A GUIDE TO PC ALLOY
What is PC/ABS?
A compounded blend of Polycarbonate and ABS. The PC contributes impact and heat distortion resistance, while the ABS contributes processability and chemical stress resistance, and cost reduction below PC.
What are the properties of PC/ABS?
Properties of PC/ABS include the following:
impact resistance between ABS and PC, (10-14 ft.-lb./in.)
strength and stiffness between PC and ABS
heat resistance superior to ABS, less than PC
flame retardant system more stable in processing than ABS
very good indoor UV light color stability
low temperature impact and ductility
superior processability to PC
When should PC/ABS be used?
PC/ABS should be used for appearance housings, and structural parts which need stiffness, gloss, impact and heat resistance which is higher than ABS, but requiring costs below Polycarbonate. Housings requiring UL V0, but not 5VA-that is, portable electronic devices, not permanently fixed electric devices are also good applications for PC/ABS. Others include appearance parts requiring color fastness under interior UV light, automotive interior parts where temperature environment is between 180 F and 230 F - "above the beltline" applications, and where non-shattering ductility is required like instrument panel retainers. Applications such as painted exterior automotive parts requiring low temperature impact greater than 10 ft.-lb./in. is another place PC/ABS should be used. Any outdoor application should be painted.
What is made with PC/ABS?
portable appliances, flashlights, phones
laptop computer cases
keyboards, monitors, printer enclosures
automotive instrument panel retainers
small tractor hoods
non-professional safety helmets
What is PC/PBT?
A compounded blend of Polycarbonate and PBT. The PC contributes impact, stiffness and heat resistance, while the PBT contributes chemical resistance. The usual moisture sensitivity of the crystalline PBT is overcome by the PC in the blend. Some grades are made using PET instead of PBT.
What are the properties of PC/PBT?
low temperature impact resistance, ductility
When should PC/PBT be used?
PC/PBT is effective where impact and chemical resistance is needed, and where low temperature impact, requiring a ductile failure mode (non-shattering breaks) is necessary. Applications such as bumpers and body moldings on autos and lawn & garden equipment, where toughness and resistance to stress cracking from fuels and lubricating fluids is required are good uses for PC/PBT. Parts made with PC/PBT are generally thick sections, as material does not flow well enough for thin wall design. The shrinkage varies based upon the relative content of the PBT, and therefore tool may be unique for this material, that is, it is not easy to substitute it for other polymers.
What is made with PC/PBT?
automotive side moldings
lawn and garden tractor hoods
hand tool housings
wiring connectors (PC/PET)