Quick answer: a 150 t plastic container making machine suits mugs, tumblers, jars and household containers with conventional walls, in two to four cavities depending on size, plus single-cavity thin-wall tubs of modest diameter. High-cavity thin-wall packaging needs far more clamp per square centimetre and faster machines, so treat it as a separate class of equipment.
The difference is the tonnage factor. Thin walls push the clamp needed per cm² well above the 2 to 3 US t/in² used for a PP mug, as the table below shows.
Key Takeaways
- A Sabic engineer writing in PlasticsToday puts thin-wall clamp at 5 to 8 US t/in², against 3 to 5 for conventional moulding.
- Four cavities of an 85 mm PP mug with a cold runner need about 86 to 129 t with a 10% margin, so clamp fits; the barrel may not.
- A 500 ml thin-wall tub with a 110 mm opening needs about 74 to 118 t for one cavity, so 150 t runs one cavity, not four.
- Under the FSSAI Packaging Regulations, PP in food contact must conform to IS 10910, with an overall migration limit of 60 mg/kg.
Which Parts Suit a Plastic Container Making Machine of 150 t?
Parts with walls thick enough for conventional moulding suit it best: mugs, tumblers, jars, storage containers and their lids, in cavity counts that keep clamp under about 136 t. Thin-wall tubs fit in one cavity or with small footprints, while high-cavity thin-wall packaging belongs on specialised machines.
Clamp per cavity on a 150 t machine (round parts, 10% margin, a starting margin, not a rule)
| Part | Projected area per cavity | Clamp per cavity | Cavities that fit 150 t |
|---|---|---|---|
| PP mug, 85 mm rim, handle 8 cm² (factor 2 to 3) | 65 cm² | 20 to 30 t | 4 with a cold runner (see example) |
| PP jar or container, 120 mm (factor 2 to 3) | 113 cm² | 35 to 53 t | 2, or 3 at the low factor |
| Thin-wall 500 ml tub, 110 mm (factor 5 to 8) | 95 cm² | 74 to 118 t | 1, or 2 only at the low factor |
The projected area method behind these figures is explained in the applications article in this series. The factors come from SPE for PP and from PlasticsToday for thin-wall work.
Our view: buy a 150 t general-purpose machine for mugs, jars and household containers, not for high-cavity thin-wall packaging. The PlasticsToday author warns that adapting a conventional machine to thin-wall work is usually unwise, because clamp speed, platen stiffness and injection speed all fall short.
What Makes a Container Thin-Wall, and Why Does It Matter?
A part is thin-wall when its flow length is roughly 100 to 200 times its wall thickness. Such parts need injection pressures above about 2,100 kg/cm², very fast fill, high-flow resins and clamp factors of 5 to 8 US t/in², against 3 to 5 for conventional parts.
Take a 500 ml round tub gated at the centre of its base: melt travels about 55 mm to the edge and 70 mm up the side, 125 mm in all. At a 1.2 mm wall that is about 104:1; at 0.6 mm it is about 208:1, well into thin-wall territory.
The same article gives fill times under one second and injection speeds above about 76 mm/s, with many jobs near 152 mm/s. It describes thin-wall machines with accumulator-assisted clamps, extra-thick platens and smaller barrels, where the shot should use at least 40% of barrel capacity.
Moulds change too. The author recommends steels harder than P-20, as many support pillars as fit, venting on core and ejector pins as well as the parting line, and roughly double the ejector pins, each twice as large, because thin walls shrink little and grip the core.
How Do Mug Walls and Handles Affect Cycle Time?
Mugs have thicker walls than packaging and a handle that can be the thickest section, so cooling sets the cycle. Cooling grows with the square of wall thickness, as the junction box article in this series explains, which makes the handle the section to design first.
Core the handle into an I or C section rather than moulding it solid, keep its thickness close to the body wall, and gate the mug at the base centre so the melt fills the body evenly before it reaches the handle. A solid handle can add seconds to every cycle and leave sink marks where it meets the body.
