|
| Absolute |
| |
A measure having as its zero point or base the complete absence of the entity being measured.
|
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| Absolute pressure |
| |
The pressure above zero absolute, i.e., the sum of atmospheric and gauge pressure. In vacuum related work it is usually expressed in millimeters, or inches, of mercury.
|
|
| Acceptance sampling |
| |
A statistical quality control method that seeks to determine the quality of a product by sampling a small portion of it. It does not assure that 100 percent of the product is acceptable, but reduces the likelihood of acceptance of a defective product.
|
|
| Accumulator |
| |
A container in which fluid (generally nitrogen) is stored under pressure as a source of fluid power.
|
|
| Acre (a) |
| |
A unit of area used in English-speaking countries, equal to 4,840 square yards (0.405 hectares).
View: Metric / Imperial Conversion
|
|
| Across the grain |
| |
The direction at right angles to the length of the fibres and other longitudinal elements of the wood.
|
|
| Active falling area |
| |
The area within two tree-length radius of where a faller or a mechanized falling machine is operating.
|
|
| Actuator |
| |
A device for converting pneumatic or hydraulic energy into mechanical energy. A motor or cylinder.
|
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| Adhesive |
| |
A substance capable of holding materials together by surface attachment. It is a general term and includes cements, mucilage, and paste, as well as glue.
|
|
| Adult wood |
| |
Wood which characteristically has relatively constant cell size, well-developed structural patterns, and stable physical behaviour; also called Mature wood.
|
|
| Adverse (grade) |
| |
Ascending grade in the direction of travel.
|
|
| Aeration |
| |
Air in the hydraulic fluid. Excessive aeration causes the fluid to appear milky and components to operate erratically because of the compressibility of the air trapped in the fluid.
|
|
| Aerial logging |
| |
A logging system which fully suspends the logs such as done by helicopters or balloons. Not to be confused with cable systems which use cables and supports.
|
|
| Age class |
| |
Any interval into which the age range of trees, forests, stands or forest types is divided for classification and use. Forest inventories commonly group trees into 20-year age class groups.
|
|
| Air velocity |
| |
The speed of airflow through the stickers, crossouts, and around the lumber expressed in feet per minute (fpm) or metres per second (mps).
|
|
| Air-dried |
| |
Lumber that was dried by exposure to air in a yard or shed, without artificial heat.
|
|
| Airflow |
| |
The pattern of air movement within a dry kiln. This pattern varies with kiln design, loading methods, and level of maintenance and operation.
|
|
| Allowable annual cut (AAC) |
| |
The volume of timber that may be harvested annually from a specific timber tenure.
|
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| Allowable cut |
| |
The amount of wood that can be removed from a landowner's property during a certain time span, without exceeding the net growth during that same time on the property
|
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| Along the grain |
| |
The direction parallel with the length of the fibres and other longitudinal elements of the wood.
|
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| Alternate top bevel |
| |
A design for a circular saw blade where teeth are alternately beveled.
|
|
| American Lumber Standards |
| |
Provisions for softwood lumber dealing with recognized classification, nomenclature, basic grades, sizes, descriptions, measurements, tally shipping, provisions, grade marking, and inspection of lumber. The primary purpose of these standards is to serve as a guide in preparing or revising grading rules of the various lumber manufacturers' associations. A purchaser must, however, make use of association rules because the basic standards are not in themselves commercial rules.
|
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| Amplifier |
| |
A device for amplifying the error signal sufficiently to cause actuation of the stroke control. Several types of servo amplifiers are used at the present time: electronic (DC, AC, phase sensitive, and magnetic) and mechanical.
|
|
| Amplitude of sound |
| |
The loudness of a sound.
|
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| Analog |
| |
A continuous range of numbers or values.
|
|
| Anisotropic |
| |
Exhibiting different properties when measured along different axes. In general, fibrous materials such as wood are anisotropic.
|
|
| Annual growth |
| |
Layer of wood developed by a tree during a given year; same as annual or seasonal increment.
|
|
| Annual growth rings |
| |
The layer of growth that a tree puts on in one year. The annual growth rings can be seen in the end grain of lumber.
|
|
| Annular area |
| |
A ring shaped area - often refers to the net effective area of the rod side of a cylinder piston, i.e., the piston area minus the cross-sectional area of the rod.
|
|
| Anti-sap stain |
| |
A wood treatment used to prevent fungus from staining the wood.
