Timber Derivatives- Manufactured Boards

Product design

Manufactures boards

Manufactured boards are now extensively used in industry and in the home. These relatively new materials are known as composites. Generally, these materials are manufactured using natural timber in thin sheets or particles, which are bonded with a resin, compressed and heated.

These products are environmentally friendly because they are often produced from waste products such as sawdust, bark and off-cuts.

Advantages & Disadvantages

Advantages cheap stable (in warm, centrally-heated environments) thin veneers of expensive timbers can be used as top, decorative layers boards are available in large sheets (1220 x 2240 and 1550 x 1550)

Disadvantages edges require ‘facings’ repair and maintenance can be difficult

Common Manufactured Boards

Name Composition Properties andworkingcharacteristics

Uses

Plywood Thin veneers, cross-laminated using anodd number of layers

Stable, strongand easy tomachine

Furniture, joinery,Constructionwork

Blockboard 25mm strips gluedtogether and facedwith ply

Stiff and heavy,good load-bearingcapabilities

Furniture,worktops, veneergroundwork

Hardboard Highly compresseswood fibres

Cardboard-like,weak and brittle

Low-costfurniture parts,e.g. cabinetsbacks, drawerbottoms

Common Manufactured Boards

Name Composition Properties andCharacteristics

Uses

MDF ( MediumDensityFibreboard)

Compressedwood fibres

Easily machined,moulded andpainted

Generalcarcass/paintedwork, veneerground

Chipboard Compressedwood chips

Stiffness andstrength vary withdensity

Furniturecarcassing, goodveneer ground

Plywood

Plywood is made from layers or plies of wood glued together.

The grain of each ply is laid at right angles to the next.

This makes the ply strong in both directions

Plywood is ideal for lightweight box construction, cabinet backs and drawer bottoms

Blockboard These boards are made

by sandwiching strips of softwood between two plies.

The outer faces of veneer have the grain running at right angles to the strips.

Ideal for furniture and worktops

Hardboard Hardboard is made by

mixing wood fibres together with water and resin glue and hot pressing into sheets.

Hardboard is not very strong and is usually supported on timber frames

Ideal for low-cost furniture parts e.g. drawer bottoms

MDF MDF is manufactured in a

similar way to hardboard but is compressed under greater pressure and is therefore much stronger.

MDF is cheap, strong and is easily shaped and finished.

Ideal for all types of furniture making and interior joinery

Chipboard Chipboard is made by gluing

chips of wood together under heat and pressure.

Standard sheet size is 1220mm x 2440mm. Common thickness is 18mm.

Veneers and plastic laminate faced chipboard is widely used for worktops, shelves and furniture making

Questions

Why are manufactured boards environmentally friendly? State two advantages of man-made boards State two disadvantages of man-made boards Name four manufactured boards and their properties State one usage for six different man-made boards