PET Preform Mould: Complete Buyer’s Guide
A PET preform mould runs you anywhere from $5,000 to $200,000+. It will run for years. Every bottle that leaves your line carries its fingerprints — good or bad.
Preform Focus
What the mould actually does. Why ±0.01 mm on wall thickness decides whether your bottle passes a burst test.
Cavity Focus
Match cavity count to your annual volume. One formula. Real output numbers, not guesses.
Steel Focus
S136, H13, P20 — and why putting the wrong one in cores costs you double inside two years.
Supplier Focus
EU vs China shops compared honestly. Hot runner brands ranked. A 10-point vetting list.
What Is a PET Preform Mould — and Why It Decides Bottle Quality
A PET preform mould is an injection mould that shapes molten PET into small, test-tube-shaped pieces called preforms. Those preforms get reheated later and stretch-blown into the bottle you ship.
The tolerance window is brutal. Drift ±0.01 mm on wall thickness and you see it in the bottle — haze, weak shoulders, scrap. The mould is not just a tool. It’s the product spec.
How the Injection Cycle Produces a Preform
- Drying: PET pellets get dehumidified first. PET is hygroscopic. Skip drying and the resin degrades on the screw.
- Melting & injection: Dried pellets melt at ~270–290 °C, then shoot into the cavities under high pressure.
- Cooling: Molten PET freezes around the core pins. Cooling channels control how fast that happens.
- Ejection: Solid preforms eject onto a conveyor — to a bin, or straight to the blow line.
Each cycle takes 8–15 seconds. Run a 192-cavity tool 24/7 and you crack 70 million preforms per month off a single mould.
Key Insight
Material distribution in the bottle is locked in at the preform stage. Get the preform right and the blown bottle has even sidewalls and clear gloss. Get it wrong and you’ll chase top-load failures forever.
Key Components of a PET Preform Mould
Know the parts and you’ll spot the difference between a $30,000 Chinese tool and a $150,000 European one in the first call.
Core Pins & Cavity Inserts
The core pin shapes the inside of the preform. The cavity insert shapes the outside. Together they hold wall thickness to ±0.01 mm. Premium tools run ASSAB S136 (DIN 1.2316) stainless — polishes to a mirror, shrugs off PET’s acidic melt, holds size at temperature.
Neck Rings: Self-Lock vs Non-Self-Lock
The neck ring forms the thread. It also wears the fastest. Two camps:
| Feature | Self-Lock | Non-Self-Lock |
|---|---|---|
| Parting line resistance | Each cavity holds itself | Leans on A-plate & slider blocks |
| Shots before flash starts | Much longer | Shorter |
| Upfront cost | Higher | Lower |
| Best for | High-volume >1M shots, multi-cavity | Lower-volume, tight budget |
| Maintenance | Service one cavity at a time | Whole mould comes apart |
Recommendation
Above 24 cavities, running real production? Self-lock. The premium pays itself back in fewer flash issues, longer service intervals, and less scrap on the floor.
Hot Runner: Where the Melt Actually Lives
The hot runner keeps PET at temperature from the nozzle to every cavity. Two gate types dominate.
- Valve gate: a pin opens and closes the gate. Clean vestiges. No stringing. Standard for water and CSD preforms. Costs more.
- Thermal gate: works on temperature differential. Cheaper, simpler, but bigger vestige and stringing risk on cold starts.
| Brand | HQ | Key Strengths | Price Tier |
|---|---|---|---|
| Husky | Canada | The default. Fits almost any machine. | Premium |
| Mould-Masters | Canada | Strong PET-specific valve gate | Premium |
| YUDO | South Korea | Valve gate at lower cost. Growing fast in Asia. | Mid-range |
| INCOE | Germany | Tight thermal uniformity across the manifold | Premium |
Choosing the Right Cavity Count for Your Volume
Cavity count drives cost more than anything else. More cavities means a bigger mould bill. It also means a much lower cost per preform.
| Cavities | Output/hr | Mould Cost (USD) | Best Application |
|---|---|---|---|
| 1–4 | 120–720 | $5,000–$15,000 | Prototyping, lab work, T1 trials |
| 6–16 | 1,000–3,200 | $15,000–$40,000 | Small pharma, cosmetics, specialty |
| 24–48 | 6,000–17,000 | $40,000–$80,000 | Mid-volume water, beverage, edible oil |
| 72–96 | 21,000–43,000 | $80,000–$140,000 | High-volume commercial beverage |
| 128–192 | 46,000–100,000+ | $140,000–$250,000+ | Large-format beverage, 24/7 lines |
How Do I Calculate My Cavity Count?
