Application Procedure and Equipment
1 – Powder coatings charging properties are optimized when powder is free-flowing and moisture-free. Aged or compacted powder may require pre-conditioning for several minutes to fluidify evenly.
2 – If storage room temperature is lower than the application area, powder coatings, which are hygroscopic, should be acclimated in unopened containers prior to adding into the spray hopper. For optimum performance, It should be applied and stored at air-conditioning area. Storage temperatures should be kept below 30 °C.
3 – Powder should not be stored in hoppers for long periods of time. If moisture condensation occurs, fluidize powder to dry-out or replace moisture-laden powder with virgin powder.
4 – Powder coatings are finely ground particulates. Respirators or dust masks should be used by workers exposed to powder in order to avoid dust inhalation.
5 – Compressed air to the gun must be oil and moisture free.
6 – Silicone should not be used in application area.
7 – For box feeders, ensure probe is fully inserted in powder and operated as per manufacturers recommendations.
8 – Contact points should be maintained to ensure metal-to-metal ground.
9 – Apply by electrostatic spray. Relative humidity should be 50-60% for corona system, lower than 40% for tribo system.
10 – Cure as per recommendations outlined above.
11 – Reclaim-to-virgin ratios should be carefully monitored to maintain spray consistency.
12 – Sieving powder before adding to hopper eliminates potential clumping or foreign matter.
13 – Test for cure of the coating by contact with a drop of MEK for 30 seconds. Surface should be wiped dry and immediately checked for softening. Only slight surface softening should occur.
TOP TIP: When spraying metallics, we recommend feeding the spray out of a fluidizing hopper – avoiding box feeders if you can. Taking this step will assist in increasing the evenness of the flow as you spray, ensuring that your gun is being fed a rolling mixture of the powder. Otherwise – and especially with unbonded metallics – you might get clumps of pigment and metallic flakes. This creates an uneven coat and is not an attractive final product.