Understanding (any) powder spray gun settings kV - µA relation

Correct powder gun setting

Top right orange ring = On / Off

Top left green LED = Activated (otherwise idle state)

powder coatin gun settings gema optiflex settings

Quick keys

Generally with E=4 and % 60

3 quick keys for recipes (under the display)

Flat parts
Second layer
Complicated shapes

Understanding parameters

kV = high voltage in kiloVolt, static friction
µA = spray current in microamps
E = total air = 4.0 Nm ³ / h (h = hour)
% = Powder output rate, for example 60% coating 40% air
Recipe # 3

kV - µA Relation

Automatic regulation of the load to the distance workpiece

The Electron control recognises the distance or workpiece surface and regulates kV and µA at that moment. If the gun tip is too close, the µA is reduced and vice versa.

High kV if:

The higher the setting, the stronger the charge / adhesion.

flat parts and for the outside of box-like parts.

Low kV if:

the more detailed and complex the part (inner surface) to improve transfer efficiency so that it penetrates to the corners

(more powder particles to the part) e.g.

50 kV with 20 to 40µA
50 to 60 air mixture %.
increase the distance between the gun and the part
to obtain a very uniform coverage on flat surfaces

1. Flat parts

Flat or first layer

100 kV / 100 µA set.

Recommended set area is 50 to 80 kV with 70 to 100 µA

3. Complicated shapes

Square edged workpieces: (outer surface)

100 kV / 22 µA set.

Works well with 90 kV and 22-35 µA

2. Overcoating or second layer / two-coat process

100 kV / 10 µA set.

Coating Gun Setting values

Coating angular workpieces

kV 90 = 90,000 V
µA 35 = 3.5 x 10-5 A
E 4.0 Nm3/h or lt/min
% 60 = powder output
= powder coating in spray air
Recipe no. 3

2. Overcoating or second layer / two-coat process

100 kV / 10 µA set.

The range of values for the second layer fluctuates between

100 kV with 10 µA and
80 kV with 10 µA
50 kV with 20 µA, even up to
20 kV with 30 µA

First coating, for example, you can leave the KV setting at 80 kV
second over-coating at 50 kV
third over-coating at 30 µA, each with a limit of 10 to 30 µA.

If you notice reionisation, i.e. the inner corners are already electrostatically charged so that no further penetration of the powder is possible, you can reduce the KV and leave the microampere setting at the lower end of the range of 10 to 30 µA microamps.