A simple and accessible tool for understanding the fundamental terms related to wood. From the meaning of sapwood and heartwood to the characteristics of texture, grain, and density. A useful resource for professionals, citizens, and students who want to familiarize themselves with the language of the sector.
Crack not parallel to an edge.
Shear deformation occurring in a plane oblique to the timber grain, as in the case of a short column that has fractured under compression parallel to the grain.
All the pieces of wood left over after the cutting to the desired dimensions, i.e. the slabs and end trimmings.
Anything that is established, authorized or performed by a national plant protection organization.
A device on the carriage of a sawing machine that allows the workpiece to be automatically disengaged from the sawing direction and then ready to be transferred to the saw again.
Wood species Scientific name: Daniellia sp.p. ATIBT nomenclature: Faro. Origin: West Africa.
Specialized cell of the radius or axial parenchyma that contains oil. It typically has a rounded shape.
Solution of one or more toxic substances in a volatile organic solvent.
Chemical solution for wood preservation in organic solvents
A coating material applied to wood, consisting of a single product composed of oils and waxes.
Evolutionary stage of the forest in which flattening, crowning and desiccation of the crowns occur.
Insect belonging to the Anobiidae family. It attacks hardwoods and softwoods. It is the most common anobiid in manufactured and structural wood in Italy.
Wood species Scientific name: Entandrophragma candollei Harms. ATIBT nomenclature: Kosipo. Origin: West Africa.
See “assembly time”.
In plywood, irregularities such as splits, open joints, and knot holes that interrupt the regular continuity of a ply.
Discontinuity between two adjacent elements of a semi-finished product (of a ply in the case of plywood).
Surface that does not allow the open vessels of coarse-pored hardwood to be completely filled. This surface makes the porous structure of the wood visible on the surface.
Stacking performed in such a way that air can circulate between pieces and especially between the faces of sawn pieces.
Process by which dried wood is immersed in a tank containing creosote, which is heated for a few hours, and then quickly transferred to a tank containing cold creosote. Alternatively, after the creosote is heated, the wood may be kept in the same tank until it cools.
In a double-deck pallet, it is the opening in the bottom deck having the purpose of allowing contact between the wheels of the forklift branches and the ground.
Part of a work comprising a set of steps that can be grouped under a single definition.
Any natural or legal person placing timber or timber products on the market.
Pitting in pluriseriate arrangement, in horizontal pairs or short horizontal rows. Note: When the pitting is thickened, the contours of the areolae tend to be rectangular, in surface view.
A system that performs a scanning survey of the material being processed (using a “scanner”) and, through electronic processing, determines the optimal cutting modes according to programmed volume or value yield targets. It then manages the feeding and functioning of the processing machine by positioning the material and cutting devices in the most appropriate manner.
Action whereby a company (or person) is commissioned to provide a certain quantity of goods or a certain type of service
Wood-based structural panel produced by recomposition of particles (strands or flakes) of predetermined shape and thickness, glued together at high temperature and pressure by the addition of an adhesive. During deposition (“mat formation”), the particles are generally layered with perpendicular orientation of their grain between contiguous layers, in order to impart directional properties and better performance characteristics to the finished panel. The particles forming the innermost layers may be smaller in size than those of the outer layers and may be oriented or not.
Adaptation of the OSB (Oriented Strand Board) manufacturing process of aligning particles in parallel to make a large structural board.
See “squaring”.
Material that exhibits unique and independent properties in three mutually orthogonal (perpendicular) planes of symmetry. It constitutes a special case of anisotropy.
Process involving the application of short, repeated alternating cycles of vacuum and pressure to wood immersed in a preservative solution in a pressure vessel.
Transformation of the cross-section from circular to elliptical shape. It is caused by the difference between shrinkage in the radial direction and shrinkage in the tangential direction.
Plywood layer whose face is visible on the outside. If the grain of the outer layer is parallel to that of the layer immediately below, the combination of the two is referred to as a ‘split outer layer’.
In a sawn timber, it is the face that was furthest from the pith in the log.
The quantity of sawn timber obtained at the sawmill from a batch of roundwood or from a set of batches. This concept is particularly important in the U.S. and Canada where roundwood is measured in quantities of sawn timber that can be obtained (see under “Virtual Volume in Sawn Timber”), while actual production may be higher or lower according to the conversion table applied for roundwood cubage. “Yield” is always the ratio of actual production to original roundwood volume.
Knot whose maximum to minimum diameter ratio is between 1.5 and 4.
