1. Advantages of plastic:
(1) Easy to process and manufacture (easy to mold)
Even if the geometry of the product is quite complex, as long as it can be removed from the mold, it is relatively easy to make. Therefore, its efficiency is far better than that of metal processing, especially injection molded products, which can be manufactured into a very complex finished product after a process.
(2) It can be colored at will according to the need, or made into transparent products
The use of plastic can be used to make colorful, transparent and beautiful products, and the characteristics of arbitrary coloring can improve the value of the commodity and give people a bright feeling.
(3) It can be made into lightweight and high-strength products
Compared with metal and ceramic products, it has light weight, good mechanical properties, and high specific strength (the ratio of strength to density), so it can be made into lightweight and high-strength products. Especially after filling glass fiber, it can improve its strength.
In addition, because plastic is light and can save energy, its products are becoming lighter.
(4) No rust, not easy to corrode
Plastics are generally resistant to various chemicals and will not rust or be corroded as easily as metals. There is no need to worry about the erosion of acids, alkalis, salts, oils, medicines, moisture and mold.
(5) It is not easy to transfer heat and has good thermal insulation performance
Due to the large specific heat and small thermal conductivity of plastics, it is not easy to transfer heat, so its thermal insulation and thermal insulation effect is good.
(6) It can not only make conductive parts, but also make insulation products
Plastic itself is a good insulating substance, and it can be said that there is no electrical product that does not use plastic. However, if the plastic is filled with metal powder or debris for molding, it can also be made into a product with good conductivity.
(7) Excellent shock absorption and sound reduction performance, and good light transmittance
Plastic has excellent shock absorption and sound damping properties; Transparent plastics (such as: PMMA, PS, PC, etc.) can be used to make transparent plastic products (such as: lenses, signs, bezels, etc.).
(8) The manufacturing cost of the product is low
Although the plastic raw material itself is not so cheap, as mentioned in item (1), the product cost can be reduced because the plastic is easy to process and the equipment cost is relatively low.
2. Disadvantages of plastic
(1) Poor heat resistance and easy combustion
This is the biggest disadvantage of plastics, compared with metal and glass products, its heat resistance is far inferior, the temperature is slightly higher, it will be deformed, and it is easy to burn. When burned, most plastics can produce a large amount of heat, smoke and toxic gases; Even thermoset resins can smoke at temperatures above 200 degrees Celsius and produce flaking.
(2) With the change of temperature, the properties will also change greatly
High temperatures go without saying, and even when encountering low temperatures, various properties will change greatly.
(3) Low mechanical strength
Compared to metals of the same volume, the mechanical strength is much lower, especially for thin products, and this difference is particularly noticeable.
(4) It is easy to be corroded by special solvents and chemicals
In general, plastics are less susceptible to chemicals, but some plastics (e.g., PC,
ABS, PS, etc.) are particularly poor in nature; In general, thermosetting resins are quite resistant to corrosion.
(5) Poor durability and easy aging
Whether it is strength, surface gloss or transparency, it is not durable, and there is creep phenomenon under load. In addition, all plastics are resistant to ultraviolet rays and sunlight, and will age under the action of light, oxygen, heat, water and atmospheric environment.
(6) It is susceptible to damage and easy to be contaminated with dust and dirt
The surface hardness of plastics is relatively low and easy to be damaged; In addition, because it is an insulator, it has static electricity, so it is easy to get dust.
(7) Poor dimensional stability
Compared with metal, plastic shrinkage is very high, so it is difficult to ensure dimensional accuracy. The size is prone to change over time when it is exposed to moisture, moisture absorption, or temperature changes during use.
