The right used PET preform injection moulding system must produce your specified preform at the required output, with compatible tooling and adequate drying, cooling and handling equipment. Clamping tonnage, cavity count and machine age are useful comparisons, but none establishes suitability on its own.

This guide explains the main checks before buying a used PET preform injection moulding system, whether you are starting production, adding capacity or replacing an existing machine.

1. Define the preform and production requirement

Start with an approved preform drawing and a production specification. Provide:

Preform: weight, overall length, wall thickness and exact neck finish, including the drawing revision.
Application: bottle volume and design, product, carbonation or hot-fill requirements, and the intended blowing process.
Material: PET grade, colour, additives and intended recycled PET content.
Production: required saleable preforms per hour, annual demand, operating hours and planned format changes.
Installation: location, electrical supply, available space, utilities, budget and target start-up date.

A description such as “28 mm preforms” is insufficient for tooling selection. Confirm the complete neck specification; for example, PCO1881 and PCO1810 are different finishes.

2. Calculate output and material throughput

Preforms per hour

Theoretical preforms per hour = active mould cavities × 3,600 ÷ cycle time in seconds.

A 72-cavity mould running a 9-second cycle produces 28,800 preforms per hour before downtime and rejects. At an illustrative combined utilisation and quality factor of 90%, saleable output would be 25,920 per scheduled hour. That factor is an example, not an assumed performance guarantee.

If your target is 30,000 saleable preforms per hour, that configuration would not meet it under those assumptions. Check active cavitation, demonstrated cycle time, product quality and the production margin required.

PET throughput and shot requirement

Nominal PET throughput in kg/h = preforms per hour × preform weight in grams ÷ 1,000.

Producing 30,000 preforms per hour at 22 g requires 660 kg/h of PET in the moulded preforms. At 40 g, the same hourly count requires 1,200 kg/h. Allow separately for process losses and operating margin.

A 72-cavity mould producing 22 g preforms places 1.584 kg of PET into the preforms each cycle. Check the injection unit's usable PET shot capacity and plasticising performance for the required cycle. A stated injection volume in cm³ should not be treated as PET shot weight without the appropriate conversion and machine data.

If wall thickness or a validated cycle is unknown, treat output as provisional. Obtain the preform drawing and relevant production evidence before confirming capacity.

3. Verify machine and mould compatibility

A mould with the desired cavity count is not automatically compatible with a particular machine. Before buying a system or a separate PET preform mould, verify:

Mechanical fit: platen dimensions, mounting arrangement, tie-bar clearance where applicable, mould thickness, opening stroke and installed weight limits.
Injection interface: nozzle and sprue connection, usable shot capacity, injection performance and plasticising capacity.
Hot runner and controls: heater zones, thermocouples, valve-gate actuation, electrical connections and control compatibility.
Cooling: circuit arrangement, connections and required water flow, pressure, temperature and quality.
Takeout and post-mould cooling: cavity pitch, end-of-arm tooling, cooling tubes or stations, and sequence compatibility.

Confirm whether the offer includes a complete mould, only a cold half, only a hot runner or selected components. Compatibility across machine generations or manufacturers must be checked against drawings and the actual installed configuration.

4. Identify the exact model and generation

Record the full model designation, serial number, manufacture year, injection unit and documented upgrades. For Husky equipment, distinguish the relevant HyPET generation and performance package; a description such as “HyPET 300” does not fully specify its capabilities.

Compare suitable configurations from manufacturers such as Husky, Netstal, SIPA and Sacmi against the same preform specification. Do not apply the output, energy figures or recycled-material capability of a current platform to an older used machine.

Check parts availability, service arrangements, control hardware and access to software backups with the relevant supplier. For older platforms, obtain confirmation of support for the exact machine before committing to the project.

5. Confirm auxiliaries and installation requirements

Assess the complete production system. The machine's capacity can be restricted by material preparation, cooling or handling.

Material preparation: loader, dehumidifying dryer, hopper capacity and any blending or dosing equipment.
Cooling: chiller or plant-water provision, pumps, filtration and any dry-air protection required to prevent condensation.
Handling: takeout robot, post-mould cooling, conveyor, inspection and preform collection equipment.
Factory services: voltage, frequency, connected load, cooling circuits, compressed air, access and lifting provisions.

Use the machine's site preparation documentation and the resin supplier's processing requirements when planning the installation. Verify dryer and cooling capacity for your intended production rate rather than assuming that existing auxiliaries are sufficient. Browse auxiliary equipment where additional equipment is needed.

For rPET production, confirm the permitted material specification, drying arrangement, melt-processing capability and required product quality with the equipment and material suppliers. An ability to process some rPET does not establish suitability for every recycled content or feedstock.

6. Inspect condition and establish acceptance criteria

Whenever possible, inspect the system in production. Record the preform drawing, material, active cavities, cycle, sustained output and rejects during the test. Check dimensions, weight consistency, neck quality, gate condition and visual defects against agreed limits; use appropriate laboratory tests for properties that cannot be assessed visually.

Review maintenance records, operating hours, screw and barrel condition, mould wear, cooling condition, takeout operation and controls. A short video of the machine cycling does not establish sustained output or acceptable preform quality.

For dismantled equipment, establish when it last ran, how it was stored and whether connections and components were labelled and protected. Include inspection, recommissioning and potential repairs in the project budget. Define acceptance criteria and responsibilities before purchase.

7. Compare total installed cost

Include tooling, missing auxiliaries, refurbishment, dismantling, export packing, freight, installation, commissioning, training and initial spares. Compare energy consumption on a consistent system boundary, making clear whether drying and cooling are included.

A lower purchase price can be offset by conversion work or a production shortfall. Select the configuration that meets the required saleable output and quality with a supportable operating cost.

Frequently asked questions

What size machine do I need for 30,000 preforms per hour?

Specify preform weight, neck finish, geometry and material first. Then check cavitation and achievable cycle, PET throughput, injection capacity, cooling and expected losses. Clamping tonnage alone cannot answer the question.

Can I reuse my existing preform mould?

Possibly. Supply the machine details, mould assembly drawings, hot runner information and takeout configuration for a compatibility assessment. Matching the brand or cavity count is insufficient.

Does the machine make finished bottles?

A conventional preform injection system makes preforms for a separate reheat stretch blow moulding machine. If you need equipment that integrates injection and bottle forming, consider injection stretch blow moulding equipment.

Are the mould, dryer and chiller included?

Only when expressly listed in the supply scope. Obtain an itemised list identifying tooling, auxiliaries, controls, documentation and any exclusions.

Discuss your preform production requirement

Send PETmachinery your preform drawing, weight, neck finish, material specification, required saleable output, installation location, budget and target date. Include existing mould details if you plan to reuse tooling.

Contact sales@petmachinery.com to discuss suitable configurations, or browse our preform injection moulding equipment and preform moulds. Availability and technical suitability are assessed for each enquiry.

For the wider production line, see our guide to choosing used PET and beverage production equipment.

Technical references

Manufacturer resources explain the importance of integrated system selection. Specifications must be verified for the used equipment being considered.

How to Choose a Used PET Preform Injection Moulding System