Packaged drinking water bottles. Carbonated soft drink bottles. Juice and iced tea bottles filled hot. Wide-mouth jars for food and household goods. Bottles for cosmetics, hair oil, disinfectants, pharmaceuticals and agrochemicals. These are the main PET injection moulding applications, and every one of them starts as a preform made on a PET injection moulding machine. The machine moulds the preform with its neck finished; a blow moulding step turns it into the container. What changes between applications is the resin grade, the neck, the preform size and the rules the pack must meet.
Key Takeaways
- PET preforms feed water, carbonated drink, hot-fill, food, FMCG, pharma and agrochemical containers. Each has its own resin grade and neck.
- Still water is the most sensitive to acetaldehyde; carbonated drinks need neck finishes that hold pressure; hot fill needs heat-resistant grades.
- Wide-mouth jar preforms have large neck ledges, so the same clamp holds far fewer jar cavities than water preform cavities.
- In India, food-contact PET falls under FSSAI packaging rules, and rigid plastic packaging faces rising recycled-content targets under the PWM Rules.
Which containers start as PET preforms?
Bottles and jars for water, carbonated drinks, juices, foods, cosmetics, hair oil, disinfectants, pharmaceuticals and agrochemicals start as preforms. Resin makers offer separate bottle grades for these uses, because hot fill, carbonation, reheat speed and barrier needs differ from one container to the next.
PET injection moulding applications with example Indian resin grades
| Application | Example Relpet grade (Reliance) | What it asks of the preform |
|---|---|---|
| Still packaged drinking water | G5761 | Low acetaldehyde for taste; clarity |
| Carbonated soft drinks | G5841 | Neck finish that holds pressure |
| Juice, iced tea, isotonics (hot fill) | H7761 | Higher neck and body crystallinity |
| Foods, cosmetics, hair oil, disinfectants, pharma | G5801 | General purpose bottle grade |
| Aerated drinks needing fast blowing | QH5821 | Fast reheat in the blow moulder |
The grade list shows how far applications split. Reliance lists G5761 for still water, G5841 for aerated drinks and agrochemicals, H7761 for hot fill with higher neck and body crystallinity, and QH5821 as a fast-reheat grade that speeds up the blowing step. Grade choice sits with the brand owner and the resin supplier, but it changes drying, melt settings and cycle on the preform machine.
How do PET injection moulding applications change the preform and mould?
Each application changes the neck, the wall and the cavity count. Water preforms are light with short necks; carbonated drink preforms need necks that seal under pressure; jar preforms have wide necks and large ledges. The mould, cavities and machine size all follow from those choices.
Water is the most taste-sensitive. Still water shows acetaldehyde that sugar would mask in a soft drink, so water preforms call for short melt time and moderate melt temperature; the first article in this series explains why.
The neck finish is the clearest example of an application driving the mould. On 250 ml to 2 litre soft drink bottles, the PCO 1881 neck was introduced to replace the older PCO 1810. The PCO 1881 neck weighs about 3.8 g against 5.1 g, is 17 mm tall instead of 21 mm, and uses two thread starts instead of three. It saves about 1.3 g of PET per preform and about 0.5 g per closure. Adoption is voluntary, and conversion means new neck inserts on the preform mould and new closure moulds.
Hot-fill bottles take contents above the temperature at which ordinary PET softens, so they use grades with higher crystallinity in the neck and body. Jars change the arithmetic of the mould: a 70 mm jar ledge has about 4.5 times the area of a 33 mm water ledge, so the clamp fills up after far fewer cavities.
Where a plant makes FMCG, pharma or agrochemical bottles, runs can be shorter and colours more varied than on a water line. That puts weight on mould change time, colour purge between jobs and a barrel that suits a wide spread of preform weights. The specifications article in this series covers when a second screw and barrel make sense.
Our view: for a new preform plant, fix the neck finish and the preform list before you choose a machine. The neck decides the mould, and the mould decides the machine.
Which Indian rules apply to PET bottles and jars?
