lektyur ng ind2-2

WOOD
• Only 300 species are utilized commercially, the rest are considered weeds
• There are about 3,800 tree species in the Phil.

• Wood Classification
1. Hardwood
• from broad-leaved deciduous trees
• contains long ducts called wood fibers that extend vertically through the trunk and serve as mechanical support
2. Softwood
• Wood that comes from coniferous trees; Ex: pinecones
• Composed of tracheids which are primitive conducting cells

• Kinds of Wood
• Walnut
o One of the most serviceable and versatile of woods
o Outstanding for its rich color, durability, and beauty
o Can be made into bowls or other small objects, a favorite for wood-carving
• Mahogany
o Excellent material for paneling hollow-cored doors; relatively inexpensive and has an attractive grain that takes in finish
• Oak
o Traditionally favorite for floors and furniture; Resistant to wear made it popular for school and office furniture
• Maple
o Has toughness and warmth of color that make it a fine material for many purposes; still appeals to people who prefer informal and hospitable room interiors with traditional character.
o Has a yellow-orange color
• Pine
o Was used extensively during the colonial period and is in demand today for m=paneling furniture
o Ex: used for splice racks, cabinets, canister sets
o Low cost and light weight
o Warps and shrinks a little
• Teak
o a tropical wood of marked strength and durability
o most desirable for contemporary artifacts and furniture
o has somewhat a lighter color that walnut
o responds to beautiful oils which brings luster
o extremely durable
• Fruitwood
o Takes a sumptuous finish and possess a wide range of warm tones
o Can be combined with leather, brass
o Contributes to opulence and richness of interiors

• Wood Property Requirements
•Grain – straight grained are preferred
•Texture – uniform textures are preferred
•Weight and density – must not be too light nor too heavy
•Seasoning characteristics – swelling of wood during seasonal conditions
•Workability – property of wood can be worked on easily
•Finishing characteristics – easy to sand; takes in stain, varnish and paint very well
•Modulus of strength – possess desires strength to carry load

•Wood Processing Technologies
•Saw-milling
oConversions of logs into lumber are usually done in the band saw. Band saw is preferred over circular saw because of the narrow kerfs of the band saw blades produce lesser wood waste during saw-milling

•Drying or Seasoning
oDrying sawn lumber is a very important process in the manufacturing of wooden products
•Ordinary air drying
•Kiln drying

•Machining
oAfter drying the wood, the next process is machining
•Planning
•Boring
•Mortising
•Shaping
•Turning
•Sanding
oFactors affecting the machining properties of surface quality of wood:
•Species
•Moisture content
•Specific gravity
•Cutting angle
•Feed rate
•Depth of cut
•Spindle speed
•Sharpness of knives or cutters
•Cellular structure of wood
oWood defects attributed to machines used:
•Raised grain – occurs in abnormal wood and low density wood
•Fussy grain – occurs in wood with low density and higher feed rate
•Chip marks – occur in low density wood and when the blower system of the furniture shop is inadequate to suck the wood particles or shavings
•Preservative treatment – treat or chemically apply wood preservatives on the components to protect them from being infested or attacked by powder post beetles, dry wood termites and other destroying organisms
 Employed by pressure/non-pressure process
 Choice of treatment depends on those (ex: outdoor furniture – treat with water-soluble preservatives to desired retention)
 Indoor furniture – non-pressure treatments such as brushing, dipping, or soaking

•Wood finishing
 application of transparent or opaque coatings usually termed as wood finishing
 protects wood from warping, raising grain, cracking, checking, shrinking and swelling
oTypes of finishing materials
• Stains – provide transparent coloring effect to any material and at the same time accentuate their natural color
 Dyes – available in the form of water stains, oil stains, spirit stains
 Chemical stains – ammonia chromates and permanganates
 Pigment stains – in the forms of liquid and powders
• Varnishes – relatively hard and reasonably elastic
 Natural varnishes
• Derived from plants, insects and vegetable matter
 Synthetic Varnishes
• Uses resin (ester gum) made from esterified (?) with glycerin
• Quick drying, hard tough material that produces high resistance to weathering, chemicals and mechanical weather
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•Weird notes: (bilis kasi maglecture ni ma’am using the acetate)
• 2 types of synthetic varnishes:
o oleoresinous varnish – contains oil or synthetic resin
o spirit varnish – contains solvents plus natural… (di ko nakopya!)

• waxes
• paints – lead base, zinc oxide, titanium, lithopine, casein, epoxy
• 4 types use oil, turpentine and drier as vehicle binder
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• good paints properties:
color consistency
color retention
brushability
leveling
running
covering
flooding – amount of water in paint
drying – quick drying (or not)
initial gloss retention
durability
package stability

• Popular finishes:
Antique
Verdigris or patinated (“terracotta”-ish, greenish)
Pickle (or two effects)
Rustic look
White washed
Stain washed
Crackle
Marbling
Splattering technique
Metallic look
Pearlized (uses silver leaf or gold leaf)
Concrete
Monochrome anique
Handpainted technique
Stencil approach
Laminated effect
Burnt
Batik or wax reist
Textural