1. There are many brands of epoxy resin, such as brominated epoxy resin and ordinary epoxy resin, there is a big difference, the general resin is about 20 yuan/kg.
2. Evaluating the properties of epoxy resin mainly depends on epoxy value, molecular weight, chlorine content, viscosity and so on. As for the quality, it depends on your technology, which is good if used properly.
Epoxy resin is an organic compound containing two or more epoxy groups in a general sense. Except for a few, their relative molecular weight is not high. The molecular structure of epoxy resin is characterized by the active epoxy group in the molecular chain. The epoxy group can be located at the end, middle or ring structure of the molecular chain. Because of the active epoxy groups in the molecular structure, they can cross-link with various curing agents to form insoluble polymers with a three-way network structure.
Polymer compounds containing epoxy groups in the molecular structure are collectively called epoxy resins. The cured epoxy resin has good physical and chemical properties. It has excellent bonding strength, good dielectric properties, low constant shrinkage, good dimensional stability, high hardness, good flexibility, and is stable to alkali and most solvents. Therefore, it is widely used in various departments of national defense and national economy as pouring, impregnating and laminating materials. Uses of adhesives, coatings, etc.
(1) Considering the product performance, we should pay attention to:
(1) Curing shrinkage of resin: low shrinkage resin should be selected.
(2) Fracture elongation: The resin with good elongation should be selected to improve the strength of Fiberglass during cracking.
(2) From the point of view of technology, the resin should satisfy the following requirements:
Good infiltration. The infiltration of fibers by high-quality Fiberglass sculpture resin is an important factor to ensure the quality of Fiberglass, and also a prerequisite for the hand pasting process. If the infiltration is not good, it will not only make the forming of Fiberglass products difficult but also make the air bubbles between resin and fiber.
(2) Proper viscosity. When the viscosity of the hand paste is too low, the phenomenon of rubbing will occur, and if the viscosity is too high, it will make the infiltration difficult.
(3) it can be gel or solidified at room temperature or low temperature, and requires no low molecular weight when curing.
(5) Cheap price and abundant supply.
At present, unsaturated polyester resin and epoxy resin are the most commonly used resins in the hand pasting process of high-quality Fiberglass statue sculpture, while the phenolic resin is seldom used alone.
2. Selection of reinforcing materials:
Fiber varieties are generally selected according to the use conditions and process design.
(1) Considering the use conditions, factors such as temperature, strength, toughness, specific gravity and insulation should be taken into account.
(2) From the point of view of technology, it is required to have the following characteristics: (1) easy infiltration: easy to be soaked by resin;
(2) Paving deformability: When pasting products with complex shapes, glass fiber products are required to adapt to the change of die shape and have certain deformability.
At present, glass fiber products are commonly used, such as twist-free roving, chopped fiber felt, surface felt, twist-free roving cloth, composite reinforcing materials, etc.
3. Selection of release agent:
In the production of high-quality Fiberglass sculpture, in order to prevent the product from bonding with the mold, a layer of separating material – demoulding agent is coated on the mould beforehand paste forming. There are many kinds of release agents, including film type, mixed solution type, and oil wax type.
When selecting release agents, many factors should be considered, such as die material, resin type, curing temperature, product appearance structure, production cycle, economic benefits, etc.
4. Choice of resin for rubber coat:
There are many kinds of rubber coat resins, which are usually selected according to the use conditions. At present, there are polyester resin and vinyl resin used in the gel coat.