At April’s NPE show in Florida, it was impressive to see how giant, working production lines could fit into limited floor space. Blown-film lines three-stories high come to mind as good examples. But I had another impression at this year’s event: how coldly mindless many kinds of automated production lines can seem.
Automation is of course a good thing for keeping costs low for products like blown film. But the continuing human creativity needed behind a good process can easily be forgotten when a production line can be so easily “switched on.” No matter how reliable automated plastics conversion processes get, the human brains hovering around the equipment still need to be humming with ideas on how to save more energy and increase efficiency.
A lot of process elements can be targeted for optimization, as Helmut Heinson of injection molding machine-maker Arburg GmbH observed in his April 3rd plenary speech at ANTEC@NPE2012®. In injection molding there are many energy- and/or time-sucking elements to look for with a critical eye, cited Heinson, like poor mold cooling (and thus excessive cycle times), multiple moving mold components, and lack of synchronization between the molding machine and peripheral equipment, he said.
Peripheral equipment is also often overlooked as a target for optimization; for instance, resin-drying equipment can be optimized to use the least energy to dry the most material (as in this example).
Characteristics of the resin can be looked at in a similar way. One basic idea is to consider how much energy per kilogram a resin requires for processing, compared with the energy of another resin that could be used in the product. Process parameters can also affect process energy consumption, given the way melted plastic flows. For example, higher injection velocities and back pressures in molding tend to reduce overall energy use, as explained in this blog entry by Andy Routsis.
Looking beyond the production facility, authors in Packaging World magazine recently proposed alternative ways of quantifying how much the quality of a packaging product is affected as it’s transported across the value chain. They offered the “total-energy” method, which is a measure of the potential energy used in moving a package; “energy-time,” which is a rate of “energy absorption” per minute of packaging transport time; and “energy-distance,” or transport energy per distance, a measurement which can be used to minimize product damage, inventory, and waste.
And for creating understanding about a product’s complete resource and waste impacts, ever-evolving methods in life cycle assessment are aids in product/process development.
So the human brain remains infinitely creative in coming up with concepts aimed at making processes and products better, in comparison with our awesome, but relatively mindless, production machinery.
P.S. – My talk at the ANTEC@NPE2012® conference – “Strengthening the Message of Sustainable Plastics Packaging” – is available in article and PowerPoint form. Go to http://www.mtextcomm.com/ to download them or see an abstract here.
Mike Tolinski is the author of Plastics and Sustainability, published in Oct. 2011 by Wiley-Scrivener, and he is Contributing Editor for Plastics Engineering magazine of the Society of Plastics Engineers in the USA. His views have been shaped by his engineering, university, and journalism experience in the plastics and manufacturing industries over the past 21 years. You can follow Mike and be alerted on blog updates via Twitter.