Air permeable felt, also called suction felt adhesive. The air duct is provided by fluffy structure, which is convenient for air extraction. In addition, it can absorb excess resin. Material and weight are two factors we need to consider when choosing air permeable felt. The common materials are polyester, nylon 66, glass fiber. The higher the compressive strength, the better the permeability. The absorbent felt is mainly selected according to the requirements of temperature resistance and compressive strength (air permeability). Generally speaking, air permeable felt is also used in prepreg hot pressing process. In some sharp places, we can also spread air permeable felt to prevent the vacuum bag film from puncturing.

Advanced non-woven fabric mixed glass fiber air permeable felt, suitable for ultra-high temperature applications. It is safer to replace woven glass fiber air permeable felt with this kind of air permeable felt. They make it easy to transport vacuum bags within any radius. At 800 ° f（427 ° C) Within the temperature range, a layer can ensure good air permeability. Air weaving? UHT 300pgl and airweave? UHT 450pgl is designed for high temperature thermosetting and thermoplastic resin systems. Advantages: ultra high temperature air permeable felt, suitable for thermoplastic processing and other applications, nonwoven structure is better than glass fiber weaving. The vacuum layer is kept in a high temperature environment. The high temperature film can be used safely at high temperature. It can be removed from the surface of the cured part well, so the film is easy to fall off very quickly. It has the flexibility to apply pressure to simple contour shapes.

How to judge the quality of air permeability felt:

1. relevant instruments (such as sample cone, clamp, rubber pad, pressure gauge or pressure gauge, smooth air suction device (fan), flowmeter, volume meter or measuring hole, etc. shall be prepared and measured in the laboratory environment. More investment and maintenance costs are needed. General enterprises do not meet the above-mentioned testing conditions;

2。 The medium pressure drop of the test is only 0.5kpa, and can only be measured at room temperature. The curing pressure is 0.78mpa, and the curing temperature is 190 ℃. The method can not evaluate the permeability of the new and old air permeable felt in the curing process (high temperature and high pressure).

3. the existing test method can only measure the permeability of the air permeability felt at 0.5kpa and room temperature. But the curing pressure and temperature can reach 0.78mpa and 190 ℃ respectively. Because of the loose structure of porous blanket, pressure and temperature have great influence on its permeability. The existing test methods can not evaluate the permeability of porous blanket under high temperature and high pressure, and can not meet the performance requirements of composite manufacturing enterprises.