EVENT REVIEW PETplanet Insider Vol. 23 No. 04/22 www.petpla.net 33 Review of PETinar Tethered Caps: Design, Produce and Inspect! A well-tuned quartet by Heike Fischer On March 24th, 2022 PETplanet Insider presented its latest online conference. PETplanet invited speakers from three companies, Universal Closures, z-moulds and Intravis to talk about their experiences and assessments of the current situation of tethered caps. The three presenters, Mark Smith (Universal Closures), Michael Fink (z-moulds) and Sascha Baumanns (Intravis) know each other from joint projects that editor Ruari McCallion has already reported on in PETplanet Insider magazine. This well-tuned quartet gave a stimulating and highly informative performance at the event. Design tethered caps Mark Smith started his presentation with a brief introduction to the EU legislation (EU 2019/904), the Single-Use Plastics Directive (SUPD). He summarised that Article 6 of the SUPD sets rules for beverage bottles up to a volume of three litres. Specifically, he stated that unintended loss of caps or lids should be prevented from July 3rd, 2024 on, and that caps must be attached to the bottle. In concrete terms, this means that a 25N tear-off resistance must be given. Mark went on to talk about the pros and cons of existing closure sizes, such as PO 1881, most common for CSD, and the challenges of the new design for a tethered solution. Mark went on to say that in cooperation with Coca-Cola, Universal Closures has designed a solution for the new size GME 30.40, which can also be used for tethered applications. The GME 30.40 preserves the internal bore diameter of PCO 1881 but offers a weight reduction of ~1.2 g through external design optimisation and material elimination. Research on the GME 30.37 revealed that, despite the shortened neck, this design does not offer sufficient technical performance, especially regarding carbonated retension and opening performance, and it lacks the physical space required to accommodate ‘net zero’ closure tethering technology. Mark went on to ask if every closure and finish can be tethered? He pointed out that this is possible in principle, but that to design a tethered closure, the goal should be to find a zero-net solution that does not affect any key functions such as weight, capping application, manufacturing, tooling design and finally customer interaction. Universal Closures already have a lot of tethered solutions for many different applications. Mark presented two different closure solutions. First, he introduced the Eagle solution: a closure based on GME 30.40 with a screw top design, and which is useable for any beverage, including CSD. It meets requirements such as clearance to finish opening, a repeatable and intuitive operation as well as an opening self-holdback. Three principal challenges have been overcome: shell integrity for high CSD performance has been maintained, as have the finish clearance before tether articulation and the compatibility with capping system and cross closure. “A key part of achieving a Mark Smith, Technical Director & VP at Universal Closures Michael Fink, VP Sales & Marketing at z-moulds Sascha Baumanns, Head of Sales at Intravis PETINAR
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