Copolyesters (PETG/PCTG/PCTA)

Posted by APC Packaging

Copolyester is the modified form of polyesters, which are combinations of diols and diacids. For instance, if we introduce diacids, like isophthalic acid, or diols, like cyclohexane dimethanol to the polyester polyethylene terephthalate (PET), the material turns into a copolyester. PETG, PCTA, and PCTG are glycol-modified copolyesters, or otherwise known as “glass” polymers.

Properties of Copolyesters

These materials are amorphous copolymer thermoplastics with above average chemical resistances when compared to other amorphous materials such as ABS or PMMA. They have excellent physical properties for a wide variety of packaging types and offer superior clarity over clarified PP.

Glass polymers have the same clarity and high luster as glass and are used for thick-walled containers for products such as high-quality cosmetics. They also have excellent chemical resistance, impact resistance and other characteristics. The variations of copolyesters differ in chemical composition but have relatively similar properties. PETG offers glass-like clarity and high stiffness.

PCTG also offers excellent clarity and better impact resistance and elongation than Polycarbonate (PC), making it suitable for relatively high load bearing applications. PCTA has a higher heat deflection temperature (HDT), toughness, and impact strength than PETG.

Uses of Copolyesters

Copolyesters grant flexibility to fulfill a wide assortment of applications. Copolyester resins have ended up being viable in packaging applications.

Copolyesters are widely used in the cosmetic industry because their superior aesthetic qualities make for a unique and eye-catching package. These materials offer brilliant sparkle and clarity, a density that approaches the feel of glass, ease of decoration, excellent chemical resistance, significant impact resistance, and the ability to mold thick walled parts without any haze or fogginess. Others have found use for copolyesters in the medical packaging, home appliances, and consumer industries.

Before selecting a copolyester resin for use, be sure to consult with our experts to help you find the best solution for your product.

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