|
|
| Anvil (swage) |
| |
The fixed jaw in a swaging device that supports the back of the tooth while the die or roller presses against the front of the tooth.
|
|
| Appearance grades |
| |
High-line regular board and dimension grades that include tighter restrictions on certain appearance characteristics, particularly wane.
|
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| Arbor |
| |
The shaft on which a circular saw blade or chip head is mounted.
|
|
| Atmospheric pressure |
| |
Pressure exerted by the atmosphere at any specific location. (Sea level pressure is approximately 14.7 pounds per square inch absolute.)
|
|
| Axial force |
| |
A push (compression) or pull (tension) acting along the length of a member, expressed in kilonewtons (pounds).
|
|
| Axial stress |
| |
The axial force acting at a point along the length of a member divided by the cross-sectional area of a member, expressed in kilopascals (pounds per square inch).
|
|
| Back clearance |
| |
The angle between the back of a tooth and a tangent of the circumference or cutting circle. Same as Clearance angle.
|
|
| Back connected |
| |
A condition where pipe connections are on normally unexposed surfaces of hydraulic equipment. (Gasket mounted units are back connected.)
|
|
| Back pressure |
| |
A pressure in series. Usually refers to pressure existing on the discharge side of a load. It adds to the pressure required to move the load.
|
|
| Backcut |
| |
The final cut in felling a tree by hand, made on the side opposite the intended direction of fall, after the undercut.
|
|
| Backhaul |
| |
A delivery by tractor-trailer originates from where the trailer is loaded, the load is delivered to a destination, then the trucker returns home. If the return is also a paying load to be delivered to the vicinity of the trucker's home, that load is called a backhaul. If the trucker returns home empty, that run is called a "deadhead".
|
|
| Backing veneer |
| |
The layer of veneer used on the reverse side of a piece of plywood from the face or decorative side.
|
|
| Backrest |
| |
A wood bench opposite the tensioner, used to support a circular saw when checking tension.
|
|
| Baffle |
| |
1. A barrier in a dry kiln used to deflect and control airflow through the lumber.
2. A device, usually a plate, installed in a reservoir to separate the pump inlet from return lines.
|
|
| Baffle, end |
| |
A hinged baffle in a dry kiln that closes the gap at the end of the lumber next to the doors.
|
|
| Baffle, floor |
| |
A hinged or stationary baffle in a dry kiln that closes the gap at the bottom of the lumber unit, preventing air from escaping under the load.
|
|
| Baffle, overhead |
| |
A hinged baffle in a dry kiln that closes the gap between the overhead fan deck and the top of the lumber load.
|
|
| Baghouse |
| |
An air pollution control device that captures particulate in filter bags.
View: Baghouse Examples
|
|
| Band saw |
| |
A saw made from steel, butt welded into an endless belt or band with teeth on one or both edges arranged to cut sequentially.
|
|
| Band sawmill |
| |
An evolution in sawmill technology that uses a thinner band saw blade (less kerf therefore less sawdust waste) than a circular saw. A bandsaw can also have teeth on both sides that allows cuts to be made in two directions instead of just one, improving efficiency and productivity.
|
|
| Bar or blade |
| |
That part of the chainsaw upon which the cutting chain moves.
|
|
| Barberchair |
| |
A vertical split in a tree, generally caused by an insufficient undercut or by neglecting to cut the sapwood on both sides of a heavy leaning tree before felling. Results in a stump which looks like a high-backed chair. Very dangerous to the faller.
|
|
| Bark |
| |
The outermost, protective layer, of a tree.
|
|
| Bark pocket |
| |
A small area of bark around which normal wood has grown; an opening between annual growth rings that contains bark. Bark pockets appear as dark streaks on radial surfaces and as rounded areas on tangential surfaces.
View: Bark Pocket
|
|
| Basal area |
| |
Cross sectional area of a tree, in square feet, measured at breast height. Used as a method of measuring the volume of timber in a given stand.
|
|
| Base of tree |
| |
That portion of a natural tree not more than three feet above ground level.
|
|
| Basis weight |
| |
1. The weight, in pounds, of a ream (500 sheets) of paper cut to a given standard size for that
particular paper grade.
