Tu Society Science: Analysis of polycarbonate from production to application of the whole process.

Polycarbonate (PC) is one of the five general engineering plastics, in the 1950s by Bayer and Ge independently manufactured, because of its transparency, impact resistance, high temperature resistance and other characteristics, in electronic appliances, automotive, medical, construction, packaging and other fields have a wide range of applications.
Because polycarbonate products can withstand steam, cleaning agents, heating and high-dose radiation disinfection, without yellowing and physical performance decline, it is widely used in artificial renal hemodialysis equipment, as well as other medical equipment that needs to be operated under transparent and intuitive conditions and needs to be repeatedly disinfected, such as the production of high-pressure syringes, surgical masks, disposable dental appliances, blood oxygenators, blood collection memory, blood separators, etc.
the processing characteristics of the PC is ambient material, its melt viscosity is sensitive to temperature.
because the PC is prone to hydrolyzing at high temperatures, the quality of the product is sensitive to the moisture content of the raw material, the raw material must be dried to less than 0.02% before molding.
PC can be used injection molding, extrusion, blow molding, flow delay and other sub-processing, but also bonding, welding and cold processing.
injection molding process is the most important forming method of PC.
products are widely used in automotive, construction, textiles, medical equipment and other fields.
mainly to equipment components, but also used in optical discs, optical caps and protective glass.
01 raw material pre-treatment PC water absorption rate is large, before processing must be preheat drying, pure PC drying 120 degrees C, modified PC generally with 110 degrees C temperature drying more than 4 hours.
drying time must not exceed 10 hours.
can generally be used to determine whether drying is sufficient by the air-to-air extruse method.
up to 20% of recycled materials.
, 100% of the use of recycled materials, the actual amount depends on the quality requirements of the product.
can not mix different mastermisses at the same time, otherwise it will seriously damage the nature of the finished product.
If the degree of dryness is very poor, the plastic moisture is more, the melting viscosity drops sharply melting out quickly, the barrel nozzle in the crackling sound constantly spewing foam-like snowballs, white smoke or gas.
If the degree of dryness is general, the melt slowly injected in the nozzle is cloudy, the surface is not bright, the interior is sandwiched with a small number of small bubbles, molding work in the vicinity of the gate or other parts of the surface rough loss of light, low impact strength.
02 injection molding machine selection of the current PC products due to cost and other reasons, multi-use modified materials, especially electrical products, but also to increase fire resistance, in flame retardant PC and other plastic alloy products molding, the requirements of the injection molding machine plasticization system is mixed good, corrosion-resistant, conventional plastic screw difficult to do.
03 injection temperature can be determined by air-to-air injection.
general PC processing temperature is 270 to 320 degrees C, some modified or low molecular weight PC is 230 to 270 degrees C.
However, it should be noted that if the temperature is too low, due to large viscosity, insufficient feeding, parts surface shrinkage or ripples, no gloss, silver silk messy;
04 injection pressure injection pressure on the performance of the parts mainly manifested in the pressure-keeping time, short pressure-keeping time, parts shrink or shrink holes, vacuum bubbles;
05 stay time in the high temperature stay for too long, the material will degrade, put also CO2, turn yellow.
do not clean the barrel with LDPE, POM, ABS or PA.
apply PS cleanup.
06 note some modified PC, due to the number of recovery times (molecular weight reduction) or various ingredients mixed is not equal, easy to produce dark brown liquid bubbles.
PC's hybrid PC has outstanding impact toughness and excellent electrical insulation, but the PC also has some defects, such as easy stress cracking, sensitivity to gaps, poor wear resistance, and poor processing mobility, which need to be improved.
the compatible between 01PC and PE's mixed PC and PE is poor, and if they mix with each other, they can easily lead to obvious stratization.
the materials after the two were mixed and modified, the impact resistance was improved, and the resistance to boiling water, processing fluidity, heat resistance and weather resistance was improved.
02PC and ABS hybrid PC and ABS compatible is not good, in order to get a good performance mix, need to use compatible agents to improve the compatible between the two.
PC/ABS hybrid is one of the earliest industrial production of PC modified products.
impact intensity, bending strength, stretch strength, thermal deformation temperature, etc. of the common mix have been greatly improved.
03PC and polyester resin co-mixed PC is amorphouse polymer, while PET and PBT are crystalline polymer, so the combination of the two is a typical amorphomorphouse polymer mixing system.
production of the two mixed is a certain difficulty, because PET, PBT crystallization makes the interface bonding bad, will cause the impact strength to decrease, for this need to add a third group to improve.
mixing the two, the raw material should be fully dried and avoid excessive temperature and long stay in the heat state, to avoid the lipid exchange between the two led to poor performance.
04PC and nylon hybrid PC and PA mix has a very high chemical resistance, excellent impact resistance and processing fluidity, is a new type of polymer alloy.
05PC and fluorine resin mixed PC and fluorine resin, not only to maintain the polycarbonate excellent heat resistance, dimensional stability and injection molding, has improved its wear resistance.
06PC's blend with acrylic resins has a beautiful pearly and metallic sheen, is eye-catching and non-toxic, is suitable for making containers for food and cosmetics, and can make artificial pearls.
PC's use of PC polycarbonate application development is to high composite, high function, specialization, serialization direction, has been introduced CD-ROM, automotive, office equipment, boxes, packaging, medicine, lighting, film and other products dedicated to the grade grade.
01 optical lighting is used in the manufacture of large lampshades, protective glass, optical instruments, such as the left and right eyepiece barrel, but also widely used in aircraft transparent materials.
02 electronic appliance polycarbonate is an excellent E (120 degrees C) class insulation materials for the manufacture of insulation plug-ins, coil frames, tube seats, insulated casings, telephone housings and parts, mine lamps, such as battery shells.
can also be used to make high-precision parts, such as optical discs, telephones, electronic computers, video recorders, telephone exchangers, signal relays and other communication equipment.
polycarbonate film is also widely used as capacitors, insulated leather bags, audio tapes, color video tapes and so on.
03 machinery and equipment for the manufacture of a variety of gears, toothsticks, worm wheels, worms, bearings, cams, bolts, levers, crankshafts, ratchets, but also for some mechanical equipment housings, covers and frames and other parts.
04 medical equipment can be used for medical purposes of cups, barrels, bottles and dental equipment, pharmaceutical containers and surgical instruments, and even can be used as artificial kidneys, artificial lungs and other artificial organs.
05 Other aspects of the building used as hollow rib double wall panels, warm room glass, etc. , in the textile industry used as textile yarn tubes, textile machine shaft tile, etc. , daily use for bottles, cutlery, toys, models, LED lamp shell and mobile phone casing.
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, the convergence of all the great.