150 ton injection moulding machine applications: largest projected area by tonnage factor
| Tonnage factor (US t/in²) | Where cited materials sit | Largest projected area at 150 t, 10% margin (a starting margin, not a rule) | Roughly a square of |
|---|---|---|---|
| 2 | Low end for PP, PE and ABS | 485 cm² | 22 × 22 cm |
| 3 | Upper end for PP, low end for general PC | 323 cm² | 18 × 18 cm |
| 4 | Upper end for ABS | 242 cm² | 15.6 × 15.6 cm |
| 5 | Upper end for general PC | 194 cm² | 13.9 × 13.9 cm |
| 8 | Top of the general 2 to 8 range | 121 cm² | 11 × 11 cm |
A 150 t machine can make any part whose projected area, multiplied by the resin's tonnage factor, stays under about 136 t once a 10% margin is held back. That window can take in larger irrigation fittings and valves, appliance and meter housings, junction boxes, storage containers, mugs, lids and multi-cavity closures. The resin sets the size limit, as the table shows.
Projected area is the shadow the part casts on the parting line, plus any cold runner, minus holes that pass right through.
Key Takeaways
- Clamp needed equals projected area times tonnage factor. With a 10% margin, 150 t covers about 485 cm² at a factor of 2 and about 121 cm² at a factor of 8.
- PP sits at 2 to 3 US t/in², an ABS grade at 2 to 4 and a general PC grade at 3 to 5, so one mould can fit in PP and fall short in PC.
- The 150 t class earns its place on jobs needing roughly 90 to 136 t. Lighter jobs may run at lower cost on a smaller press.
- Larger irrigation valves and quick-coupled fittings follow BIS standards such as IS 18286 and IS 17425, and their bigger sizes can outgrow a 100 t clamp.
Which 150 Ton Injection Moulding Machine Applications Fit Best?
The best fits are parts that need roughly 90 to 136 t of clamp after the margin. Below about 90 t, a 100 t press can often run the same mould with less power. Above 136 t, flash and mould damage become real risks, so choose a larger press.
Cavity count moves the answer more than product name. Four cavities needing 30 t each sit inside the window; six do not. If you plan to add cavities later, size for the final count.
Clamp is only one of three fits. The mould must pass between the tie bars, its shut height must sit inside the machine's minimum and maximum mould thickness, and deep parts such as containers need enough opening stroke to drop clear. Check all three on the data sheet before cutting steel.
Our view is plain: a 150 t general-purpose machine suits medium parts in commodity and engineering resins, and is a poor buy for high-cavity thin-wall packaging. Thin walls call for much higher clamp factors and faster machines, as the containers and mugs article in this series explains.
How Do You Check Whether Your Part Fits 150 t?
Measure the projected area of one cavity and subtract through-holes. Multiply by the number of cavities and add the cold runner area. Multiply that total by the resin's tonnage factor, then add your margin. If the result stays under 150 t, the clamp side of the job fits.
This is the method RJG trainer Jeremy Williams sets out in Plastics Technology, with 3 US t/in² recommended as a starting point when nothing better is known. He lists what pushes the factor up or down: melt flow, flow length, wall thickness, gate size, gate location, the number of gates and the volume of resin.
Flow length against wall thickness is the one to watch on medium parts. Williams suggests an aspect ratio below 150:1 carries a low risk of sinks, short shots and dimensional trouble. A long, thin housing wall can therefore need a higher factor than its resin alone suggests.
More clamp is not safer. Williams describes a mould needing about 100 t that was clamped at the 400 t maximum; its cavity block split in two places. SPE's Plastics Engineering magazine adds that excess force can crack cylinder mounting plates and even fracture the machine frame. Set clamp from the calculation.
Published factors are in US t/in², and 1 US t/in² is about 0.14 metric t/cm². The shot must also suit the barrel, which the screw options article in this series covers.
Which Materials Change What a 150 t Machine Can Make?
