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Physical Properties of Wood

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Title: Physical Properties of Wood


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Physical Properties of Wood
  • Tensile Strength
  • Compression Strength
  • Splitting Strength

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Biological Properties Xylem
  • Conducts water and minerals from soil upward
  • gymnosperms
  • Tracheids
  • Softwoods, e.g. pine, spruce, cedar
  • angiosperm
  • Tracheids
  • Vessel elements
  • Hardwoods, e.g. maple, oak, mahogany

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Fig. 38.13a
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Stems Secondary growth
  • Vascular tissue, (xylem) makes up the bulk of the
    stem
  • Form tree rings

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Example Gymnosperms
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Example Angiosperms
Brazilian Rosewood
African Mahogany
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Links to Other Resources
  • For those of you who asked for more information,
    the Guild of American Luthiers (luth.org below)
    is a great resource. Note wood suppliers, and
    harp-making links are on that page, for those who
    asked.
  • http//www.luth.org/
  • http//www.luth.org/hot.htm
  • http//www.frettedinstrumentguildofamerica.org/pag
    es/872009/index.htm
  • http//www.violadabraccio.com/
  • http//www.cs.dartmouth.edu/lsa/index.html
  • http//www.folkharpsociety.org/index.html

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Cork
  • Characteristics due to many air-filled cells,
    good insulating material, lightweight, floats
  • Cork cambium develops within the secondary phloem
  • Quercus suber - cork oak

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What is paper?
  • Paper derives from the word "papyrus
  • paper includes a wide range of products with very
    different applications communication, cultural,
    educational, artistic, hygienic, sanitary as well
    as storage and transport of all kinds of goods.
    It's almost impossible to imagine a life without
    paper.
  • The best paper is pure cellulose

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Paper trivia
  • Each American uses about 144 pounds of paper per
    year!
  • more than 500,000 trees per week are used to
    produce the 2/3 of newspapers that are never
    recycled
  • every ton of paper that is recycled saves 17
    trees, 7,000 gallons of water, 4,100 kilowatts
    of electricity
  • producing paper from recycled fibers reduces air
    pollutants by as much as 74 and water pollutants
    by as much as 35
  • every ton of paper recycled leaves 3.3 cubic
    yards of free space in landfills

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Historical writing surfaces
  • papyrus (Cyperus papyrus, Cyperaceae) - Egyptians
  • rice paper (Fatsia papyrifera, Araliaceae) -
    Orient
  • mulberry paper (Broussonetia papyrifera,
    Moaraceae) - Mayans

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Paper
  • separated plant fibers that have been matted
    together to form a sheet
  • true paper
  • thin sheets must be made from fiber that has been
    macerated until each individual filament is a
    separate unit
  • fibers are then intermixed with water, and, by
    the use of a sieve like screen, are lifted from
    the water in the form of a thin stratum, the
    water draining through the small openings of the
    screen leaving a sheet of matted fiber upon the
    screen's surface
  • This thin layer of intertwined fiber is paper

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Making Paper
  • Harvesting
  • Cooking with lye
  • Rinsing
  • Beating or blend to make pulp
  • Add laundry starch to size
  • Mould and Deckle
  • http//www.missioncreekpress.com/plants.htm

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Bamboo
  • No secondary xylem, primary growth only
  • Segmented, hollow tubes, typical grass stem
  • Used for fishing poles, caning for furniture,
    house construction in tropics, skyscraper
    scaffolding in Japan
  • Pandas feed on young leaves stems of bamboo
  • Bamboos have unusual life cycle, some species
    grow for decades without flowering, then all the
    members of a species worldwide will flower and
    die the same year
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