- Spanne, Mårten, et al.
Characteristics of Particle Emissions at Paint Manufacturing
Ingår i: Journal of Aerosol Science. ; 27 S1, s. S437-S438
- The handling of pigments and powders in paint manufacturing cause emissions of airborne particles. A great variety of substances occur. Previous studies (Bohgard et al., 1994) of simulations of pouring of pigments, which occur in small scale weighing procedures, showed typically bimodal size distribution including a sub-micron and a super-micron mode.The objective of the study was to get detailed knowledge on the relation between different source processes (depending on production technology, equipment and the manual handling routines) and aerosol characteristics.Super-micron particles were continuously measured with a time-of-flight instrument (Aerodynamic Particle Sizer, APS TSI Inc.) and sub-micron particles with an electric mobility spectrometer (Scanning Mobility Particle Sizer, SMPS TSI Inc.). In addition filter sampling techniques for standardised work-place sampling (so-called total dust filter cassettes, a cyclone sampler for respirable dust and IOM-samplers for inhalable dust) have been used for idealised exposure/area measurements using a rotating mannequin as a carrier of these samplers. The filters were analysed gravimetrically and with Particle Induced X-ray Emission Analysis. The aerosols were measured during manufacturing of batches of paint. Sources and source mechanisms, as pouring pigments from bags, disposal of packages, mixing of powders and pigments and suspected re-suspension sources, were documented simultaneously with the performance of the measurements.Figure 1 shows examples of size distributions obtained with the APS and SMPS. The size distributions have essentially bimodal shapes with median diameters of 0.05 -0.4 [mu ]m and of 2-5 [mu ]m respectively. Rapid variation in concentration occurs.Preliminary results show that several sources occur. Irregular activities and events as disposal of package material, cleaning, leakage from conveyor tubes and re-suspension due to wind velocities from open gates and moving vehicles significantly contribute to the particle concentrations.Filter sampling with the samplers mounted on a mannequin torso, rotating 360 degrees forth and back, is advantageous by giving idealised measures on exposure. Samplers mounted on equal horizontal level will have equal sampling location integrated over time. Furthermore, the sampling procedure emulate sampling in accordance with sampling conventions. Inlet characteristics of samplers mounted on a body differ from characteristics of free-hanging samplers (Vincent, 1989). Higher estimated mass concentrations were obtained with the IOM-samplers for inhalable dust than with the 37 mm open-face [ldquo ]total dust[rdquo ] cassettes.Figure omitted