How to Bond Polyethylene Terephthalate (PET Plastic)

Polyethylene terephthalate (PET) is produced through the condensation reaction of either dimethyl terephthalate (DMT) or pure terephthalic acid (PTA) with ethylene glycol. For nearly all PET injection molding applications, the PET is either glass- or mineral-filled. Reinforced PET is the stiffest of all commonly used thermoplastic materials. It also has high tensile strength, excellent heat resistance, outstanding weatherability, and minimal water absorption. PET is chemically resistant to most chemicals over a broad temperature range, including motor fuels, oils, and hydrocarbon solvents.

PET is widely used across industries due to its excellent properties. In electronics, it’s used for computer fans, fuse holders, and insulated housings due to its electrical insulation characteristics. It’s also popular in food packaging because of its transparency, strength, and barrier properties that ensure shelf life and product protection. PET is often used as a filament in 3D printing.

The surface tension of PET typically ranges between 42 and 48 dyn/cm.

PET is sold under various trade names, including Cleartuf, Ektar FB, Impet, Kodapak PET, Lumirror, Mylar, Petlon, Petra, Rynite, Selar, Tenite PET, Traytuf, and Valox, depending on the manufacturer and specific application.

PET plastic is suitable for 3D printing due to its ease of printability, smooth surface, and water-resistant properties. It also has good thermal characteristics, aiding in effective cooling during printing to minimize warping.

Bonding
Before gluing, thoroughly clean the surface to remove dirt, grease, and contaminants, as these can affect adhesion. Use a non-residue cleaner for best results.
PET can be a challenging plastic to bond, and in many cases (depending on strength requirements), surface treatment using primer or corona/plasma treatment is recommended before gluing.

Then select a glue compatible with PET and carefully follow the manufacturer’s instructions for application and curing.

Suitable PET adhesives include epoxy, polyurethane, or cyanoacrylate. For specific guidance, refer to the adhesive manufacturer’s instructions.

• Epoxy glue is ideal for bonding PET materials due to its ability to create strong, lasting bonds. It is known for its high strength, durability, and chemical resistance. Commonly used in industrial bonding.
• Polyurethane glue is valued for its versatility and strength, making it ideal for bonding PET and other plastics. It offers good flexibility, water resistance, and wear resistance, making it suitable for industrial applications requiring strong and flexible joints.
• Cyanoacrylate glue, also known as super glue, is known for its fast bonding and strength on various materials, including PET. It creates strong and durable bonds, ideal for small repairs and quick applications.

After bonding, allow the PET adhesive to cure completely.

After bonding PET, it’s important to conduct a quality test to ensure the bond meets strength and durability requirements. This confirms proper curing and adequate adhesion strength.

Manufacturers
These are some well-known trade names of PET materials and their respective manufacturers:

Cleartuf and Traytuf from Goodyear
Ektar FB from Eastman Performance
Impet from Hoechst Celanese
Kodapak PET and Tenite PET from Eastman Chemical Products
Lumirror from Toray Industries
Mylar, Rynite, and Selar from E.I. DuPont
Petlon from Albis Corp
Petra from Allied-Signal Corp
Valox from GE Plastics

Contact us

Do you have questions about bonding or need advice on choosing the right adhesive for your application? Our experts are ready to help you achieve reliable and durable bonding.
We offer solutions with adhesive products that are tailored to meet your specific needs.
Contact us today for professional advice and support.

Call us at +45 66171802 to speak directly with one of our specialists, or send us an email at info@hojstrup.dk.
We ensure that you receive the best guidance and support for your bonding projects.