Take your annual volume, divide by operating hours, divide by shots per hour. Add a buffer. Round up.
Cavity Count Formula
Required cavities = (Annual target ÷ Operating hours/yr) ÷ (3,600 ÷ Cycle time in seconds)
Worked example: 50M preforms/yr, 8,000 hrs, 10-sec cycle
- 50,000,000 ÷ 8,000 = 6,250 preforms/hr
- 3,600 ÷ 10 sec = 360 shots/hr
- 6,250 ÷ 360 = 17.4 → round up to 24 cavities
Add 15–20% on top for downtime and scrap. Always.
Steel Selection — The Factor Most Buyers Get Wrong
Buyers argue about cavity count and hot runner brand. They accept whatever steel the quote lists. That’s the costliest mistake we see.
Steel grade decides your real cost per million preforms.
| Property | S136 (DIN 1.2316) | H13 (DIN 1.2344) | P20 (DIN 1.2311) |
|---|---|---|---|
| Hardness (HRC) | 48–52 | 48–52 | 28–34 (pre-hardened) |
| Corrosion resistance | Excellent — stainless | Moderate | Poor — needs plating |
| Polishability | Mirror (SPI A-1) | Good (SPI A-2) | OK (SPI B-1) |
| Typical lifespan | 3–5M+ shots | 2–3M shots | 1–2M shots |
| Relative cost | 1.0× (baseline) | 0.7× | 0.4× |
| Best use | Cores, cavities, neck rings | Gate inserts, some cavities | Plates, housing only |
Warning
PET puts out acidic byproducts during processing. Swap H13 or P20 into the cores to save 30% on the steel bill, and you’ll replace those cores 40–60% sooner. The savings are a mirage.
Engineering Note
S136 is the standard for every contact surface. Ask for the steel mill cert. Cross-check it against the parts before signing off. If your supplier can’t produce the cert, that’s your answer.
Lifespan, Maintenance & Total Cost of Ownership
The sticker price is only 30–40% of what the mould costs you over its life. Spare parts, downtime, refurbs — that’s the other 60–70%. Quote-to-quote comparisons miss this.
| Component | Typical Lifespan | Replacement Cost | Notes |
|---|---|---|---|
| Mould housing/plates | 10–15M+ shots | Almost never | P20, structural |
| Core pins | 3–5M shots | $200–$800 each | S136. Swap one at a time. |
| Cavity inserts | 3–5M shots | $300–$1,200 each | S136. Individually replaceable. |
| Neck rings | 5–30M shots (nitrided) | $150–$500 each | Wears hardest |
| Gate inserts | 1–3M shots | $100–$400 each | Replaced most often |
Scheduled Maintenance Checklist
Every 500K Shots
Every 1M Shots
Every 3M Shots
Machine Compatibility: Matching the Mould to Your IMM
A mould that doesn’t fit the press is a $100,000 paperweight. We’ve seen it happen. Confirm these in writing before you sign:
- Platen size — leave room for cooling hose connections, not just the mould footprint
- Mould pitch — has to match the take-out robot’s arm spacing
- Stack height — closed mould must fit inside the machine’s min/max daylight
- Hot runner interface — electrical, hydraulic, cooling — all must match what’s on the press
- Tie bar spacing — outer mould dims have to clear the tie bars
| Machine Brand | Common Cavity Range | Notes |
|---|---|---|
| Husky HyPET | 24–192 | The reference interface. Most Chinese moulds are built to it. |
| Netstal PET-LINE | 24–128 | European build. Low energy per preform. |
| SIPA XFORM | 48–128 | Integrated preform-to-bottle systems |
| SACMI IPS | 32–128 | Also runs compression moulding |
| ASB Nissei | 1–16 | Single-stage ISBM and specialty work |
rPET & Sustainability: How Preform Moulds Are Adapting
Recycled PET isn’t optional anymore. The EU’s Single-Use Plastics Directive demands 25% recycled content by 2025, 30% by 2030. Coca-Cola, Nestlé, PepsiCo have all pledged above those numbers. That changes how the mould has to be specified.
What rPET Throws at the Mould
- IV varies batch to batch — your processing window widens
- Higher acetaldehyde (AA) — risky for water bottles, you’ll taste it
- Dirtier melt — hot runner wears faster
- Colour shift and haze — your cavity polish has to be better, not worse
Mould Changes Required
Future-Proofing Advice
Running 100% virgin today? Spec rPET-ready anyway. Retrofitting a finished mould is doable but expensive and never as clean as building for it from day one. Rules are tightening faster than most procurement teams expect.
