Around the world, health has taken priority over sustainability. As we begin to cautiously emerge from the pandemic, Nigel Flowers, Managing Director of Sumitomo (SHI) Demag examines how brands can move forward with their sustainable packaging initiatives and discusses the consumer behaviours and attitudes towards single use packaging that may stick around in the foreseeable future.
In the early days of the COVID-19, sentiments towards sustainability diminished. Although this was anticipated to be a short-term shift, concerns around hygiene, sanitation, cross-infection and the protection of health took priority. Initiatives like bring your own containers and resusable coffee cups were suspended. Substrate choices veered back to the ‘perceived’ enemy - plastic. The big question facing packaging producers now is how much consumers in the future will be prepared to trade off product safety, security and hygiene against sustainability and whether there is a middle ground.
For several decades now light-weighting and consumer convenience have given packaging manufacturers the strong commercial incentive to do more with less. No strangers to responding to demographic and lifestyle changes and balancing a wide range of variables, including cost, increased strength, recycle rates and functional requirements, lightweight formats have become the industry norm. Especially in food and medical packaging. More recently, the market has been moving more towards novelty solutions that improve performance, functionality and shelf impact.
Most companies operating in this competitive arena produce millions of packaging containers, caps and closures every year. Volume, raw material waste and precision are fundamental to each packaging manufacturers’ financial viability, with many facilities operating 20+ machines to meet supplier demand.
To successfully succeed in the thin walling arena, injection moulders need to examine every potential application to ensure that the selection of materials, machine and tooling give the optimum blend of speed, quality and consistency.
Until March, eschewing plastic was the campaign of the day. The tide was turning. And I’m in no doubt that public rallying for circular packaging will resume in the next six months. Attitudes and actions will inevitably shift again.
What this pandemic has clearly illustrated however, is the context in which decisions about packaging need to be made. Exploiting people’s fears about reinfection and sanitation should not be used as an argument to revert or redefine legislation. Understandably, the UK’s ban on plastic straws, cotton buds and stirrers has been delayed for six months by DEFRA until October 2020. This is a temporary measure, but concurrently must not threaten progress towards more sustainable packaging.
As a material, plastic is inextricably linked with energy and resource savings. Its low weight makes it both cost effective and flexible to use, adding to the sustainability score when measuring environmental, social and governance (ESG) performance. If anything, this pandemic has presented retailers, brand owners and packaging manufacturers with the opportunity to review, realign and reinforce the value of their packaging.
From a machinery performance viewpoint, thinner wall sections bring changes in processing requirements. Among them, higher pressures and speeds, faster cooling times, and modifications to part-ejection and gating arrangements. These process changes need to be factored into the mould, machinery, and packaging component design.
Even when using less raw material, packaging forms the protective layer so still needs to be engineered to provide strength. Choosing the best machine for your packaging application is critical. Understanding the melt stability and how the plastic will perform as an end product should form the basis of all decisions.
To support these efforts, Sumitomo (SHI) Demag continues to pioneer the development of packaging machines. The company’s El-Exis SP range, available globally, now comprises 10 machines, with a clamp force range of between 150 and 1,000 tons.
Capable of delivering dry cycle times of less than two seconds, the latest generation of EL-Exis SP’s are specifically designed to withstand the higher stresses and injection pressures that are so critical in achieving repeatability, particularly in thin walling. This range is aimed squarely at high volume manufacturers of polymer products, including caps and closures, thin wall containers and lids.
With the introduction of a new control valve regulating the hydraulic pressure during the loading of the accumulator, the range consumes up to 15% less energy that previous generations of El-Exis machines. These savings are dependent upon the packaging application, moulding cycle time and process parameters.
Additionally, all-electric drives set a new benchmark for achieving absolute processing precision, accuracy and dynamics. These are essential criteria in the quest to achieve the highest process consistency, as well as reducing scrap to a minimum during start-up and during ongoing production. The fast and precise response of these direct drives also enables special processes to be implemented with pinpoint accuracy, opening up new possibilities for packaging moulders.
Ahead of our time
Like any other business, economic viability is just as important a consideration for packaging moulders. Low unit costs, high output coupled with energy savings all need to be factored in. That’s why so many packaging manufacturers today are prepared to invest in new high-performance plant.
Increasingly, packaging moulders are looking to injection machinery suppliers to provide turnkey solutions, including robotic product handling, advice with tooling, training and testing and all the know-how and support that underpins efficient manufacturing.
Automated vision quality control is one area where significant advances have been made. At K-2019, we showcased our fastest closure turnkey exhibit to-date featuring the inspection Capwatcher Q Line from Intravis. Comprising eight high-resolution cameras, this technology collects, visualises and provides up to 144,000 cavity-based measurements per minute. It also sources a unique inline temperature measurement for each closure, which allows moulders to determine the shrinkage behaviour of each and every closure. From a quality control perspective, this is groundbreaking stuff and significantly reduces production waste.
Another way to achieve thinner yet stronger packaging containers is to apply injection compression techniques to stack moulds. With this, packaging moulders can increase output while reducing the wall thickness of containers and lids from 0.45mm to 0.35mm. This saves around 25% in raw polypropylene materials compared to the standard injection moulding process, while maintaining comparable mechanical properties.
Completing the chain of custody
Sustainability and production efficiency is also intrinsically linked to skills. As we reopen our society, resource efficiency has probably superseded sustainability as an immediate priority. Attracting new people with the appetite for innovation is as critical as ever.
Workforce and skill shortages can have a profound impact on cost, overruns and quality. Demands to create smaller, lighter parts have made thin-wall moulding one of the most sought after capabilities in the injection moulding community.
In mid-June the company reopened its training facility doors. To further assist moulders of all sizes and sectors, this July Sumitomo (SHI) Demag will also host a free series of Webinars covering some of the basic principles of injection moulding. The first discusses how to calculate a correct clamping force
Packaging businesses we are in daily contact with are very much back to business. Nevertheless, the pandemic has forced another re-think to our way of living and future reliance on packaging. While food and medical packaging saw rises in demand, other categories softened.
Responding to a pandemic of this scale will always be a series of educated guesses. I’m personally encouraged to hear how packaging moulders are flexing to this unknown landscape and acknowledging the fragility as well as the resilience of their product portfolios. Equally, the climate emergency has not been forgotten.
As public health concerns gradually ease, I suspect demand for reusable and sustainable solutions will swiftly resume. However, the exact timings will be very much determined by consumers. Understanding how people interact with packaging and the channels they purchase through will be a clear driver, ensuring consumer safety, product security and future sustainability are evenly balanced.