Generally wooden mould are made from
The Role of a Brick Mould
A brick mould is a simple but essential tool used in the traditional manufacturing of bricks. It's a frame used to shape prepared clay into a rectangular block. The choice of material for the mould is critical. It must be durable enough to withstand the abrasive nature of clay, resistant to the constant exposure to water, and economical enough for widespread use.
📝 Detailed Analysis of the Options
(a) Plywood
Plywood is an engineered wood made of glued layers. The constant wetting and drying involved in brick making would cause the layers to separate (delaminate), making it unsuitable for a durable mould.
(b) Shisham wood
This is the correct answer. Shisham (also known as Indian Rosewood) is a hard, strong, and dense timber. It has good resistance to decay and does not warp or split easily, making it highly suitable for the rough use and wet conditions of brick moulding. It is also a traditionally available and cost-effective choice in the Indian subcontinent, where much of this type of brick making occurs.
(c) Deodar wood
Deodar is a durable softwood, but it is not as hard or wear-resistant as Shisham. It would wear out more quickly from the abrasive action of the clay, making it a less ideal choice for a long-lasting mould.
(d) Teak wood
Teak is an excellent timber with outstanding durability and water resistance, arguably superior to Shisham. However, Teak is significantly more expensive. For a simple, functional tool like a brick mould, using Teak would be uneconomical and an unnecessary expense.
Mould Dimensions & Shrinkage
A crucial aspect of a brick mould's design is its size. The mould must be larger than the desired final brick size. This is to account for the shrinkage that occurs when the wet clay brick dries and is subsequently fired in a kiln.
- Shrinkage Allowance: The mould is typically made about 8% to 12% larger in each dimension. A common rule of thumb is to make it 1/10th larger.
- Example Dimensions: For a standard brick size of 19 cm x 9 cm x 9 cm, the inner dimensions of the mould would be kept at approximately 21 cm x 10 cm x 10 cm to produce a correctly sized brick after shrinkage.
📊 Comparison of Woods for Brick Moulds
| Wood Type | Suitability for Moulds | Key Properties | Relative Cost |
|---|---|---|---|
| Shisham | Excellent (Traditional Choice) | Hard, durable, water-resistant | Economical |
| Teak | Excellent (Overkill) | Very hard, highly durable, superior water resistance | Very High |
| Deodar | Fair | Durable softwood, but less wear-resistant | Moderate |
| Plywood | Poor | Prone to delamination when wet | Low |