Plastic screws are also known as plastic screws. The commonly used plastic screws in China are made of hot melt injection molding. They are divided into main materials: nylon PA66 screws, PP screws, PVC screws, PE screws, etc. Each material has different characteristics, so the scope of application is also the difference.

Since the large-scale application of plastic products in industry and life in the 1970s, plastic products have become a relatively important branch of the petrochemical industry and have been used in many applications. Compared with traditional metal screws, plastic screws have excellent performance in many aspects.

1. Divided by material

Nylon screws, PC screws, PVDF screws, PP screws, PTFE screws, PEEK screws, PPS screws, PFA screws and PI screws, etc.

Second, according to the type of screw head

Pan head plastic screws, countersunk plastic screws, external hexagonal plastic screws, internal hexagonal plastic screws, plastic set screws, etc.

Three, according to the shape of the slot

Cross, one character (slotted), hexagon, rice character, plum blossom, etc.

Fourth, according to screw specifications

Metric thread M2, M2.5, M3, M4, M5, M6, M8, M10, M12

American screw thread 2-56, 4-40, 6-32, 8-32, 10-32

According to the above classification, many different types of plastic screws can be combined

Plastic screw performance index

The most important physical performance index

(1) Torsion resistance of the joint between the head and the screw

(2) Whether the head groove, especially the cross head, fits the standard head size of the screwdriver.

(3) The thread outer diameter, middle diameter and bottom diameter of plastic screws are standardized. Due to the water absorption of different plastics leading to size differences in different usage environments, this standard is not as strict as metal screws.

The most important chemical performance index

(1) Acid resistance

(2) Alkali resistance

(3) Fire rating

(4) Insulation performance

Advantages of plastic screws

(1) Compared with ordinary metal screws, the biggest advantage of plastic screws is that they have good insulation properties and are not conductive.

(2) In addition, due to non-metallic manufacturing, there will be no signal interference such as eddy currents under the influence of current or other electrical signals, and its anti-interference is somewhat suitable for communications and other industries.

(3) Plastic screws have better acid and alkali resistance. Among them, the best PVDF screw is polypropylene. Both have strong acid and alkali resistance. Compared with the former two, nylon screws have strong acid and alkali resistance. The alkali performance is relatively poor, so plastic screws, especially PVDF screws, have a wide range of applications in the strong acid and alkali environment of some electroplating industries.

Defects of plastic screws

(1) The biggest defect of plastic screws is that the torque and strength of ordinary plastic screws are not as good as ordinary metal screws. If the torque is too large, there is a possibility of slippage or head fracture.

(2) Due to the shrinkage of different plastics, changes in temperature and humidity, and the length of the molding cycle, the size error of the plastic screw is allowed to be large. In addition, due to the soft material of ordinary plastics, conventional ring gauge measurement methods cannot be used.

Application fields of plastic screws

Plastic screws have high-quality characteristics such as insulation, non-magnetic, corrosion resistance, beauty, and never rust. Modified engineering plastics have the strength and impact resistance comparable to metals. The plastic screws we often say are commonly called nylon screws. After 30% glass fiber, its mechanical properties are far better than ordinary nylon. The materials used in plastic screws are becoming more and more diversified, the performance is continuously improved, and the application fields are becoming wider and wider.

(1) Medical equipment industry (insulation, non-magnetic, environmental protection, anti-interference signal, making medical machinery and equipment safer to use)

(2) Wind power industry (isolation and insulation of chassis circuit PCB boards)

(3) Aerospace industry (insulation on electronic equipment, anti-interference signal)

(4) Office equipment industry (never rust, beautiful and practical)

(5) Petrochemical industry (high temperature resistance, chemical resistance, corrosion resistance, extending the service life of equipment)

(6) Electronic industry (insulation, anti-interference, light weight)