PET preforms - repurposing production for COVID-19 test kits

  • Mecmesin

One thing, which has characterised the fight against COVID-19 has been the ingenuity and innovation shown by manufacturers to repurpose their own mass-production facilities to make essential items. Everything from Personal Protective Equipment (PPE) to medical ventilators, through to COVID-19 testing kits - a fact recognised by Coca-Cola executives when approached to plug a gap in the supply chain.

Southeastern Container, a co-operative of Coca-Cola bottlers, makes PET preforms for the network of bottlers in the US and Canada, They adapted a standard 20oz bottle-preform to become a small ruggedised vial suitable for Coronavirus test specimens. Its size lent itself perfectly to holding the long COVID-19 swab and the tamper-proof screw-closure provides a safe seal to prevent leakage during handling and transportation. Leveraging production capacity at their plants would significantly boost supply by providing up to 7 million 'preform test tubes' per week for use by testing companies around the USA.

In their conventional use, PET preforms are typically blow-moulded to create the ubiquitous plastic bottles containing carbonated and still beverages. The production process to fill and seal these bottles with a screw-cap is a demanding one, so a number of tests are performed to ensure quality control specifications are met for this core packaging. These tests are conducted in accordance with in-house company standard methods or to internationally recognised test standards.


  • Motorised or software-controlled top-load tester
  • Appropriately-rated loadcell
  • Vented compression plate
  • Software-controlled torque testing system
  • Cap mandrels

Top-load Axial Strength Test

To make sure that the plastic bottle can withstand the forces encountered when the screw-cap is pushed down onto it after the filling process and later when it is stacked in the warehouse, an axial compressive strength test is performed. Test standards based on ISBT (Standard Test Methods for PET Bottles) and ASTM D2659 (Column Crush Properties of Blown Thermoplastic Containers) are commonly adopted by manufacturers.

Mecmesin's top-load testers are in wide use by many packaging manufacturers and contract bottlers. Their simplicity and affordability make them the test equipment of choice for installing in the QC lab or next to the production line.

Torque Test

When it come to checking the strength required to effectively seal the bottle when applying the screw-cap closure whilst ensuring it can still be easily opened by the consumer, a Mecmesin torque tester is a popular solution. Testing in accordance with in-house methods and international standards such as ASTM D2063 and ASTM D7860 is assured.

Test equipment

  • Top-load Testers
  • Torque Testers
  • Wide range of standard accessories
  • Mecmesin can 3D-print custom-fit fixtures, such as cap mandrels for exact matching to component geometry

Test standards

ASTM D2659
Standard Test Method for Column Crush Properties of Blown Thermoplastic Containers

ASTM D2063/D2063M
Standard Test Methods for Measurement of Torque Retention for Packages with Continuous Thread Closures Using Non-Automated (Manual) Torque Testing Equipment

ASTM D7860-14
Standard Test Methods for Measurement of Torque Retention for Child Resistant and Non-Child Resistant Packages with Continuous Thread Closures Using Automated Torque Testing Equipment


  • Intuitive software to apply bespoke procedures or international standards
  • Pre-programmed test routines for QC checks at point-of-manufacture
  • Consistent output of calculated results and Pass/Fail indication
  • Extensive reporting to log results for audit purposes

See also

Cosmetic packaging pull-off test

A bench-top testing system was required to repeatably test the pull-off force on a variety of cosmetic containers. The system needed to allow a relatively high volume of containers to be tested with the minimum level of training required for users. Mecmesin's solution avoided the risk of damaging the loadcell by excessive torque on tightening the collet grip, and the lipstick barrel was first inserted in the grip and then connected to the gauge by a flexible chain-link.

Food packaging made from thermoformed plastics and intended for freezing, requires testing to ensure optimum functionality when closing and sealing the container. The closing effort of the lid is measured by using a motorised force tester controlled by software together with a custom-designed fixture to hold standard-sized ice cream tubs. In addition the ‘top-load’ crush strength of the container itself can also be tested on the same machine to guarantee it is rigid enough to avoid buckling and spillage when the lid is applied.

Mecmesin develops Combi Cork-i Extraction Tester for leading Scottish whisky

To improve the quality and storage of a premium product, the R&D team at a leading Scottish whisky maker needed to optimise the design of their bottle stoppers. They decided that the strength and performance of their reusable stoppers could be ensured by systematic testing of the characteristics of both portions of the stoppers. Working closely with the R&D team, Mecmesin developed the Combi Cork-i Extraction Tester, an innovative multi-function cork extraction testing system that tests both phases of de-corking synchronously.

Greek beauty product manufacturer guarantees production quality by updating to Mecmesin's digital torque testers

A manufacturer of a wide range of skin, hair-care, make-up and sun-care products based in Greece needed to replace their outdated torque testers with up-to-date digital torque testers to guarantee production quality and to ensure their products remained sealed. Mecmesin supplied the company with two Tornado 10N.m digital torque testers, which have the ability to test tamper-evident closures, an intrinsic part of their specification.

  • Jo Webb
  • Product Info
  • English
  • Created 19 Jun 2020
  • Modified 14 Aug 2020
  • Hits 107