Symbolizing Adhesives for
A new ASTM International standard, D7447, Practice for Symbolizing Adhesive Applications, provides a convenient way for engineers to represent adhesives on a computer-aided design drawing. The standard, a collaborative effort between ASTM and the Adhesive and Sealant Council, is under the jurisdiction of Subcommittee D14.60 on Adhesive Material Classification System, which is part of ASTM International Committee D14 on Adhesives.
Lawrence Sloan, president of the Adhesive and Sealant Council and a D14 member, says that D7447 originated with a focus group that ASC conducted with engineers, designers and architects to learn about their perceptions of adhesives. The focus group results indicated that those questioned would be more apt to specify adhesives if they could be represented conveniently on a CAD drawing rather than the current method of embedding comments in a “notes” section.
Designers, engineers, architects and anyone else preparing a CAD drawing would benefit from use of D7447, according to Sloan.
ASC based the methodology of the symbol on the American National Standards Institute/American Welding Society A2.3 standard, Symbols for Welding and Nondestructive Testing, and the International Organization for Standardization (ISO) 15785 standard, Technical Drawings — Symbolic Presentation and Indication of Adhesive, Fold and Pressed Joints.
“ASC approached ASTM in 2006 with the idea of creating a new standard in tandem with the symbol, as it was felt that standardization would help build international credibility within the design-engineering community,” says Sloan. “Plus, we received grassroots interest from Mercedes and other automotive companies in Germany supporting our decision to work with ASTM.”
ASC has also developed an electronic file based on D7447 that consists of a series of fields that the designer can populate with information such as adhesive chemistry type and physical form, surface preparation, curing information and more.
“The electronic file is a convenient way for the designer to represent an adhesive’s many characteristics in one symbol by eliminating the tedious task of manually adding adhesives in the ‘notes’ section of a CAD program,” says Sloan.
Technical Information: Lawrence Sloan, Adhesive and Sealant Council, Bethesda, Md.
Phone: 301-986-9700, ext. 111
ASTM Staff: Joseph Hugo