Case Study: A 48-Cavity Water Preform Mould Running a 13-Second Cycle in Malaysia

The result in one line

A Malaysian customer is producing 500–600 ml water bottle preforms in a 48-cavity mould on a 13-second cycle — 13,292 preforms an hour, about 319,000 a day and roughly 106 million a year on a two-shift-plus schedule. The machine is a efficent HPET2300-320S7 from our Efficient (servo energy-saving) preform series, running a matched preform mould.

This is not a machine specification. It is a number a moulding plant has to hold every hour of every shift, and the interesting part is not the machine — it is everything around it that makes 13 seconds repeatable.

What 13 seconds actually means

Cycle time is easy to quote and hard to hold, so it is worth translating into the three numbers a plant manager actually manages.

Output. At 13 seconds the machine completes 276.9 cycles an hour. Across 48 cavities that is 13,292 preforms an hour — and because the per-cavity rate is set purely by the cycle (276.9 per cavity per hour), the only way past this number is more cavities or a shorter cycle, not a bigger machine.

Shot weight. 48 cavities × 8–11 g gives a shot weight of 384–528 g. That is the number the injection unit has to deliver, cleanly and completely, every 13 seconds.

Material flow. 13,292 preforms an hour at 8–11 g works out at 106–146 kg/h of PET, or roughly 2.6–3.5 tonnes a day and 850–1,170 tonnes a year at 8,000 running hours.

Those three numbers are the reason a 48-cavity job is a system project rather than a machine purchase.

What it takes to hold 13 seconds

Drying has to be sized for the throughput, not for the machine. At 106–146 kg/h and the standard PET drying requirement of 160–180 °C for 4–6 hours to below 0.005 % moisture, the drying hopper must hold roughly 0.4–0.9 tonnes of material to give the resin its full residence time. An undersized dryer shows up first as haze and brittleness, and second as a cycle you have to slow down to compensate.

Mould cooling sets the cycle. Preform moulds typically run at 10–20 °C to prevent premature crystallisation, and cooling is the dominant share of the 13 seconds. Two things decide whether the cycle is real or aspirational: whether the cooling channels remove heat uniformly across the 48 cavities, and whether the fastest and slowest cavities are close enough that the mould is not being run at the pace of its worst cavity. With a 48-cavity tool, cavity-to-cavity variation is worth more attention than any machine setting.

The injection unit has to keep up, not just fill. To sustain a 13-second cycle the barrel must plasticise at least 30–41 g/s — the shot weight divided by the cycle time. Undersize this and the mould becomes irrelevant; the barrel sets the pace.

Take-out is inside the cycle. Ejecting and clearing 48 preforms has to happen inside those 13 seconds without marking the neck finish. Ejector stroke and take-out timing are not accessories to the cycle; they are part of it.

Stability is the deliverable. Once the cycle is found, it has to hold. That means monitoring preform weight, neck and gate dimensions, wall distribution and haze as running production controls — not as a one-off sample check on the day of commissioning.

Why the customer cares about 13 seconds

For a water bottle, preform weight is the largest single lever on cost per bottle, and a fast, stable cycle is what makes lightweighting safe to commit to. A 13-second cycle at 48 cavities is a production promise: it fixes how many bottles the plant can supply, how much resin it buys a year, and how much energy it spends per thousand preforms.

Getting there is the easy half. The reason this project works is that the cycle is repeatable across all 48 cavities, shift after shift, at a preform weight the blow moulding line accepts without argument.

How efficent runs a project like this

The machine and the preform mould are designed and tested as a matched set before shipment, so the customer does not spend the first week reconciling two suppliers. Commissioning, operator training and process optimisation are handled by our engineering team, with remote and on-site support afterwards — including through our regional service network, which matters when a plant is running three shifts and cannot wait for a time zone.

If you are planning a high-cavity water preform job, send us three numbers — preform weight, cavity count and target output. We will tell you which machine the job actually needs. 

Notes on the figures

Given by the project: 48 cavities, 13 s cycle, machine model, product (500–600 ml water preform, 8–11 g), country.

Derived in this article (stated so you can check the arithmetic):

• Cycles per hour = 3,600 ÷ 13 s = 276.9

• Output = 276.9 × 48 = 13,292 pcs/h; × 24 h ≈ 319,000 pcs/day

• Annual output assumes

8,000 running hours per year

(a common planning basis, not a measured availability figure)

• Shot weight = 48 × 8–11 g = 384–528 g

• Material throughput = 13,292 pcs/h × 8–11 g = 106–146 kg/h

• Plasticising requirement = shot weight ÷ cycle time = 30–41 g/s

• Drying hopper size = material throughput × 4–6 h residence = 0.4–0.9 t

Supporting process requirements (drying conditions, preform mould temperature, cavity balance, preform acceptance checks) follow published PET processing guidance — see the sources below.

Sources

• Alpine Mold,

PET Injection Molding Guideline: A Complete Guide for Engineers and Manufacturers

, published 2025-08-01 — PET drying conditions (160–180 °C, 4–6 h, <0.005 % moisture), preform mould temperature (10–20 °C), machine and tooling requirements.

• Cavity Mold,

PET Preform Injection Molds: Design and Process Basics

, updated 2025-09-01 — cavity balance, cooling, cavity-to-cavity variation and preform approval criteria.

• efficent preform injection machine series information (Efficient / servo energy-saving series) and standard project support scope.