2. For linerboard and corrugating medium, the weight of the paper per 1,000 sq. ft.
|
|
| Baud rate |
| |
The speed at which data is transmitted and received over serial communication lines. The equipment on both sides of the communications line must be set up to send and receive data at the same rate.
|
|
| BCTMP |
| |
Bleached chemi-thermomechanical pulp.
|
|
| Bearings |
| |
A part on which the arbor, pivot, pin, or the like, turns or revolves.
|
|
| Beehive burner |
| |
A wood waste incinerator.
|
|
| Belt |
| |
Part of the conveyor on which pieces of wood are displaced.
|
|
| Bending strength |
| |
A measure of the resistance of wood to an applied bending stress which is a combination of three primary stresses, i.e., compressive, tensile, and shear stresses.
|
|
| Bevel cut |
| |
An angled cut through a board.
|
|
| Big box stores |
| |
Large, warehouse-type lumber and building material stores catering to do-it-yourself (DIY) shoppers. Home Depot and Lowes are examples.
|
|
| Bight |
| |
A work area made hazardous by a line or equipment under tension.
|
|
| Biodegradable |
| |
Something that breaks down to its component parts in the environment.
|
|
| Biomass |
| |
The quantity of biological matter of one or more species present on a unit area. With respect to trees, biomass can be expressed in terms of various components (wood, bark, foliage, roots, etc.) of all trees on a unit area or of a single tree; biomass quantities of trees are commonly expressed on an oven-dry weight basis.
|
|
| Biomass boiler |
| |
Biomass boilers burn bark, sander dust and other wood-related scrap not usable in product production. Also called "hogged fuel" boilers, biomass boilers make steam and heat for mill use.
|
|
| Bit |
| |
The smallest unit of memory in a computer. A bit is a single digit and can only have the values 0 or 1. Bits are combined into words of memory.
|
|
| Bite (feed per tooth) |
| |
The depth of cut per tooth, inch. In general, the formula is: bite = distance between teeth (in inches) times feed speed (in feet per minute) divided by saw velocity (in feet per minute). More simply it is the distance the log or cant advances into the saw between successive teeth.
View: Bandmill Formula, Gang Edger Formula, Quad Sawbox Formula
|
|
| Bleaching, pulp |
| |
The process of removing residual lignin from pulp to improve the brightness and strength.
|
|
| Bleed-off |
| |
To divert a specific controllable portion of hydraulic pump delivery directly to reservoir.
|
|
| Blow down |
| |
Tree or trees felled by wind. Also known as Windfall.
|
|
| Blue stain |
| |
A bluish or dim-grayish discoloration of the sapwood caused by the growth of certain dark-colored fungi on the surface and in the interior of the wood, made possible by the same conditions that favor the growth of other fungi. Also known as Sap stain or Sapwood stain.
View: Blue Stain
|
|
| Board |
| |
Lumber that is nominally less than two inches thick and two inches or more wide.
|
|
| Board edger |
| |
Machine centre for removing the wane from the sides of flitches.
View: Board Edger Examples
|
|
| Board foot |
| |
A unit of measurement of lumber represented by a board 1 foot long, 12 inches wide, and 1 inch thick or its metric equivalent. In practice, the board foot calculation for lumber 1 inch or more in thickness is based on its nominal thickness and width and the actual length. Lumber with a nominal thickness of less than 1 inch is calculated as 1 inch.
View: Board Foot
|
|
| Boiler |
| |
Steam generation equipment.
|
|
| Bolt |
| |
A short section of a tree trunk. In veneer production, a short log of a length suitable for peeling in a lathe.
|
|
| Bolt circle |
| |
A circle scribed around the arbor hole of a circle saw which has one or more holes laid out to receive bolts.
|
|
| Bond strength |
| |
The unit load applied in tension, compression, flexure, cleavage, or shear, required to break an adhesive assembly, with failure occurring in or near the plane of the bond.
|
|
| Bone-dry ton (BDT) |
| |
Material that weighs 2,000 pounds at zero percent moisture content. Also known as an Ovendry ton or Bone Dry Metric Ton.
|
|
| Bone-dry unit (BDU) |
| |
A quantity of wood residue that would weigh 2,400 pounds at zero percent moisture content.
|
|
| Boom |
| |
A raft of logs or a string of logs chained together, end to end, used to hold floating logs. A means of log storage or transportation.
|
|
| Boomboat |
| |
Any boat used to push or pull logs, boom, bundles, or bags, in booming ground operations.
|
|
| Bound moisture |
| |
Moisture which is closely bound to the cell wall constituents of wood.
|
|
| Bound water |
| |
Water that is bound within the cell wall of wood. Water held in wood below the fiber saturation point. Bound water moves by diffusion.
|
|
| Bow |
| |
A lumber defect referring to deviation from a straight line drawn end to end along the wide face of a piece of lumber. See also Warp.
