Degreasing and Solvent Cleaning

Degreasing has always been considered an integral part of ideal surface preparation, but under current environmental pressures, it is quite normal to find it has been partly eliminated or even totally eliminated. The need for thorough degreasing becomes more relevant where the environmental resistance of the bond is important and especially where an abrasive technique has left a contaminated surface. 

Degreasing of plastics with solvents can cause problems  

If solvent degreasing/cleaning is going to be employed, then a fast drying solvent which has a relatively low solvating power towards the plastics being degreased needs to be used. 

Aqueous degreasing can be effective, especially when fully automated. However, any aqueous process can leave a surface which requires desorption of water, which adds another process. 

Unfortunately, for low pressure moulding and casting in particular, the ultimate bonds are often only achieved if desorption of the adsorbed water and gases is specified. This is most evident with polyamides, some polyesters, PU, melamine and urea resins and some epoxy resins. 

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