Food and beverage PET must meet the FSSAI Packaging Regulations, 2018, which call for PET to conform to IS 12252. Rigid plastic packaging also falls under the Plastic Waste Management Rules, whose 2026 amendment set recycled-content targets rising from 30% in 2025-26 to 60% by 2028-29.
The FSSAI regulations set an overall migration limit of 60 mg/kg or 10 mg/dm², tested to IS 9845, and ask food businesses for an NABL lab certificate for packaging in direct food contact. For packaged drinking water bottles they list PET among permitted plastics and require transparency of at least 85%.
The recycled-content targets carry an exemption where FSSAI and similar rules restrict recycled material. Recycled plastics in food packaging are allowed as and when FSSAI frames standards and guidelines for them. Check the current position with your customer before quoting a food-contact preform with recycled content.
The amendment, notified on 31 March 2026, also brings reuse targets for rigid packaging and lets shortfalls for 2025-26 be carried forward for up to three years. Penalties run from ₹10,000 to ₹15,00,000. For a preform maker, this matters through the brand owners who buy the preforms and must meet the targets.
How do you match a PET machine to your application?
List the containers you will make, with neck finish, preform weight and contents. Group them by neck size, because each group may need its own mould and cavity count. Then size the clamp and barrel per group. See the PET injection moulding machine range for the next step.
Frequently Asked Questions About PET Injection Moulding Applications
Can one PET machine make both water and carbonated drink preforms?
Yes, with the right moulds, provided neck finish, preform weight and cavity count suit the clamp and barrel. Each neck finish needs its own neck inserts or mould. A barrel sized for heavy preforms may hold light water preforms too long, so check the shot against the barrel for each job.
What is the PCO 1881 neck finish?
PCO 1881 is a short neck finish for soft drink bottles introduced to replace PCO 1810 on 250 ml to 2 litre bottles. It weighs about 3.8 g against 5.1 g and saves about 1.3 g of PET per preform. Adoption is voluntary and needs new neck inserts and closure moulds.
Which Indian standard covers PET for food packaging?
The FSSAI Packaging Regulations, 2018 list IS 12252 for PET and PBT used in contact with food. They also set an overall migration limit of 60 mg/kg or 10 mg/dm² tested to IS 9845. Packaged drinking water bottles must have transparency of at least 85%.
Are recycled PET preforms allowed for food in India?
Recycled plastics may be used for food packaging as and when FSSAI frames standards and guidelines for them. The PWM recycled-content targets carry an exemption where FSSAI rules restrict recycled material. Check the current FSSAI position and your customer requirements before quoting recycled content for food contact.
Why do hot-fill bottles need a different PET grade?
Hot-fill bottles are filled with hot juice, iced tea or isotonic drinks, which can soften ordinary bottle-grade PET. Hot-fill grades such as Relpet H7761 are listed with higher neck and body crystallinity to resist that heat. The preform mould and blowing process are set up for the grade.
Related Articles
- What Is a PET Injection Moulding Machine?
- How Is a PET Preform Made?
- PET Injection Moulding Machine vs Standard Horizontal Machine
- Important Specifications to Consider Before Buying a PET Injection Moulding Machine
Sources & References
- FSSAI: Food Safety and Standards (Packaging) Regulations, 2018, compendium
- Polymerupdate, D. K. Jha: India eases plastic recycling regulations (8 Apr 2026)
- Packaging Digest, A. Steeman: Short, Shorter, the Shortest (Jan 2014)
- UL Prospector: Polyester: Relpet grade listing
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.
Limitation of Liability: Pratishna Engineers makes no representation or warranty, express or implied, regarding the completeness, accuracy or suitability of the information for any particular application. To the extent permitted by applicable law, Pratishna Engineers shall not be liable for any loss, damage, cost or consequence arising from reliance on or use of the information contained in this document. Final machine selection, configuration and application suitability should be confirmed with Pratishna Engineers based on complete and accurate project requirements.
