Hardwood

Chemical hardwood (non-coniferous)

Description

One of two common classifications for trees, hardwood (angiosperm) and Softwood (gymnosperm). Hardwoods are broad-leaved deciduous trees that vary widely in color and grain pattern. Examples of hardwood trees are: Ash, Beech, Birch, Cherry, Mahogany, Maple, Oak, Poplar, and Walnut. Hardwood trees are found in temperate and tropical climate zones. Most of the wood used for cabinetry, furniture and flooring is obtained from hardwood trees. Only a small amount of hardwood is used for paper pulp. The term hardwood is somewhat confusing since some deciduous trees, such as basswood, have timber that is softer than some coniferous trees, such as yellow pine.

Synonyms and Related Terms

bois dur (Fr.); koboku (Jap.); frondosa (Esp.) ;folhosa (Port.); latifoglia (It.); nonconiferous wood; angiosperm; deciduous

Physical and Chemical Properties

Contain open-ended pores or vessels.

Paper fiber type: hardwood. Using transmitted light microscopy, pulp is identified by the presence of vessel elements with species specific morphological characteristics such as pitting, type of perforation, size, shape, etc. Fibers are short with thin walls. Appearance with Graff "C" stain: varies with pulping process and bleaching; Kraft=dark blue, sulfite=light blue. Average dimensions of fibers: length, 0.9 mm; width, 15-25 μm. Common pulping method: kraft dominates, but several species can be pulped using the Sulfite process.

Additional Images

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  Red oak paper pulp stained with Graff "C" stain

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  American sycamore paper pulp stained with Graff "C" stain

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  Red gum paper pulp stained with Graff "C" stain

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  Yellow poplar paper pulp stained with Graff "C" stain

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  Black cherry paper pulp stained with Graff "C" stain

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  Yellow birch paper pulp stained with Graff "C" stain

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  Aspen paper pulp stained with Graff "C" stain

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  Ash paper pulp stained with Graff "C" stain

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  Elm paper pulp stained with Graff "C" stain

Resources and Citations

• Alden Identification Services, Microscopic Wood Identification: Link

• 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

• Walter C. McCrone, John Gustave Delly, The Particle Atlas, W. McCrone Associates, Chicago, IV, 1972

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

• The Dictionary of Paper, American Paper Institute, New York, Fourth Edition, 1980

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

• Museum of Japanese Traditional Art Crafts at http://www.nihon-kogeikai.com/ (Jap. term)