What a 220 ton container moulding machine can carry: largest total projected area across all cavities, with a 10% reserve (a starting margin, not a rule)
| Product group | Tonnage factor (US t/in²) | Largest total area at 220 t | What that can mean |
|---|---|---|---|
| Reusable PP containers and storage boxes | 2 to 3 | 474 to 711 cm² | Two 180 × 130 mm boxes (468 cm²) at either factor |
| Lids for those containers | 2 to 3 | 474 to 711 cm² | The same cavity count as the matching box, plus any cold-runner area |
| Small pails and buckets in PP or HDPE | 2 to 3 | 474 to 711 cm² | One 200 mm round pail (314 cm²) with room to spare |
| Thin-wall tubs and lids | 5 to 8 | 178 to 284 cm² | Two 120 mm round lids (226 cm²), but only at the lower factor |
| ABS houseware and appliance covers | 2 to 4 | 356 to 711 cm² | Depends on wall and flow length; size on the upper factor |
A 220 ton container moulding machine suits reusable PP containers, their lids, small pails and houseware, often in two to four cavities. Thin-wall tubs and lids also fit, at lower cavity counts. The limit is total projected area: with a 10% reserve, 220 t carries about 474 to 711 cm² of conventional PP but only about 178 to 284 cm² of thin-wall work.
Clamp is the first check, not the only one. Tie-bar gap, opening stroke and shot size can each rule out a mould that the clamp would accept. Those checks are covered below and in the other articles in this series.
Key Takeaways
- Projected area times a tonnage factor sets the clamp; PP sits at about 2 to 3 US t/in², thin-wall work at 5 to 8.
- With a 10% reserve, 220 t holds roughly 474 to 711 cm² of conventional PP container area across all cavities.
- A cold runner adds its own area to the total; on a hot runner only the cavities count.
- Food containers in India must be made from plastics that meet the Indian Standards listed in the FSSAI Packaging Regulations, such as IS 10910 for PP.
What Can a 220 Ton Container Moulding Machine Make?
Reusable PP food and storage containers, their lids, small pails, household bins and houseware fit well, often in two to four cavities. Thin-wall disposable tubs and lids fit too, but at lower cavity counts, because thin walls need about twice the clamp per square centimetre or more.
Cavity count follows from the rim. The mould sees a container from above, so its projected area is the rim outline, not the surface area of the walls. A 180 × 130 mm box has 234 cm² of projected area, so two fit at either PP factor. Four would need about 290 to 434 t.
Lids need the same clamp as their boxes, because the rim outline is the same, but they need far less shot and opening stroke. Small pails are light on clamp but tall, which moves the limit to stroke and mould height. The ice cream containers article in this series covers that check.
How Do You Check Whether a Container Fits 220 t?
Multiply the projected area of one part by the number of cavities, add any cold-runner area, then multiply by a tonnage factor for the resin and wall. Convert to metric tonnes per square centimetre, add a reserve, and compare the result with 220 t.
The method comes from a Plastics Technology article by John Williams of RJG. It deducts cored-out through areas, such as handle slots, and recommends 3 US t/in² as a starting point where you have no better data. In metric, 1 US t/in² is 0.1406 t/cm², so factors of 2, 3 and 5 become 0.281, 0.422 and 0.703 t/cm².
An SPE Plastics Engineering article by A. Urbina puts the range at 2 to 8 US t/in², with polyethylene at the low end, polycarbonate near the top and PP at 2 to 3. Flow length, wall thickness, gate size and melt flow all move the factor, which is why a thin wall raises it.
For thin walls, Gary Tremblay of Sabic Innovative Plastics gives 5 to 8 US t/in² in PlasticsToday, against 3 to 5 for conventional moulding. That is the range used for thin-wall tubs and lids in the table above.
What Else Can Stop a Container Mould Running at 220 t?
Mould size, opening stroke and shot. The mould must pass between the tie bars and sit within the machine's mould-height range, the platens must open far enough to clear a deep part, and the shot must use a healthy share of the barrel. Any one can fail first.
