220 ton PET machine applications: product groups and the first check for each
| PET product | What matters most | First check on a 220 t machine |
|---|---|---|
| Water and soft drink bottle preforms in high cavity counts | Low acetaldehyde for water, a neck that matches the closure | Cavities that fit between the tie bars, and injection rate for all of them |
| Edible oil and larger bottle preforms | Heavier shots and longer bodies | Shot against the barrel, and opening stroke against preform length |
| Hot-fill juice bottle preforms | A resin grade made for hot fill | Cooling and cycle on a thicker neck |
| Wide-mouth jar preforms | Large neck diameter | Projected area per cavity, the one case where clamp can bind |
| Pharma, cosmetic and FMCG bottle preforms | Colour, clarity, many neck finishes | Changeover time and purge between colours |
The 220 ton PET machine applications that fit best are high-volume water and soft drink preforms in many cavities, edible oil and larger bottle preforms, hot-fill juice preforms, wide-mouth jar preforms and FMCG bottle preforms. For narrow-neck bottles, mould width, shot and injection rate set the cavity count. Clamp only binds on wide-neck jars.
Below you will find each product group, the point where clamp becomes the limit, how a neck finish change affects the moulds you buy, and the Indian rules for food and water bottles.
Key Takeaways
- A 220 t clamp has room for far more narrow-neck preform cavities than most moulds can fit between the tie bars.
- Wide-mouth jar preforms are where clamp starts to decide cavity count, because projected area grows with the square of the neck diameter.
- Moving from the PCO 1810 neck to PCO 1881 saves about 1.3 g of PET per preform but means new preform and closure moulds.
- Food and water bottles fall under the FSSAI Packaging Regulations, which call for PET to IS 12252 and at least 85% transparency for drinking water bottles.
Which 220 Ton PET Machine Applications Fit Best?
Jobs that need volume or size fit best: water and soft drink preforms in high cavity counts, edible oil and larger bottle preforms with heavier shots, and wide-mouth jar preforms in modest counts. Small pharma preforms can run here too, but a smaller machine often suits them better.
The reason is the barrel. A small shot in a large barrel stays hot for longer, and PET picks up acetaldehyde and loses viscosity as it waits. The screw options article in this series explains how screw size changes this.
Edible oil and larger bottle preforms bring a different check. Bruce Catoen's machine sizing guide in MoldMaking Technology puts the opening stroke at no less than 2.5 times the part height. A long preform also needs room to clear its core and open the neck splits, so ask the mould maker for the stroke the tool needs.
Our view: a 220 t PET machine earns its cost on cavities and shot weight, not on clamp. If your products are small preforms in small batches, spend the money on a smaller machine and a second mould.
When Does Clamp Become the Limit at 220 t?
Clamp becomes the limit on wide-neck preforms. A preform mould sees each cavity end-on, so the projected area is the circle of its widest diameter. For a narrow bottle neck that area is small. For a jar, it grows with the square of the diameter, and clamp starts to count.
The method comes from John Williams of RJG, writing in Plastics Technology: projected area of one part times the cavities, plus any cold-runner area, times a tonnage factor. He gives typical factors of 2 to 10 tons/in². A hot runner preform mould counts only the cavities, as there is no cold runner.
Take a 33 mm support ledge. At an assumed 5 US tons/in² and a 10% reserve (a starting margin, not a rule), a 220 t clamp covers about 33 such cavities. Jar preforms are another matter, as the worked example below shows. The higher-cavity article in this series covers what limits narrow-neck moulds instead.
Does a Neck Finish Change Affect What You Can Run?
Yes, through your moulds. A lighter neck such as PCO 1881 saves resin on every preform, but it needs new preform moulds and new closure moulds. On a 220 t machine running many cavities, the saving per preform multiplies quickly, and so does the retooling cost.
A Packaging Digest column by Anton Steeman sets out the numbers for 250 ml to 2 litre soft drink bottles. The PCO 1881 neck weighs about 3.8 g against 5.1 g for PCO 1810, and is 17 mm tall instead of 21 mm. The standard 28 mm closure also gets about 0.5 g lighter.
The same column notes that adoption is voluntary and that bottling plants can face conversion costs of up to EUR 250,000. Agree the neck finish with your bottler and closure supplier before you order a high-cavity mould.
Which Indian Rules Apply to Food and Water Preforms?
The FSSAI Packaging Regulations 2018 apply to bottles that will hold food, drinks or drinking water. PET in food contact must conform to IS 12252, and packaged drinking water bottles need at least 85% transparency. Your buyer will ask for test records from an accredited lab.
The regulations set an overall migration limit of 60 mg/kg or 10 mg/dm², tested to IS 9845, and require pigments to meet IS 9833. Food businesses need a certificate of conformity from an NABL-accredited lab for packaging in direct food contact, so keep resin lot records with each batch.
Recycled PET in food contact is allowed only as and when FSSAI frames standards and guidelines for it. Check the current position before you plan rPET in a food preform.
What Should You Send to Check a PET Product on 220 t?
Send the preform drawing with weight, length, neck finish and largest outer diameter, the resin grade, the cavity count you want and the bottle it will become. With those, clamp, stroke, shot and mould fit can be checked in one pass. See the 220 ton PET injection moulding machine page.
Frequently Asked Questions About PET Products on a 220 t Machine
Can a 220 t machine make preforms for 5 litre bottles?
It can, if the preform weight sits within the barrel's healthy range and the opening stroke clears the long body and core. Clamp is seldom the issue for a narrow neck. Send the preform weight and length so the shot and stroke can be checked against the cavity count you want.
Is a 220 t machine too big for small pharma preforms?
Often it is. A small shot in a large barrel spends longer at melt temperature, which raises acetaldehyde and IV loss. If small pharma preforms are a minor share of your work, run them on a smaller machine and keep the 220 t press on volume preforms.
Why does a jar preform need so much more clamp than a bottle preform?
Projected area grows with the square of the diameter. A 70 mm jar neck has about 4.5 times the area of a 33 mm support ledge, so each jar cavity uses as much clamp as four or five bottle cavities. Clamp is the first check for jars.
Should I switch my moulds to the PCO 1881 neck?
Only if your bottlers and closure suppliers are moving too. The neck saves PET on every preform, but it needs new preform moulds, new closure moulds and changes at the bottling plant. Agree the finish with your buyers before you order a new high-cavity mould.
Do hot-fill juice preforms need a special resin?
Yes. Hot-fill bottles use resin grades made for higher neck and body crystallinity so they hold their shape when filled hot. Ask your resin supplier for the hot-fill grade and its processing window, and confirm the bottle tests with your buyer before trials.
Related Articles
- Higher-Cavity Preform Moulds on a 220 Ton Machine
- Three Screw Options for PET on a 220 Ton Machine Explained
- Hot Runner Preform Moulds: What the Machine Must Provide
Sources & References
- Plastics Technology, J. Williams (RJG): Clamp Tonnage: More Is Better...Right?
- MoldMaking Technology, B. Catoen: Machine Sizing and Specification for Optimal Mold Performance, Part 1
- Packaging Digest, A. Steeman: Short, Shorter, the Shortest
- Food Safety and Standards Authority of India (FSSAI): Food Safety and Standards (Packaging) Regulations, 2018, compendium
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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