View: Bow
|
|
| Braze |
| |
As in welding, a method of adhering or soldering carbide or other hard metal teeth inserts, or joining pieces of metal.
|
|
| Breather |
| |
A device which permits air to move in and out of a container or component to maintain atmospheric pressure.
|
|
| British thermal unit (Btu) |
| |
The quantity of heat required to raise the temperature of one pound of water by one degree Fahrenheit.
View: Metric / Imperial Conversion
|
|
| Broad-leaved trees |
| |
Trees which shed their leaves in the autumn. Most broadleaved or deciduous trees are hardwoods and have broad leaves.
|
|
| Brow log |
| |
A log or a suitable substitute placed parallel to any roadway at a landing or dump to protect the carrier and facilitate the safe loading or unloading of logs, timber products, or materials.
|
|
| Brown rot |
| |
Any decay in wood in which the attack is confined to the cellulose and associated carbohydrates rather than the lignin, producing a light to dark brown friable residue - hence the term "dry rot". An advanced stage of brown rot where the wood splits along rectangular planes, in shrinking, is referred to as "cubical rot".
|
|
| Buck |
| |
To saw felled trees into log lengths. Note: In some two person felling operations, one member may fall the tree and the other may limb and buck it. The second person is often called a "bucker". Usually the two members interchange the duties throughout the work day.
|
|
| Bucking |
| |
Cross-cutting felled trees into logs or bolts.
|
|
| Buckskin |
| |
A log or tree with the bark fallen off.
|
|
| Bulbs |
| |
General term referring to the drybulb and wetbulb sensors within a kiln.
|
|
| Bulk density |
| |
Factor used to convert between solid wood equivalent of processed wood such as chips, pulp, particleboard, and sawdust. The solid wood equivalent volume is considered to have a bulk density factor of one.
|
|
| Bunk |
| |
To place the empty trailer of a logging truck on the tractor unit's bunk for the trip back to the landing.
|
|
| Bunk support |
| |
The horizontal kiln truck supports on which the lumber is placed for drying.
|
|
| Burl |
| |
A swirl or twist in the grain of wood, usually occurring near a knot, but which itself does not contain a knot. Valued as the source of highly-figured burl veneers used for ornamental purposes.
|
|
| Butt |
| |
Bottom of a felled part of a tree; large end of a log.
|
|
| Butt cut |
| |
The first cut above the stump of a tree.
|
|
| Butt log |
| |
First log cut above the stump. Also known as Butt cut.
|
|
| Butt rot |
| |
Decay or rot characteristically confined to the base or lower bole of a tree.
|
|
| Cable logging |
| |
A yarding system employing winches and cables from a fixed position (usually a yarder and tower of some sort).
|
|
| Cable yarding |
| |
The movement of felled trees or logs from the area where they are felled to the landing on a system composed of a cable suspended from spars and/or towers. The trees or logs may be either dragged across the ground on the cable or carried while suspended from the cable.
|
|
| Calender |
| |
To make the surface of paper smooth by pressing it between steel rollers during manufacture.
|
|
| Calibration |
| |
1. Adjusting the control or recording equipment to reflect the actual control or recording
temperatures.
2. Procedures that involve scanning an object of known size. Calibration is used to adjust
scanner readings for greater accuracy.
|
|
| Calorific value |
| |
The potential heat-production value of a wood source. Depends on the cellulose-lignin ratio, the percentage of extractives, and the moisture content.
|
|
| Cambium |
| |
The layer of tissue dividing the bark from the wood, which forms new bark to the outside and new wood to the inside as the tree grows.
|
|
| Can velocity |
| |
The velocity of the gas in the passages between the filter units in the filter house of a gas filter.
|
|
| Canopy |
| |
The forest layer made up of the crowns of the tallest trees.
|
|
| Cant |
| |
Piece of wood produced by a canter that requires further breakdown.
|
|
| Canter |
| |
A machine that converts logs into a square, rectangular or two-sided cant for further processing. Canters may be configured with conical disk heads or drum heads. They may include double length or single length infeeds. Circular or band saw sections can be included to produce side boards.
