ASTM International

Standard Practice for Evaluating and Comparing Transfer Efficiency of Spray Applied Coatings Under General Laboratory Conditions
 N D5327

Annotation

This practice covers the evaluation and comparison of the transfer efficiency of spray-applied coatings under general laboratory conditions. Transfer efficiency is the ratio of paint solids deposited to the total paint solids used during the application process, expressed as a percent. This practice can be used to study the effect on transfer efficiency of changing operating variables and paint formulations. Key variables that need to be controlled are listed in 8.13.

NOTE 1—It is important that all process or formulation parameters, except that which is intentionally being changed, be kept consistent from test to test. If not done, the results of the study are to be questioned.

The reproducibility of this practice is highly dependent on the degree of control of the parameters listed in Section 8 of the practice.

Limitations—This laboratory practice indicates only the direction of the effect of operating variables and liquid paint formulations on transfer efficiency under conditions of the laboratory test: the magnitude of the effect can be determined only with specific plant experience. In fact, the nature of the critical parameters that affect transfer efficiency makes clear that it is not possible to extrapolate laboratory results.

NOTE 2—The laboratory practice outlined involves general laboratory spray equipment and procedures and is derived from Test Method D5009. This practice and Test Method D5009 are both derived from a study and report of transfer efficiency measurements conducted for the U.S. Environmental Protection Agency. For laboratories that have access to a conveyor and mass flow measurement equipment, a suitable, potentially more reproducible, tested method is defined in Test Method D5009.