Polyethylene Terephthalate (PET) is a thermoplastic material from the Polyester family.
PET is a lightweight, strong and inert material that is easily transported and recyclable. PET is extremely versatile and can be used in food and drink packaging, for making disposable medical devices and industrial films and wraps.
Main PET properties
– Surface energy: 44mJ/m²
– Maximum service temperature: 70°C
– Melting temperature: 250°C
Speciality adhesives for bonding PET are available, without the need for a pre-treatment.
How to bond PET
The first factors to consider when selecting the best adhesive for bonding PET is the solvent and temperature resistance of the adhesive.
Structural acrylic adhesives such as the Permabond TA4610 can be used to bond untreated PET. They provide a high bond strength without having to use a primer or surface treatment.
Structural acrylic adhesives provide good resistance to polar solvents and non-polar solvents. Depending on the application, structural acrylic adhesives are available with faster and slower set times.
Permabond Cyanoacrylate adhesives can be used to bond PET with a primer such as the Permabond POP. Recommended adhesives for bonding PET are the Permabond 105 and Permabond 2050. Both adhesives can provide high strength bonds within seconds and they provide good resistance to non-polar solvents. In general, most cyanoacrylate adhesives have poor resistance to polar solvents so should not be used in applications involving water, alcohol or other polar solvents.
Permabond TA4610 and Permabond Cyanoacrylate adhesives have a temperature resistance that exceeds the temperature resistance of PET, making it suitable for PET bonding applications.
Surface preparation and bonding untreated PET
Surfaces should be clean, dry and free from grease before applying the adhesive. Isopropanol wipes can be used to degrease the surface. For tips on best practice, read our post on: Surface Preparation for Adhesive Bonding
Structural acrylic adhesives
Permabond TA4610 can be applied without a primer or surface treatment. The adhesive can be applied through a static mixer nozzle.
Prime the surface using Permabond POP and apply the cyanoacrylate adhesive. Permabond POP is an adhesion promoter for Cyanoacrylate adhesives and is not recommend for use with other adhesives.
The other option is to treat the PET surface using flame, corona or plasma treatment, which will increase the surface energy and improve the adhesion.
Contact us for specific product recommendations on a suitable adhesive for bonding PET plastic
Looking for tips on bonding other plastics, read: What you need to know on bonding plastics