Tuesday, January 19, 2016

Stages of Powder Coating Cure

As a powder coating is subjected to heat, its cure proceeds along various stages.

Stage 1: Melt Point
Powder particles begin changing from a solid to semi-liquid state.

Stage 2: Flow Stage
Powder is fully liquefied, reaching lowest viscosity, allowing the film to smooth out.

Stage 3: Cross Linking Stage
Sufficient, sustained heat triggers large scale reaction within film; this reaction is the initial step to total chemical and physical change of product.

Stage 4: Gel Stage
At the point when sufficient crosslinking has occurred, solidification of the film takes place.

Stage 5: Cure Development
The final and most critical stage: baking. Baking causes a reaction of   majority of crosslinking sites and development of optimal film properties.

Stage 6: Over Cure
The film will start to lose some flexibility turning yellow in color with potentially decreased gloss below expected levels. Inter-coat adhesion is compromised and catastrophic failures become likely.

For more information on curing powder coatings, read TCI's Troubleshooting Guide, or contact us today to speak with one of our professional service technicians. We can help you with application questions or any of your powder coating needs.

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