Special liquid silicone in thermal expansion molding and application of composite materials
Introduction: Special liquid silicone is composed of AB two-component silicone, where A is silicone and B is a platinum catalyst. Special liquid silicone will undergo a vulcanization process and become an elastic soft body after vulcanization. It has the characteristics of environmental protection, non-toxic and odorless, strong heat resistance, large expansion coefficient, high tear resistance, and aging resistance. Special liquid silicone acts as an auxiliary material for composite materials and is widely used in composite thermal expansion process, airbag blowing process, vacuum induction process, hot pressing mold process, etc. Next, we will introduce the molding and application of special liquid silicone in thermal expansion process.
Process principle: The thermal expansion molding process of composite materials uses silicone as the core mold, the rigid material as the female mold, and the composite material is placed between the core mold and the female mold. When the mold is heated, the volume expansion of the core mold will be limited by the female mold, and the pressure generated by the core mold in the membrane cavity realizes the pressurized curing molding of the composite material.
Technical description:
1. Make silicone core mold: Use Hongtu's specially adjusted liquid silicone "addition type HT-FC" series silicone, with a hardness range of 30-40A (Shore hardness). Mix the AB two-component glue in a 1:1 ratio, and pour it into the rigid female mold after vacuum degassing for curing and molding.
2. Cut the required carbon fiber prepreg area and wrap it on the surface of the silicone core mold, and lay it in the female mold.
3. Put the prefabricated silicone core mold in the female mold and close the mold up and down.
4. Install heating equipment on the female mold
5. Heat molding
6. Cool and demold to get the fiber product.
Conclusion: Using silicone as the core mold material is simple in operation and has a short production cycle, which improves production efficiency. From the production process, the curing pressure source is improved, and no external pressure source is required. Because silicone expands when heated, it can generate pressure by itself. It is not easy to wrinkle and easy to demold. From the product quality, we can ensure that the pressure is applied evenly during the molding process, the surface quality of the pipe is good, there are no internal defects, the resin content is high, the product strength is high and the weight is lighter. Finally, the core mold made of silicone can be used repeatedly, effectively reducing labor and material costs!
