There are many factors will affect pultruded profiles strength, today we’ll talk about how internal demoulding release agent affects FRP profiles.
We know that the demoulding release agent with strong hydrophilic characteristics will have an influence on the strength of the pultruded product, it will bring more water into the pultrusion production process. At the same time, in the process of the resin mixture, there will be much air in the water that goes into the resin. On the other hand, due to its strong hydrophilic surface activity, the water can be easily emulsified into very small water droplets, and are evenly dispersed into the resin mixture. In the process of pultrusion, the water enters into the resin and the fiber interface, and the interface between the resin and fiber will be affected so that the interfacial strength will be reduced. The moisture content in the matrix can also affect the strength of the substrate after curing. The more water goes into the resin, the greater the impact will be.
The release agent in the pultrusion process won’t be completely precipitated from products, there will be some residual in the internal of the product. Hydrophilic release agent has a strong hydrophilic characteristic, it will become the channel of water molecules going out. Water molecules will use these channels to speed up erosion and damage to the product in the future.
Now there is demoulding release agent on the market is claimed that they are neutral, and well soluble in water within the mold release agent. It is expected that this type of release agent will have a certain degree of influence on the strength of the products due to its strong hydrophilicity.
Pultrusion process seems to be a simple process, but it is also a very complex technology. Which uses a variety of raw materials, and each of the different types of raw materials. It may also have a variety of process problems. When we find these problems, we should find the reason first to solve the problem.