Gluing Plastic Made Easy

All over Ireland, there are companies gluing plastics to themselves and a myriad of other materials. How many different types of plastics are there……….dozens upon dozens!!

We divide plastics into two groups, called Thermoplastics & Thermosets. Thermoplastics are created by long molecules that are not connected to each other, they can be melted down and reformed repeatedly.  Thermosets are crosslinked when they are produced and they can not be melted without distroying them.

Gluing plastics can be a challenge. The problem arises because several commonly used plastics have surfaces which are difficult to cover with glue. The glue does not coat the surface and on a miroscopic scale, the surface ‘rejects’ the adhesive. As an example, HDPE (High Density Polyethylene) & PP (Polypropylene) are typically difficult to glue together. For these plastics, the surface can be modified so as to allow the glue to ‘wet’ the surface. This modification may consist of sanding with abrasive paper or priming. Often times, a customer may have to carry out detailed, time consuming, surface preparation.

Last week, the Glue Guru was contacted by a company making hair brushes. They were using super glue to glue polyethylene to polystyrene. With each surface, they had to solvent wipe , sand , prime & apply the glue. Phew, what a job!!

We evaluated several adhesives both with and without the use of surface preparation. The key to offering an adhesive solution is to hopefully decrease the time and effort involved in surface preparation while offering bonds which are exeptionally strong. We tried some of our cyanoacrylate superglue adhesives and our X65 superglue gave excellent bonds with the use of our X80 primer for the polyethylene. This removed the requirement for the customer to abrade & solvent wipe.

We have a range of adhesives for bonding both Thermoplastics & Thermosets, ranging from single component adhesives like acrylics & cyanoacrylates to two component 10:1 acrylics and two component 1:1 polyurethanes.

Every week, sometimes twice a week, we receive enquiries for gluing plastics of all types. We always have a solution!

For immediate advice, contact the Glue Guru. glueguru@wipolymers.ie