Page 20 - Plastics News August 2020

Advances in Thin-Guage Thermoforming

High speeds, automation, smarter process control, delivering a holistic solution.
integrated vision systems, and better decoration
Automation means more than just parts handling.
techniques are becoming more common among Consider inspection and quality control, as well. The
practitioners of the 'art' of thermoforming labor savings associated with automation are well-
Conor Carlin understood in many industries. The economics vary
This article highlights five areas of thin-gauge across countries, regions, and market segments. Labor
thermoforming where advances in technology are costs are perhaps the biggest driver of investment, but
occurring at a fast pace, looking at the interplay of low-value-added items can restrict a CFOs willingness to
plastic materials, metal tooling, and production implement automation.
equipment. It is not meant to be comprehensive, and Automation II: Inspection & Quality Control
adoption is not uniform around the world. Like any Automation is more than just parts handling, however.
specialized topic, the deeper you dig, the more details High-quality parts, or parts where high precision
you find. There is a wide variety of applications in demands increased quality inspection and related costs,
thermoforming that covers both heavy-gauge and thin- are manufactured on high-speed thermoforming lines
gauge processes. with integrated cameras and rejection stations. In a
Thermoforming is not so far behind its injection cousins globalized economy where commoditization is rampant,
where technology advances are concerned. High speeds, especially in packaging, it is not easy to justify
automation, smarter process control, integrated vision investments that can adversely affect cost structures.
systems, and better decoration techniques are Up until recently, it was assumed that costs would
becoming more common.. outweigh the benefits of vision inspection systems in
Automation I: Part Handling thermoforming. A true accounting of costs will include
It is safe to say that when most thermoformers are asked quality—e.g., reject rates, part failure, scrap rates.
about automation, they typically think of end-of-line What is more difficult to measure, however, is
solutions related to part removal. It is not, however, a reputational cost associated with bad lots. What is the
cost of part failure on automated filling lines for baby
one-size-fits-all answer. From simple A/B stacking
mechanisms to robotic palletizing systems, there are a food? Inspection systems provide greater awareness and
lot of ways for thermoformers to move parts. Perhaps visibility. That information, as a process-control tool,
the most common automation approach is to use a two- highlights where problems are. Reject rates most
axis handling system where formed parts are clamped certainly increase initially, but the percentage of quality
parts goes up over time. Identifying imperfections or
and broken from the web as part of the basic stacking
system, then transferred via linear drives to a conveyor flaws in parameters such as concentricity, flange
belt. The parameters for the stacking movements are set thickness, and sidewall accuracy before parts are
through a teach-in mode. Through optimization, speeds packed and shipped can substantially insure the bottom
up to 40 cycles/min are possible with standard up- line. High-speed lines with up to 1400 cups/min can
stacking motions. Other options include 180° or 90° separate, convey, inspect, and restack parts.
rotations to create A/B stacks. Improved Productivity: Software & Process Control
At best, software is a productivity-enhancing tool. At
worst, it creates additional work and frustration for
users. Generally speaking, we have to adapt our
behaviors when we adopt new software. We need to
consider both software that improves how the machine
operates and software that improves the productivity of
the user. Creating networks between machines and
manufacturing extension systems (MES) is a known best
practice and is getting more attention under the rubric
Once parts are stacked, they can be moved to final of Industry 4.0. With 1-ms control for input parameters
packing stations, which can be as simple as automated now possible, exporting data to csv files can create a
sleeving systems or as complex as fully articulated surfeit of data. Yet separating the signal from the noise is
robotic arms that place entire stacks into pre-erected a critical first step in assessing data. The advent of “Big
boxes. Of course, these machines are typically not Data” means that we have a lot more information
“core” to the thermoforming process itself, but the available, but not necessarily more time in which to
ability to integrate downstream equipment is key to
analyze it. This has important implications for operators

August 2020 18 Plastics News