PC engineering plastic are thermoplastic engineering plastic with excellent performance, and are also polycarbonate resins. They are polymerized by bisphenol-a in dihydroxy compounds and diphenyl carbonate in carbonate compounds through the ester exchange method (melt method).

Plastic Introduction

It is a thermoplastic engineering plastic with excellent performance, outstanding impact resistance, good creep resistance and dimensional stability, heat resistance, low water absorption, non-toxicity, and excellent dielectric properties. It is the only product with good transparency among the five major engineering plastic, and it is also the general engineering plastic with the fastest growth rate in recent years.

The commonly used abbreviation PC for polycarbonate is a colorless, transparent, amorphous thermoplastic material. Its name comes from the CO3 group inside it. Chemical properties Polycarbonate is acid-resistant and oil-resistant. Polycarbonate is not resistant to ultraviolet light and strong alkali. Physical properties Polycarbonate is colorless, transparent, heat-resistant, impact-resistant, flame-retardant, and has good mechanical properties within the normal use temperature. Compared with polymethyl methacrylate, which has similar performance, polycarbonate has better impact resistance, high refractive index, good processing performance, and has UL94V-0 flame retardant performance without additives. However, polymethyl methacrylate is relatively cheaper than polycarbonate, and large devices can be produced by bulk polymerization. With the increasing scale of polycarbonate production, the price difference between polycarbonate and polymethyl methacrylate is shrinking. Polycarbonate has poor wear resistance. Some polycarbonate devices used for easy wear require special surface treatment. PC production history and application Polycarbonate is a common material in daily life. Due to its colorless transparency and excellent impact resistance, common daily applications include optical discs, eye lenses, water bottles, bulletproof glass, goggles, bank bulletproof glass, headlights, etc. Polycarbonate is also used to make helmets and masks for astronauts who landed on the moon. Laptop shells are also made of polycarbonate. Impact on the environment Food contact Producers and buyers of food storage goods prefer polycarbonate fibers because of its clarity and toughness. Polycarbonate is lightweight and highly resistant to breakage when compared to silica glass. Polycarbonate is used in both single-use and reusable plastic water bottles. More than 100 studies have investigated the ecological effects of bisphenol-Aleachates on polycarbonate. Howdeshell et al. found that an endocrine disruptor, Bisphenol-A (C15H16O2) (phenol methyl ether), appeared to leach into water from polycarbonate animal cages at room temperature and that it may be responsible for the enlargement of reproductive organs in female rats. A paper published in August 2005 analyzing the effects of low doses of bisphenol-Aleachate seemed to suggest a relationship between financial support and the conclusions drawn: industry-funded studies tended to find no significant effects; government-funded studies tended to find significant effects. Sodium hydroxide and other alkaline cleaners should not be used on polycarbonate because they react chemically with other substances or they may result in the release of Bisphenol-A (C15H16O2), a known endocrine disruptor (affecting the reproductive system). Polycarbonate PC is also a material used in laptop shells. Its raw material is petroleum. After being processed by a polyester chip factory, it becomes polyester chip particles, and then processed by a plastic factory to become a finished product. From a practical point of view, its heat dissipation performance is better than that of ABS plastic, and the heat dispersion is more uniform. The most prominent use of this material is FUJITSU, which uses this material in many models, and the entire shell is made of this material. Whether from the surface or from the touch, PC-GF-## material feels like metal. If there is no logo in the laptop, you may think it is an alloy if you don't observe it carefully from the outer surface.

Plastic processing method

PA66 plastic raw material, PC can be injection molded, extruded, molded, blow molded, thermoformed, printed, bonded, coated and machined. The most important processing method is injection molding. It must be pre-dried before molding, and the moisture content should be less than 0.02%. Trace moisture processing at high temperature will cause the product to have a turbid color, silver threads and bubbles. PC has a considerable forced high elastic deformation ability at room temperature. It has high impact toughness, so it can be cold pressed, cold drawn, cold rolled and other cold forming processes. The molecular weight of PC for extrusion should be greater than 30,000, and a gradual compression screw should be used, with a length-to-diameter ratio of 1:18~24 and a compression ratio of 1:2.5. Extrusion blow molding, injection-blow molding, and injection-stretch-blow molding can be used to form high-quality, high-transparency bottles. There are many types of PC alloys. To improve the defects of high PC melt viscosity (processability) and easy stress cracking of products, PC forms alloys or blends with different polymers to improve material properties. Specifically, there are PC/ABS alloys, PC/ASA alloys, PC/PBT alloys, PC/PET alloys, PC/PET/elastomer blends, PC/MBS blends, PC/PTFE alloys, PC/PA alloys, etc., which have the advantages of two material properties and reduce costs. For example, in PC/ABS alloys, PC mainly contributes to high heat resistance, good toughness and impact strength, high strength and flame retardancy, while ABS can improve formability, apparent quality and reduce density.

Application Introduction

The three major application areas of PC are glass assembly industry, automobile industry and electronic and electrical industry, followed by industrial machinery parts, optical disks, packaging, office equipment such as computers, medical and health care, films, leisure and protective equipment, etc. PC can be used as door and window glass, and PC laminates are widely used in protective windows of banks, embassies, detention centers and public places, aircraft cabin covers, lighting equipment, industrial safety baffles and bulletproof glass. PC sheets can be used to make various signs, such as gasoline pump dials, car dashboards, warehouse and outdoor commercial signs, dot slide indicators, PC resins are used in car camera systems, instrument panel systems and interior decoration systems, used as headlight covers, front and rear fenders with reinforcement ribs, reflector frames, door frame covers, operating lever covers, spoilers, PC is used as junction boxes, sockets, plugs and sleeves, gaskets, TV conversion devices, connectors for communication cables under telephone line brackets, switch boxes, telephone switchboards, switchboard components, relay housings, PC can be used as low-load parts, used in household appliance motors, vacuum cleaners, shampooers, coffee machines, toasters, power tool handles, various gears, worm gears, bushings, guides, refrigerator shelves. PC is an ideal material for CD storage media. PC bottles (containers) are transparent, light, and have good impact resistance. They can withstand certain high temperatures and corrosive solution washings and can be used as recyclable bottles (containers). PC and PC alloys can be used to make computer racks, housings and auxiliary machines, and printer parts. Modified PC is resistant to high-energy radiation sterilization, boiling and baking disinfection, and can be used for blood specimen collection equipment, blood oxygenators, surgical instruments, kidney dialyzers, etc. PC can be used to make helmets and safety helmets, protective masks, sunglasses and sports goggles. PC film is widely used in printed charts, medical packaging, and membrane commutators.

Plastic properties

1. Rigid and tough, with high impact resistance, high dimensional stability and a wide range of operating temperatures, good electrical insulation and heat resistance and non-toxicity, and can be obtained through injection molding and extrusion molding to achieve the expected effect, so it has developed very rapidly, and the world's annual consumption has exceeded 300,000 tons.

2. Polycarbonate is a transparent, slightly yellow or white, rigid and tough polymer. When burning, it burns slowly and extinguishes slowly after leaving the fire. The flame is yellow and black smoke is carbon bundles. After burning, it melts and bubbles, and emits a fruity smell.

3. Polycarbonate has excellent performance and good light transmittance, and its light transmittance is close to 90%. The relative density is 1.20, which is larger than polyolefin, smaller than polyoxymethylene and polyvinyl chloride, and similar to polymethyl methacrylate.

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