The 260 ton PET machine applications that fit best are volume jobs: water, soft drink and edible oil bottle preforms in high cavity counts, heavy preforms for large bottles, wide-mouth jar preforms, and non-food preforms for agrochemical, detergent and personal care packs. At this size the useful question is not whether a product fits, but how many cavities of it one mould can carry.
This article maps each product group, the clamp room 260 t gives for preforms, the Indian resin grades used for each bottle type, and the checks that limit a large PET machine before clamp does.
Key Takeaways
- With a 10% reserve (a starting margin, not a rule), 260 t covers about 579 cm² of preform projected area at a 400 bar guide pressure, or about 336 cm² on a cautious 5 US t/in² basis.
- High counts of light preforms and low counts of heavy or wide-mouth preforms both fit, so the product mix decides the mould, not the clamp alone.
- Reliance lists separate Relpet grades for still water, aerated drinks, hot fill and fast reheat, so the bottle sets the resin before the machine is chosen.
- Shot against the barrel, mould width between the tie bars and mould weight on the platens limit a 260 t PET machine as often as clamp does.
Which 260 Ton PET Machine Applications Fit Best?
Jobs where volume justifies a large mould: light water and soft drink preforms in high cavity counts, heavy preforms for 5 litre and larger bottles, wide-mouth jar preforms, and edible oil preforms. Short runs and frequent neck changes tend to suit a smaller machine with a cheaper mould better.
260 ton PET machine applications: what each product group needs and what to check first
| PET product | What matters most | First check on a 260 t machine |
|---|---|---|
| Light water and soft drink preforms | Cavity count, cycle time, low acetaldehyde | Tie-bar gap and injection rate for the full cavity count |
| Heavy preforms for 5 litre and larger bottles | Thick walls, long cooling, large shot | Shot against the barrel, and opening stroke for a long core |
| Wide-mouth jar preforms | Large neck diameter, more area per cavity | Projected area and mould width per cavity |
| Edible oil bottle preforms | Clarity, a neck that suits the closure | Cavity count against monthly volume |
| Agrochemical, detergent and personal care preforms | Colour, tint, frequent changes | Purge time and mould change time on a large tool |
Our view: buy 260 t for one or two high-volume moulds that will run for months, not as a general machine for every neck in your catalogue. A large mould standing idle during colour or neck changes loses more output per hour than a small one.
How Much Preform Area Does 260 t Hold?
With a 10% reserve, 260 t leaves about 236 t to work with. At a 400 bar guide pressure, that covers about 579 cm² of projected area; on a cautious 5 US t/in² basis, about 336 cm². For preforms, projected area is the widest circle per cavity, times the cavities.
In practice, 579 cm² means about 67 cavities of a 33 mm support ledge by clamp alone, or 18 cavities of a 63 mm jar ledge. Few preform moulds reach the first figure, because the tie-bar gap fills before the clamp runs out.
Where the two pressure bases come from, and how to choose between them for your mould, is set out in the high-cavity sizing article in this series. The worked example below applies both to a jar preform mould, where the gap between them decides the cavity count.
Which Resin Grade Suits Each Application?
The bottle decides. Still water, aerated drinks, hot-fill juices and general food or cosmetic bottles each have their own bottle-grade PET, chosen for strength, carbonation, heat or clarity. Fix the grade with your customer and the resin supplier before the mould and machine, because it sets drying and processing.
Reliance's Relpet range shows how the grades split by use. UL Prospector's listing gives G5761 for still water, G5801 for foods, beverages, water and FMCG containers such as cosmetics and hair oil, and G5841 for aerated drinks and agrochemicals. H7761 is for hot fill, with higher neck and body crystallinity, and QH5821 is a fast-reheat grade.
A 260 t machine running one mould may switch between grades of the same family, but each grade still needs its own drying check and trial. The acetaldehyde question, which matters most for still water, is covered in the heavy preforms article in this series.
