POLYESTER (PBT & PET)
Polyesters are engineering thermoplastics based on Polybutylene Terephthalate (PBT) and Polyethylene Terephthalate (PET). They combine excellent mechanical, electrical and thermal properties with very good chemical resistance and dimensional stability.
Please Note: This page is for information purposes only. Rutland Plastics is an Injection Moulder and does not supply polymers.
PROPERTIES
Polyesters have high hardness and good impact strength. Together with excellent dimensional stability (due to low water absorption compared with Nylons, for example) they also provide high heat resistance. The materials have both good chemical and weathering resistance.
COLOURING
The natural colour of the material is transparent so it is available in a wide range of colours and can be easily self-coloured using masterbatch. There is now a wide range of masterbatches specific for use with PET.
Finishing
The material can be machined on conventional lathes using standard metal machining tools. Can be glued using adhesives. Can be decorated by all known printing systems but due to the chemical resistance of the material it is difficult for inks to adhere so a primer should be used. Parts can readily be painted. Vacuum metallization is the best method for plating. Parts can be vibration, spin, hot-plate and ultrasonically welded.
CHEMICAL RESISTANCE
| Mineral Acids (dilute) | Excellent |
| Mineral Acids (concentrated) | Poor |
| Alkali | Fair |
| Alcohol | Excellent |
| Ketone | Fair |
| Aromatic Hydrocarbon | Fair |
| Chlorinated Hydrocarbon | Fair |
| Detergents | Good |
| Oils, Greases | Excellent |
PBT & PET USE
| PET | |
| Carbonated Soft Drink Bottles | 49.0% |
| Mineral Water Bottles | 29.2% |
| PET Sheet | 11.7% |
| Beer/Wine/Spirit Bottles | 6.1% |
| Other | 13.1% |
| PBT | |
| Electric/Electronic | 38.7% |
| Automotive | 22.5% |
| Household Appliances | 7.3% |
| Other | 31.6% |
APPLICATIONS
The main application for PET is in the manufacture of blow moulded bottles. PBT is used for high quality and high stress engineering components such as automotive windscreen wiper arms, door handles and particularly electronic parts; household appliances and in electric and electronic engineering, for example circuit breakers.
