To celebrate the 20th anniversary of Plastics News in 2009, we continue with our weekly countdown of the Top 20 stories covering issues of lasting impact. Plastics News staff members voted on the stories.
The series will end with the No. 1 story in our 20th Anniversary special edition March 16.
No. 17: Advances in automation
A huge advance in automation over the past two decades has helped the U.S. plastics processing industry boost productivity, become more efficient, safer, turn out consistently higher-quality parts — and for many companies, survive in the global economy.
When Plastics News began publishing in 1989, it was still common to see molding shops with operators at every injection press, opening the gates and grabbing the parts out. Some factories did have some simple parts-pickers to remove the sprues, which dropped into a grinder, but often just got thrown in the trash. Back then ``automation'' often meant a press was unattended but the parts simply dropped into a box underneath.
Fast-forward to today. Robots have evolved from the exotic to must-have, and higher robot usage has brought down the price of automation.
You hear it time and again. ``The simple jobs have moved away to China.'' Automation is the most obvious way to fight cheap labor. Also, the robot industry is working to make automation more flexible, less of a hard and fixed asset, so the robot you buy for a job today can be reconfigured for another job down the road.
Robot makers say the U.S. plastics industry still lags behind Europe and Asia, which embraced automation more quickly. But we're moving ahead. Yes, a few U.S. plants operate ``lights-out.'' But the broad impact of automation is that, in the late 2000s, it's typical to find even small U.S. molders running advanced robots on every machine.
And it's more than sprue pickers and pick-and-place robots. Beam robots reach down into the press and move parts to conveyor belts. Assembly work is done right at the press, sometimes by robots. Camera vision-inspection systems can check every part for quality. End-of-arm tooling can report if a mold cavity isn't functioning. All the data gets fed back to the machine controller, and the press can self-adjust.
Articulating-arm robots, first seen welding steel on car assembly lines, have moved into the plastics industry. One pioneer is Bemis Manufacturing Co., which in the early 1990s installed six-axis robots on every one of the 50-plus presses in one building. Molded parts can get drilled, trimmed, welded or positioned for pad printing, decorating and quality checking, by articulating robots mounted beside or on top of the press.
Already, a few forward-looking companies have teamed up more than one robot in beside-the-press work cells, the robots handing the parts off to each other, as they perform different finishing functions. Expect to see more processors adopt these combinations of beam and articulating robots to create beside-the-press work cells that, 20 years ago, were the stuff of science fiction.
The advance of automation isn't limited to injection molding. Robot makers are pushing robots into profile extrusion, to put windows of fencing onto a pallet. In many plants that make flexible pipe and tubing, automatic coilers wind the finished product.
Packaging has long been highly automated. ``Automate or die,'' said Robert Schad, founder of Husky Injection Molding Systems Ltd., way back in the 1960s. Packaging has to be able to collect and organize the massive volumes of parts that flow from presses, blow molding machines, thermoformers and blown film lines.
More recently, the growth of in-mold labeling requires specialized, high-speed robots.
On injection presses making yogurt cups or other packages, side-entry robots zip into the mold in a blur of movement to remove parts. Some of the best can get them out of the way before the mold snaps closed, faster than letting the parts fall down from gravity.
It's almost like a robot can beat a fundamental law of physics.
Bregar is an Akron-based senior reporter, and one of Plastics News' original staffers.