Types of Patterns in Casting Process
- Single piece pattern
- Split Pattern or two piece pattern
- Gated pattern
- Cope and drag pattern
- Match plate pattern
- Loose piece pattern
- Follow board pattern
- Sweep pattern
- Skeleton pattern
1. Single piece pattern
Inexpensive and simplest one Single piece, Simple job, Useful for Small scale production Pattern will be entirely in the drag One surface is flat and at the parting line, Used for very small scale production.
2. Split Pattern or two piece pattern
Split Pattern is used for intricate casting, Split along the parting line, Used where depth of job is too high, Aligned with dowel pins fitted to cope.
3. Gated pattern
Gating and runner system are integrated with the pattern
4. Cope and drag pattern
Similar to split pattern, For cope and drag, separately attached gating system to metal plate, Heavy and inconvenient for handling, Useful for Continuous production.
5. Match plate pattern
Similar to cope and drag patterns with gating and risering system mounted on a single matching plate, Pattern and match plate are made up of metal (Al), Useful for small casting with high dimensional accuracy, Suitable for large scale production, Gating system is attached to the match plate, Expensive.
6. Loose piece pattern
Withdrawing of the pattern from the mould is difficult, Useful for highly skilled job, Expensive.
7. Follow board pattern
Used for structurally weak portions Bottom board is modified as follow board.
8. Sweep pattern
Useful for Axi-symmetrical and prismatic shape, Suitable for large scale production.
9. Skeleton pattern
Stripes of wood are used for building final pattern, Suitable for large casting.