The pultrsuion production is a continuous process, so the fine stripping effect is the main condition to ensure the smooth progress of the FRP production process.
Problems in the use of release agent:
Since most liquid release agent is acidic, it should be noted in the use of the following issues:
1. It will lead to color changes when using acid sensitive pigment;
2. When using alkaline fillers, such as calcium carbonate, acid release agent will react with the cause of the increase in the viscosity of the mixture, but won’t affect the release effect;
3. If the filler is made of alumina, acid stripping agent in addition to will increase the viscosity of the mixture, but also in the mixed material curing process release moisture, resulting in bubbles, cracks and other issues.
Usually, the starting amount of the release agent is 1% of the amount of resin, and the effective range is based on the weight of the resin 0.75-2%. It should be adjusted according to the actual situation.
1. For simple and thin wall fiberglass pultruded profile, the amount can be 0.8% or less;
2. For thick wall thickness FRP profiles or the shape is complex, it need to add some more.
3. In the high filler system, we should increase the amount of internal release agent, but the amount of internal release agent increasing will delay the curing.