Robots, technology assist Allied Plastics in production
Founded in 1995, Allied Plastics has become a global leader in plastic thermoforming. The company took an important step in its evolution after investing in its first robotic trim cell in 2010. Since that initial investment, three additional robots have been incorporated into Allied’s production operation — and more could be on their way in coming years.
Tim Neal, co-owner of Allied Plastics, says the advantage of robotic trimming comes down to one word: speed.
“Historically in the plastic thermoforming industry, 5-axis CNC routers are used,” Neal says. “These CNC machines are fantastic and still widely used today. We actually have eight of them here at Allied Plastics.”
But as Neal points out, CNC machines can only go so fast. They trim plastic at a decent pace, but the time it takes to move from part to part can really add up. For large-volume jobs and larger-sized parts, this “unproductive time” can add up even more.
Large-volume runs require maximum productivity
Allied Plastics’ need for a robotic trim cell became obvious in 2010 when the company landed a large contract with a major OEM in the agriculture industry.
“More than anything else, robotics was gaining in popularity because of its speed,” Neal says. “From a tolerance standpoint, the general thought is that a robot is not quite as good as a CNC machine. But when it comes to speed and efficiency, a robot can trim plastic parts so much faster.”
To satisfy this huge new contract, speed and efficiency was what Allied Plastics needed. A robot’s consistent, repeatable performance would more than offset the very modest difference in tolerance.
“With a robot, it takes a little time upfront to get everything set up,” says Dave Coombs, lead robot engineer at Allied Plastics. “But once everything is set up correctly in the programming, a robot’s repeatability is outstanding. A robot will cut a part the exact same way it did two weeks ago.”
Allied Plastics’ first robotic trim cell consisted of a single robot with two tables. That setup allowed production workers to unload/load one station while the other station trimmed a part. “With a CNC router, the machine just sits there idle as it is unloaded and reloaded,” Neal explains. “But with a robot, everything is continuous. It is constant productivity.”
That initial project went so well that Allied Plastics was able to land an even larger account from another prominent OEM in the ag industry. “We were able to showcase our speed by running a dry cycle on their most-used part,” Neal recalls. “Once we did that, we were awarded the business.”
Two robots tackle oversized parts
Allied Plastics added its second robotic trim cell in 2012. This cell featured two robots working in tandem.
“With the new contract we had just landed, we wanted to go even faster,” Neal points out. The part itself was a large tractor cab roof. One robot can only reach so far. But two robots working together — each on different areas of the part — would speed up production immensely.
As lead robot engineer, it was Dave Coombs’ job to make sure the two robots could work efficiently without getting in each other’s way.
First of all, the dual-robot trim cell was set up with two tables, each of which could rotate 360° while a part was being trimmed. This helped two robots operate efficiently in tandem. Secondly, Coombs utilized a programming technique called “wait statements” where a certain amount of time is allotted for one robot to finish what it’s doing and get out of the way.
Simulation software allowed Coombs to watch how the two robots would perform based on the programming code he had written. Once he was satisfied with what the simulation software was suggesting, he went down to the production floor to observe a couple of test runs.
“We slowed the robots way down on those first couple tests so we could better observe what was happening,” Coombs says. “When we were happy with what we were seeing, we cranked the speed back up and got to work.”
Coombs says the robotic trim cells are actually allowing Allied Plastics to produce certain parts a CNC machine could not produce due to their size. The size of a part determines how fast you can cut it.
“A robot’s trimming speed is about the same as a CNC machine, but it’s a robot’s rapid movements when the tool is out of the part that makes all the difference,” Coombs explains. “That is where we’ve gained a lot of speed and efficiency.”
Robots raise productivity on smaller parts, too
The robotic trim cells don’t just give Allied Plastics an advantage with large parts. In fact, the company invested in its fourth robot in July 2020. This trim cell is set up to produce smaller plastic parts down to the 12- to 24-inch range.
“We have quickly found that the robot is allowing us to produce these smaller parts at a much faster rate,” Neal points out. “Production is up around 50%.”
That kind of productivity gain is of benefit to not only Allied Plastics, but also its customers.
“By gaining the speed and efficiency we have, our lead times have gone way down in most instances,” Neal says. “The best part is that because a robot’s actions are so repeatable, product quality and consistency have been superb.”