Like all effect powder coatings, transparent powder coatings with effect pigments also demand higher requirements of the coating pro-cess than single-color powder coatings. The transparency of the cured paint film is an additional challenge with these products.
This Processing Instruction, VR 205, was prepared in order to provide users with assistance in processing IGP transparent powder coatings with a metallic effect (G -> 5th position of the IGP article description).
As opposed to deviations in the effect pigment content or the effect pigment alignment in the powder coating, deviating coating thick-nesses or different substrates can result in a visually different effect appearance.
IGP effect powder coatings come in five main processing categories, from 1-STAR * to 5-STAR*****.
Because transparent powder coatings with effect particles, as described above, present users with higher requirements than normal powder coatings, they are labeled with the 1* classification.
This processing instruction was issued to inform users about possible causes of faults and to provide a guideline for optimal coating results.

One Batch, one Application Facility

If the components are installed directly adjacent to each other, we recommend determining the required powder amount for the entire order and planning a certain reserve in order to coat the entire application with a single production batch. This guarantees absolute color and effect consistency of the coating on all objects.

Experience has shown that varying results in terms of shade and effect formation can occur when the product is applied using devices from different manufacturers (due to the different characteristic curves generated by the high-voltage generators).

Processing one order in different cabin types should be avoided. No changes to the coating plant processing or application parameters may be made when processing a certain consignment. If it is determined that plant data / application parameters are ideal, they must be documented and observed. This procedure and the parameter settings must also be observed for follow-up orders.

We urgently recommend producing limiting samples to check the match with the shade ordered (input inspection) as well as to monitor the shade and effect appearance throughout production. An inspection to determine any deviation from the tolerance limits on coated parts must be carried out under suitable lighting before supply (output inspection).

The coating thickness and the substrate have a significant influence on the visual appearance of the coating. For this reason, limiting samples and release samples must be produced on the same substrate and with the same pre-treatment. The coating thickness of the samples must also be identical to the target thickness of the subsequent production coating.

If it is not possible to avoid different substrates / pre-treatments, we urgently recommend applying the coating in a two-coat system. This involves first coating a neutral substrate, then applying the transparent effect powder coating.

To ensure the coating plant achieves reproducible coating results, the maintenance work for replacing parts subject to wear in the entire plant must be performed at the specified intervals, as recommended by the manufacturer. Various functional tests, e. g. checking the high voltage, must be carried out at regular intervals.

Different curing temperatures and heating speeds of the parts must be avoided. Furthermore, thick and thin-walled parts must be coated separately. Observe the recommended range of curing conditions without fail.

• TI 000 classification of effect powder coatings
• All corresponing technical data sheets

The values stated here are recommended values. When processing IGP transparent powder coatings with effect pigments, we recommend that you adjust the processing parameters of the coating plant to the product to be processed.