Plywood

Vessel by Rude Osonik
MFA #1988.234

Description

A layered assembly of hardwood or softwood veneers bonded together at right angles with an adhesive. Plywood was originally called scale boards in a 1865 US patent. In the nineteenth century, plywood was manufactured from hardwoods (Maple, Birch, etc.) and used by furniture makers for concealed parts such as drawer bottoms. By the beginning of the 20th century, plywood was used for doors, seats, and desk tops. Douglas fir softwood plywood was first made in 1905; southern pine became extensively used in 1964 for softwood plywood. Plywood has been used in airplanes, automobiles, and house construction. Early panels were adhered with Hide glue, Blood glue, Cassava flour, Casein glue, and Soybean glue. In 1935, plywood was made with synthetic thermosetting formaldehyde adhesives (Phenol formaldehyde, and Urea formaldehyde). By 1939 Melamine formaldehyde resins were used and a few years later Resorcinol adhesives were also in use. At one point, water-resistant phenol formaldehyde adhesives are used for exterior-use plywood and urea formaldehyde resins are used in interior-use plywood, but concerns for emissions from both of the glues have resulted in the use of low formaldehyde-emitting glues systems that are denoted by an "E" rating. Plywood has a high strength-to weight ratio, is resistant to splitting, can be molded into compound curves, and is more dimensionally stable than solid wood.

Plywoods

Synonyms and Related Terms

laminated wood; Holzwerkstoff (Deut.); contrachapado (Esp.); tripley (Esp.); contreplaqué (Fr.); compensato (It.); triplex (Ned.); multiplex (Ned.); sklejka (Pol.); contraplacado (Port.); veneered construction; Plyshield; Haskelite; Harbord; Plankweld; Plycrete; Plymetal; Weldtex; Weldwood; scale board

Collection risks

Some plywoods contain Urea formaldehyde adhesives which emit Formaldehyde.

Working Properties

Softwood plywood is typically made from Cedar, Douglas fir, SPF (Spruce/Pine/Fir) or Redwood. It is typically used in home construction for roofing and flooring as well as for fencing, and boxes.

Hardwood plywood is made from dicot trees (Beech, Oak, Mahogany) to produce high strength, damage-resistant boards.

Veneer plywood is faced with more expensive hard woods such as Ash, Oak, Birch, Maple, Mahogany, Rosewood or Teak.

For additional information, see:

• AIC Conservation Wiki: Using Plywood in Exhibit Case Construction

Resources and Citations

• Wikipedia: https://en.wikipedia.org/wiki/Plywood (accessed April 2020)

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996

• Thomas C. Jester (ed.), Twentieth-Century Building Materials, McGraw-Hill Companies, Washington DC, 1995

• Encyclopedia Britannica, http://www.britannica.com Comment: wood" [Accessed October 31, 2001].

• R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 618

• Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)

• Caring for your Collections, Arthur W Schulz (ed.), Harry N. Abrams, Inc. , New York, 1992

• Pam Hatchfield, Pollutants in the Museum Environment, Archetype Press, London, 2002

• Richard S. Lewis, Hawley's Condensed Chemical Dictionary, Van Nostrand Reinhold, New York, 10th ed., 1993

• Theodore J. Reinhart, 'Glossary of Terms', Engineered Plastics, ASM International, 1988

• Random House, Webster's Encyclopedic Unabridged Dictionary of the English Language, Grammercy Book, New York, 1997

• The American Heritage Dictionary or Encarta, via Microsoft Bookshelf 98, Microsoft Corp., 1998