Woods and Plastics

Comprehensive vocabulary flashcards covering wood classification, anatomical structure, properties, defects, sawing methods, lumber measurement, wood composites, millwork, and architectural plastics.

Softwoods

Woods derived from conifers (evergreens) that have needles instead of leaves, such as pine.

Hardwoods

Woods derived from broad-leaved or deciduous trees, encompassing most Philippine construction timber.

Sapwood

The softer, younger outer portion of a log located between the cambium and heartwood that contains living cells, is lighter in color, permeable, and less durable.

Heartwood

The older, harder central core of a tree composed of inactive cells that provides mechanical support and is denser, darker, less permeable, and more durable than sapwood.

Wood Decay

A defect in wood caused by fungal attack, primarily occurring when moisture content is above the fiber-saturation point.

Checks

Cracks or lengthwise separations across annual growth rings caused by irregular shrinkage during drying.

Shakes

Cracks running between and parallel to the annual growth rings of a tree.

Knots

Irregular growths in the body of a tree caused by embedded branches that interrupt the smooth curve of the wood grain.

Pitchpockets

Well-defined openings between annual growth rings containing solid or liquid pitch.

Wane

A wood defect defined by the absence or lack of wood on the edge or corner of a piece.

Warping

Distortion in the plane surface of a board resulting from unequal shrinkage during drying.

Crook

A form of warp where the board edge becomes convex or concave longitudinally.

Bow

A form of warp where the face of the board becomes convex or concave longitudinally.

Cup

A form of warp where the face of the board becomes convex or concave across its width.

Twist

A form of warp characterized by a distortion in which one corner of the board is raised.

Plainsawing

A method of sawing lumber tangent to the annual growth rings (at an angle of $0^\times$ to $45^\times$) to produce pleasing grain patterns.

Quartersawing

A method of sawing lumber radially across annual growth rings (at an angle of $45^\times$ to $90^\times$) to minimize shrinkage and ensure tight joints.

Board Foot

The standard unit of measurement for lumber, equal to a piece of wood $1\,in.$ thick, $12\,in.$ wide, and $12\,in.$ long, calculated as $\text{Board Feet} = \frac{\text{Thickness (in.)} \times \text{Width (in.)} \times \text{Length (ft.)}}{12}$.

Fiber-Saturation Point

The condition reached when all free water is removed from cell cavities while cell walls remain saturated with absorbed water, occurring at approximately $30\%$ moisture content.

Equilibrium Moisture Content (E.M.C.)

The state of dryness where the vapor pressure in the surrounding air balances the vapor pressure on the wood surface, ranging between $12\%$ and $16\%$ moisture content in the Philippines.

Seasoning

The process of removing moisture from green wood to increase strength, reduce weight, minimize shrinkage, and prevent fungal or insect attack.

Subterranean Termites

Soil-dwelling insects that construct earthen tubes to access wood and cellulose materials, eating along the direction of the grain.

Non-Subterranean Termites

Wood-boring insects that inhabit timber above ground and require full-length chemical preservers to prevent infestation.

Coal-Tar Creosote

A black or brownish oil distilled from coal tar that provides high toxicity to wood-destroying organisms and water insolubility, but possesses a strong odor and cannot be painted.

Pentachlorophenol

An oil-type wood preservative consisting of petroleum oils with $5\%$ pentachlorophenol, commonly specified for utility poles and cross arms.

Chromated Copper Arsenate (CCA)

A water-borne wood preservative applied via pressure treatment that undergoes chemical fixation with wood fibers, making it leach-resistant and safe for human contact applications.

Plywood

A wood composite made of several thin veneers glued together with alternating grain orientations at right angles to maximize strength and stability.

Hardboard

A dense, rigid panel manufactured by refining wood chips into threadlike fibers and compressing them under heat and hydraulic pressure (e.g., Lawanit, Masonite).

Chipboard

A rigid sheet made by bonding wood particles together with phenolic resin or urea formaldehyde adhesive under heat and pressure.

Medium Density Fiberboard (MDF)

A flat, stiff composite panel composed of wood fibers glued under heat and pressure, featuring no knots, internal voids, or recognizable grain.

Gypsum Board

A fire-resistant interior panel consisting of a gypsum core wrapped in smooth, durable paper, used extensively in dry-wall construction.

Fibercement Board

A building board manufactured from $72\%$ Portland Cement, $20\%$ mineralized cellulose fibers, and $8\%$ calcium carbonate.

Particle Board

A composite board produced by pressing and gluing small wood chips, sawdust, or agricultural residues such as bagasse or rice straw.

Millwork

Finished lumber items processed and cut at a planing mill, including mouldings, doors, windows, trim, and decorative woodwork.

Thermoplastics

A class of synthetic resins with linear molecular structures that soften when heated and harden when cooled repeatedly (e.g., Acrylic, PVC, Polyethylene).

Thermosetting Plastics

Synthetic plastics with three-dimensional molecular structures that set permanently into shape under heat and pressure during molding and cannot be remelted (e.g., Epoxy, Polyester, Melamine).

Acrylic

A transparent, shatterproof thermoplastic commonly known by brand names like Lucite and Plexiglass, used for skylights, lighting diffusers, and safety glazing.

Polyvinyl Chloride (PVC)

A rigid, solvent-resistant, and flame-resistant thermoplastic used for piping, resilient floor tiles, and films.

Epoxy

A thermosetting resin utilized in building construction for its outstanding adhesive properties, chemical-resistant coatings, and specialized caulking compounds.

Lamination

A manufacturing process where paper or fabric sheets impregnated with thermosetting resins are bonded together under heat and pressure to create decorative or structural sheets.