What Limits a 260 t PET Machine Besides Clamp?
Three things: the shot against the barrel, the mould against the tie bars, and the mould weight on the platens. A large preform mould can pass the clamp check and still fail one of these, so ask for all three figures before you fix the cavity count.
Bruce Catoen's sizing guide in MoldMaking Technology says the parts' projected area must sit wholly inside the tie bars, and that the maximum mould weight must be checked for both platens. High-cavity preform moulds are heavy, with a core, neck splits and a hot-runner nozzle for every cavity.
The shot works in both directions. A light preform in a large barrel spends longer in the melt, while a heavy preform can need a larger barrel than the clamp suggests. Jim Bozzelli of Plastics Technology notes that a second barrel ordered with a new machine can be low cost, which suits a plant running both kinds of job.
The heavy preforms article in this series sets out the barrel window, and the post-mould cooling article covers the handling that high output needs.
What Should You Send to Match Your Products to 260 t?
Send each preform drawing with weight, length, neck finish and support-ledge diameter, the resin grade, the cavity count you want and the monthly volume per product. With those, clamp, shot, tie-bar fit and mould weight can be checked together. See the 260 ton PET injection moulding machine page.
Frequently Asked Questions About PET Products on a 260 t Machine
Is 260 t too large for 28 mm water bottle preforms?
Not if the mould has enough cavities to use it. A light preform in a low-cavity mould leaves most of the clamp and barrel idle and keeps the melt hot for longer. Match the cavity count to the tie-bar space and the barrel, or run that job on a smaller machine.
Can one 260 t machine run both light and heavy preforms?
Yes, with separate moulds, if each passes its own checks. The catch is the barrel: a screw sized for a heavy preform can hold a light shot too long and raise acetaldehyde. Bozzelli notes that a skilled operator can change a barrel in under 30 minutes, so a second barrel is worth pricing.
Can a 260 t machine make preforms for 20 litre water jars?
It depends on the preform weight against the barrel, its length against the opening stroke, and the blow moulder downstream. A very heavy single preform may need a larger barrel than the clamp suggests. Catoen puts opening stroke at least 2.5 times the part height, so check stroke against the preform length.
Why do jar preforms take more clamp than bottle preforms?
Because projected area grows with the square of the ledge diameter. A 63 mm ledge has about 3.6 times the area of a 33 mm ledge, so each jar cavity uses as much clamp as three to four bottle cavities. Wide moulds also reach the tie bars sooner.
Should a 260 t PET machine run frequent colour changes?
It can, but each change on a large mould costs more output than on a small one, because purging and the first stable shots tie up every cavity. Group colours and tints into long runs, or keep frequent-change products on a smaller machine with a smaller mould.
Related Articles
- Heavy Large-Volume Preforms on a 260 Ton Machine
- PET 260 Ton: Sizing a Machine for High-Cavity Preform Moulds
- Post-Mould Cooling and Handling for High-Output Preform Production
Sources & References
- UL Prospector: Polyester: Relpet grade listing
- MoldMaking Technology, B. Catoen: Machine Sizing and Specification for Optimal Mold Performance, Part 1
- Plastics Technology, J. Bozzelli: A Simpler Way to Calculate Shot Size vs. Barrel Capacity
- SPE Plastics Engineering, A. Urbina: Mastering Clamping Force Calculation
Technical Disclaimer
Disclaimer: The information provided in this document is for general informational and educational purposes only. It is based on technical references and industry information available at the time of preparation and may be subject to change. It does not constitute engineering, technical, commercial or professional advice, nor does it constitute a quotation, specification, warranty or contractual commitment by Pratishna Engineers.
Actual injection moulding machine and process requirements vary according to the component design, material, mould, production volume, machine configuration and operating conditions. The information, examples, calculations and recommendations provided should be independently evaluated and verified for the specific application before making any equipment, process or production decision. Information obtained from third-party sources remains subject to the accuracy and limitations of those sources.
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