filter frame surface without obvious pollution, no dents, scars, no scratches, coating, no flaking, no burrs, or rust spots; High-efficiency filter frame (sticky seal side) should be flat, with no obvious deviation; High-efficiency filter frame strength should meet the requirements, such as placed on a flat surface, shaking, no deformation of the frame, shaking situation.

The seal between the filter paper and the frame of the high-efficiency filter should be tight, without gaps and holes; the sealant strip between the high-efficiency filter and the frame should be connected, without fracture, and visually flat, and the thickness of the sealant strip between the high-efficiency filter and the frame should not exceed 8mm, with a compression rate of 25%-30%.

The number of layers of filter paper folded on one side meets the requirements, the height of the paper partition should be between 4.0-4.5mm; the filter paper is free from damage, stains, debris, wrinkles, glue, and patches; the partition is free from obvious damage, flush and even; the sealant is neat and free from cracks, the height of filter paper and partition infiltration is not more than 5mm, and there should be no cracks, bubbles, holes, and wrinkles in the frame where the filter paper and sealant are stuck together.