Injection Molding Case Studies: Doing It Cheaper, Faster
These days, a penny saved probably equals at least two or three pennies earned. Here's how some of Canada's injection molders are keeping more of their money by working cheaper -- and faster, too -- w...
These days, a penny saved probably equals at least two or three pennies earned. Here’s how some of Canada’s injection molders are keeping more of their money by working cheaper — and faster, too — with either new or refurbished machines.
If they can do it, why can’t you?
Television buffs from the 1970s might recall that it cost $6 million to get disabled astronaut Steve Austin working better, stronger and faster than ever before. Not many of us have that kind of money to throw around these days. Luckily, though, if you’re an injection molder looking to do more with your machinery, it won’t cost you nearly that much. Canadian Plastics spoke with several injection molders — ranging in size from 200 employees down to a one-man shop — about how they’re working better, faster and cheaper than ever before, with both old and new injection presses. They’re doing it; what about you?
PLASTIQUES GPR INC. St-Felix-de-Valois, Que.
The 200-employee, family-run custom injection molding shop had a long history of selling machines that had reached 80,000 service hours, but had recently been haunted by a bad experience: selling a unit to a shop in Florida, only to have it sold again to a direct competitor of Plastiques GPR back in Quebec. So when the company’s 1996 Engel 600 ton machine reached the magic number of 80,000 service hours last year, they decided to try a new strategy that they hoped would achieve roughly the same result as getting a new model.
After consulting with the service staff at Engel’s Guelph, Ont. facility, Plastiques GPR decided to have the unit refurbished to allow it do as much as a new unit.
“Engel made an evaluation and gave us a refurbishment price, which was low enough that we were able to go ahead with the refurbishment, as well as the screw and barrel change,” said Gino Belleville, the company’s production and sales manager.
Four months after being shipped to Guelph, the 600-ton was returned…looking and operating like a new machine. “The refurbishment changed the wiring, the computer screen, the hydraulic valves, the pumps, the motors, and the toggle parts,” Belleville said. “They repaired, but didn’t replace, the platen, the tie bar, and the frame, and even repainted the machine.”
The unit also had a new, larger barrel and screw -not technically part of the refurbishment. “The ratio between the old barrel and screw was 18:1, and we now have 24:1,” Belleville said. “The screw was extended by about three feet, which necessitated an expansion of the frame and base.”
The final step involved installing updated software. “The new software didn’t require our operators to be specially trained because our facility already had other Engel machines running the same version,” Belleville said.
The machine now runs the same applications as previously, but with a 15 to 20 per cent shorter cycle time. “This has increased the projects that we can take on,” Belleville explained. “We’re a custom molder, and often get orders at the last minute -the machine is now versatile enough to do applications that we wouldn’t have used it for before, including compost containers, snow sleds, shovels and industrial parts for the tooling industry.”
The new screw is also well suited to HDPE, which the company had been reluctant to put through the machine before. “We’re now running a lot of HDPE applications, which, again, opens us up to new contracts” Belleville said.
In the end, Belleville said, the recent downsizing at Engel’s Guelph plant didn’t affect their ability to service the machine. “The Engel 600 ton is a very good general purpose machine, and we’re pleased to have been able to keep it.”
Engel Canada Inc. (Guelph, Ont.);
Nu-Stat Enterprises Ltd. Vaughan, Ont.
It’s safe to say that when Lothar Witt, owner of Nu-Stat Enterprises buys an injection molding machine, that machine had better be operator friendly — because he’s going to be the only operator.
Nu-Stat is that rarest of creatures, a true one-man outfit. Witt is not only the owner and president, he’s also the mold designer, mold maker, mold set-up crew, machine operator, parts packager and shipper. Oh, and he just turned 70.
Suffice it to say that Witt has a host of production challenges unique from those of any other injection molder that you can name. So when he went shopping for a second I/M machine for his 3,600 square foot facility, the goal was to find a reliable unit for commodity molding that fit his energy needs and wouldn’t require any babysitting.
Having experienced maintenance issues with his first injection machine, a 135-ton unit, Witt decided to go with a different OEM the second time around.
He knew that, with only 60 amps of power supply available for the machine and a chiller, whatever he bought had better be more than usually energy efficient, as well as versatile enough to handle the wide range of commodity parts in which he specializes.
After doing his research, Witt selected a new Negri Bossi V160 (160 metric tons) with CANbus controls.
Right off the bat, Witt noticed a big difference in energy consumption between the new Negri Bossi and his older machine. “My hydro bill for the V160 is one-half the amount of the other unit, even though it’s a larger machine,” he said. “It only requires between 40 to 45 amps of hook-up power, and this savings has allowed me to stay competitive and hold onto important contracts.”
Of the two units, the V160 also has the faster startup time, Witt continued — an important point, since, with his shop shutting down at night, production has to start anew each and every morning. “When I arrive in the morning, the other machine takes me a good 45 minutes to warm up,” he said. “Because of the way the Negri Bossi machine is built, though, with a smaller motor and smaller hydraulic tank, it only takes approximately 15 minutes to warm up, which gives me a 30 minute head start in part production.”
