The corrosion resistance of the phenolic resin acid catalyst
In the process of industrial production, the first problem is the acid corrosion of the pultrusion mold. In production practice, only after a few hours, the surface layer of chromium plating will be acidic corrosion, and strip off from the surface of the steel. Some people attempt to solve the problem of corrosion resistance by adding suitable internal mold release agent to phenolic resin. But the test results showed that the use of internal mold release agent, the chromium layer and mold steel will still be stripped off, just the time of the stripping will extend.
Phenolic resin curing in high temperature and high viscosity
To avoid the corrosion of acid catalyzed phenolic resin, some people has tested in pultrusion process with phenolic resin. Some phenolic resin can be quickly cured at 130 -150. The resin layer with sandpaper for example, after 5-6 minutes at the temperature of 130 DEG C under curing. Acid catalyzed phenolic resin of the pultrusion temperature is about 10, according to the curing temperature rise 180, curing time can be shortened by half of the experience of the law, 130 degrees 6 minutes of curing resin, at 180, it only takes a few seconds to complete the curing. So it is possible to use high temperature cured phenolic resin in the process of pultrusion. In general, high temperature curing phenolic resin viscosity is higher, about 4000-6000cP. In order to improve the surface quality of the products, it is necessary to add the filler, then the viscosity will increase, which will have a negative impact on the pultrusion process.