Effect of Position and Motion on Personal Exposure in a HVLP Spray Painting Operation

Details

• Personal Author:
  McKernan JL
• Description:
  Worker exposure to particles is a problem in most spray painting processes. Previous studies, using a stationary mannequin and simple spray nozzle, showed that dimensional analysis could be used to correlate a dimensionless breathing zone concentration (which requires knowing the gun transfer efficiency) with a dimensionless nozzle pressure term (the Carlton number). This work expands on that study by using a real high volume-low pressure (HVLP) gun, and adding a representative spraying motion. A robot-mannequin, capable of holding and actuating the spray gun, and also performing a repeated side-to-side spraying motion was used. Vacuum pump oil was sprayed onto a flat plate in a wind tunnel to determine the relationship between nozzle pressure and breathing zone concentration. "Breathing zone" samples were collected using a cassette modified to mimic the 10M inlet. Data collected in the absence of motion show that the dimensionless concentration in the 900 position is lower than the 1800 position until a crossover point is reached at low values of the Carlton number (8 x 10s). After this point, the dimensionless breathing zone concentration in the 1800 position is lower than in the 900 orientation. For the case with motion, the importance of position to dimensionless breathing zone concentration was mitigated. Using task representative Carlton number values (alpha values) allows for simplification of the results. Alpha values for the 900 and 1800 orientations without motion were 0.232 and 0.028. It was observed that the motion mitigated the positional effect in such a way as to make the alpha value for motion close to the average of the two no motion alpha values, 0.102. These results allow for the supposition of a formula to predict breathing zone concentrations or transfer efficiencies for conventional and HVLP spraying guns. The results also stress the association between contaminant generation, transport, and exposure. Models, such as the one used, are beneficial because they relate exposure to processes parameters that can be controlled to reduce it. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Methane Mining Occupational Health Safety
• Keywords:
  Aerosol Particles Aerosols Air Contamination Mathematical Models Models Occupational Exposure Paints Paint Spraying Sampling Methods Spray Painting Work Environment

  More +
• Publisher:
  University of North Carolina at Chapel Hill
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Dissertation
• Place as Subject:
  North Carolina ; OSHA Region 4
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  1-77
• NIOSHTIC Number:
  nn:20024721
• Citation:
  Chapel Hill, NC: University of North Carolina at Chapel Hill, 1997 Jan; 1-77
• Federal Fiscal Year:
  1997
• NORA Priority Area:
  Research Tools and Approaches: Exposure Assessment Methods
• Performing Organization:
  University of North Carolina, Chapel Hill, North Carolina
• Peer Reviewed:
  False
• Start Date:
  19950930
• Source Full Name:
  Effect of position and motion on personal exposure in a HVLP spray painting operation
• End Date:
  19990929
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:bdcb10b6c9f91ba5b1df779453e57145282d28663f97cc12f61e9c5cda40f770100aaf7a9c0b0697fceb368da21410846efa76a1f1edb72bd24f1d46fc7f90a2
• Download URL:
  https://stacks.cdc.gov/view/cdc/196368/cdc_196368_DS1.pdf
• File Type:
  [PDF - 4.27 MB ]