Thermoformers speed custom clamshell creation

January 29, 2014

9 Min Read
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What type of packaging do consumers look for with a prepackaged meal? Are they satisfied with a white, foam container that hides the meal, or do they prefer a container with a colored base and a clear top that displays the food? Do they look for containers that provide dining directly to the table, or would they rather have dishes to wash at the end of the day?

Packaging has a tremendous effect on a consumer's take-out or prepared-meal dining experience. Not only does it influence their purchasing decision, but it can also enhance their enjoyment of the meal. A professional packaging presentation showcases the product, while providing the brand with a high-quality appearance.

Duni AB (www.duni.com), a global company based in Sweden, offers food-packaging solutions for the restaurant and foodservice industry, as well as for retail applications, including prepackaged convenience foods, carry-out and to-go containers, and home meal replacement (HMR) solutions. In addition, it supplies a range of paper products, such as napkins, table coverings and beverage cups, for catering and foodservice customers. In North America, Duni operates two divisions—in Atlanta and Thomaston, GA—under the Duni Corp. name.

Recently, Duni Corp.'s Thomaston facility installed two new thermoforming lines from Brown Machine LLC (www.brown-machine.com) to increase production capabilities for its custom-designed clamshell food packaging.

In the highly competitive plastics market, Duni has found that the new equipment allows for faster tooling changeovers and provides major improvements in machine uptime and high-quality molding performance.

A s Randy Ballinger, maintenance manager for Duni's Thomaston facility, explains, the main products manufactured at the plant are polystyrene clamshell food containers, many of which are custom-designed and include embossed logos, per the customers' request. "Product design starts with the customer," he says. "New tooling designs are tested in our facility to make sure they will be successful. Some of our tooling is quite complicated. For example, we produce a lot of different configurations with one to four compartments, so tool changes are challenging.

"We can offer the retail customer a clear lid and a solid, black base. We also offer the option of our patented, tear-away lid." Another option is microwavability, with some containers able to handle temperatures up to 225 deg F.

Duni operates several in-house extrusion lines to produce all of the PS rollstock used on its thermoforming machines. According to Ballinger, what sets Duni apart is its ability to produce a triple-stream sheet, with black in the center and clear plastic on each side to form clear lids. "As far as I know, we are one of only a few companies in the world that can merge the black and clear together in a seamless fashion," he says. "Both materials are polystyrene, but the black has a higher rubber content, which makes it more pliable."

Duni thermoforming engineer Colin Lee adds that the containers' one-piece construction is another benefit for packaging specifiers. "With the one-piece unit, they don't have to buy containers with lids; it all comes in one convenient package," he says.

About 18 months ago, Duni added two new thermoforming lines from Brown to its existing collection of nine machines. Each new line includes a Brown roll-fed in-line Model CS-5500SP thermoformer with independent plug motion and a horizontal trim press with a Servo Flex feed system. Both thermoformers also incorporate a host of other features, including advanced, quick-change capabilities and a user-friendly, open-architecture control system.

During operation of the new lines, material is unwound from the roll stand and indexed via servo-controlled material conveyance rails through the multiple-stop, temperature-controlled oven. The material is then carried into a precision-guided, servo-actuated form station with servo-controlled vacuum bleed/main vacuum, air-eject and pressure capabilities. The formed web is then moved into a match-metal horizontal trim press with linear guiding for a precise feed-and-trim process.

The new thermoformers can handle molds up to 50350 in. and up to a 7-in.-deep container. Observes Ballinger, "Output on the two fifty-inch machines is equal to four or five of our other thermoforming machines, depending on which jobs are running. But, while most of our older machines are assigned primarily to short-run operations, we do all larger-volume runs on the Brown machines."

When Duni decided to expand its production operation two years ago, Ballinger and Lee put together a set of specifications for what was needed. When they contacted a few of the leading machine builders, they discovered that some unique and important features were being offered that they hadn't even known were available. Eventually, they finalized the overall scope of the work they wanted to perform and narrowed their search down to machine builders that could meet their requirements in terms of cost, value, quality, service and reputation/longevity of the company.

Next, they visited various machine manufacturers to determine which company could best meet their objectives. They looked at different features of the machinery and obtained quotes for a variety of thermoforming equipment.

Says Ballinger, "After looking at different machine makers, I really felt like I was supported best by Brown. I have to look at service capability, because when a machine is down, everyone looks to my department. All they want to know is when the machine will be back in production. As a maintenance manager, I have always said that the vendors you chose to do business with are a direct reflection on your job performance. I had to stake my reputation on the machines, so I had to look at the longevity of the company.

"What I like about Brown's service department is that it has so many dimensions. If I need a retrofit kit, I call the service manager, and he connects me with a guy who works specifically with retrofit kits. If I have a process problem, direct and specialized help is available. We have modems in the machine controls so that service personnel can dial in, look at a machine and see what it is doing—as if they were standing in our facility. Brown technicians have helped us either by coming to our facility or by discussing issues over the phone. Those kinds of features and that kind of service certainly have gone a long way to enable us to bring these machines up to their present performance."

Ballinger was also sold on the features of Brown's T-350L trim presses. The presses' stationary platen is designed for quick change of the trim dies using a separate mounting plate that allows the die assembly to be removed from the exit end of the trim press. In addition, the machine has the capability of side-loading the tooling.

According to Ballinger, the Servo Flex feed from Brown provides extreme accuracy and virtually infinite product placement flexibility. The servo-designed pusher system allows maximum acceleration, deceleration and length of travel, providing precise repeatability of product placement. All parameters are easily changed at the operator interface.

"We do as many as forty changeovers in a week across our eleven thermoformers," Ballinger says. "Any feature that will save time is going to help make us more efficient. This has been a big issue in the plastics industry. We have seen huge resin price increases, but we can't pass them all on to the customer. Instead, we have to look for ways to become more efficient so that we can absorb these costs to maintain our prices and remain competitive in the market. Some of the features on the new Brown machines have allowed us to do that.

"One key example is when we go from a one-component to a three-component product. There is a lot of difference in the material heating requirements. Because we specified a flexible oven with multiple zones and advanced oven controls, we can save recipes for each product; we don't waste time troubleshooting to get that line up and running first. Having those heat properties stored is important to us, especially when considering the amount of jobs and changeovers we perform here.

"A lot of our production is what we call 'logoed' products, with the customer's logo formed into the clamshell's cover. We might run 100,000 units with the logo, then switch to a run of 50,000 units without the logo for a neutral product. In a job-shop environment like ours, we need to be able to change tooling quickly. We are set up so that we can make a logo change on any of our machines in a half hour or so, versus taking up to two hours to change out logos, as we did before. We can change a complete set of tooling in four hours or less."

For the future, flexibility is key. "One of the biggest future benefits I see with the Brown equipment is the third-motion feature we put on the machines when we ordered them," says Lee. "In the past, we've had machinery that only allowed us to do shallow-depth products. With the third motion, we can handle deeper products—up to seven inches. It allows us to get better material distribution down the sidewall of the container, helping tremendously with quality."

Explains Ballinger, "The reason we got all the bells and whistles on these machines is because that is what is dictated by the market's future demands. Quick-change on tooling is no longer a feature; it is a standard. Pin-chain rails on the forming station that are automated for faster changeovers are now standard. The market expects us to be efficient on both logo and complete-tool changeovers.

"We made a major investment in time-saving features because we knew it would pay us back each time we do a changeover. That is why purchasing the Brown machines, with their host of features, has proven to be a good investment for our future."


More information is available:

Brown Machine, 989/435-7741. www.brown-machine.com.

Duni Corp., 706/647-2205. www.duni.com.

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