The V160 is quiet, too, meaning that Witt can hear the telephone ringing in the front office even while standing next to the machine — because, as you’ve probably guessed, he’s the receptionist, too. “The Negri Bossi is so quiet that, at first, I almost wasn’t aware it was running,” he said.
There’s no worry about deciphering over-complex controls, either. “The computer is built so that anyone can understand it and operate it,” Witt explained. “The computer will tell me, using words rather than symbols, what a problem is — for example, the gate isn’t closed properly. My other machine will identify the problem in an equation format, which is much harder to understand.”
Clearly, Witt is getting just what he wanted out of the V160. “The V160 is a true fully automatic machine,” he said. “I’m comfortable in not having to keep an eye on it all of the time, which is very important in a one-man shop because it allows me focus on other business while still running parts.”
Negri Bossi Inc. (Mississauga, Ont.);
Plastiques Moore Inc.
The 35-worker strong Plastiques Moore has set for itself the challenging goal of expanding its market share in the highly competitive medical components industry. There’s just one problem: when it comes to molding medical parts — which require unusual precision, not to mention contamination-free conditions — not just any I/M machine will do.
In October 2009, the company purchased a new Arburg Allrounder 630 S ECO hydraulic unit fitted with Arburg’s Multilift H horizontally operating robotic system.
“We chose to go with Arburg equi
pment because, based on our experiences, Arburg units have very few maintenance problems,” said Mario Dorval, production manager at Plastiques Moore. The result, he continued, is less time spent on maintaining and repairing each machine, more time spent in part production.
“Also, we find the presses to be much more efficient than competing brands, with more room for maneuvering during the installation and removal of the molds,” he noted. “Finally, we’ve always found that the control panels are easy to use for the press operators.”
The new Allrounder and automation equipment satisfied the key criteria of reducing both the handling of components and the risk of part contamination, Dorval said.
But there’s more. “Instead of production in a semi-automatic mode with an operator, which can sometimes create variations in the cycle time, the robot standardizes the cycle time,” Dorval explained. “This will help us to maintain our production efficiency, thereby increasing our competitiveness.”
Valuable shop floor space has also been saved, as well. “Because the Multilift H grips the rear end of the machine, the ejection of the plastic components is done horizontally from the back of the press, taking up less space and allowing optimal access to the equipment,” he said.
There’s no doubt that the company considers its recent purchases as money well spent. “The addition of these two new pieces of equipment will allow us to con-tinue our plan to modernize and increase our produc-tion capacity of precision medical parts,” Dorval said.
Arburg Inc. (Newington, Conn.);
Dier International Plastics Inc. (Unionville, Ont.);
D Cube (Montreal);
An 80-employee strong custom mold shop with 13 injection molding machines, GLP Hi-Tech wanted to trim its energy usage, but without going down the all-electric route. “We’ve had all-electric machines in the past, but we weren’t familiar enough with them technically to feel comfortable, and therefore didn’t find enough advantage to continue with them,” said company general manager Christian Boudreau. “For the kind of technical parts molding that we do — including medical, industrial and electrical parts — we prefer the direct hydraulic machine.” The goal, then, was to approximate the low energy consumption of an all-electric unit without giving up the “feel” of a hydraulic.
In an earlier time, GLP Hi-Tech might have been out of luck — but this is a new day. After surveying the latest I/M equipment on display at the K-2007 show in Germany, Boudreau and his colleagues selected a Nissei FNX 140-ton hybrid machine, one of Nissei’s FNX series. Available in a range between 89 and 502 U.S. tons, the FNX units feature the X Pump system, a hybrid pump that combines servomotor drive technology and hydraulic drive technology as the driving source for the molding machine. By controlling the rotation of the servomotor, the motor provides driving power only when required.
The FNX 140 consumes approximately 30 per cent less energy than the standard hydraulic machine that it replaced on GLP’s shop floor, without sacrificing the advantages of a direct hydraulic unit. “The motor runs only when we need all of our flow,” Boudreau said. “When the motor is not turning, no electricity is being used, which translates into a lot of savings.”
And this isn’t all. “With our very thick parts and long cycle times, the motor gives precise packing pressure needed, which wasn’t true with a hydraulic machine,” Boudreau continued. “With the machine’s servo valve, everything is closed loop: it adjusts for the pressure you need, and the motor and pump push exactly the quantity that you need. There’s no leaking, as happens with hydraulic machines, because it’s a closed loop system.”
In other ways, though, the FNX 160 is reassuringly familiar. “Set up and control operation are the same as with traditional hydraulic units, and the machine still has all of the hydraulic valves and hoses, meaning the guys on our shop floor don’t have any difficulties,” Boudrea said.
Part of GLP’s strategy for remaining remaining competitive lies in replacing molding machines relatively frequently fre — usually within five years of purchase — which means that the company is due to replace another traditional hydraulic machine any time now. Boudreau has no doubts about where they’ll turn. “We’re definitely planning to replace our older units with new FNX machines,” he said. “In fact, we anticipate that the units will be even more effective at higher tonnage, because we’ll have more savings to achieve.”
Nissei Plastics Industrial Co./En-Plas Inc.