scope:

This Recommended Practice (RP) provides guidelines and recommended procedures for controlling dirt contamination (particles, fibrous material, etc.) in controlled environments used for paint spraying.

BACKGROUND AND PURPOSE

The quality of paint-spray coatings is highly dependent on stringent control of the environments in which they are applied. Airborne fibres cause significant blemishes. In some applications, particles as small as 5 μm, individually or in groups, maybe responsible for visible blemishes on painted parts.

Diligent effort is required of everyone who works in or near the surface preparation, spraying, and drying areas to eliminate this major source of surface defects. Among the factors that need to be controlled are air cleanliness, surface cleaning and preparation , gowning systems for personnel, laundering of reusable garments, and process-related consumables. This document provides a uniform basis for describing, procuring, operating, and testing the performance of controlled paint-spraying environments and related operational functions, with the goal of preventing "dirt" defects (i.e., paint-finish defects from undesirable/unwanted inclusion of contaminants in the paint film, caused by disturbances in the painting process).