PVDF Coatings Review

Finishing and Plating Specifications

PVDF (polyvinylidene fluoride) is a chemical resistant barrier coating made of a composite fluoropolymer resin and ceramic pigment. They are applied to ferrous and nonferrous materials to provide protection from the ambient environment and can last decades without the coating fading.

PVDF is a specialty plastic material in the fluoropolymer family; it is used generally in applications requiring the highest purity, strength, and resistance to solvents, acids, bases and heat and low smoke generation during a fire event. Compared to other fluoropolymers, it has an easier melt process because of its relatively low melting point of around 177 °C.

It has a low density (1.78) and low cost compared to the other fluoropolymers. It is available as piping products, sheet, tubing, films, plate and an insulator for premium wire. It can be injected, molded or welded and is commonly used in the chemical, semiconductor, medical and defense industries, as well as in lithium ion batteries. It is also available as a crosslinked closed cell foam, used increasingly in aviation and aerospace applications.

A fine powder grade, KYNAR 500 PVDF or HYLAR 5000 PVDF, is also used as the principal ingredient of high-end paints for metals. These PVDF paints have extremely good gloss and color retention, and they are in use on many prominent buildings around the world, e.g. the Petronas Towers in Malaysia and Taipei 101 in Taiwan, as well as on commercial and residential metal roofing.

PVDF membranes are used for western blots for immobilization of proteins, due to its non-specific affinity for amino acids.

PVDF is primarily used on architectural chemical processing equipment and other applications requiring corrosion protection and improved cosmetic appearances. PVDF unaffected by most chemicals and solvents and has very good wear and abrasion resistance. PVDF coating also exhibits a high dielectric strength, excellent resistance to weathering and the ability to self extinguish.

The foundation of PVDF stability is within the carbon-fluorine bond common to all fluoropolymer materials. With a combination of carbon-fluorine bonds (providing stability) and carbon-hydrogen bonds, a unique structure with balanced properties is created that makes PVDF particularly suitable as a base for liquid coatings. PVDF is inherently non reactive and has the ability to withstand long-term UV and gamma radiation resulting in excellent color and gloss retention without chalking. PVDF also resists acids, alkalis and oils.

Polyvinylidene Fluoride (PVDF) Coating Characteristics:

• Thickness .020" - .030"
• Use Temperature 500°F max
• Chemical Resistance (ASTM D543) Excellent
• Abrasion Resistance (ASTM D4060) Excellent
• Tensile Strength at Break (ASTM D638) 6525 PSI
• Coefficient of Friction (ASTM D1894) .4 Static, .3 Dynamic
• Dielectric Strength (ASTM D149) 260 Volts per mil
• Hardness (ASTM D676) 80 (shore D)