Wood Science

1
Wood Science

• Forest Operations
• Solid wood manufacturing
• Composite wood manufacturing
• Pulping
• Specialty products

2
Forest Operations

• Harvesting Process - Completes the cycle of
  growth for a stand of timber.
• Harvest operations involve machinery that can
  damage the forest
• Operations attempt to achieve the goals of the
  forest manager to modify conditions in a stand of
  timber

3
Forest Products

• Forests produce wood - Wood can be used for many
  purposes
• Pulp and paper
• Composite wood products...
• Lumber
• Veneer...

4
Wood Characteristics

• Density
• Workability
• Strength
• Strength to weight ratio
• Resistance to decay
• Color and grain
• Chemical characteristics

5
Solid Wood Products

• Primarily Lumber
• Dimension Lumber
• Hardwoods
• Process
• Sawing - slabbing, edging, trimming
• Grading
• Drying Process (optional)

6
Composite Wood Products

• Plywood - Veneers of wood, 1/16th inch, glued and
  laminated..
• Glulam Timbers - Laminates of wood with grain
  glued parallel to each other - Finger joints
  common - Why do this?
• Particle Board - Planer shavings, sawdust and
  glue - Compressed into solid piece.
• Oriented Strand Board - three layers of chips or
  strands with the layers oriented in different
  pattern to increase strength.

7
Composite Wood Products

• Parallam - Most recent development in engineered
  wood - Long strands of wood compressed, with glue
  and microwaved. Extruded wood in dimensions up
  to 2 foot by 2 foot.
• Laminated Veneer Lumber (LVL) - Similar technique
  to plywood, many layers of wood in specific
  orientations compressed and glued. Lumber
  substitute. Again, product can be manufactured
  in a variety of dimensions, and is a substitute
  for lumber.

8
Pulp and Paper

• Pulp and paper manufacturing consume 68 percent
  of all wood fiber produced in the US.
• Three methods of pulping - Kraft (or sulfate),
  soda, and sulfite
• Other methods include ground-wood, and
  semi-chemical.
• Typically takes at least two tons of raw wood to
  make one ton of pulp for paper...

9
Other Forest Products

• Firewood - Less emphasis in the US on wood as
  fuel, predominant in other countries.
• Christmas Trees - Very profitable for landowners
  with small acreage. Very labor intensive. Retail
  value of over 600 million!
• Naval Stores - Rosin and turpentine production
  from the resin of slash pine (Pinus palustrus)
  and loblolly pine (Pinus taeda). Dynamite...
• Maple Syrup - Northern production from the sugar
  maple (Acer Saccharum). Up to 40 gallons of syrup
  per acre on good sites. It takes 30 to 50
  gallons of sap to make one gallon of syrup!