The resins obtained by polycondensation of phenolic compounds and aldehyde compounds are collectively called phenolic resins. Among them, the phenolic resin obtained by polycondensation of phenol and formaldehyde is the heaviest. Among the polycondensation plastics, phenolic resin-based plastics are the most widely used and have the largest output.

Phenolic resins and plastics are a variety of materials that are readily available, inexpensive, and excellent in performance. They have been in use for more than 90 years, and they are widely used in electrical and electronic, instrumentation, chemical, textile, automotive, construction, machinery, light industry , Household appliances and utensils, military industry, and even aerospace and other departments have become indispensable important raw materials in social development, mainly having the following advantages;

1. The price of thermosetting plastics is low, only 1/2~1/5 of that of thermoplastics, because its ingredients contain more than 40% of various low-cost fillers.

2. New molding processing technology is constantly emerging and improving. Thermosetting injection molding technology has become the "mainstream production technology" of thermosetting plastic parts in industrialized countries, and can be in parallel with thermoplastic molding technology.

3. The appearance of thermosetting plastic products has a gloss that thermoplastic products cannot compare with.

4. After the acid resin and filler are used, the mechanical strength can reach the performance of replacing wood with plastic and steel with plastic, which can be used in various occasions.

5. Phenolic plastic products have high rigidity and insolubility, and can be used in the range of 150℃~200℃, and even at extreme temperatures, it will not soften and deform, and the surface of the parts will burn.

6. Under the condition of water lubrication, it has a low friction coefficient (0.01~0.03) and a high PV limit value, which can be used as bearings, gears, cams, etc. Especially under the condition that oil lubrication cannot be used, it shows its superiority.

7. Thermosetting plastic products have the characteristics of high pressure resistance, aging resistance, and flame resistance, which are incomparable with thermoplastic products, so thermosetting plastics can be used to fill the gap between thermoplastics and metal products.

The requirements of the thermosetting injection molding process are closely related to the conditions that the bakelite machine can meet, the performance parameters of the bakelite material, and the reasonable structure of the bakelite mold. For example: Bakelite machine barrel temperature, screw speed, injection pressure, mold clamping pressure, back pressure, bakelite injection speed, injection volume, mold holding time, holding time and mold temperature are all thermosetting injection molding The important conditions for continuous injection molding are organically linked to each other and are indispensable.