Quality

››› Folding

It’s The Quality

Equipment offers XLT Ovens better tolerances, higher

quality and reliabilityThese stainless steel ovens have posed interesting problems for their manufacturer, XLT Ovens.

By Russ OlexaV.P., Associate Publisherrolexa@fsmdirect.com

Aat XLT Ovens, just about 98 percent of their ovens’ construction is stainless steel — expensive, 304-stainless steel. Any marks on these sheet-metal parts during processing means they’re scrapped.

This was one problem the company was experiencing during production. Another was bending them. Some parts are up to 6 ft. long and require two operators to manipulate them. If one operator makes a mistake during the bending process, the part is scrapped.

Q ››› Folding

Eventually the company found a way to solve these problems.

Originally, XLT started out in the 1950s as Wolfe Electric producing fans for appliances. Then the company passed to the owner’s son, Dwayne Wolfe, who was doing job-shop type work along with a couple of different products such as a sheet-metal de-coiler.

Then Dwayne’s son, Ron, took over about 12 years ago and also built fans for appliances, along with job-shop work and building several different products says Kelly Berreth, manufacturing engineer.

“We had a customer who had a problem with a fan for a pizza oven,” says Berreth.

“He couldn’t get it balanced. Once we got it balanced, the customer decided to have us refurbish all his ovens.”

With this success, the company’s production changed to primarily refurbishing ovens.

“But as supply and demand goes, the more refurbishing you do, the harder it is to get ovens to refurbish,” mentions Berreth. “We rebuilt just about every conveyor-style pizza oven there is. When the conveyor oven market was drying up for used units for refurbishing, it was time to start making our own ovens.

“And after refurbishing all these various oven styles, we knew what was good and bad about them to make a superior conveyer-style

oven. Once we started with our own ovens in the 1990s, we went from a one-year to five-year warranty for parts and service, which is the best in the market.”

In 1995, the company started building its own ovens, called E Flow Ovens. Then about 12 years ago it started building the XLT Oven Line.

Production equipmentWhen they first began oven production, the company was primarily an assembly shop. They had vendors doing all the parts.

“But the part service, quality and delivery weren’t what we needed and we were getting

parts that were damaged,” says Bereth. “It became apparent that we had to do our own production. To do this, we started out with a single-station, tracer-style punch machine along with plasma cutters and a scissor-style shear.

“Our first CNC machine was a 19-station, turret-punch press that we still have. We then went to a larger punch press along with press brakes and a laser cutting machine.”

The company primarily works with 20, 18, 14 and 11-gauge, 304-stainless steel.

Steve Beeny, engineering manager, says, “Later we added an automated combination laser/punch press that had a parts picker. This

Because parts remain flat on the folding center, there is no problem with them kinking that could lead to higher scrap rates for the company.

Q ››› Folding

equipment was expensive, but we felt it would pay for itself.”

But the company’s owner believes in using equipment to get the job done, and Ron Wolfe wasn’t timid about investing in it for the present and the future. This thinking eventually grew the company into a 200,000 sq. ft. building where cellular-style production and lean manufacturing are the norm.

Folding versus bendingThe next step for the company was to eliminate problems that were caused by bending. When forming large parts on a press brake with two operators, there was a high chance that the part could kink during the process. Also, press brake bending could easily scratch the material. This led to high scrap rates.

Beeny and Berreth began a search to find equipment that could solve these problems.

They eventually settled on a RAS MULTIbend Center® panel folder in 2006 that kept parts flat on the table during bending. This equipment supports the overall folding and eliminates any possible part kinking. Also, the way parts were moved around on the machine’s table kept them from scratching. They also purchased stainless steel with a plastic coating on it to further prevent scratching during production.

“The part we had as a buy off for the RAS MULTIbend Center® had 16 folds in it and it was a large part,” says Beeny. “We had a huge scrap rate on it, as it took multiple setups and two press brakes along with two operators to handle the part. The part was the front of the oven, and if the operators didn’t handle it correctly, it would show a flaw in it that we didn’t want and couldn’t have. This was an imperfection, and we couldn’t afford not to

get a piece of equipment to automate this production that would also help us reduce or eliminate our scrap rates.”