Melt viscosity changes the answer most. SPE's Plastics Engineering magazine places tonnage factors between 2 and 8 US t/in², with polyethylene at the low end, polycarbonate toward the top and PP at 2 to 3. A part that fits easily in PP may not fit in PC.
ABS sits between them. INEOS lists 2 to 4 US t/in² for its Lustran ABS 248, a grade it names for small appliance housings and toys. On 150 t with the margin, that range moves the largest ABS part from about 485 cm² down to about 242 cm².
For polycarbonate, a Bayer MaterialScience (now Covestro) datasheet for Makrolon 2558 gives 3 to 5 US t/in². That puts the largest general PC part on 150 t at about 323 cm² down to 194 cm², roughly two thirds of the PP figure.
Where you have no factor at all, the SPE article offers 400 bar of cavity pressure as a guide value. That is about 408 kg/cm², or 0.41 t/cm², close to the 3 US t/in² starting point above. Do not compare melt flow index across resin families, though: Williams notes PC moulds as a viscous resin whatever its MFI.
Which Indian Standards Shape Larger Fittings and Valves?
Micro-irrigation parts are covered by BIS standards that fix sizes and tests before any machine is chosen. The BIS compendium lists IS 17425 for quick-coupled PE pipes and fittings from 40 to 200 mm outside diameter and IS 18286 for manually operated plastics valves from DN 8 to DN 110.
The upper sizes in those ranges are where a 150 t clamp can earn its keep. A valve body near DN 110 or a coupler for a 160 mm pipe has a large projected area in a stiff resin, and the clamp, mould size and shot all grow together. Small emitters to IS 13487 sit at the other end, where cavity count decides.
Electrical boxes follow their own standard and Quality Control Order, covered in the junction boxes article in this series.
What Should You Send to Check Your Part?
Send the part drawing or a sample, the resin grade, the number of cavities, the runner type, the mould's outside size and shut height, and your monthly quantity. With those, projected area, clamp and shot can be checked before any machine is named. See the 150 ton horizontal injection moulding machine page.
Frequently Asked Questions About 150 Ton Injection Moulding Machine Applications
Is a 150 ton machine just a larger 100 ton machine?
Not quite. The clamp is half as strong again, but the platens, tie-bar spacing, mould height range, opening stroke and screw options usually change too. Those decide whether your mould fits physically and whether the shot suits the barrel. Compare the full data sheets, not the clamp figure alone, before moving a job up.
How do I measure projected area from a sample part?
Place the part with its opening direction facing you and trace its outline on squared paper, or take the area from the CAD model viewed along the mould opening axis. Subtract any holes that pass right through, then add the cold runner. Multiply by the cavity count for the total.
Can a 150 ton machine run a mould built for a smaller press?
Often, provided the mould is thick enough for the minimum mould height, the locating ring and sprue suit, and the ejector pattern lines up. Set the clamp force to what the mould needs, not the machine maximum, because over-clamping a small mould can crush vents and crack cavity blocks.
What cavity pressure should I assume with no data?
An SPE Plastics Engineering article gives 400 bar as a guide value when no material data is available. That works out to about 0.41 t per cm² of projected area. Treat it as a first estimate only, and replace it with the resin supplier's figure or a filling study once you have them.
Does a thicker wall need more clamp?
Usually less, not more. Thicker walls let melt flow with lower pressure, so the tonnage factor can fall. Thin walls with long flow paths need higher pressure and a higher factor. The trade-off is cooling: a thicker wall cools much more slowly, so the cycle and cost rise even if the clamp need drops.
Related Articles
- Three Screw Options on a 150 Ton Machine: Which One Fits Your Part?
- Moulding Junction Boxes and Housings on a 150 Ton Machine
- 150 Ton Machine for Small Containers and Mugs
Sources & References
- Plastics Technology, J. Williams (RJG): Clamp Tonnage: More Is Better...Right?
- Plastics Engineering (SPE), A. Urbina: Mastering Clamping Force Calculation
- INEOS ABS via UL IDES: Lustran ABS 248 technical data sheet
- Bureau of Indian Standards: Compendium of Indian Standards: Micro-Irrigation Systems
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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