Overview
ISO 8130-10:2021 specifies a laboratory method to determine the deposition efficiency of sprayed coating powders - the mass fraction (%) of powder that deposits on a test item under defined spray gun and environmental conditions. The method applies to powders charged by corona or tribo systems and is intended for comparative evaluation of powders and guns when tests are carried out consecutively (to minimize environmental and equipment variability).
Key topics and requirements
- Purpose: measure the proportion of powder deposited versus powder sprayed and report the result as a mass fraction (%) for powder coating testing.
- Test specimen and setup:
- Five grounded steel tubes (25 mm × 500 mm) wrapped in clean aluminium foil; the central tube’s foil is weighed to determine deposited mass.
- Powder spray system (corona or tribo gun) mounted in an air extraction booth, with a non-conductive shield to control exposure.
- Controlled parameters and apparatus:
- Recommended sample size: 2 kg.
- Test temperature: (23 ± 2) °C and relative humidity 20–70 % (state actual ranges if not controllable).
- Powder flow-rate determination by spraying into a pre-weighed vacuum-cleaner bag for 60 s.
- Corona gun: powder flow ≈ (150 ± 7.5) g/min; gun potential typically set to (60 ± 1) kV (true gun potential).
- Tribo gun: delivery air pressure 300 kPa for flow-rate set-up.
- Spray time: (6.0 ± 0.5) s; air flow across booth opening: 0.4–1.0 m/s.
- Oven is used to melt (not cure) the deposited powder before re-weighing.
- Calculation and reporting:
- Deposition efficiency = (mass deposited / mass sprayed) × 100 % (mass sprayed = powder flow rate × spray time, with unit conversions as needed).
- Duplicate tests are required; if results differ by >5 %, a third run is performed. Results reported to one decimal place.
- Test report must include powder identification (type, PSD, density, composition, shape, flow properties), gun settings (voltage, polarity, air pressure, nozzle), booth and environmental data, and any deviations or anomalies.
Applications and users
- Quality control and R&D in powder coating manufacturing.
- Comparative performance testing of coating powders and application equipment (corona vs tribo).
- Spray gun and process optimization in coating applicator operations.
- Independent testing laboratories and suppliers evaluating deposition efficiency for specification, selection, and troubleshooting.
Related standards
- ISO 8130-14 - Vocabulary for coating powders
- ISO 15528 - Sampling of paints, varnishes and raw materials
Keywords: ISO 8130-10:2021, deposition efficiency, coating powders, corona charging, tribo charging, powder coating testing, powder flow rate, spray gun, powder deposition.
