Fiberboard

Fiber boards are made ​​of wood, sawmill by-products or waste wood, but also from other wood fiber-containing plants such as flax or canola. All products have in common is that the wood is digested up to the wood fiber, fiber bundles or fiber fragments. The structural cohesion is mainly due to the entanglement of the wood fibers and their own wood binding forces, it can also be used as binders adhesives. The term fiber board ( also fiberboard) refers to a product group from the area of ​​wood-based materials.

Properties

Fiber boards are produced as single and multi- layer boards and behave like the flat pressed particle board in the plane of the plate in all directions evenly. So they point in the plane of the plate on the same kind swelling and shrinking behavior. Depending on the manufacturing method and the density following subgroups can be distinguished:

• If the wood fiber boards manufactured using the wet method, a distinction is made in porous medium, hard fiber boards: The wood fiber insulation board (HFD ) (also Porous fiber board or soft board (SB ) called ) is done ( 230-350 kg / m³) its use for heat and sound insulation in construction, a board material of low density. Fibrous porous sheets can be bound with bitumen.
• The Medium-hard fiber board ( MB ) is a plate material with a density of 350 to 800 kg / m³.
• The hard fiber board ( HB or HFH ) (also called fiberboard ) with a density of about 800 kg / m³ is used for formwork, interior, doors, furniture, packaging. Extra hard fiberboard ( HFE) have showed a significantly higher density.

• The medium-density fiberboard (MDF) solves by their homogeneity, higher strength and better surface properties increasingly flat pressure plates ( P2 ) from.
• The high- density fiber board (HDF ) is made with glue -soaked and under pressure and heat pressed wood fibers that have been especially highly compressed. It is used as a carrier material for high load at low material thickness (eg, laminate floors).

Also widespread is the plastic coated hardboard KB or MFB EN 622-2 (HB ) for furniture backs and drawer bottoms.

Production

The fiber is produced from woody plant material. This is done by chopping the raw material, followed by steaming, boiling, and chemical or mechanical disruption through to single fiber, fiber bundles or fiber fragments. Modern biotechnology uses to facilitate digestion and to reduce the use of chemicals enzymes - these methods are called biopulping. The digestion process largely correspond to the methods of the paper and pulp industry. The fiber thus obtained is partially subjected to a bleach, to achieve higher degrees of whiteness for high-quality applications. For this, the lignin, which has a substantial proportion of the dark coloration of the woody substance is degraded by enzymes, for example - the so-called Biobleaching.

By type of web formation, a distinction the following manufacturing processes:

• The wet process, the fibers sediment from an aqueous fiber suspension to the fleece
• The environmentally friendly dry process, the dry fibers are compacted mechanically or pneumatically to a non-woven

The resulting mats are then pressed. The cohesion of the fibers in the web due to felting and, where appropriate binder added. Modern production methods avoid using chemical binding additives, they engage in part to the present in the wood lignin as a binder back.

Use

Hard fiber boards are mainly used in automotive and furniture industry. In construction they are used for concrete formwork, prefabricated houses and interiors, eg for base plates, are used. Medium density fibreboard find as furniture and kitchen fronts, in-store and in loudspeaker application. Fiberboard low density are used in particular as wood fiber insulation in interior.

Economic Importance

Worldwide, the medium density fibreboard (MDF) is especially of great economic importance. Because of its technical characteristics, it is one even in Europe and Germany to the fastest growing wood products. In 2007, more than 55 million cubic meters MDF panels were created ( source FAO ) worldwide. 2008, however, occurred in Germany and Europe to a significant drop in production .. The insulation material from renewable raw materials, the wood fiber insulation boards are the major products in addition to cellulose and flax and hemp short fibers in the form of nonwovens.