View: Canter Examples
|
|
| Capillary action |
| |
The combination of solid-liquid adhesion and surface tension by which liquid moves through a cellular structure.
|
|
| Carbide |
| |
Tungsten carbide used for tooth inserts that are attached to the tooth face tip to provide a hard wear surface.
|
|
| Cardboard |
| |
A thin, stiff paperboard made of pressed paper pulp or sheets of paper pasted together. Used for playing cards, greeting cards, etc. Corrugated containers are not made of cardboard.
|
|
| Carriage |
| |
A frame on which are mounted the headblocks, setworks, and other mechanisms for holding a log while it is being sawed, and also for advancing the log toward the saw line after a cut has been made. The carriage frame is mounted on trucks which travel on tracks, the carriage being actuated by a hydraulic piston, or motor and cable.
|
|
| Cartridge |
| |
1. The replaceable element of a fluid filter.
2. The pumping unit from a vane pump, composed of the rotor, ring, vanes and one or both side
plates.
|
|
| Casehardening |
| |
A condition of stress-and-set in dry wood in which the outer fibers are under compressive stress and the inner fibers under tensile stress. The stresses persist after the lumber is dry and cause warp if the wood is remachined after drying. See Reverse casehardening.
|
|
| Cat |
| |
Often short for Caterpillar tractor, or any other brand of bulldozer-type tractor. May refer to a skidding tractor or a earthmoving bulldozer.
|
|
| Cat face |
| |
Deformed tree trunk surface usually caused by fire, disease or rot.
|
|
| Cat skinner |
| |
The person who operates a cat.
|
|
| Cavitation |
| |
A localized gaseous condition within a liquid stream which occurs where the pressure is reduced to the vapor pressure.
|
|
| CCA |
| |
Copper Chrome Arsenate, a wood preservative.
|
|
| Cell |
| |
General term for the minute units of wood structure including wood fibres, vessel segments and other elements.
|
|
| Cellulose |
| |
The carbohydrate that is the principal constituent of wood and forms the framework of the wood cells.
|
|
| Celsius (C) |
| |
The international temperature scale in which water freezes at 0 and boils at 100 under normal atmospheric conditions. °C = (°F - 32) ÷ 1.8.
|
|
| Centimetre (cm) |
| |
A metric unit of length equal to one hundredth of a metre. 2.54 cm is equal to one inch.
View: Metric / Imperial Conversion
|
|
| Centrifugal force |
| |
The force which impels a thing, or parts of a thing, outward from a center of rotation.
|
|
| Channel |
| |
A fluid passage, the length of which is large with respect to its cross-sectional dimension.
|
|
| Charge (supercharge) |
| |
1. To replenish a hydraulic system above atmospheric pressure.
2. To fill an accumulator with fluid under pressure. (See Precharge pressure)
|
|
| Charge pressure |
| |
The pressure at which replenishing fluid is forced into the hydraulic system (above atmospheric pressure).
|
|
| Check |
| |
A splitting of the wood fibers within or on a log or lumber. Checks result from uneven wood shrinkage.
View: Checks
|
|
| Check valve |
| |
A valve which permits flow of fluid in one direction only.
|
|
| Chemical pulp |
| |
The product of the reduction of wood or other fiber into component parts during cooking with various chemical liquors in processes such as sulfate, sulfite, and soda pulping.
|
|
| Chemically protected lumber |
| |
Lumber treated with anti-stain chemicals to protect it in transit.
|
|
| Chemimechanical pulp (CMP) |
| |
A product made by pretreating chips with chemicals at a temperature usually below 100°C, followed by atmospheric refining.
|
|
| Chip |
| |
1. (n.) Small piece of wood used as fibre for the pulp process; the product of canter chipper
heads and chippers. Chips are larger and coarser than sawdust.
2. (v.) To mechanically reduce logs or whole trees to small pieces for fuel, pulp, or chipboard
manufacture.
|
|
| Chip load |
| |
The quantity of wood removed by an individual knife as it cuts on each pass.
|
|
| Chipboard |
| |
A paperboard, thicker than cardboard, used for backing sheets on padded writing paper, partitions within boxes, shoeboxes, etc.
|
|
| Chipper |
| |
Device used to transform pieces of wood to chips.
