Quick answer: a 260 ton container moulding machine can run one 5 litre PP pail, one 10 litre pail where the grade flows easily, four to seven 1 kg paint or grease tubs, two or three reusable 1 litre food boxes, two or three thin-wall 500 ml tubs, or five to eight 100 ml cups. Each range runs from a cautious tonnage factor to an easy one.
Clamp sets the first limit. Opening stroke, shot size, cooling and mould size can set the next one, and on small parts a 260 t press can be the wrong size altogether.
Key Takeaways
- With a 10% reserve, 260 t holds about 560 cm² of rim area at 3 US t/in² and about 210 cm² at a thin-wall factor of 8.
- A container's projected area is its rim outline times the cavity count, plus any cold runner, whatever the depth.
- Rigid plastic packaging in India must contain at least 30% recycled material in 2025-26, rising to 60% by 2028-29.
- A mould that covers less than about 70% of the tie-bar distance can let the platens bow, so small moulds belong on smaller machines.
How Do You Work Out What a 260 Ton Container Moulding Machine Can Hold?
Multiply the projected area by a tonnage factor for the resin and wall, then add a reserve. For a container, projected area is the rim outline times the number of cavities, plus any cold runner. If the result stays under about 236 t, clamp will not be the limit.
The method comes from a Plastics Technology column by RJG trainer Jeremy Williams. He gives typical factors of 2 to 10 US tons per square inch and recommends 3 as a starting point. On a hot runner, only the cavities count; a cold runner adds its full area.
A separate SPE Plastics Engineering article by A. Urbina places polyethylene at the low end of a 2 to 8 range and PP at 2 to 3. One US t/in² is about 0.141 t/cm², so a factor of 3 becomes 0.422 t/cm². The 10% reserve used across this series is a starting margin, not a rule, and 260 t divided by 1.1 gives the 236 t working ceiling.
Largest rim area a 260 t clamp can hold with a 10% reserve (calculated)
| Factor (US t/in²) | Factor (t/cm²) | Typical case | Largest area | Round rim |
|---|---|---|---|---|
| 2 | 0.281 | PE or PP, easy flow, thicker walls | 840 cm² | 327 mm |
| 3 | 0.422 | Common starting point | 560 cm² | 267 mm |
| 4 | 0.562 | Stiffer grades, longer flow | 420 cm² | 231 mm |
| 5 | 0.703 | Lower end of thin-wall range | 336 cm² | 207 mm |
| 8 | 1.125 | Upper end of thin-wall range | 210 cm² | 164 mm |
Which Containers Fit, and in How Many Cavities?
On clamp alone, 260 t carries a 5 litre pail, one 10 litre pail only near factor 2.5, four to seven 1 kg tubs, two or three reusable 1 litre boxes, two or three thin-wall 500 ml tubs and five to eight 100 ml cups. Rim sizes below are illustrations.
Cavities a 260 t clamp can carry, by container (calculated, hot runner, 10% reserve; rim sizes are assumptions)
| Container | Resin | Rim | Area per cavity | Cavities by clamp |
|---|---|---|---|---|
| 5 litre pail | PP | 230 mm round | 415.5 cm² | 1 (2 only near factor 2) |
| 10 litre pail | PP | 290 mm round | 660.5 cm² | 1 if factor is 2.5 or less |
| 1 kg paint or grease tub | PP or HDPE | 120 mm round | 113.1 cm² | 4 to 7 (factor 3 to 2) |
| Reusable 1 litre box | PP | 180 × 130 mm | 234 cm² | 2 to 3 (factor 3 to 2) |
| Thin-wall 500 ml tub | PP | 115 mm round | 103.9 cm² | 2 to 3 (factor 8 to 5) |
| 100 ml cup | PP or PS | 70 mm round | 38.5 cm² | 5 to 8 (factor 8 to 5) |
Pails sit at the top of the range. The pail article in this series covers the stroke, shot and grade checks that decide whether a 10 litre pail runs. Thin-wall tubs and cups lose most of their cavities to the higher factor, and the high-cavity thin-wall article explains why a stack mould can win some of them back.
Lids belong in the same plan. A lid shares its container's rim outline, so it needs similar clamp per cavity even though it is flat. Running bodies and lids in one family mould saves a machine but makes the fill harder to balance.
