In solidification before the general is not high molecular weight solid or viscous liquid; molding process can soften or flow, with plasticity, can be made into a certain shape, but also chemical reaction and crosslinking curing; sometimes release some by-products, such as water . In this case,
This reaction is irreversible, once cured, re-pressurized heating can not be softened again or flow; temperature is too high, the decomposition or carbonation. This is essentially the difference from the thermoplastic resin. In this case,
Thermosetting resin after curing, due to intermolecular crosslinking, the formation of network structure, so rigid, high hardness, high temperature, non-flammable, product dimensional stability, but brittle. In this case,
Therefore, the vast majority of thermosetting resin in the molding products before adding a variety of reinforcement materials, such as wood flour, mineral powder, fiber or textiles to enhance, made of reinforced plastic - bakelite. In the thermosetting resin, adding reinforcing materials and other additives, such as curing agent, coloring agent, lubricant, etc., that can be made of thermosetting plastics, some powdery, granular, and some made into groups, sheet, collectively referred to as molding compound . In this case,
Thermosetting plastics commonly used processing methods are molding, laminating, transfer molding, casting, etc., some varieties can also be used for injection molding.

Standard for Inspection of Plastic Products
Common bad:
1. Insufficient filling is the phenomenon that the molten plastic does not completely flow through the corners of the molding space (mold cavity) 2. Burr: BURR occurs when the molten plastic flows into the parting surface or the lateral core shape; Force enough, but in the runner and the flow channel convergence at the film-like excess resin is FLUSH.
3. Shrinkage: The surface of a molded product is depressed. This is caused by volume contraction, usually found in the fleshy part, the rib or the protruding back, and the part of the flesh that is not directly fleshy.
4: Bubble: there is water in the molten plastic, volatile gases in the molding process into the molded product inside the residual phenomenon that the bubble.