PET Blow Moulding — Comparing Machine Configurations and Price Levels

1. Why compare blow configurations

PET blow moulding machines look similar and diverge in what they cost and what they can run. The differences are in linear vs rotary type, cavity count, oven control and whether the blower stands alone or joins a combiblock. Comparing on a normalised scope prevents paying for speed the volume will never use — or buying below what a high-volume SKU demands.

The selection logic that fixes the architecture is in the PET blow moulding selection guide; this page compares the tiers once that choice is made.

The bottle format mix sets the tier as much as the speed does. A line built only for 0.2–2 L round sits in a different tier from one that must also run a non-round or a large bottle, and a large-format blower is its own tier entirely. When a quotation says 'high-speed', check which format it means — 48,000 BPH on 0.5 L and 6,000 BPH on 10 L are both 'high-speed' for their format and very different machines.

A blow comparison also has to cover the preform and mould, because the bottle is made in the machine, not supplied to it. Cheap quotations sometimes leave preform design and mould making to the buyer, which shifts real cost and risk out of the machine price. Name the preform and mould responsibility in the scope, because a line that arrives without a proven mould is not a running line, only a capable one waiting on tooling and a preform that has not been proved to blow.

2. Three configuration tiers

Most blow lines fall into three tiers, set by output and automation rather than by quality. A regional line happy at 6,000 BPH gains nothing from a 40-cavity rotary it cannot feed.

A large-format tier sits across these for 3–15 L bottles: fewer cavities, a different clamp family, and a much lower BPH for the same machine size. Do not read a high small-format rating as applicable to large bottles.

Oven control is where much of the type cost lives. A longer, better-controlled oven heats the preform more evenly, which shows up as consistent wall thickness and fewer weak bottles at speed. A cheaper oven saves capex and costs bottle quality or speed; specify the oven control with the machine, because retrofitting it is rarely clean.

Cavity count and oven length move together, and both show up in price. More cavities need a longer oven to heat them, so a high-cavity line is longer and dearer before you count the type. When two quotes differ on cavities, check the oven length and the lamp control alongside, because a short oven behind many cavities is a line that cannot reach rate on a difficult bottle. The oven is where bottle quality is set, so it belongs in the comparison, not in the fine print of the quote.

3. Linear vs rotary and what it changes

Linear moves preforms intermittently and is cheaper and more flexible; rotary moves them continuously and is faster and smoother at steady output. The cost difference is in the carousel, the oven length and the control, and it is worth paying only where the volume uses it.

The air conveyor between a separate blower and filler is a real cost and a real source of bottle loss, because bottles travel on their base and need stiffness to survive it. Removing it in a combiblock is what lets the bottle be lighter and the floor smaller. The conveyor is the hidden line item in any separate-blower quotation — name it before comparing.

The cavity count should be sized to your sustained output, not to the peak the brochure shows. A line with spare cavities you never use is capital on the floor; a line short of cavities runs below rate and never catches up. Match cavities to your main format at your main speed, and treat any headroom as a deliberate margin, not an accident. The type and the cavity count are one decision stated twice, so compare them as a pair, not as a type and a number quoted separately.

4. Separate blower vs combiblock

The architecture choice is a cost and a layout decision as much as a speed one. A separate blower feeds a filler through an air conveyor and needs neck-handled bottle handling; a combiblock blows and fills in one machine and removes the conveyor. The block wins on bottle weight, floor area and operator count above roughly 12,000 BPH, and loses on flexibility below it or where empty bottles are sold.

The full comparison is in combiblock vs separate line, and capacity bands are in combiblock capacity selection.

A second TCO trap is the commissioning spare part set. A line quoted without it looks cheaper until the first worn mould or oven lamp stops production and the part is a lead time away. The set is small relative to the machine but large relative to a day of downtime, so confirm it is included and that long-lead items — especially moulds — are identified at handover.

Flexibility is the quiet cost of the block. A separate blower can be re-pointed at a different filler or sold as empty bottles, while a block is committed to one integrated line; for a plant that sells empties or runs a broad format range, that flexibility is worth more than the floor and operator saving. Weigh the architecture against the business model, not just the per-bottle cost, because the cheaper-per-bottle choice can be the wrong one for a flexible or trading business that needs to shift what it makes and who it supplies.

5. Comparing on total cost, not sticker price

Two lines at the same headline price rarely cost the same to own. Evaluate on normalised scope and on the items below, treating all figures as indicative and configuration-dependent.

A sixth mistake is forgetting the format family in the comparison. Two quotes may both say 'rotary, 20 cavities' while one covers 0.2–2 L only and the other also covers a large format — the second is a different and larger machine for the same headline. Name every format in the scope before comparing.

High-pressure air is the dominant utility on a blow line, larger than the oven power for most formats, because every bottle is blown with compressed air and recovery only returns part of it. Compare the net air demand and the recovery at the blower, because the compressor is a recurring cost the machine price never shows. A line with better recovery pays back in run cost across millions of bottles a year, so the air side belongs in the total-cost comparison, not just the floor plan and the headline electricity estimate.

6. Common comparison mistakes

Five errors recur in blow moulding quotations:

1. Comparing different scopes. One quote includes oven control and moulds; the other omits them.
2. Rating on the smallest bottle. A line quoted at 24,000 BPH on 0.5 L may not hold it on 1.5 L; confirm on your main size.
3. Buying rotary below the crossover. A 40-cavity rotary for 6,000 BPH is idle capacity.
4. Ignoring the architecture. A block specified below its economic speed costs more per bottle than a separate line.
5. Forgetting large format. Small and large formats are different families; one blower does not run both.

Lead time belongs in the comparison even though it is not in the price. A high-speed rotary from a busy builder may carry a longer slot than a linear from a smaller shop, and the difference can matter more than the tier if your market window is fixed. Put the delivery date and payment milestones on the table with the configuration.

7. Which tier to specify

Match the tier to sustained output and format mix, not to ambition:

1. Regional / flexible: economy tier, linear blower, separate filler.
2. Growing volume: mainstream tier, linear or rotary at the crossover.
3. High-volume single format: high-speed rotary, usually in a combiblock.
4. Large format: separate large-format blower, different family.
5. Multi-format: specify every format now; moulds handle one family, not two.

The blower range is in blow moulding machines, and the block family is in the combiblock range. Complete lines are scoped in water, carbonated drinks and juice production line solutions. Common questions are answered in the PET blow moulding FAQ.

Frequently asked questions