Top PET Preform Mould Manufacturers: Honest Comparison (2025)
Tier 1 — Premium OEMs (Europe & North America)
| Manufacturer | HQ | Max Cavities | Key Differentiator |
|---|---|---|---|
| Husky | Canada | 192 | The category default. Largest installed base. Full system. |
| SIPA | Italy | 128 | End-to-end preform-to-bottle. Strong rPET work. |
| KTW | Germany | 144 | German precision. Very flexible on custom specs. |
| MHT | Germany | 192 | Advanced hot runner. Built for high-speed lines. |
| Otto Hofstetter | Switzerland | 192 | Swiss tooling. Runs forever if you maintain it. |
Tier 2 — Value Manufacturers (Mostly China)
| Manufacturer | Location | Max Cavities | Key Differentiator |
|---|---|---|---|
| Demark | Taizhou, China | 72 | 30+ years. Strong in mid-cavity range. |
| Foray | China | 144 | Broad catalog. English support is actually usable. |
| Huayan | Guangzhou, China | 176 | Intelligent systems. Newer tech stack. |
| PETform | Turkey | 192 | European-style quality at mid-range prices. |
10-Point Chinese Supplier Vetting Checklist
Questions to Ask Before You Order
- Do you hold ISO 9001? Verify it with the issuing body, not just a PDF.
- Can you confirm FDA compliance for food-contact or pharma work?
- Will you run a trial mould (T1) and ship sample preforms before final delivery?
- Will you supply a laser scan dimensional report? Neck finish must come in at ±0.01 mm.
- Can you produce steel mill certs showing the actual S136 or H13 grade?
- What hot runner brand and serial numbers are going in? Spell it out.
- Give me 3–5 reference customers currently running production on your moulds.
- What are your warranty terms? Industry standard is 1 year or 1M shots on structural parts.
- Do you stock cores, gate inserts, and neck rings as spares?
- What after-sales do you provide — installation, remote troubleshooting, maintenance contracts?
Red Flags
- Quotes a price without seeing your drawings
- Can’t explain gate location or cooling layout
- Doesn’t ask about your injection machine
- Vague steel descriptions, no documentation
- No DFM. No trial production.
- No PET preform mould history specifically
- Won’t share trial videos or dim reports
- No clear modification or warranty policy
- Only argument they have is “lowest price”
Frequently Asked Questions
What is the difference between a PET preform mould and a blow mould?
The preform mould is the injection mould. It makes the small test-tube-shaped preform. The blow mould is a separate tool, sitting on the stretch-blow machine, that expands that preform into the finished bottle. Every PET bottle needs both tools at two different stages.
How many cavities do I need in a PET preform mould?
It depends on annual volume and operating hours. Use this: Required cavities = (Annual target ÷ Operating hours/yr) ÷ (3,600 ÷ Cycle time in seconds). For most lines running 20–80M bottles a year, 48–96 cavities is the sweet spot. Add a 15–20% buffer for downtime.
What steel is best for PET preform moulds?
S136 (DIN 1.2316) for everything that touches melt — cores, cavities, neck rings. You get HRC 48–52, real corrosion resistance against PET’s acidic byproducts, and mirror polish. H13 is fine for gate inserts. P20 belongs in plates and housing. Nowhere else.
How long does a PET preform mould last?
S136 cores and cavities, maintained properly, give 3–5M shots. Nitrided neck rings stretch to 10–30M. The housing itself can pass 15M. With scheduled component swaps, the full mould keeps running past 10M shots total.
How much does a PET preform mould cost?
Wide range. Low-cavity moulds (2–16 cav) from China start at $5,000–$15,000. Mid-range (24–72 cav) lands at $40,000–$120,000. High-cavitation (96–192 cav) from premium European shops runs past $200,000. Evaluate on cost-per-million-preforms, not the sticker.
Can PET preform moulds process recycled PET (rPET)?
Yes, with specific changes. Larger hot runner flow channels. More cavity venting. Corrosion-resistant surface treatments. Cooling re-tuned for the rPET blend. If you plan to run 30%+ rPET, tell your mould supplier on day one. Retrofitting later costs more and works worse.
What is a self-lock PET preform mould?
A self-lock design means each cavity insert and slider holds its own parting line under injection pressure. Standard moulds rely on the A-plate and slider blocks to do that work collectively. Self-lock pushes flash out further in the mould’s life. Use it on any high-volume, multi-cavity job.
Ready to Specify Your PET Preform Mould?
Use this guide as your spec sheet. Lock the cavity count. Insist on S136 for every wear surface. Pick the hot runner brand. Confirm machine fit on paper before you sign anything.
