What is a MDF made of?
What is a MDF made of?
Wood pulled apart into individual fibres, mixed with resin and wax, and pressed hot into a board.
MDF has no grain, so it routs and moulds cleanly in any direction and takes paint better than any solid timber — which is exactly why skirting, architrave and painted doors are made from it. The same absence of grain means an edge has nothing for a screw thread to grip, so screws must have a pilot hole and should not be relied on in the edge of a board at all. The serious point is dust: machining MDF produces very fine wood dust carrying resin, hardwood and softwood dust are classified as carcinogenic to humans, and cutting a sheet without extraction and a properly fitted mask is genuinely worth avoiding. Water swells it irreversibly, so a soaked MDF panel never recovers.
Component by component
| Part | Material | Why that material |
|---|---|---|
| fibre | softwood chips steamed and torn into fibres in a refiner | Working at fibre level rather than chip level is what gives MDF a completely uniform, grainless body that machines like a solid. |
| resin | urea-formaldehyde, or melamine-urea-formaldehyde in moisture-resistant grades | It cures under heat in the press in minutes; the melamine version resists hydrolysis, which is why MR board survives a kitchen. |
| wax | paraffin wax emulsion, around 1% | It slows water absorption at the surface, though it does nothing about the swelling that soaks a cut edge. |
| density | pressed to roughly 600-800 kg/m³ | That is denser than most of the softwood it is made from, which is why MDF sheets are so much heavier than they look. |
Other building materials objects
- Glass Sand melted with soda ash and limestone — three cheap minerals, floated flat on molten tin.
- Concrete Stone and sand glued by cement paste — and it hardens by a chemical reaction with water, not by drying.
- Road asphalt About 95% crushed stone and sand, glued together by roughly 5% bitumen from the bottom of an oil refinery.
- Brick Clay and shale moulded and fired until the particles partly fuse — a manufactured rock.
- Mirror A sheet of ordinary glass with a microscopically thin silver layer on the back, sealed under paint.
- Plywood Thin wood veneers glued in alternating grain directions — the cross-lamination is the entire idea.
Common questions
- What is a MDF made of?
- Wood pulled apart into individual fibres, mixed with resin and wax, and pressed hot into a board.
- What is the fibre of a MDF made of?
- Softwood chips steamed and torn into fibres in a refiner. Working at fibre level rather than chip level is what gives MDF a completely uniform, grainless body that machines like a solid.
- What is the resin of a MDF made of?
- Urea-formaldehyde, or melamine-urea-formaldehyde in moisture-resistant grades. It cures under heat in the press in minutes; the melamine version resists hydrolysis, which is why MR board survives a kitchen.
Related pages
- Glass Sand melted with soda ash and limestone — three cheap minerals, floated flat on molten tin.
- Concrete Stone and sand glued by cement paste — and it hardens by a chemical reaction with water, not by drying.
- Road asphalt About 95% crushed stone and sand, glued together by roughly 5% bitumen from the bottom of an oil refinery.
- Brick Clay and shale moulded and fired until the particles partly fuse — a manufactured rock.
- Mirror A sheet of ordinary glass with a microscopically thin silver layer on the back, sealed under paint.
- Plywood Thin wood veneers glued in alternating grain directions — the cross-lamination is the entire idea.
- Pencil Stationery and paper
- Tennis ball Sport and games
- Banknote Around the house
- Golf ball Sport and games
- Paper Stationery and paper
- Soccer ball Sport and games
Sources
- Typical range compiled from manufacturer specifications — At One Place