Wide moulds fail on the tie-bar gap even when clamp is spare. Keep the cavities and their projected area inside the tie bars, because force near the bars is not the same as force at the centre. Ask for the clear distance between tie bars, not only the platen size.
Too much clamp is also a risk, as the FAQs below explain. Set clamp from the calculation plus a modest reserve, not from the machine's maximum. Mould height and stroke are covered in the ice cream containers article in this series, and screw choice in the screw options article.
Which Indian Rules Apply to Food and Household Containers?
For food contact, the FSSAI Packaging Regulations 2018 require plastics to conform to listed Indian Standards, such as IS 10910 for PP, IS 10146 for PE and IS 10142 for PS. Household containers that never touch food are outside these rules, but buyers may still ask for them.
FSSAI sets an overall migration limit of 60 mg/kg or 10 mg/dm², tested to IS 9845, with specific limits for metals such as barium and zinc. Pigments must meet IS 9833 and printing inks IS 15495. Food businesses need a certificate of conformity from an NABL-accredited lab for packaging in direct food contact.
Recycled plastics may be used for food contact only as and when FSSAI frames standards and guidelines for them. Keep that in mind before mixing regrind or recycled feed into a food container.
Our view: if one 220 t machine will mould both food and non-food containers, set up separate material lines and purge routines from day one. Recycled feed reaching a food job by mistake is a compliance problem, not a quality one.
What Should You Send Before Choosing a 220 t Machine for Containers?
Send each container's rim size, depth, wall thickness, resin grade, runner type and target cavity count. With those, clamp, tie-bar fit, stroke and shot can be checked together before a mould is ordered. See the 220 ton horizontal injection moulding machine page.
Frequently Asked Questions About Container Moulding at 220 t
Can a 220 t machine run four-cavity container moulds?
Yes, if each cavity is small enough. With a 10% reserve and a PP factor of 3 US t/in², 220 t carries about 474 cm², so four cavities fit when each rim is under about 118 cm², such as a 110 × 105 mm box. Larger rims need fewer cavities or a lower, confirmed factor.
Does a hot runner reduce the clamp a container mould needs?
Yes. It removes the runner from the projected area, because only the cavities count. On a two-cavity box with a 20 cm² cold runner, that saves about 9 t at the upper PP factor. A hot runner also cuts regrind, but it adds cost, heaters and maintenance to the mould.
Is HDPE or PP better for containers on a 220 t machine?
Both run well. PE sits at the low end of the tonnage factor range, so it can need slightly less clamp than PP for the same rim. PP is stiffer and suits hot filling better, while HDPE stays tougher in the cold. Choose on the product's use first, then size the clamp.
Can a 220 t machine mould plastic crates?
Only small ones. A crate's projected area is its footprint minus the through slots. A 400 × 300 mm crate covers 1,200 cm² before slots, so at a factor of 2 the slots must remove about 41% of the footprint to bring the net area down to about 711 cm². Check the net area first.
What happens if I run the clamp higher than the mould needs?
You risk damage without any gain. Plastics Technology lists over-clamping effects such as burns, short shots, crushed vents, a rolled parting line, broken inserts and cracked cavity blocks, and SPE notes that excess force can crack cylinder mounting plates and the machine frame. Set clamp from the calculation plus a modest reserve.
Related Articles
- IML Tubs and Lids on a 220 Ton Machine
- Three Screw Options on a 220 Ton Container Machine Explained
- Ice Cream Containers: Mould Height and Cycle Time on a 220 Ton Machine
Sources & References
- Plastics Technology, J. Williams (RJG): Clamp Tonnage: More Is Better...Right?
- SPE Plastics Engineering, A. Urbina: Mastering Clamping Force Calculation
- PlasticsToday, G. Tremblay (Sabic Innovative Plastics): Never too thin
- Food Safety and Standards Authority of India (FSSAI): Food Safety and Standards (Packaging) Regulations, 2018, compendium
Technical Disclaimer
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