The correct surface preparation is importance to achieve the required level performance from the adhesive bond. The primary aims of the preparation are to remove surface contaminations such as wax, plasticizer and to enhance the wet ability of the surface to ensure a modified surface chemistry to achieve better bonding, with adhesive the most common process used for pre-treatment sole surface are solvent wiping and halogenations process.
It is often necessary to pre-treat the rubber before bonding. Pre-treatments range from physical methods such as “Roughing the surface”. Physical methods may remove cohesively weak layers from the polymer and increasing of surface area.. This is essential to achieve good bonding, unless these layers can be absorbed by the adhesive. However, physical methods will only be effective if the underlying rubber possesses suitable groups which can interact strongly with the adhesive. Chemical methods “Chemical roughing” may also remove weak layers or chemically modify them so that they are more compatible with the adhesive; in addition chemical methods may roughen a surface. However, an effective chemical method will also modify the chemistry of the rubber so that the interaction with the adhesive is increased