View: Chipper Examples
|
|
| Chipper canter |
| |
A headrig machine that reduces debarked logs directly to chips and cants without producing sawdust.
|
|
| Choke |
| |
A restriction, the length of which is large with respect to its cross-sectional dimension.
|
|
| Choker |
| |
Short length of wire rope that forms a noose around the end of a log for hauling.
|
|
| Chromated Copper Arsenate (CCA) |
| |
The most commonly used chemical for pressure treating lumber.
|
|
| Circuit |
| |
An arrangement of components interconnected to perform a specific function within a system.
|
|
| Circular headsaw |
| |
A circular plate having cutting teeth on the circumference and used to ripsaw logs.
|
|
| Circular saw |
| |
A circular metal plate with teeth on the circumference that rotates on an arbor.
|
|
| Circular sawmill |
| |
The traditional sawmill uses a circular saw. Circular saws are thicker (larger kerf) than band saws and produce more sawdust. Logs can be cut moving on the carriage in only one direction, then the carriage returns and turns the log for the next cut.
|
|
| Clear |
| |
Lumber or logs that are free or practically free of defects. First quality lumber or log.
|
|
| Clear-cut |
| |
An area in which all of the trees have been or will be felled, bucked and skidded in one operation. When all trees in a given area are felled.
|
|
| Clearance angle |
| |
The angle between a tangent to the cutting circle of a tooth and a line along the top of the tooth intersecting this tangent.
|
|
| Climb cut |
| |
The circular saw blade rotates in the same direction as the material is fed during the cutting process.
|
|
| Climb sawing |
| |
See Climb cut.
|
|
| Clipper loss |
| |
During the manufacture of veneer, the ribbon of veneer is cut to specific sizes by a device called a clipper. Losses during this step occur because of unacceptable defects (knots, rot, etc.) in the veneer, splits and breakage, or sizing.
|
|
| Closed canopy |
| |
The description given to a stand when the crowns of the main level of trees forming the canopy are touching and intermingled, and form a barrier to light penetrating the forest floor from above.
|
|
| Closed center circuit |
| |
One in which flow through the system is blocked in neutral and pressure is maintained at the maximum pressure control setting.
|
|
| Closed center valve |
| |
One in which all ports are blocked in the center or neutral position.
|
|
| Closed loop |
| |
A system in which the output of one or more elements is compared to some other signal to provide an actuating signal to control the output of the loop.
|
|
| Co-gen operation |
| |
Refers to the production of usable steam and electricity using a particular kind of fuel (for example, woodchips, oil, coal, hydro).
|
|
| Cogeneration |
| |
The process of burning fuel to produce electricity and usable steam.
|
|
| Coils |
| |
The radiant heating surface within steam or oil-heated kilns. The coils contain the steam or oil and transfer its heat through the coil wall to heat the kiln air, producing condensate in the process.
|
|
| Coils, center |
| |
The steam or oil coils that are positioned between the kiln tracks. Also called Booster coils.
|
|
| Coils, overhead |
| |
The steam or oil coils positioned overhead at or on the fan deck.
|
|
| Cold deck |
| |
A stack of logs left for later transportation (in the woods), or a deck of logs at the mill for winter use.
|
|
| Collapse |
| |
The flattening of single cells or rows of cells during the drying or pressure treatment of wood. Often characterized by a caved-in or corrugated ("washboarded") appearance of the wood surface.
|
|
| Collar |
| |
A flange mounted on the saw arbor to support the blade on one or both sides. If the collar is fixed to the arbor, it is called the fixed collar. If not, it is a loose collar.
|
|
| Collarless saws |
| |
The saw floats on the arbor being keyed directly to the arbor itself.
|
|
| Column |
| |
A free standing axially loaded compression member, usually vertical.
|
|
| Combustion |
| |
Consumption by oxidation, evolving heat, and, generally, also flame and incandescence.
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| Command signal (or input signal) |
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An external signal to which the servo must respond.
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| Commercial thinning |
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A silviculture treatment that "thins" out an overstocked stand by removing trees that are large enough to be sold as products such as poles or fence posts. It is carried out to improve the health and growth rate of the remaining crop trees. As compared to "juvenile spacing".
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| Compaction |
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Close packing of chips in a given volume of space in order to minimize the voids between the individual chips.
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| Compensator control |
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A displacement control for variable pumps and motors which alters displacement in response to pressure changes in the system as related to its adjusted pressure setting.
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| Composites |
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Built-up, bonded products consisting wholly of natural wood, or in combination with metals, plastics, etc.
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| Compressibility |
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The change in volume of a unit volume of a fluid when it is subjected to a unit change in pressure.
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| Compression failure |
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Deformation of the wood fibres resulting from excessive compression along the grain either in direct end compression or in bending. In surfaced lumber, compression failures may appear as fine wrinkles across the face of the piece.
