Particle board

[edit] Introduction

Particle board is the contemporary name for what used to most commonly be called chipboard, it is a type of fibreboard and might also be referred to as low density fibreboard (LDF). It is a versatile, material that is relatively cheap and can be used to make furniture (including carcasses for kitchen units), other cabinet applications, floor decking, flooring shelving and general building work. There are a number of different products that fall under the category of particle board which vary baed on how they are made, composite additions and how they are faced.

[edit] Types

There are a variety of particle products with differing core densities and finishes;

• Single-layer particle board; with the same density and size particle throughout.
• Three-layer particle board; with denser smaller particles at the top and bottom and larger at the core.
• Multi-layer particle board; gradually denser smaller particles towards the edges.
• Graded-Density particle board; as above with gradually denser smaller particles towards the edges.
• Melamine particle board; same density with top and bottom finish layer bonded with melamine-urea formaldehyde resin, throughout making is more resistant to moisture.
• Cement-bonded particle board; with magnesium-based or Portland cement as the bonding agent similar density and size particles throughout. Heavier weight, resistant to moisture, fire, termites, and rot.
• Veneered particle board; single or multi-layered with a wood veneer finish top and bottom.
• Laminated particle board; finished with a surface made up of layered flat paper and resins.

[edit] History

Although the material was originally formulated in late 19th century Germany, it was not until the Second World War that it was produced commercially. The earlier board products were often made using blood albumin glue, whilst later commercial products used phenolic resins, amino formaldehyde-, urea formaldehyde-, or urea melamine-based, today there are also particle board products that use glues with lesser environmental impacts.

All particle boards comprise of a small chips and flakes of softwood of varying sizes tand density hat are impregnated with adhesive (usually amino formaldehyde-, urea formaldehyde-, or urea melamine-based) and subjected to high temperature (up to 220°C) and pressure (2-4MP). When cooled, the boards are cut and sanded, sold either as plain board or faced with laminate as described above.

[edit] Properties

Displaying greater uniformity, particleboard is a more economical, denser and more stable material than solid timber under a variety of conditions, in particular tolerating the dryness induced by central heating systems. However, depending on the specific product used it can be affected by atmospheric changes and, when damp, is likely to swell. It can also discolour when it absorbs moisture. If moisture exposure is anticipated, the particle board is usually treated with a sealer or painted, it is not usually used for external applications but some variations such as Cement-bonded particle board, may be.

Although generally not as strong as solid timber, depending on the specific product particle board can be used as an adequate substitute for most purposes, because of the variety of specifications and grades, it is important to ensure the grade and type is matched to the application. This applies particularly to flooring.

When specified for flooring, it is important to ensure the board has the requisite strength, usually described by manufacturers as ‘flooring grade’ in thickness of 18-19mm or 21-22mm, and in sheet sizes usually of 8ft x 4ft (2.4m x 1.2m). Flooring boards can be supplied with tongue and groove edges on all sides to ensure a more monolithic, stronger deck.

[edit] Working

Normal hand or machine tools can be used for working chipboard. Chipboard can be screwed into successfully but the denser grades will provide greater strength and resistance to screw failure.

[edit] Testing

BS EN 312:2010 is the European Standard which specifies the requirements for flat-pressed or calendar-pressed, un-faced particleboards as defined in EN 309. It gives information on the general requirements of chipboard for various applications, the mechanical and swelling properties, moisture resistance, requirements for load-bearing applications (in both dry and humid conditions) and other information.

Test methods for chipboard are laid down by EN 120, 322, 323 and 324.

[edit] Related articles on Designing Buildings

• Adhesives.
• Blockboard.
• Cedar.
• Chipboard.
• Confederation of Timber Industries.
• Cross-laminated timber.
• Engineered bamboo.
• Glulam.
• Hardboard.
• Laminated veneer lumber LVL.
• Lime wood.
• Low-density fibreboard LDF.
• Medium density fibreboard - MDF.
• Modified wood.
• Oriented strand board.
• Plywood.
• Softwood.
• Timber.
• Timber construction for London.
• Timber preservation.
• Timber vs wood.
• Types of timber.