More effective quality testing of the synthetic, hollow filaments that are often used in the manufacture of lower cost paintbrushes is the purpose of a new standard approved by ASTM International Committee D01 on Paint and Related Coatings, Materials and Applications.
The new standard, D7233, Test Method for Testing Fracture of Level Paintbrush Filaments, was developed by Subcommittee D01.61 on Paint Application Tools.
John Feathers, technology associate, DuPont Filaments, and chair of Subcommittee D01.61, says that previously, the low cost paintbrush market was served by brushes that used natural hog bristle while professional brushes were made with solid filaments.
“While the hollow filaments did provide lighter weight and cheaper manufacturing cost, they’ve often had quality issues such as fracturing when bent during painting,” says Feathers. “Failure to recover to a straight position after flexing during painting often results in filaments sticking out from the brush, resulting in poor control of the paint application.”
Feathers says that D7233 and the equipment detailed within it will allow suppliers of hollow filaments for paintbrushes to better assess the tendency of the filaments to fracture.
“This method can be used between filament suppliers and brush manufacturers to establish an acceptable quality specification for the filaments,” notes Feathers. “In addition, the method is useful when developing new hollow filament cross-sectional shapes to reduce or eliminate fracture when bending.”
In addition to being used by firms that supply synthetic filaments to the paintbrush market and brush manufacturers, Feathers says that the standard could also apply to other markets such as those for brooms and cosmetic brushes.
Subcommittee D01.61 consists of raw material suppliers, paint sundry manufacturers, test laboratory suppliers and cooperators, and general users of paint applicators. Past and current activities have included the development of standards and practices for assessing quality attributes and performance of paintbrushes and rollers.
The subcommittee invites all those interested to participate in its standards development activities. New projects for D01.61 include a proposed standard for paint pads as well as to document terminology for the industry.
“We welcome input from paint suppliers and painting professionals to guide us toward the need for additional standards,” says Feathers. “We always have a need for testing cooperators who can help us assess method consistency and repeatability through round-robin lab tests. It is in this stage of standard development that we learn the most about realistic use of the new method.”
Technical Information: John Feathers, DuPont Filaments, Washington, W.Va.
ASTM Staff: Jeffrey Adkins