ISO 8130-10:2021 pdf download – Coating powders — Part 10: Determination of deposition efficiency.
7 Procedure 7.1 Carry out the test in duplicate at a temperature of (23 ± 2) °C and a relative humidity between 20 % and 70 %. In view of the large volume of air which can pass through the air extraction booth during the test, it may not be possible to control the temperature and humidity. Under these circumstances, the range of temperature and humidity shall be stated in the test report. 7.2 Wrap the five items (5.1) with aluminium foil (5.2) such that the top and bottom edges fold over into the tube to ensure good electrical contact. Weigh, on the balance (5.6) to the nearest 0,1 g, the foil to be used for the central tube. 7.3 Determine the powder flow rate by spraying powder through the powder spray system (5.8) for 60 s as measured by the timing device (5.7) into a pre-weighed vacuum-cleaner bag (5.4). Re-weigh the bag and its contents to 0,1 g and calculate the powder flow rate in grams per minute. a) When using a corona charge gun, adjust the control of the powder spray device to achieve a powder flow rate of (150 ± 7,5) g/min. It is essential that the high voltage is turned off during this operation. b) When using a tribo charge gun, adjust the delivery air pressure to 300 kPa and measure the powder flow rate as described in the first paragraph of 7.3. 7.4 Place the suspension device (5.3) with the five tubes in the spray booth. 7.5 Mount and level the spray gun in the extraction booth so that it is aimed at the middle of the central tube at a distance such that the powder will cover approximately 60 % of the length of the central tube. Record this distance. Ensure the air flow across the booth opening is set between 0,4 m/s and 1,0 m/s and the air flows parallel to the spraying direction. It may be difficult to cover 60 % of the target length when narrow cone applicators are used. Any deviation shall be recorded in the test report.