Issue: Update older TIG units with smaller, portable welding machines. Solution: Maxstar® 200 DC TIG/Stick inverter-based power source. Results: Flexible welding cells, less spaces occupied, improved welding performance.

Three years ago, tons of stainless steel gleamed in the light of Baxter Manufacturing's warehouse. Rack ovens, deck ovens, proof boxes, donut fryers, bagel boilers, ingredient bins and related bakery systems lined the walls, destined for the world's supermarkets, sub shops, pizza parlors, bakeries and delis. But after becoming part of Hobart Bakery Systems, and subsequently Illinois Tool Works (ITW), the warehouse stands empty — and employees have never been happier.

“We don't stock finished product anymore because we build to order. Once a finished product rolls off the line, we pack and ship it the same day,” says Ralph Thompson Jr., general foreman 1 (first shift). “We used to have rows and rows of finished product stocked, and now there's a lot of empty space. Our new manufacturing philosophy emphasizes increasing inventory turns to improve efficiency, so now we ship out an oven as soon as we finish it.”

The company's new manufacturing practices work well, resulting in a much needed productivity increase. In 1998, Baxter produced 989 rack ovens and 970 proof boxes (its two biggest sellers). Those numbers respectively increased to 1,255 and 1,174 in 1999; the company estimated it sold more than 1,300 rack ovens and 1,400 proof boxes in 2000. This year, when Baxter's Orting, Wash. facility becomes the manufacturing center for all three brands of Hobart Bakery Systems products — Hobart, Baxter and Baker's Aid — the plant needs to increase rack oven production by another 600 units.

Adding new production lines and manufacturing areas will soon fill much of the empty warehouse. With floor space becoming a prime concern, Thompson eagerly agreed to beta-test the Maxstar 200, a compact new DC TIG/Stick welding machine from Miller Electric.

For TIG welding, Baxter currently relies on about 20 Miller Syncrowave® 250 AC/DC machines. This unit has been the industry standard for years, but like all conventional technology machines, it weighs a lot (355 lb.) and takes up space (19.25 in. wide x 27 in. deep). Conversely, the Maxstar 200 uses inverter technology that reduces weight to 37 lb. and shrinks its footprint to 7.5 in. wide x 17.5 in. deep.

“Space is our number one issue right now,” says Thompson, “and we can fit more arcs in an area with an inverter. We also appreciate a TIG machine that we can move around really quickly.” Because of its small size, Baxter's Welding Foreman Tim Sloss initially wondered if the Maxstar 200 would function well as a production unit.

“That machine looks like it was built for portable applications [such as mechanical contracting] that do not require welding all day,” says Sloss. “However, we put the Maxstar on our rack oven line and pounded on it eight hours a day, 40 hours a week.

We put a good load test on the machine, and it's worked excellent for us.” TIG welding the rack oven, as well as the TIG welding on most other bakery products, requires joining 14, 16 and 18 ga. 304 stainless steel at 45 to 85 amps. Operators use 308 stainless steel filler rod and 3/32 in. lanthenated tungstens.

“Miller designed the Maxstar 200 to function as a production TIG machine for fabricators like Baxter,” states Bob Plummer, sales representative for Pacific Welding Supplies, Inc., Tacoma, Wash. “With most stainless steel TIG welding done at 100 amps or less, the Maxstar's 1 to 200 amp range — with a 40 percent duty cycle at 200 amps — gives Baxter plenty of power. It is also available with features typically found on large production units, including a built-in pulser, sequencer and trigger hold.”

Although it is a production machine, the Maxstar 200's light weight also makes it suitable for portable applications. Baxter's appreciation for portability increased quickly when it implemented ITW/Hobart Bakery Systems' “product-focused manufacturing area” concept. This involves placing all the resources needed to produce a product in one area or in one line, rather than scattering them throughout the plant.

For example, a rack oven previously traveled about 2-1/2 miles during production. Now it travels 800 to 900 ft. This slashed production time and accounted for the productivity increase noted earlier. It also means that if one area experiences a slow down — recall that Baxter builds on demand to meet customer orders — the company can shift resources to other areas.

“Shifting a production welding unit between manufacturing departments used to call for a forklift,” says Thompson. “Now, we can carry the Miller inverter with its shoulder strap, yet its welding output stays right up there with the bigger machines.” Baxter tested the Maxstar 200 in its ingredient bin area, TIG department (manufacturing of miscellaneous components), mini rack oven line, rack oven line and grinding department.

“The Maxstar 200's Auto-Line™ technology gives Baxter more location flexibility than any other welding power source,” notes Plummer. “It accepts any input voltage ranging from 115 to 460 V, single- or three-phase. After attaching the appropriate plug, the operator could run this inverter unit anywhere in the plant.”

