Multi-cavity plastic injection mould

High-productivity tooling for your large production runs

One Multi-cavity mould produces several identical parts in a single injection cycle: 8, 16, 32, or even 64 or 128 parts. This technology is essential for large series (100,000 to several million parts/year), as it divides the effective cycle time by the number of impressions and amortises the investment over very low unit costs.

Hybster designs multi-cavity moulds for high-volume sectors: automotive, packaging, consumer electronics, medical devices and industrial equipment. Combined with hot channels and the conformal cooling, the multi-cavity mould represents the state of the art in mass-production of plastic parts.

What is a multi-cavity mould?

A multi-cavity mould incorporates several identical cavities within a single mould base, fed by a system of branching channels (hot or cold). During each cycle, the injection moulding machine injects the material into all the cavities simultaneously, producing N identical parts in a single operation.

Common configurations

• 4 and 8 footprints standard configurations for medium parts (10 to 200 g).
• 16 and 32 prints : for small parts in large series (plugs, caps, connectors, small technical parts).
• 48 to 128 prints Very high rate, tiny parts (medical parts, mini-components).

Advantages of multi-finger

• Productivity multiplied by the number of prints: 8 prints = 8 pieces per cycle.
• Unit cost significantly reduced : spreading the cost of machine time and labour across multiple parts.
• Quick ROI on large series Investment premium amortised in a few months to 1-2 years depending on volume.
• Production consistency : all parts in a series come from the same batch, ensuring perfect consistency.
• Simplified automation Robotic grippers, vision control, and palletising are easily industrialised.

When to opt for a multi-cavity mould?

• Annual volume > 100,000 units The ROI is starting to become attractive on 4-8 impressions.
• Annual volume > 1 million units : 16–32-slot configurations become cost-effective.
• Small parts (caps, lids, connectors) where a large number of moulds can be fitted onto a standard press.
• High target cadence to reduce the number of presses required for production.
• Dimensionally mature parts Fixed design, no short-term modifications planned.

For more modest volumes, stick to a small-batch mould single run. If you have several complementary pieces to produce together rather than identical ones, opt for a family mould.

Technical challenges of multi-imprinting

Fill balancing

All impressions must fill simultaneously and identically. An imbalance generates variable quality parts (under-filled, over-filled, with sink marks). Solutions:

• Balanced footprint layout symmetrical with respect to the central injection point.
• Balanced power channels Calculated lengths and sections for equal distribution.
• Independent valve gated hot runner systems to synchronise the opening of each PI.
• Moldflow rheological simulation Systematic before manufacturing.

Thermal regulation

The greater the number of cavities, the more complex thermal management becomes. Conformal cooling is often essential when there are more than 16 cavities to prevent variations in quality between the outer and central cavities.

Press capacity required

A multi-cavity mould requires a press with: higher clamping force (proportional to the number of cavities), sufficient injection volume, and platen sizes large enough to accommodate the mould. Hybster systematically checks compatibility with your existing press fleet before finalising the design.

Steels and mould materials

• Hardened and tempered steel 1.2767 or H13 for footprints: durability exceeding 5 million cycles.
• 1.2316 steel (Stavax) for glass-fibre-reinforced materials: increased abrasion resistance.
• Range 1.1730 or 1.2311 for the structure: a balance between strength and cost.
• DMLS inserts for conformal cooling on critical impressions.

Our method

1. Economic study of the number of footprints

We encrypt the investment and unit cost for different configurations (2, 4, 8, 16 prints) for your target volume and amortisation period. This analysis allows you to choose the best investment/cost per piece ratio.

2. Design and simulation

3D mould design with optimised cavity layout, sizing of feed channels (hot or cold), positioning of the cooling system, selection of steels and heat treatments. Systematic Moldflow simulation to validate flow balance.

3. Large-scale manufacturing by partners

Multi-cavity moulds are manufactured by toolmakers equipped with high-precision, large-capacity machining centres. Hybster selects its partners according to complexity: France/Germany for critical moulds (medical, automotive), Eastern Europe or China for standard configurations.

4. Development and qualification

The development of a multi-cavity mould is crucial: the dimensional accuracy of each cavity must be verified individually, temperatures must be balanced, and the overall cycle must be optimised. Testing over 50 to 200 cycles to stabilise the process, followed by statistical process control (SPC) on the initial production runs.

Indicative costs and timescales

• Cold runner two-impression mould £15,000 to £35,000, 10 to 14 weeks.
• Four-to-eight cavity mould, hardened steel + hot runners : €40,000 to €90,000, 14 to 18 weeks.
• High-speed 16-cavity mould €70,000 to €150,000, 16 to 22 weeks.
• Mould 32+ impressions for stoppers/caps : €120,000 to €300,000+, 20 to 28 weeks.

To go further

• Combine with a high cadence: hot runner mould.
• For different simultaneous parts: family mould.
• For smaller quantities: small-batch mould.
• Full offer: Hybster plastic injection moulds.