Depending on the substrate material and the adhesive being used, different degrees of surface preparation are required. At an absolute minimum it is recommended that the surfaces to be bonded are wiped clean with a lint-free cloth soaked in a suitable solvent or cleaning agent (to remove loose particles and organic deposits such as grease). If the substrate is metallic or inorganic (eg. glass, alumina, etc), abrasion with grit paper (to remove unwanted surface layers and roughen the surface) followed by a solvent wipe is recommended. Some polymers may produce a less stable bonding surface should they be subjected to abrasion. In other instances, grit-blasting and etching processes are advised, whilst some materials require the application of a primer before they can be successfully bonded.
For polymers with low surface energy (e.g. polyethylene (PE), polypropylene (PP)) exposure to corona discharge, flame and plasma treatments will improve adhesion. The first two methods are used for preparing surfaces of polyolefin (e.g. PE) for printing and adhesion to paints, and also for adhesive bonding.
For further information please contact us.