Kaiping is proud to announce a new addition to our release agent product line – now targeting the air filter segment.

Regular replacement of the air filter is one of the routine maintenance items for automobiles.

Working Principle of Air Filters:
During operation, an automobile engine draws in a large volume of air. This air must pass through the air filter to remove dust and particulates, preventing abrasive damage to the piston assembly and cylinders, which would otherwise shorten engine life. Despite its small size, the air filter plays a critical role in the long-term performance of the vehicle.

Types and Manufacturing Process of Air Filters

Air filters come in various types and configurations, but their basic structure remains simple: they consist of a filter element and a housing (end cap/frame). The filter element is typically made of filter paper or polyurethane, while the housing material can be iron, PP (polypropylene), polyurethane, etc.

For trucks, freight vehicles, and construction machinery, the air filter generally comprises a filter element and end caps. The filter media can be filter paper (dry-type) or polyurethane (wet-type). Polyurethane is used in wet-type filters in the form of soft, porous sponge-like foam, which is treated with oil immersion or oil bath during installation. Such filters are reusable after proper cleaning, though their filtration efficiency is lower than that of dry-type filters.

For passenger cars, the air filter typically consists of a dry-type filter element and a polyurethane frame. The filter media is filter paper or non-woven fabric, which is pleated to increase the surface area for air passage. The polyurethane frame is produced by casting PU elastomer, eliminating the need for iron end caps and rubber sealing rings found in traditional designs.

Typical Manufacturing Process:
The production is carried out in a closed mold (usually aluminum). The prepared filter paper is placed in the upper mold, while the lower mold is pre-coated or sprayed with a specialized release agent. The A/B components are then poured, followed by mold clamping. After a few minutes, the mold is opened, and the finished air filter is demolded.

Kaiping Release Agent for Air Filters

Kaiping Chemical, as a domestic manufacturer specializing in release agents for automotive polyurethane components, has established a strong presence in the flexible PU foam sector. This year, the company is expanding into rigid foam, semi-rigid foam, and elastomer applications—and air filters, falling under the elastomer category, are naturally a key development focus.

Through months of R&D validation and market application analysis, the release agent for air filters recently launched by Kaiping offers the following product advantages:

• Low odor, environmentally friendly

• Excellent adhesion to mold surfaces

• Superior release performance

• Extended durability – one proper spray application enables 3–5 release cycles

• Good surface gloss on finished parts

• No surface pitting or pinholing

• Minimal buildup, easy mold cleaning