Can a 260 t Machine Be Too Big for Small Containers?
Yes. A small mould on a large press can let the platens bow under clamp, which shows up as flash in the middle of the mould. A large machine running a small product also uses more energy per part than the job needs, so both cost and quality suffer.
A Plastics Technology guide to mould mounting gives a rule of thumb: the mould should cover at least 70% of the distance between the tie bars. Most machine manuals state a minimum mould size, and very small moulds can cause serious platen damage. Check this before you move a cup mould from a 150 t press to a 260 t one.
Energy points the same way, because a large press carries bigger pumps, heaters and platens than a small job needs. Our view: buy 260 t for pails, large tubs and multi-cavity moulds that fill the platen, and keep two-cavity jobs on the smaller presses in your plant.
What Else Limits a Container Job Besides Clamp?
Opening stroke for deep parts, shot size for heavy or multi-cavity shots, and cooling at the thickest section. Recycled content is now a fourth limit, because India's packaging rules set minimum recycled shares that change how the resin behaves in the mould and the barrel.
PWM (Amendment) Rules notified on 31 March 2026 require rigid plastic packaging to contain at least 30% recycled material in 2025-26, rising to 60% by 2028-29. Shortfalls for 2025-26 can be carried forward for up to three years, and there are exemptions where FSSAI and similar rules restrict recycled content.
Paint, lubricant and chemical pails are rigid packaging, so the targets can apply to them. Food containers may fall under the exemption. Either way, run mould trials with the blend you will use in production, because a mould that fills only on virgin resin leaves no room for lot-to-lot variation.
Output is the last check. Cycle, good-shot share and effective hours decide whether the cavity count you chose meets the monthly order, which the output planning article in this series works through.
What Should You Send Before Choosing a 260 t Container Machine?
Send each container drawing with rim size, depth and wall thickness, the resin grade and planned recycled share, the target cavity count and the monthly volume. With these, clamp, stroke, shot, mould size and cooling can be checked before a mould is ordered. See the 260 ton horizontal injection moulding machine page.
Frequently Asked Questions About 260 Ton Container Moulding
Can a 260 t machine run a 20 litre pail?
Not on clamp in most cases. A 20 litre pail with a rim of about 330 mm has a projected area near 855 cm², which needs about 264 t even at a factor of 2 with a 10% reserve. Its height also calls for a long opening stroke, so check both figures with the mould maker.
Do square containers need more clamp than round ones?
For the same width, yes. A square rim of 120 mm covers 144 cm², against 113 cm² for a 120 mm round rim, about 27% more. Square corners are also slower to fill and cool evenly, so the tonnage factor can rise as well. Size square and rectangular containers on their true outline.
Is a 260 t machine a good choice for a mixed container range?
It can be, if most moulds are large enough to cover the platen properly. Mixed ranges often include both pails and small tubs. Group the large moulds on the 260 t press and the small ones on a smaller machine, so each runs with sound platen support and sensible energy use.
Does a cold runner change the cavity count on 260 t?
It can. A cold runner adds its full projected area to the clamp sum, and on a six-cavity tub mould that can push the total past the working ceiling. It also adds a runner to regrind on every shot. A hot runner keeps the clamp sum to the cavities alone.
How should I plan for recycled PP in pails?
Trial the actual blend, not virgin resin. Recycled lots can vary in melt flow, colour and contamination, so check fill, drop strength at the handle lugs and colour match across several lots. Keep lot records, because the recycled-content targets in India rise every year to 2028-29.
Related Articles
- Moulding Pails and Large Tubs on a 260 Ton Machine
- High-Cavity Thin-Wall Moulds on a 260 Ton Machine
- Sweet Boxes and Food Trays: Planning Output on a 260 Ton Machine
Sources & References
- Plastics Technology, J. Williams (RJG): Clamp Tonnage: More Is Better...Right?
- SPE Plastics Engineering, A. Urbina: Mastering Clamping Force Calculation
- Plastics Technology, P. Witaszek, J. Klees, J. Fattori, E. Di Siro, J. Bozzelli: How to Mount an Injection Mold
- Polymerupdate, D. K. Jha: India eases plastic recycling regulations
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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