Significant difference between major and minor diameters in the cross-section of a trunk or log.
Wood with moisture content of 0. It is obtained by drying wood (generally done only on small test samples) in a ventilated stove at a temperature of 103 ± 2 °C until it reaches constant mass (generally, constant mass is considered to be reached when the weight of two successive weighings, taken at 6 h intervals, do not differ by more than 0.1 of the anhydrous mass of the test specimen).
Condition achieved by wood (usually a test sample) after treatment in a ventilated stove at 103±2 °C until, following successive weighings, no mass change of less than 1% is recorded.
Wood species Scientific name: Guibourtia ehie J. Lèon. Origin: African tropical zone, western sector.
An expression that, when referring to a measurement (usually diameter), indicates that it is including the bark.
Wood that absorbs an excessive amount of preservative.
The forward projection given to the sides of a stack to protect pieces from rain. The overhang of a long piece in a stack with non-planar faces.
See “overlay panel”.
See “overlap”.
Defect due to the overlapping of two adjacent plies (or two portions of a ply characterised by the presence of a split) in a sheet of plywood.
Thin sheet of material with decorative characteristics that is bonded by pressure and temperature to a plywood or other wood-based panel. The most commonly used decorative overlays are: – continuous laminate (formed by a sheet of decorative paper overlaid with one or more sheets impregnated with phenolic or melamine resin, produced continuously using a double conveyor press); – decorative sheet (formed by a cellulosic substrate weighing between 40 and 140 g/mý impregnated or not with melamine thermosetting resin); – heat-transfer printing (transfer, by means of temperature and pressure, of a complete coating system, consisting of a decorative design and its protective layer and a mylar film serving as a substrate to the backing board); – high-pressure plastic laminate (plastic coating consisting of a sheet of paper or other material laminated under very high pressure with thermosetting resin); – low basis weight paper (paper weighing less than 30 g/mý, printed and generally coated with resin); – impregnated or saturated paper (decorative paper weighing between 60 and 130 g/mý, saturated with reactive resin and only partially cured during production. The resin used is generally of the melamine or polyester type); – vinyl film (sheet of polyvinyl chloride or PVC imprinted with wood grain design or other patterns).
Element with an interlocking system, having a thickness such that it can be laid on a continuous supporting surface.
Condition of plant suffering caused by excessive shading.
See “crosscut allowance”.
A chemical reaction in which the release of one or more electrons by an element occurs, resulting in an increase in its oxidation number. Every oxidation reaction is associated with a reduction reaction. In wood, oxidation processes may involve cellulose, hemicelluloses, lignin, extractives.
Wood species Scientific name: Dacryodes buettneri Lam (= Panhylobus buettneri Engl.). Origin: African tropical zone, western sector.
A species of saddle with a suitably padded wooden frame that is placed on the backs of pack animals to enable them to carry loads.
Load of a back carrying animal. By analogy, it is also referred to the load of the tractor equipped with cages.
Formation of a large stack with individual stacks of boards separated by rafters or pallets.
Material used for holding, protecting, or transporting a commodity.
Sturdy, flat wooden platform on which stacks of material are placed, thus remaining raised off the ground and can be easily manoeuvred using forklifts.
Machinery used for squaring wood-based panels.
Interior covering or buffering system consisting of wood-based panels (mainly decorative) joined together to form a continuous surface.
Wood species Scientific name: Millettia stuhlmannii Taub. Origin: Africa
Pulp of cellulosic materials of plant origin prepared for making paper or paperboard: bamboo pulp, gorse pulp, etc. Note: wood pulp is one of them.
A wooden assortment for the production of paper and related products.
Thick and consistent paper product (conventionally weighing more than 400 g/m²), intended for various uses (for boxes, book covers, etc.).
A registered trademark of Trust Joist MacMillan to denote a patented parallel strand lumber consisting of dried veneer reduced to strips 12-13 mm wide and 2500 mm long. These strips are aligned in parallel fibers and bonded with adhesive mixture for outdoor use under appropriate pressure and temperature conditions to form large beams from which, by sawing, smaller structural members can be made.
Engineered wood-based product composed by gluing together long particles (strands) aligned in parallel. Such particles are pre-treated with adhesive, heated with microwaves, and pressed to form large beams from which, by sawing, smaller structural elements can be made. The term is also used as a synonym for “Parallam.”
Wood species Scientific name: Araucaria angustifolia (Bertol.) O.Ktze. Origin: Brazil, Argentine.
Organism that lives on or within a larger organism while nourishing from it.