Production Flow

Production at Baxter begins in the tube shop when raw materials arrive by truck. Baxter uses some aluminum and mild steel, but mostly fabricates its bakery products from 304 stainless steel sheet in 14, 16, 18 and 20 gauge. Round and square tubing stay in the tube shop for cutting, while flat stock goes to the sheet shop for shearing or, if part complexity warrants — and most do — to a 2,000 watt Cincinnati CL 707 or a 3,500 watt Bystronic CO2 laser.

“There's no comparing the speed of a laser to mechanical cutting,” says Chris Haagen, laser operator. “One of our oven floors has a pretty extensive corner notch that used to take seven set-ups on the notching machine and two saw cuts. With the laser, I cut two floors in one minute and 45 seconds. The cuts always remain consistent between pieces, and the part can go straight to the bender. The laser does the work of a notcher, saw, punch and deburring machine.”

Baxter invested in its first laser five years ago and added the second one two years ago because of demand. Use of its old Weideman and W.A. Whitney turret punches has dropped significantly. Thompson says that while punch manufacturers have made vast improvements that speed tooling changes, changing dies still takes too much time and the part still needs deburring.

“Most of the runs on a rack oven call for 60 pieces of the same part, and there are 1,200 parts on a rack oven,” he says. “With seven or eight different punches on each part, you can imagine how much time it took to get through a whole run before we purchased the laser.”

Once cut, three Cincinnati Milicron and one Tries & Krump press brake bend parts to shape. Components then move to the product-focused manufacturing areas. Taking a simple product as an example, Thompson explains the production of a stainless steel ingredient bin: After a press brake rolls the edge of a 20 gauge flat sheet around a piece of bar stock to make a lip for the lid, an operator places the part in the bending machine that forms the part into a roughly rectangular shape. It then goes to a seam welding station. Clamps hold the sheet in place while a linear track welding machine, powered by a Syncrowave 250, TIG welds a seam.

To stretch the bin into its rectangular shape, the operator places the looped stainless on a pneumatically-operated frame. Since stretching can cause slight misalignment, the bottom of the sheet is trimmed to keep the top square. The operator then tack welds a bottom to the rectangular frame and places the part in a mechanized track welding machine. This machine rotates the part while an operator manually guides a TIG torch to weld on the bottom. This weld, like many at Baxter, calls for purging the backside of the weld with 100 percent argon gas to ensure complete penetration and proper shielding with a single-side weld.

To permit mobility, Baxter welds casters to the bottom of the bin. The operator then places the finished bin and its lid directly into a shipping carton, which then moves to the loading dock. All this activity takes place within a 15 x 30 ft. area, where it was once spread throughout the plant.

“We borrowed the concept for streamlining production in the ingredient bin area after I took a tour of Miller's plant in Appleton, Wis.,” notes Thompson. “We make the ingredient bins [with Miller TIG machines] employing the same production philosophy as Miller does to produce its TIG welding products.” Using other ITW companies as benchmarks (ITW acquired Miller in 1993) helps Baxter improve efficiency and do it quickly.

TIG Quality

While the Maxstar's small footprint and multi-voltage flexibility appeals most to Thompson, he adds that “weld quality has to be right on, or we can't use a machine. We TIG weld all visible welds, and there are a lot of welds on the outside of our products. We've always wanted to TIG because it eliminates grinding and polishing, but especially because it looks good to the customer's eye.”

Steve Walston, a journeyman welder in the TIG Department, says “the Maxstar 200 definitely has a steady arc on it, and that's comparing it to our Syncrowave machines. The Maxstar 200 produces a really consistent bead, and the high frequency start comes on strong, consistent and fast.”

Brett McCreery, a welding operator in the Grinding Area, agrees, saying, “I feel like I have a lot more control over the heat, and the heat stays steady. The Maxstar 200 starts a lot quicker than my old inverter, too.”

Pacific Welding Supplies' Plummer notes that the Maxstar 200 lights the tungsten so quickly because of its built-in high frequency (HF) TIG arc starter. This feature also eliminates the need to purchase a separate HF unit and cables, saving about $800.

“This new inverter makes sense for a place like the Grinding Area,” Thompson adds, “because there's an incredible amount of grinding dust here, as well as grit from the nearby bead blaster.” The Maxstar 200 uses Miller's Wind Tunnel Technology™ to protect the unit's electronic components from any dust sucked in by the cooling fan. Coupled with the Fan-On-Demand™ feature, which turns on the cooling fan only when needed, Wind Tunnel Technology produces a substantially more robust and reliable welding unit.

With a list price around $2,000 for the standard unit, the Maxstar 200 inverter costs about 20 percent less than a conventional AC/DC TIG machine. Coupled with the space and moving time it saves, Thompson will have no problem integrating new Maxstar 200s into Baxter's operation as demand warrants. Given that Hobart Bakery Systems plans to fold the manufacturing functions of two other facilities into Baxter's Orting location, and that the company already runs two shifts, demand for more welding machines is just over the horizon.