Forestry 280: Hand lens cross-sections,Woods 14-27: Softwoods without normal resin canals
Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in...
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Transcript of Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in...
![Page 1: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/1.jpg)
Wood Technology
![Page 2: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/2.jpg)
Structure and Growth
Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods
Annual rings- composed of springwood and summerwood Depends on type of wood Growing conditions
![Page 3: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/3.jpg)
Structure and Growth
Sapwood- thick living cells Heartwood- inactive sapwood Cambium- layer inside the bark where the
water travels
![Page 4: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/4.jpg)
Structure and Growth
Softwood cell structure Tracheids- transport sap and strengthen wood Thin rectangular cell units
Hardwood cell structure Vessels- conducting sap vertically Porous wood with large holes or pores
![Page 5: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/5.jpg)
Moisture Content
Trees can be up to 75% water Fiber Saturation Point- cells wall are full of
water while cell capsule is empty % Moisture Content=
Initial Wt. – Oven-dry Wt x 100
Oven-dry Wt
![Page 6: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/6.jpg)
Drying Methods
Air Drying- 30 to 60 days during active drying weather, up to 6 months during unfavorable weather
Oven drying- 1in board can be dried 6 to 10% MC in 3 to 4 days Increases heat while decreasing humidity
![Page 7: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/7.jpg)
Drying Methods
Radio-frequency drying- drying time approximately 24 hours Hardwood dry best with this method Improves color and quality Causes uniform drying
![Page 8: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/8.jpg)
Equilibrium Moisture Content
Moisture content in the wood is equal or close to the moisture content in the air
Slight changes cause door and windows to stick during humid weather
![Page 9: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/9.jpg)
Lumbering
Bucking- limbs are removed and log is cut into specific lengths
Logs can be stored in water to prevent insect damage and splitting
![Page 10: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/10.jpg)
Plywood and Veneer
Rotary- follows the growth rings when being cut Veneer is very wide
Plain slicing- parallel slices through log Produces a variegated figure
Quarter slicing- parallel slices in a quarter portion of a log Causes striped wood look
![Page 11: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/11.jpg)
Manufactured Board
Hardboard- (Masonry Board) formed by bonding wood fibers together
Particle Board- bonding wood flakes and chips together
![Page 12: Wood Technology. Structure and Growth Formed of long tubular fibers, about 1/25in in length in hardwoods and 1/8in for softwoods Annual rings- composed.](https://reader035.fdocuments.us/reader035/viewer/2022062422/56649ed45503460f94be458f/html5/thumbnails/12.jpg)
Manufactured Board
Wafer Board- wafers randomly formed together
Oriented strand board-formed from long strands of wood parallel to one another