Development of Draft Protocol for Testing of Structural Components and Systems
(a joint initiative of MoHUPA under technology submission of Pradhan Mantri Awas Yojna & IIT, KANPUR)
Low Density Fiber Board
Low Density Fibre Board, also known as Particle board and chipboard, is an engineered wood product manufactured from wood chips, sawmill shavings, or even sawdust, and a synthetic resin or other suitable binder, which is pressed and extruded. Particle board is cheaper, denser and more uniform than conventional wood and plywood and is substituted for them when cost is more important than strength and appearance. Medium-density fibreboard and hardboard, also called high-density fiberboard, are stronger and denser than particleboard. Different grades of particleboard have different densities, with higher density connoting greater strength and greater resistance to failure of screw fasteners.
The specification for particle board shall conform to IS 3129(1985)-for low density boards, IS 3087(2005)-for medium density boards, IS 3478(1966)-for high density boards.
- Classes and Types: Low Density Fibre Board are divided into three types depending on their specific gravity:
- Low density particle boards with specific gravity less than 0.4,
- Medium density particle boards with specific gravity between 0.5 and 0.9, Further medium density particle boards are classified into the following cases;
- High density particle boards with specific gravity greater than 0.9. High density wood particle boards phall be of two types depending on the type of synthetic resin used for manufacture, and each type shall be of two grades depending on the extent of resin content as shown below:
- Timber and Other Ligno-Cellulosic Material- Timber and other ligno-cellulosic material like bagasse, solapith, jute sticks, rice husk, pea-nut shells, etc., may be used for the manufacture of these boards. These shall be lightweight materials of bulk density preferably not exceeding 400 kg/m3 and shall be free from extraneous matter and dust.
- Adhesive - The adhesive used for bonding particles together shall be BWR or BWP type conforming to IS: 848-1974. The adhesive shall be either a phenol-formaldehyde or Urea-Formaldehyde type fortified with melamine.
- Sizing Material- Paraffin wax dissolved in mineral spirit or alternatively emulsified with water or melted shall be used as sizing material up to a maximum of one percent.
- Dimensions and Tolerances:
- Low density particle boards: The dimensions of low density particle boards shall be as follows:
- Medium density particle boards: The sizes of the medium density particle boards shall be as follows:
- High density particle boards: The dimensions of high density particle boards shall be as follows:
- Physical Requirements:
- Low density particle boards:
- Medium density particle boards:
- High density particle boards:
The flat pressed-three layer, multilayer and graded class shall be of two types, namely, Grade I and Grade II, the grading is based on the physical and mechanical properties as given in table 1.
Length in mm: 3600, 3000, 2700, 2400, 2100, 1800, 1500, 1200, 1000, 900, 600, 450 and 300
Width in mm: 1800, 1500, 1200, 1000, 900, 600, 450 and 300
Thickness - The thickness of low density panicle boards shall be 12mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm and 50mm.
Tolerances - The tolerances on the nominal sizes of finished boards shall be as follows:
NOTE- Any other dimensions as agreed to between the manufacturer and the purchaser, shall be permissible.
Unless otherwise specified, the thickness of particle boards shall be 6 mm, 9 mm, 12 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm and 45 mm. The following tolerances on dimensions of finished boards shall be permissible:
Length in mm: 2400, 2100, 1800, 1500, 1200, 1000, 900, 600 and 450
Width in mm: 1500, 1200, 1000, 900, 600, and 450
The thickness of high density particle board shall be 4mm, 6mm, 9mm,12mm, 15mm, 20 mm, 25mm, 30mm, 35mm, 40mm and 50mm The tolerances on the nominal sizes of finished boards shall be as follows: