Appendix I
GUIDANCE FOR CALCULATING VOC USED IN SURFACE COATINGS
The calculation method requires the following information:
An example calculation is as follows:
|
Total coated surface area of final assembled product |
= 1,5 m2. |
|
The VOC content of the coating compound (in g/L) |
= 120 g/L. |
|
The volume (1) of coating compound present before coating operation |
= 18,5 L. |
|
The number of identical units processed during the coating operation |
= 4. |
|
The volume (1) of coating compound remaining after coating operation |
= 12,5 L |
|
(1)
Note that weight measurements can be used instead of volume so long as the density of the coating compound is known and accounted for in the calculation. |
|
|
Total area coated |
= 4 × 1,5 m2 |
= 6 m2. |
|
Total volume of coating compound used |
= 18,5 — 12,5 |
= 6 L. |
|
Total VOC applied to surface |
= 3,9 L × 120 g/L |
= 468 g |
|
Total VOC applied per m2 |
= 468 g/6 m2 |
= 78 g/m2. |
Where more than one coating compound is applied, such as primers or finishing coats, the volumetric consumption and VOC contents shall also be calculated and added together.
Options to lower the total quantity of VOCs content used in coating operations include using more efficient techniques. Indicative efficiencies of different coating techniques are shown below.
Table
Indicative efficiency factors for coating techniques:
|
Coating technique |
Effectiveness (%) |
Efficiency factor |
|
Spraying device without recycling |
50 |
0,5 |
|
Electrostatic spraying |
65 |
0,65 |
|
Spraying device with recycling |
70 |
0,7 |
|
Spraying bell/disk |
80 |
0,8 |
|
Roller varnishing |
95 |
0,95 |
|
Blanket varnishing |
95 |
0,95 |
|
Vacuum varnishing |
95 |
0,95 |
|
Dipping |
95 |
0,95 |
|
Rinsing |
95 |
0,95 |