Hardboard, also called high-density fiberboard (HDF),[1] is a type of fiberboard, which is an engineered wood product.[2] It is used in furniture and in the construction industry.
Hardboard is similar to particle board and medium-density fiberboard, but is denser and much stronger and harder because it is made out of exploded wood fibers that have been highly compressed.[3] Consequently, the density of hardboard is 500 kg/m3 (31 lb/cu ft) or more[4] and is usually about 800–1,040 kg/m3 (50–65 lb/cu ft).[5] It differs from particle board in that the bonding of the wood fibers requires no additional adhesive, the original lignin in the wood fibers sufficing to bond the hardboard together,[6] although resin is often added.
Hardboard is produced in either a wet or dry process. The wet process, known as the Mason Method,[7] leaves one smooth side and one textured side, while the dry processed hardboard is smooth on both sides. Masonite is produced using the wet process only.
A product resembling hardboard was first made in England in 1898 by hot pressing waste paper.[8] In the 1900s, fiber building board of relatively low density was manufactured in Canada. In the early 1920s, improved methods of compressing wet wood pulp at high temperatures resulted in a higher density product.[8]
Unlike solid wood, hardboard is very homogeneous with no grain. A wood veneer can be glued onto it to give the appearance of solid wood. Other overlays include Formica, laminated papers, ceramics,[citation needed] and vinyl. It has many uses, such as a substrate. It is used in construction, flooring, furniture, home appliances, automobiles and cabinetry, and is popular among acrylic and oil painters as a painting surface due to its economical price (though it must be coated with gesso or canvas before use).[9] Hardboard has often been used as the surface material in clipboards, especially older models. It is also used as the final layer in many skateboard ramps and the half-pipe. Hardboard is also used extensively in theatrical environments, often used as the final painted surface of a stage and on walking surfaces of constructed scenery. Hardboard is also used to make puzzles, game boards, and other toys.
Tempered hardboard is a hardboard that has been coated with a thin film of linseed oil and then baked; this gives it more water resistance, impact resistance, hardness, rigidity and tensile strength. An earlier tempering process involved immersing the board in linseed oil or tung oil until it was 5 to 6 percent saturated, and heating to 170 °C (338 °F).[10] Tempered hardboard is used in construction siding.
Perforated hardboard, also called pegboard, is tempered hardboard that has a uniform array of 1⁄8-or-1⁄4-inch (3.2 or 6.4 mm) holes in it, into which tool-hanging hooks or store fixtures can be placed.
Hardboard has become less popular in the construction industry in recent years due to new environmental targets[11] to procure more sustainable temporary protection materials.
