UV Powder Coatings

The fundamental benefit of UV powder coatings is that they can be processed at considerably lower temperatures than traditional thermoset powders. While ordinary thermoset powders require temperatures in the range of 350 to 400°F (177 to 204°C), commercial UV curable powders require temperatures that are not higher than 220 to 250°F (104 to 121°C). A comparison of the two types is in Table 7.7. 

In contrast to the conventional powder coating, the melt and cure processes of UV curable powders are decoupled, so that while heat is used to flow the material, it does not cure the powder, and the cross-linking occurs only after the exposure to UV light. Because the temperature required for melting the 

Comparison of Heating and Curing Methods for Thermosetting and UV Curable Powders 

Thermosetting Powders Heating/Curing Temperature, c (op) Total Curing Time, min Substrate 

UV curable powders is in the 175 to 250°F (80 to 121°C) range/ much less heat is required, and it is needed only long enough to melt the powder, not to cure it. Cross-linking by the UV light is nearly instantaneous thus, the process is finished in a fraction of the time required for convenfional powders. 

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Although UV powder coatings can be applied to a variety of substrates, including metals and plastics with high melting temperatures, their primary advantage is for coating of substrates, which ared ... 

Preassembled parts Preassembled parts may contain components made from heat-sensitive substrates (e.g., plastic inserts, wiring). In contrast to the conventional method, where individual components are coated prior to assembly to avoid heat damage, UV powder coating permits the manufacturer to fully assemble a part prior to coating. 

Currently, the UV powder coating technology is used on a large scale for the following products ... 

Talbert, R. (Ed.), UV Powder Coating Application Guide, RadTech International North America, Chevy Chase, MD (2002). 

Table 7.8 Typical Curing Conditions for UV Powder Coatings on MDF. ..169...

Letterpress and Offset Letterpress (Dry Offset) Lithography Rotogravure Printing Rapid Prototyping UV Powder Coatings... 

The Chemistry of UV-Curable Powders Material and Substrate Preparation Powder Coating Application Substrates Suitable for UV Powder Coating... 

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