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Polyester, Silicone Polyester, Plastisol, PVDF - Coatings on Metal Sheets

2005

Dear All,

We are a insulated metal sandwich panel manufacturer and we are using prepainted steel sheets in our production.

However, we are facing serious deficiency in getting clear explanations regarding the coating types of these steels.

Is there anyone who could make satisfactory explanations regarding these coating types:
Polyester, Silicone Polyester, Plastisol, PVDF

We roughly know that Plastisol and PVDF are more resistant coating types and plastisol would be more food-friendly, but we cannot go further than that because not even our suppliers can provide fulfilling descriptions.

In this respect, we would really appreciate if anyone could point out the main descriptions, similarities and differences/advantages of these paint types.

Thanks in advance.

ALI IHSAN CETINER
Sandwich Panel Manufacturing - Istanbul, Turkey

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2005

Polyester's are made from reacting a polyfunctional alcohol with a polyfunctional organic acid to make a polymer. With the number of hydroxyl and carboxyl groups on each molecule and possible lengths of the these molecules a great deal of diversity is possible. Polyester coatings are the most common coating used on coil lines. Jack of all trades general purpose coating. Alkyds are a subgroup of the polyester family.

Some of this functionality can be used to cross link with other resin systems such as silicones where The main use is for siding. They have very good weatherability. High temperature resistance is another property of silicone polyester's. Stove pipe is an example where this is used.

Plastisols are resin systems that have been heavily chlorinated and then dissolved in plasticizer. Their claim to fame is chemical resistance. PVDF is a just substituting fluoride for the chloride for even better properties and of course expense.

Ronald Zeeman
Coil Coating - Brampton, ON, Canada