Primers fluoropolymers

This section does not cover the topic of coatings and finishes. These finishes are usually highly formulated and are applied as multiple-pass coatings which include special primers and intermediate layers. They may include pigments, additives, other resins, and more than one fluoropolymer. The main applications of fluoropolymer finishes are in cookware and industrial anticorrosion and high-temperature uses. A separate volume, Fluorinated Coatings and Finishes, a Plastics Design Library (PDL) volume in the Fluorine Handbook Series published by William Andrew, Inc., covers the topic. 

The adhesives will bond almost all materials (though a primer may be needed with some), except polyolefin plastics (eg Polythene) and other low surface-energy types such as fluoropolymers (eg Teflon) and silicone-based rubbers. Alkaline glass may cause premature bond failure and all glasses should be silane primed if at all possible, as this considerably improves the joint s humidity resistance. May stress crack stressed mouldings or susceptible plastics - polycarbonate, for example. 

Like PEEK and POM, this material has a very low surface energy and so will require some form of surface treatment prior to bonding with engineering adhesives (Table 2.17). Cyanoacrylate with primer shows some adhesion but etching kits for the fluoropolymers are also available. 

These two-part acrylics do not require any pre-treatment of the joint surfaces or any surface primer and will bond polyethylene, polypropylene and ethylene copolymers with shear strengths in the range 4-8 N/mm. They can be used on many other substrates and so can be used as a general-purpose adhesive, although they are not recommended for bonding PTFE or the fluoropolymers. The resistance to water and high humidity environments is good but the mix ratio is critical to avoid unpredictable results. 

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