Medium-density fibreboard

'Medium-density fibreboard' ('MDF' or 'MDFB') is an engineered wood product formed by breaking down softwood into wood fibres, often in a defibrator, combining it with wax and resin, and forming panels by applying high temperature and pressure. It is a building material similar in application to plywood but made up of sawdust. It is denser than normal particleboard.
Large-scale production of MDF began in the 1980s. Its name derives from the distinction in densities of fibreboard. MDF typically has a density of 600-800 kg/m³. Particle board is a low-density fibreboard and has a density of 160-450 kg/m³, while hardboard, also called high-density fibreboard, has a density of 500-1,450 kg/m³. Similar manufacturing processes are used in making all types of fibreboard.
One contentious issue is the use of formaldehyde resins and the associated health risks. Thus, other resins are being introduced.

Uses and applications

MDF is useful in many applications, particularly where particleboard was previously used. It is not useful for outdoor use because it will swell upon contact with water; nonetheless, it has better moisture tolerance than particleboard. Because MDF is fibre-based, it has a remarkably consistent structure. This quality makes it easy to machine or employ in woodworking applications. MDF is often used with melamine or wood veneers.
MDF is a good material for cabinetry, particularly including acoustic enclosures such as loudspeakers or subwoofers due to its high sound insular properties.

In media

Famously, MDF was used often on the British TV's Changing Rooms, leading to "'YMDF'", a YMCA parody.
Alan Partridge said "MDF's banned in America" in one episode of the program I'm Alan Partridge, which lead to his friend Dan's wife saying "So's that" and pointing to a video of her and Dan having sex (not seen). (Note however that MDF is not actually banned in America.)