Berreth notes, “Buying the RAS MULTIbend Center® was a trying decision, because there were a lot of different companies out there, and we had a particular part that they had to fold for us to purchase the machine. If they couldn’t do it, we wouldn’t buy it.”

But it was the RAS folder that stood out from the other manufacturers. Berreth says, “We heard service nightmare stories (about some of the other manufacturer’s equipment). I looked at all of them very closely. At first we were looking for a folding machine that would manipulate the part staying flat on the machine. We weren’t necessarily looking for

automation. Moving our parts around is one of the largest ways for them to be damaged. One of the biggest sellers of the RAS machine was how it manipulates the part in the back and keeps it on the ball transfers and on a smooth surface.”

The first RAS MULTIbend Center® the company purchased manipulated the part but it was manually loaded and unloaded.

Then the company’s next step was to trade this unit for two 79.26-2 MULTIbend Centers® that had part manipulation automation and a robotic loader to move the flat blanks to the machine. But the part was still manually unloaded because some of them needed secondary processes after folding.

“Some of our folded parts had other parts nested within them that needed to be separated out from the nest manually after folding. We had to leave the center portion part in the nest for the RAS manipulator to grip and manipulate it. This necessitated manual secondary work after the RAS folded the main part around the nested center part,” says Beeny.

The RAS MULTIbend Center® can fold a finished part that is roughly 10 in. by 17 in. up to 60 in. by 100 in.

Bereth says that they purchased another RAS MULTIbend Center® and a RAS MINIbend Center® at the same time when they traded in their older MULTIbend Center®.

An example of some of the bends required to form parts for an oven. This part is part of the fan ducting system.

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“Primarily it was redundancy in case something went wrong with the first one. We wanted a second machine. Even if the machine was repaired the next day, we would lose a day of production. This can hurt us, because we primarily build ovens using a one-piece flow. Since we were looking for a second machine for redundancy, we decided to go with a robot for unloading,” remarks Bereth.

RAS’ MULTIbend Center® helped the company with their parts’ tight tolerances along with their consistency and quality. But another benefit of having two MULTIbend Centers® was inventory reduction, says Beeny. “With one machine we have to fold up a week’s worth of parts. We have eight different oven styles, so we would have quite a few part stacks lying around. When they are all folded, they take up more space than when flat.

“We thought we would store more flat than folded, and fold them on demand. If we had a break down, it hurt our production schedule. Now with single-piece flow, our inventory levels are lower. We can come off of our turret-punch presses or lasers and store the flat sheets on a shelf. Then when we need the parts, we just pick them off the shelf and fold them.”

Folding smaller partsXLT has many small parts that didn’t fit on the larger RAS units. They were still being done on press brakes. There was a need for automating the folding of these small parts too.

Beeny says, “We needed a smaller folding center. With a smaller one, we could fold up more parts that don’t fit on the larger RAS equipment. The RAS MULTIbend Center‘s® center tool and its part manipulator limits the size of the part that we can bend.

“We were thinking originally that it would be nothing more than a downsized version of the larger MULTIbend Center®. But RAS’ MINIbend Center® isn’t, it’s a completely different way of folding. It still uses a panel-folding style, because the part stays flat which helps reduce distortions and other problems. But the MINIbend Center® folds both up and down and holds the part in the air using an anvil device.”

The RAS MINIbend Center® can fold a part as small as 1.57 in. by 1.968 in. in 11-gauge mild-sheet material.

Beeny is using the MINIbend Center® for parts that are under 24 in. “What we like about the machine is the part consistency and reliability. The first part looks just like the last one of a large run. We have to be consistent and hold our tolerances, because for us, it’s all about quality,” he concludes.

RAS Systems Inc.XLT

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