PET: Polyethylene Terephthalate
PET is one of the most widely used plastics in the packaging industry. It is a thermoplastic polymer made by the polymerization of ethylene glycol and terephthalic acid. PET is clear, lightweight, and has good tensile strength and barrier properties. It is commonly used for water bottles, food containers, and pharmaceutical packaging.
Key characteristics of PET include:
- High clarity, making it suitable for product display
- Good strength-to-weight ratio
- Resistance to moisture and many chemicals
- Compatibility with various cap types and sealing methods
- Recyclability in most municipal recycling systems
PETG: Glycol-Modified Polyethylene Terephthalate
PETG is a modified version of PET, created by adding a glycol modifier during polymerization. This small change in molecular structure results in a more flexible, impact-resistant, and easier-to-process material. PETG is not as stiff as PET but offers better performance in applications where formability is important.
Key differences between PET and PETG:
- PETG is more ductile and less brittle than PET
- PETG can be thermoformed at lower temperatures
- It has higher impact resistance, making it suitable for cosmetic packaging, display cases, and some medical trays
- PETG is not always accepted in PET recycling streams due to its different melting behavior
Although PETG is less common in high-volume food packaging, it is widely used in industries requiring custom shapes, printing compatibility, and better surface durability.
Terylene: Polyester Fiber Form of PET
Terylene is a trade name for a type of polyester fiber made from the same base polymer as PET. While PET and Terylene are chemically similar, their applications are different due to their physical form. Terylene is used primarily in textile manufacturing, including clothing, curtains, industrial fabrics, and tire cords.
Key facts about Terylene:
- Produced by melt spinning PET into fine fibers
- Known for its strength, wrinkle resistance, and durability
- Not used for rigid packaging containers
- Often blended with other fibers for performance textiles
Terylene does not refer to a packaging-grade plastic but rather to a fibrous material used in fabric and textile applications. It cannot be used as a substitute for PET or PETG in blow-molded containers or rigid plastic packaging.