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Differences Between PETG and APET
Between all of the different substrates with PET in the name, keeping them straight can get complicated. The differences between various types of PET packaging are critically important, though, and, at times, names can be misleading.
For example, APET is a type of PET packaging, and the similarly named PETG is in the same polyester family with PET. This is because PETG is made with an additive that gives it a few distinct advantages.
What is APET?
APET is PET packaging but in a specific stage of processing. PET, of course, is the highly common substrate used to make products like water bottles. When it’s being molded in an amorphous state, it goes by the name APET. The plastic manufacturer has to be careful with the material during the molding stage, because if it is heated too long, it can compromise both the aesthetics and the durability of the final product, making it hazy and brittle.
The Unique Properties of PETG
Though their names sound alike, PETG is very different from APET. PETG is similar to PET packaging, but with a key difference: cyclohexanedimethanol (CHDM). Remember how overheating PET leaves it hazy and brittle? Adding CHDM to make PETG removes this risk, preventing the material from crystallizing and becoming breakable. This is because CHDM adds a secondary diol monomer to the polymer backbone and breaks up the linear ethylene glycol chain and inhibits crystallization. Its slightly softer exterior makes it highly impact-resistant, though it scratches more easily, and can be weakened by UV light. And, unlike PET, this material is RF-sealable.
Should You Choose PETG or PET Packaging?
While PETG and APET/PET packaging have their key differences, they are also similar in many ways. For example, these materials are both FDA-friendly, so they can be used for food packaging. Additionally, they both have reasons that proper manufacturing can be difficult. While overheating PET can lead to a hazy, brittle finish that is both aesthetically unappealing and ineffective, PETG has its own complications. PETG is notably sticky when being manufactured, so if the company producing the package doesn’t have the necessary experience with the material, it can be left with noticeable imperfections and de-nesting issues.
While APET and PETG are distinctly different, neither one is universally better or worse than the other—they each have their own advantages and disadvantages.