What is MDF ?
Wood-based panel manufactured from lignocellulosic fibres by the “dry process”, i.e. having a fibre moisture content less than 20% at the forming stage and being essentially produced under heat and pressure with the addition of an adhesive.
How is it made?
The raw material (forest thinnings, sawmill byproducts, etc.) is chipped.
Reduction to fibres:
The chips are softened by pre-heating in low-pressure steam and then fed by Archimedean screw between segmented grinding discs, one of which rotates at great speed.
Adhesive, usually urea formaldehyde, and wax emulsion are applied to the fibre within the inlet pipe to the drying tube.
Drying / storage:
Drying of the fibre/adhesive mix is performed in a long drying tube (blowline). The dry fibre is stored in silos to await further processing.
A mattress is dry-formed on caul plates. This is gradually compressed by steel belts. For thick boards, more than one mat may be piled on another.
The dry mattress is pre-pressed to consolidate it and then cut and formed to press sizes, finally to be cured with heat and pressure in a multi-daylight or a continuous press.
Trimming and sanding:
After cooling, each panel is trimmed and sanded to precise dimensions.
What is it used for?
Standard boards for a wide range of interior uses are available in Europe with thicknesses in the range of 1,8 to 60 mm.
Unlike most other wood based sheet materials, the uniform and close packed fibre distribution throughout the thickness of MDF allows detailed machining operations to be carried out on the faces and edgeswithout breakout or the exposure of voids within the core of the board.
Standard MDF is being used successfully for the manufacture of table tops, door panels and drawer fronts with moulded edges or profiled surfaces. The smooth and stable surfaces of MDF provide an excellent substrate for painting or the application of decorative foils or wood veneers. The inherent stability, good machinability and high strength of MDF creates opportunities for it to be used as an alternative to solid wood for applications such as drawer sides, cabinet rails, mirror surrounds and mouldings.
Although primarily developed for use in furniture, standard MDF is being used increasingly for shop fitments, exhibition displays, wall panelling, architectural mouldings and many other applications where its good machining and finishing characteristics are used to advantage.
Moisture resistant , flame retardant , high density and exterior grades of MDF are available for use in more demanding situations.
Moisture resistant boards are being used for bathroom fitments, doors, window boards and other interior building applications where resistance to damp conditions or intermittent wetting are important requirements.
Flame retardant boards are being used increasingly for fitted furniture, doors and panelling in public buildings and other areas which have to conform to national fire regulations.
High density boards have improved machining and finishing characteristics as well as higher strength. They are used for the manufacture of specialised components, high quality kitchen and bedroom doors with complicated machined profiles, for instance, and for some structural applications as a replacement for solid wood.
Exterior boards with appropriate high durability surface coatings can be used for low load bearing, constructional applications for door and window components, road signs and shop fronts, for instance, and for garden furniture.