A plant that receives its sustenance from the standing trees on which it grows. Its roots leave traces in wood (e.g. mistletoe).
Axial parenchyma associated with vascular vessels or tracheids. Note: It includes discontinuous, vasicentric, aliform and confluent paratracheal parenchyma.
A tissue composed of cells (called parenchyma cells) that are typically brick-shaped, isodiametric, and with simple pit. They have a reserve function and can be arranged in the plant in both axial and transverse directions. Its arrangement is a useful diagnostic for the recognition of wood species under the microscope.
Axial parenchyma that in cross section is arranged along tangential lines (or bands) which consist of one or more rows of cells included in an annual ring.
Parenchyma that constitutes all or part of the rays. It is also called “ray parenchyma”.
Axial series of one or more parenchymal cells derived from a single fusiform initial.
Wood flooring with a top layer thickness of no less than 2.5 mm before installation.
Incorrect term. See “parquet.”
Floorboard glued and/or jointed to the side.
Trade term referring to parquet strips of intermediate size between it and the flooring board.
Parquet consisting of elements of equal length and width with heads cut at an angle of 90°. The elements are positioned perpendicular to each other and at an angle of 45° to the wall or crosspiece.
Parquet consisting of elements of equal length and width with heads cut at an angle between 45° and 60°. The elements, placed head to head, create a parallel pattern.
Laying unit consisting of pre-assembled flooring elements.
Pre-assembled laying unit consisting of elements that are joined side by side or end to end to form a repeatable pattern.
Narrow and generally short solid wood element, of regular thickness and with or without profiled sides and ends. It also has parallel edges. It can be assembled with other similar elements.
Knot tightly connected (adhered) for 1/4 to 3/4 of its perimeter with the surrounding wood (or semi-finished product).
A term used to refer to a particle board formed by particles of increasing particle size from the surfaces to the center. Its structure is determined by special arrangements inherent in the deposition of the particles during the forming of the mat, but without showing distinct layering. The finer particles composing the outer part of the panel determine its greater regularity of surfaces and suitability for subsequent coating.
See “particleboard”.
Panels formed from particles of wood (chips, splinters, sawdust) and/or other lignocellulosic material (plant residues, bagasse fragments, and similar) glued together with adhesive and then consolidated with each other in controlled conditions of temperature and pressure by means of a parallel-plate press that exerts pressure perpendicular to the faces of the panel. There are two main product categories: – traditional particle panels, in which particles, coated with adhesive mixture, are deposited to form a mat before pressing. The mat may involve a sharp separation between surface and inner layers (multi-layer particleboard) or a gradual change in particle geometry between the surface and the center of thickness (particle board with progressive grain size). These types of panels are distinguished by the different size of particles used (flakeboards, waferboards, strandboards, particleboards) and by their density, which can range from less than 600 to more than 800 kg/mý; – extruded panels, made by extruding particles through a jig. Panels made of larger particles are mainly intended for the building industry (and some also have good structural characteristics), while those made of finer particles are mainly used as backing boards in the furniture and furnishings industry. Since European production of particleboard is almost exclusively limited to those made from finer particles (also called “small chips”), the term “chipboard” is commonly used instead of the more correct term “particleboard”. Considering the pressing methods used, the particles are oriented with their main axis parallel to the panel faces. This results in a greater possibility of swelling in the direction of the panel thickness if the panel is subject to moisture changes.
Separation element between two areas.
Piece of veneer, of determinate shape, arranged for a repair.
Portion of a sheet, of a specific shape (usually oval or elliptical) intended for repairing a plywood. The same term is also used for other semi-finished wood-based products (e.g. sawn timber, solid wood panels, etc.).
A design that originates from the arrangement of the elements that make up a parquet floor (herringbone, a tolda di nave, a cassero, ecc.).
Wood species Scientific name: Balfourodendron riedelianum Engl. Origin: Southern Brazil, Paraguay, northern Argentina.
Wood species Scientific name: Pyrus communis L. Wood belonging to some species of the genus Sorbus is also sometimes marketed under the name ‘Pear’. Origin: Central and Southern Europe, Western Asia.
Hand tool for turning logs. It consists of a sturdy handle and a curved metal hook.
Woody assortment (usually trunk or stump obtained from the basal portion of a stem) particularly suitable for the production of veneer. After eventual steaming treatment and subsequent cross cutting, it is debarked and then attached to the veneer machine for industrial processing. In North America such assortments are mostly made from conifer stems, in Africa, Asia and Europe mainly from broadleaf trees.