Surface preparation and pretreatments
Working directions for the surface preparation essential for optimum adhesion between structural materials bonded with Araldite® adhesives. Araldite® adhesives form extremely strong and durable bonds with plastics, metals, glass, rubber and many other materials. Designers in every sphere of industry increasingly find that bonding with Araldite® provides the answer to production problems posed by new materials, new uses of existing materials, and new techniques and manufacturing methods.
1
Surface pretreatments.indd 1
12/04/07 9:50:57
Introduction
Araldite® resins adhere firmly to most materials. Bonds of great strength are obtained after removal of grease and loose surface deposits, e.g. rust, from the surfaces to be joined, but when maximum strength is required a more thorough mechanical or a chemical pretreatment is recommended.
Surface preparation
Surfaces are prepared by one of the following pretreatment procedures (listed in order of increasing effectiveness). 1. Degrease only. 2. Degrease, abrade and remove loose particles. 3. Degrease and chemically pretreat Care must be taken to avoid contaminating the surfaces during or after pretreatment. Wear clean gloves. Contamination may be caused by finger marking – or by cloths which are not perfectly clean – or by oil – contaminated abrasives – or by sub-standard degreasing or chemical solutions. Contamination may also be caused by other work processes taking place in the bonding area. Particularly to be excluded are oil vapours from machinery, spraying operations (paint, mould release-agent, etc.) and processes involving powdered materials. Whatever the pretreatment procedure used, it is good practice to bond the surfaces as soon as possible after completion of the pretreatment – i.e. when surface properties are at their best. Note If the scheduling of bonding operations on multi-part assemblies causes delay between pretreatment and