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| Compression wood |
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Abnormal wood formed on the lower side of branches and inclined trunks of softwood trees. Compression wood is identified by its relatively wide annual rings (usually eccentric when viewed on cross section of branch or trunk), relatively large amount of summerwood, sometimes more than 50% of the width of the annual rings in which it occurs, and its lack of demarcation between earlywood and latewood in the same annual rings. Compression wood shrinks excessively lengthwise, as compared with normal wood.
View: Compression Wood
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| Computer simulations |
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Computer software that models actions or occurrences in the real world.
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| Condensate |
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Water formed by removing heat from steam within the kiln heating coils.
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| Conditioning |
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A process for relieving the stresses present in wood at the end of drying.
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| Conditioning treatment |
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A treatment applied to equilibrate the moisture content of wood to a particular value.
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| Conifer |
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Tree that is a gymnosperm, usually Evergreen, with cones and needle-shaped or scalelike leaves, producing wood known commercially as softwood.
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| Coniferous |
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A type of tree which is cone-bearing and has needles or scale-like leaves, such as Pine and Spruce.
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| Containerboard |
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The components (linerboard, corrugating medium and chipboard) used to manufacture corrugated and solid fiberboard.
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| Control |
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A device used to regulate the function of a unit (See Hydraulic control, Manual control, Mechanical control, and Compensator control).
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| Control console |
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Fabricated metal cabinet housing buttons and switches for the control of a machine center.
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| Control valve |
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A device that controls the flow of liquids or gases.
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| Conventional cut |
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The circular saw rotates in a direction counter or opposite to the direction of the feed. Also called Counter sawing.
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| Conveyor |
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Wood transport system (logs, lumbers, chips, etc.).
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| Cord |
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Stacks of wood 4' high by 4' wide by 8' long. One cord is the equivalent of 128 cubic feet, 4.7 cubic yards. The weight of a cord varies if it is green (freshly cut), seasoned (partially air dried), or dry (KD or kiln-dried). Commonly used for smaller timber utilized for firewood or pulping.
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| Cord |
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A stack of wood consisting of 128 cubic feet (3.62 cubic meters). A cord has standard dimensions of 4 x 4 x 8 feet, including air space and bark.
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| Core |
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The innermost portion of plywood usually composed of veneer. Also referred to as a "center." A core may also be made of fiberboard, particleboard or lumber.
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| Core stock |
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A solid or discontinuous center ply used in panel-type glued structures such as furniture panels and solid hollowcore doors.
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| Corrugated containers |
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Containers made with corrugating medium and linerboard.
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| Corrugating medium |
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The wavy center of the wall of a corrugated box which cushions the product from shock during shipment (see flute). This layer can contain up to 100% post-consumer recycled fiber content without reducing its ability to protect the product.
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| Counter cutting |
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The circular saw blade rotates in a direction counter or opposite to the direction of the feed.
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| Counterbalance valve |
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A pressure control valve which maintains back pressure to prevent a load from falling.
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| Cracking pressure |
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The pressure at which a pressure actuated valve begins to pass fluid.
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| Cripple |
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A cut in an unseasoned joist, bearer or stud designed to reduce movement in a floor or wall as the structural timber seasons.
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| Crook |
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A deviation edgewise from a straight line drawn end to end of a piece of lumber. See also Warp.
View: Crook
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| Crosscut |
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Cutting across the grain, e.g., a “crosscut” saw.
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| Crossouts |
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Horizontal spacers between units of lumber. They align over the sticks and serve to separate the units for forklift handling.
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| Crown |
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1. The live branches and foliage of a tree.
2. The upper part of a tree.
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| Cubic recovery ratio (CRR) |
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In a material balance diagram, the ratio of wood product recovered divided by the wood raw material used, both measured in cubic volume. The fraction of wood raw material converted to the intended product.
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| Cunit |
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A measurement equal to 100 cubic feet of solid wood.
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| Cup |
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Deviation in the face of a piece of lumber from a straight line drawn from edge to edge of a piece of lumber. See also Warp.
View: Cup
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| Cure |
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To change the properties of an adhesive by chemical reaction (which may be condensation, polymerization, or vulcanization) and thereby develop maximum strength. Usually accomplished by the action of heat or a catalyst with or without pressure.
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| Curve Sawing |
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Sawing a log or cant following the arc or curvature of the log or cant. Also referred to as sweep sawing or shape sawing. Some systems follow an arc and other systems can follow a coumpound curve.
View: Curve Sawing Examples
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| Cushion |
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A device sometimes built into the ends of a hydraulic or pneumatic cylinder which restricts the flow of fluid at the outlet port, thereby arresting the motion of the piston rod.
