Soybean flour is formulated into adhesive systems as either the main polymeric component, incorporated as extenders for other resins. Their primary application is in the manufacture of plywood, softboard laminating, paper overlaying, and other less stringent applications. These adhesives are inexpensive and can be used for making semi-water resistant plywood and for coating some types of paper. Soybean flour can be combined with phenolic adhesive resins to make hot press interior plywood glues.
RESULTING PROPERTIES
Soybean glues generally are considered to have limited water resistance but recover their strength on drying. Soybean glues are susceptible to mold growth. However, a variety of efficient preservatives are available. A typical dry glue soybean flour composition is listed above. It must be added to phenolic resin solution for maximum adhesive properties (see below).
