Significant recent and on-going investment ensures world class capability.

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Research & development

Continually pushing the boundaries ensuring we stay at the forefront of PET
The laboratory


The Laboratory

Esterform is the only UK independent polyethylene terepthalate (PET) preform and bottle supplier with a true on-site PET analysis facility. This facility was originally opened to provide internal quality assurance for Esterform products.

The Laboratory is responsible for ensuring the quality and consistency of the Esterform brand, throughout the production-supply chain. The laboratory’s unique system of primary and secondary analysis ensures total quality control from production through to delivery.

Externally, PET analysis is offered to Esterform’s customers. This gives an exceptional level of service, offering customers the opportunity to discuss any aspect of PET properties or performance with a member of the technical department.


New materials


New materials

Our laboratory is a critical resource in supporting new product development. Frequently our clients have specific performance requirements that can be supported by the use of specific grades of PET or additives. The Esterform laboratory can provide the detailed empirical testing that ensures the pack performs to meet these needs.

Barrier technology is always a critical issue, especially when working on glass replacement projects. To date, Esterform has focused on monolayer barrier additives to prevent UV light degradation; and additives that enhance the shelf life of the filled product by reducing the ingress of oxygen, and the egress of carbon dioxide.

Esterform’s technical team is always investigating new materials that might be suitable for future development. If you have specific performance criteria, which challenges standard materials please get in touch to discuss them with the Esterform team


Post-consumer PET &

Post-consumer recycled (PCR)
PET & Plant Based Materials

Esterform’s in-house blending facility enables us to offer customised levels of  post-consumer recycled PET (RPET) in our products. Only food contact grades from approved sources are used by Esterform, and subject to minimum batch sizes we can set specifications to support your brand ethics

The polymer industry is experimenting with the new plant based intermediate materials (bioMEG and bioPTA) that can be used to produce PET. Waste vegetation such as husks and bark and other cellulosic materials is being targeted for the production of these vital intermediates. Production capacity for them is extremely limited at present, but we are keeping track of developments for the future.


Frequently asked questions

FAQs all about Polyethylene Terephthalate (PET) preforms, bottles and jars
What is a preform?

A preform is the first stage in the production of a PET container. PET needs to be heated and stretched to make it strong and flexible. The first part of the production process for a PET bottle or jar is to injection mould a “test tube” like part, called a preform. The neck of the preform remains the same but the body of the preform is heated and stretched inside a mould to form the container shape. This normally occurs at a later date on a reheat blow moulding machine.

How is PET made?

Ethylene glycol (MEG) and terephthalic acid (TPA) react with a catalyst at a high temperature and high pressure, to produce clear amorphous PET. The amorphous PET is then further solid state polymerised, to increase its molecular weight and viscosity.

At what temperature can PET containers be filled?

Standard PET bottles can withstand filling temperatures of a maximum of 54 degrees Celsius (54°C). However, liquids contract on cooling, causing a vacuum inside a sealed container. Bottle design must therefore play an important part in preventing bottle distortion and panelling of the cooled bottle.

Does PET contain any harmful chemicals?

No. PET does not contain any harmful chemicals or substances.

Other types of plastic may contain chemicals such as Bisphenol A (BPA) and phthalates, but these chemicals are not used at any stage of the PET bottle manufacturing process.

Is PET food contact safe?

Yes. Esterform PET bottles are well within the limits set out in the European Union regulations for plastic materials and articles intended to come into contact with food. (EU 10/2011). Esterform also regularly checks to ensure it is complying with the latest European guidelines.

Can PET be recycled?

Yes. PET is widely recycled, and Esterform uses some of this recycled PET material to make new bottles.

Does Esterform produce caps and closures?

No. Esterform only makes PET bottles, jars and preforms.

Does Esterform make bottles from any other materials?

No. Esterform only uses PET in its manufacturing operation.