Latex Paint Open Time
A new ASTM International standard provides a means of determining open time. Open time is the time available where the paint can be worked into a previously painted area. Open time is a key performance property for coatings, particularly for brush applications.
D7488, Test Method for Open Time of Latex Paints, was developed by Subcommittee D01.42 on Architectural Coatings, part of ASTM International Committee D01 on Paint and Related Coatings, Materials and Applications.
“Historically, solvents used in coating formulations assisted in delivering good open time of a formulated coating,” says Carol Hawkins, a scientist with Dow Chemical Co., and chairman of D01.42. “As we move away from using solvents in coatings due to changes in regulations for volatile organic compounds, it is important to develop a test method that formulators can use to determine open time of a coating.”
Hawkins says that the formulators who will use the standard would likely represent manufacturers of architectural paints and paint additives.
According to Hawkins, participation is always welcome in D01.42. “We welcome a broad group of participants into our subcommittee, including manufacturers of raw material and paint, as well as consultants,” says Hawkins.
Technical Information: Carol Hawkins, Dow Chemical Co., Spring House, Pa.
ASTM Staff: Jeffrey Adkins