Injection moulding [2,1]

Economic Considerations

• Production rates are high, cycle times of 10 to 6O seconds typical.
• Lead times can be several weeks duo to manufacturing of complex dies.
• Economical for high production runs - typically 10,000+.
• Tooling costs are high. Dies are usually made from tool steel,
• Equipment costs are moderate to high.
• Direct labour costs are low.
• Finishing costs are low - little trimming required.

Typical Applications

• Containers.
• Bottle tops.
• Housings.

Design Aspects

• Very complex shapes and intricate detail possible.
• Pockets, holes, bosses and minor re-entrant features common.
• Uniform section thickness should be maintained.
• Maximum section, typically = 13mm.
• Minimum section = 0.4mm for thermoplastics.
• Sizes range from 10g to 25kg in weight for thermoplastics, 6kg maximum for thermosets.

Vacuum forming [2.3]

Economic Considerations

• Process cycle times range from 10 to 60 seconds.
• Set-up times and change-over times are low.
• Production volume trends vary from small batches (10) to high volume, 1,000+.
• Tooling costs are low to moderate, depending on complexity.
• Equipment costs are low to moderate, but can be high it automated.
• Labour costs are low to moderate.
• Finishing costs are low.

Typical Applications

• Open plastic containers.
• Electronic enclosures.
• Bath tubs.

Design Aspects

• Shape complexity limited to mouldings in one plane.
• Open forms of constant thickness without re-entrant angles.
• Maximum section 3mm.
• Minimum section = 0.05mm to 0.5mm, depending on material used.
• Sizes range from 25mm2 to 7.5m x 2.5m in area.

Compression moulding [2.2]

Economic Considerations

• Production cycle times from 20 to 600 seconds typical.
• Production volumes are typically 1,000+, but can be as low as 100 for large parts.
• Tooling costs are generally high.
• Equipment costs are moderate to high.
• Direct labour and finishing costs are generally low. Flash removal required.

Typical Applications

• Dishes.
• Container caps.

Design Aspects

• Shape complexity is limited to relatively simple forms. Moulding in one plane only.
• Holes, protrusions, pockets and minor to entrant features are possible.
• Maximum section, typically = 25mm.
• Minimum section = 0.25mm.
• Sizes range from several grammes to 15kg in weight.

Blow Moulding [2.4]

Economic Considerations

• Production rates between 100 and 2,500 pieces/hour, depending on size.
• Production volumes of up to 10,000,000, but also suitable for quantities as low as 1,000.
• Tooling costs are moderate to high.
• Equipment costs are moderate to high.
• Direct labour costs are low, one operator can manage several machines.
• Finishing cots are low: trimming only.

Typical Applications

• Hollow plastic parts with relatively thin walls.
• Bottles.

Design Aspects

• Complexity limited to hollow, well rounded, thin walled parts with low degree of asymmetry.
• Threads, inserts and undercuts all possible.
• Holes cannot be moulded.
• Maximum section = 6mm. Thick sections may need cooling aids (carbon dioxide or nitrogen).
• Minimum section 0.25mm.
• Sizes range from 12mm in length to volumes up to 3m3.