Carpenter Ants and Powder-Pest Beetles

use wood for shelter rather than for food, but if

they are not found and are left undisturbed they

can do extensive damage. They convert wood to

powder, shredded fibers or pellets. Their channels

are likely to cut across the grain. The damage to

wood by the various marine organisms, mollusks

and crustaceans in salt water or brackish water is

best arrested by heavy, thorough treatment with

coal-tar creosote or creosote-coal tar solutions.

Chromated Zinc Chloride (CZC)

Gives protection against decay, insects and fire;

can be painted on; has no objectionable odor.

Wood Composites

are those products made from a

mixture of wood and other materials. Most wood

composites are produced in large sheets, usually

1220mm (4’) x 2440mm (8’).

Standard hardboard

is light brown in color and has a fairly hard, smooth

surface on one side and a screened impression on

the other. It is flexible and easy to bend. It is suitable

for interior use only and where it is not subject to

moisture.

Panel hardboard

is somewhat denser than the Standard but not as

dense as Tempered.

Tempered hard board

is the densest type, made by impregnating standard

board with tempering compound of oils and resins and

baking it to polymerize the tempering materials. It is

dark brown in color, brittle and stiff, with improved

machining qualities and greater resistance to moisture

and water penetration, making it ideal for exterior use

Fiberboards

are finishing materials made from

vegetable fibers such as corn or sugarcane stalks

pressed into sheets. It is not very strong, but has

good insulating properties therefore it is usually used

for ceiling only.

Wall Board

This type is used for surface layer on interior walls and

ceilings. The regular wallboard comes with grey liner

paper backing and special paper finish on the facing

and edges suitable for decoration.

Backing Board

This is used as base layer in multi-ply construction,

where several layers of gypsum boards are desired for

high fire resistance, sound control and strength in walls.

Core Board

To save space, this type is used as a base in a multi-

ply construction of self-supporting (studless) gypsum

walls. It comes in 1” (25mm) thickness or 2- factory-

laminated, 1⁄2 “ thick layers of backing board .

Type X Gypsum Board

For use in fire-rated assemblies, this may be wallboard,

backing board, or coreboard made more fire-resistant

by addition of glass-fiber or other reinforcing materials

Water-Resistant Backing Gypsum Board

This type comes with water-resistant gypsum core and

water-repellant face paper. It maybe used as base for

walls of bathrooms, showers, and other areas exposed

to wetting.

Gypsum Sheathing

This type is used as fire protection and bracing of

exterior frame walls. It must be protected from the

weather by an exterior facing.

Gypsum Formboard

This type is used as a permanent form in the casting of

gypsum concrete roof decks.

Celluilosics

primarily cellulose acetate or butyrate, used

principally for paints and lacquers, and transparent

sheeting.

Polyethyline (PE)

Ziegler PE is a hard,

strong, tough and rigid

thermoplastic for household

and industrial applications.

Polystyrene

In spite of its sensitivity to solvent action, its is one

of most important thermoplastics because of its

excellent transparency and rigidity and its easy

moldability. It is non-water absorbent, it is found in

colorful, but brittle wall tiles. It is one of several

plastics used in lighting fixture diffusers.

Polycarbonates

a family of linear polyesters, is a white, substantially

amorphous, very tough and strong material with good

heat resistance up to 150 deg C and excellent

dimensional stability.

Polyproylene

tough plastic with good resistance to heat and

chemical action.

Nylon

The term nylon refers to a family of polymers called

linear polyamides. It is desired for the following

properties: exceptionally strong, elastic, abrasion

resistant, easy to wash, resistant to damage from oil

and many chemicals, can be precolored or dyed in

wide range of colors, and resilient .

Fluroplastics

are a class of paraffinic polymers that have some or

all of the hydrogen replaced by fluorine. The

fluoroplastic group is characterized by excellent

chemical resistance, excellent heat resistance, good

electrical properties, and excellent wear resistance.

ACRYLONITRILE BUTADIENE STYRENE (ABS)

is a styrenic resin with improved toughness and

heat resistance. ABS exhibits high gloss, low

shrinkage, and good dimensional stability, is widely

used in injection molding of appliances, furniture, and

automotive parts.

MELAMINE and UREA

hard, durable and dimensionally stable, these

similar plastics are resistant to chemicals, electric

potential, and heat. Melamine is well known for its use

in molded dishes, while urea is useful for incandescent

light diffusion and for baked enamels .

Epoxy

used in buildings for its remarkable adhesive

qualities. It may also be used for special paints that

are chemically resistant and for special caulking

compounds.

Alkyds

appear chiefly as molded electrical parts, and as the

vehicle in paints, lacquers, and enamels .

Phenolics

used for paints, baked enamels, adhesives,

impregnating resins for paper and wood, and finish

hardware.

Polyester

the plastic most

commonly used in large

glass-fiber reinforced

translucent panels that are

strong, rigid, and impact-

resistant. Also used for

impregnating paper and

wood, as laminating

material, and for contact

adhesive.

Silicones

used for clear, water-

repellant paints for

concrete and masonry

surfaces above grade .

Sheets

Usually made of acrylate, polyester, or polystyrene

plastics, either plain or reinforced with glass-fiber, are

available in flat or corrugated sheets and various

deformed shapes.

Film Sheets

As water barrier or dampproofing material, it is

generally made of polyethylene and polyvinyl and

come in thicknesses ranging from 1 to 10 mils

(0.001 to 0.01 inch) and in rolls of 50’ length and 3’

to 40’ width.

Foam

Used as flotation material, thermal insulators,

and shock-resistant mountings. Offers possibilities

for lightweight materials of high strength .