Grade matters as well. Reliance lists its Repol H110MAS, a nucleated PP homopolymer for rigid packaging and houseware, at a melt flow rate of 11 g/10 min with a heat deflection temperature of 110 °C and a mould temperature of 20 to 50 °C. The cool mould range suits fast cycles on chilled water.
Hourly output is 3,600 divided by the cycle in seconds, times cavities, times the share of good shots. Clamp often allows more mug cavities than the barrel does, as the worked example below shows.
What Food-Contact Rules Apply to Containers and Mugs?
Under the FSSAI Packaging Regulations, 2018, plastics in contact with food must conform to the listed Indian Standards, such as IS 10910 for PP and IS 10146 for PE. Overall migration is limited to 60 mg/kg or 10 mg/dm², tested to IS 9845.
Colour is covered too: pigments must meet IS 9833, and food businesses need a certificate of conformity from an NABL-accredited lab for packaging in direct food contact. Reliance states that Repol H110MAS complies with IS 10910, but the finished, coloured part is what gets tested.
Recycled content pulls the other way. Polymerupdate reports that under the Plastic Waste Management Rules as amended on 31 March 2026, rigid plastic packaging must contain at least 30% recycled material in 2025-26, rising to 60% by 2028-29, with exemptions where FSSAI and similar rules restrict recycled content. Under the FSSAI rules, recycled plastics may be used for food as and when FSSAI frames standards for them.
What Should You Send for a Container or Mug Check?
Send the drawing or a sample, part weight, wall thickness at the thinnest and thickest points, rim diameter and height, the resin grade, the cavity count you want and your monthly volume. With those, clamp, shot and cycle can be checked together. See the 150 ton horizontal injection moulding machine page.
Frequently Asked Questions About Plastic Container Making Machines
Can a mug and its lid run in one family mould?
They can, but the two parts rarely fill alike. A thick mug body and a thin lid need different pressures and cooling times, so one part tends to flash or short while the other is right. Family moulds suit parts of similar wall and weight; otherwise separate tools give steadier quality.
Why do thin-wall containers need such fast injection?
A thin wall loses heat to the mould very quickly, so the melt front can freeze before the cavity is full. Filling in under a second keeps the melt hot enough to reach the rim. That demands high injection speed, high pressure and a resin with high flow, which conventional machines may not deliver.
Can recycled PP go into food containers in India?
Only where the rules allow it. The FSSAI Packaging Regulations permit recycled plastics for food contact as and when FSSAI frames standards and guidelines for them. The recycled-content targets under the Plastic Waste Management Rules also provide exemptions where food rules restrict recycled material, so check the current position for your product.
Does PP need drying before moulding containers?
PP absorbs very little moisture, so virgin pellets usually mould without drying. Masterbatch carriers, regrind stored in humid conditions or additives can bring in surface moisture, which shows as splay or bubbles. If those defects appear during the monsoon, try a short drying run before changing the process.
How many lid cavities can a 150 ton machine run?
Work it out from projected area. A 90 mm round PP lid is about 64 cm², needing roughly 20 to 30 t per cavity with a 10% margin. That allows about five to seven cavities before runner area. If the lid is thin enough to count as thin-wall, the higher factor cuts that sharply.
Related Articles
- What Can You Make on a 150 Ton Injection Moulding Machine?
- Three Screw Options on a 150 Ton Machine: Which One Fits Your Part?
- Moulding Junction Boxes and Housings on a 150 Ton Machine
Sources & References
- PlasticsToday, G. Tremblay (Sabic Innovative Plastics): Never too thin
- FSSAI: Food Safety and Standards (Packaging) Regulations, 2018, compendium
- Reliance Industries Limited: Repol H110MAS technical data sheet (July 2024)
- Polymerupdate, D. K. Jha: India eases plastic recycling regulations (8 April 2026)
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.
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