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Need for phosphating before fluidized bedthermoplastics?

Does anyone know if it is necessary to use an iron or zincphosphate when using thermoplastics in a fluid bed process? I thoughtthat phosphates were used primarily in electrostatic powder sprayoperations.

Chris

Chris Ballew
- Newport, TN. USA

If you are preheating the metal prior to coating it will be effectively destroyed by the heat. You can use iron phosphate if itis a convenient method of cleaning the parts. Temperatures below 250deg C are just about allowable to zinc phos but there will be someloss of performance. Post cure certainly benefits from properpretreat giving enhanced performance.

Roger Bridger
Walterisation (UK) Ltd - Croydon, UK

If you are applying an organic coating such as plastisol over steel, then yes, you may use iron phosphate as a pretreatment to facilitate adhesion. I have direct experience with just such an application with a fluidized bed.

Ron Woods
Benchmark Products Inc. - Indianapolis, Indiana

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