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| Cut sheets |
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Fine paper cut to letter or legal size for use in printers, copiers and fax machines.
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| Cut-to-length harvester (CTL) |
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A self-propelled tracked or wheeled harvesting machine, designed to fell, limb, and buck a tree into logs, usually 20 feet or less in length. Most commonly the harvesting head is mounted to an articulating arm. Not to be confused with a full-tree length harvester or feller-buncher. Most commonly CTL harvesters work with forwarders which transport the bunched log piles to the landing.
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| Cutting circle |
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The circle described by the outer rim or extremity of the teeth of a circular saw.
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| Cylinder |
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A device which converts fluid power or air into linear mechanical force and motion. It usually consists of a movable element such as a piston and piston rod, plunger rod, plunger or ram, operating within a cylindrical bore.
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| Dado |
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A groove cut into one piece to accommodate another piece. A dado is three-sided and cut into a board, usually across the grain, as opposed to a rabbet, which has two sides and is at the edge of the board.
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| Dangling head |
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A type of harvesting head, usually used on a CTL harvester, with a wrist-like action and attachment to the harvester boom. Also called a "single-grip harvesting head" and can rotate in all three axes.
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| DBH |
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See Diameter at breast height.
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| De-superheater |
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A device for removing the excess heat in steam as its pressure is reduced.
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| De-vent |
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To close the vent connection of a pressure control valve permitting the valve to function at its adjusted pressure setting.
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| Deadband |
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The region or band of no response where an error signal will not cause a corresponding actuation of the controlled variable.
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| Deadpile |
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Stack lumber in units without stickers.
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| Debark |
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To remove bark from trees or logs.
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| Debarker |
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Machine which removes bark from a log.
View: Debarker Examples
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| Decay |
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The decomposition of wood substance caused by the action of wood- destroying fungi, resulting in softening, loss of strength, weight, and often in change of texture and color.
View: Decay
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| Decay, brown rot |
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Wood decay in which the attack concentrates on the cellulose and associated carbohydrates rather than on the lignin, producing a light to dark brown pliable residue. Sometimes referred to as "Dry rot".
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| Decay, heart rot |
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Any rot characteristically confined to the heartwood originating in the living tree.
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| Decay, incipient |
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The early stage of decay that has not proceeded far enough to soften or otherwise apparently impair the hardness of the wood. It is usually accompanied by a slight discoloration or bleaching of wood.
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| Decay, white-rot |
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Decay attacking both the cellulose and the lignin, producing a generally whitish residue that may be spongy or stringy.
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| Deciduous |
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A type of tree with broad leaves that usually are shed annually, such as aspen. Commonly referred to as Hardwood.
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| Deck |
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A stack of trees or logs.
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| Decompression |
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The slow release of confined fluid to gradually reduce pressure on the fluid.
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| Defect |
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A characteristic of a tree, log, lumber, or other product that makes it either less desirable or completely unsuitable for the intended purpose. Examples are knots, decay, insect holes, and diagonal grain.
View: Knot Defects, Manufacturing Defects, Natural Defects, Seasoning Defects
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| Degrade |
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Drop in lumber grade due to manufacturing or drying practices.
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| Dehumidifier kiln |
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A kiln working on the heat pump principle. Moisture evaporated from the timber by a flow of warm air is condensed on the evaporator coils of a refrigeration unit and drained away. The refrigerant is compressed and passed through condenser coils, re-heating the air stream.
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| Delamination |
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The separation of the layers of laminated wood or plywood at the glueline, usually caused by moisture, mismanufacture, or defective glue.
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| Delimber |
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Landing-based piece of equipment used to limb trees brought in unlimbed, usually cut with full tree length harvesters. May be of the stroke delimber type or pull-through delimber model.
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| Delivery |
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The volume of fluid discharged by a pump in a given time, usually expressed in gallons per minute (gpm).
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| Delta |
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The amount of change in a number, size or position.
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| Dense |
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A reference to the specific gravity of wood. Lumber classified as "dense" has six or more annual rings per inch, plus one-third or more summerwood, measured at either end. Pieces averaging less than six rings per inch also qualify if the rings average one-half or more summerwood.
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| Density |
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As usually applied to wood of normal cellular form, density is the mass of wood substance enclosed within the boundary surfaces of a wood-plus-voids complex having unit volume. It is variously expressed as pounds per cubic foot, kilograms per cubic metre, or grams per cubic centimetre at a specified moisture conte |
