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APPLICATIONS
FRPE Hardening Ink and Lacquer Drying Photopolymers Sunlight Simulation UV Glue Processing Wood LacqueringExposure of Photopolymers
The curing of polyester is a chemical reaction during which the existing polymers are combined together to become a solid three-dimensional matrix. This reaction can be started by mixing hardening agent with polyester, after which there is still the opportunity to give the right shape to the polyester. It is also possible to mix a photo-initiator with the polyester that after exposure will decompose in reactive components, starting the destruction process.
Polyester provided with a photo-initiator is also called a photo-polymer. Working with photo-polymers offers a number of striking advantages:
- As long as the resin has not been not exposed to UV light, it remains liquid. The setting time is almost infinite, and the remainder can easily be recycled.
- Curing goes very quickly; within minutes the piece of work can be taken out of the mold, and the mold can be prepared for the next piece.
- No matter how complicated or how big the piece of work, the application of the resin is not limited by time.
- Brushes and rollers will not gel. The resin will remain liquid as long as is not exposed to UV.
Powder coating
After applying a classic powder coating, this is heated to 250°C. This is necessary to melt the powder and to let it flow over the work piece, and to polymerize the melted powder to obtain a strong surface coating.
When applying UV powder both aspects are separated:
- After applying the powder it is melted by heating.
- Then it is exposed with an UV source and the splitting up of the photo-initiator will start the polymerization.
- The flow phase can last as long as necessary. For materials on which the resin is resistant to flow, extra time can allow the powder to melt and deliquesce.
- A powder with lower melt temperature can be chosen, making it possible to lacquer materials (MDF, chipboard) that are not resistant to the temperatures of the classic powder lacquer.
- And since the melting phase can last longer without the film polymerizing, the final result will be much smoother that those obtained with the old-fashioned powder system.
