As known,Hongfa Shunda is a manufacturer of kinds of enclosures for electronic device,and plastic enclosure is the mainly used housing for PCB,because it with light weight,lower cost and good insulation.
As a 20 years factory,Hongfa has more than hundreds of standard plastic enclosures in stock for choice,but all of them are used ABS material.There’re many kinds of plastic material in the market,PC material is also most used plastic.Why we only used ABS material for our case?
First let us to study the difference between ABS and PC material.
- ABS
ABS resin is a copolymer of three monomers, acrylonitrile (A), butadiene (B) and styrene (S). Strength (properties of butadiene), heat resistance and corrosion resistance (excellent properties of acrylonitrile), high surface hardness, good chemical resistance, and by changing the ratio of the above three components, various ABS properties can be changed. performance, so ABS engineering plastics have a wide range of uses.Specific gravity of ABS plastic: 1.05 g/cm3; Molding shrinkage: 0.4-0.7%; Molding temperature: 200-240 degrees Celsius; Drying conditions: 80-90 degrees Celsius for 2 hours.
Characteristic of ABS:
1). Good comprehensive performance, high impact strength, chemical stability and good electrical properties.
2). It has good weldability with 372 plexiglass, and can be made into two-color plastic parts, and the surface can be chrome-plated and painted.
3). There are high impact resistance, high heat resistance, flame retardant, reinforced, transparent and other grades.
4). The fluidity is a little worse than HIPS, better than PMMA, PC, etc., and the flexibility is good.
Molding characteristics of ABS:
a. Amorphous material, with medium fluidity and high moisture absorption, must be fully dried. Plastic parts with glossy surfaces must be preheated and dried at 80-90 degrees for 3 hours for a long time.
b. It is advisable to take high material temperature and high mold temperature, but if the material temperature is too high, it is easy to decompose (the decomposition temperature is 270 degrees). For plastic parts with high precision, the mold temperature should be 50-60 degrees, and for high gloss and heat resistance For plastic parts, the mold temperature should be 60-80 degrees.
c. To solve the water streak, it is necessary to improve the fluidity of the material, adopt methods such as high material temperature, high mold temperature, or changing the water level.
d. If heat-resistant or flame-retardant materials are formed, plastic decomposition products will remain on the surface of the mold after 3-7 days of production, which will cause the surface of the mold to shine. The mold needs to be cleaned in time, and the surface of the mold needs to increase the exhaust position.
2. PC
PC name: Polycarbonate Polycarbonate is a new thermoplastic engineering plastic. Polycarbonate has excellent electrical insulation properties and mechanical properties, especially impact resistance, high toughness, and a wide range of allowable temperatures (- 100-130℃), high transparency (known as “transparent metal”), non-toxic, easy to process and shape. It can not only replace some metals, but also replace glass, wood and so on. In recent years, polycarbonate has developed rapidly and has been widely used in machinery, automobiles, aircraft, instrumentation, electrical appliances and other industries. Polycarbonate is a general term for a class of polymer compounds containing carbonate in the molecular chain. Polycarbonate is a new type of thermoplastic with a transparency of 90% and is known as a transparent metal. Rigid and tough, with high impact resistance, high dimensional stability and a wide range of operating temperatures, good insulation and heat resistance and non-toxic.
Polycarbonate burning characteristics
Slow burning, slowly extinguished after leaving the fire, the flame is yellow, and the black smoke carbon beam. After burning, the plastic melts, foams, and emits a special smell of flowers and fruits. Polycarbonate has a specific gravity of 1.20, is transparent, and has a slightly yellowish color. Polycarbonate properties: Polycarbonate resins have developed many modified varieties through copoly merization, blending and reinforcement. After the polycarbonate resin is blended with polyolefin, it has higher impact toughness, boiling water resistance and aging resistance, lower melt viscosity and injection temperature, so it is easy to process and shape. After polycarbonate is blended with this 20-40% ABS resin, it has excellent comprehensive properties. It not only has the high mechanical strength and heat resistance of polycarbonate resin, but also has the characteristics of good fluidity and easy processing of ABS. , the performance indicators are mostly between polycarbonate and ABS.
So the difference between ABS and PC:
1. Different functions
The outstanding point of abs is that the surface can be electroplated, vacuum coated, printed, painted and painted,
PC is the best impact-resistant plastic variety. The disadvantage is that the product is easy to crack and has low fatigue strength.
2. Different materials
PC is an engineering plastic with high price, but it has the advantages of transparency, high impact resistance, high temperature resistance and high dimensional accuracy, but it also has the weaknesses of difficult molding and strong internal stress. Mainly used in home appliance lighting and other industries.
ABS belongs to ordinary plastics, and has the characteristics of easy molding and post-processing. Mainly used for shell products.
3. Different advantages
PC has good transparency, excellent comprehensive properties, high mechanical strength, good toughness, good heat and weather resistance, high dimensional stability, easy coloring, and low water absorption.
ABS has high mechanical strength and good comprehensive properties of “toughness, toughness and steel”. ABS is easy to absorb moisture, has low shrinkage (0.60%), stable dimensions, easy molding and processing, and is widely used.
So consider the application, the characteristic and the cost,Hongfa choose ABS material as our mainly material of plastic enclosures.But if you want to use PC material,we also can change the material as required.
