March 9, 2010
Family-owned, fifth-generation manufacturer Irwin Seating Co., headquartered in Grand Rapids, Mich. has been thinking about the comfort and functionality of the public seating it has manufactured for more than 100 years. The company's 35 presses are used to stamp the components that support the seats, mount them to the floor, and attach them to the backs; as well as pivots, brackets, and other internal mechanisms. Irwin does all the stamping, welding painting, and upholstery work in its 470,000-sq.-ft. facility. Some of the seating company's recent projects include the stadium seating for the New Jersey Devils, Miami Heat, and the Indiana Colts.
The Academy Awards®, airing this month, offers a retrospective look at the best movies you may have seen last year. Seeing clips of the nominated films may remind you of your experience while viewing them in the cinema. Perhaps you bounced in your seat during an especially startling moment; rocked back to laugh during a funny scene; or lifted the armrest for a closer encounter with the person you went to the theater with—all while paying little notice to the chair in which you sat.
Fortunately, family-owned, fifth-generation manufacturer Irwin Seating Co., with headquarters in Grand Rapids, Mich., has been thinking about the comfort and functionality of the public seating it has made for more than 100 years.
Irwin Seating Co. started manufacturing in 1908, making desk seating for schools. Soon the company grew and expanded its product line to include theater and cinema seating, as well as worship, stadium, and other arena seating (see Figure 1).
The company's 35 presses are used to stamp the components that support the seats, mount them to the floor, and attach them to the backs; as well as pivots, brackets, and other internal mechanisms (see Figure 2). Irwin performs stamping, welding, painting, and upholstery work in its 470,000-sq.-ft. facility.
Like all old, established companies, Irwin has remained relevant by continuously reviewing and improving its products and streamlining its processes.
JIT. Irwin transitioned from batch processing to just-in-time manufacturing. It was a hard philosophy to break, a company spokesperson said. Now all parts have a manufacturing order, and everything is made-to-order.
The company's steel supplier is located right across the railroad tracks, so material is delivered hourly. Now, instead of the stock filling a whole wall, it fits on a few racks. The stock is both coil and blanks, depending on the order size and press run. The new system has resulted in about 20 inventory turns a year.
All the parts coming off of the presses feed directly to racks across the aisle from the robotic welding area, and then move on to the paint area (see Figure 3).
QDC. Because dies are very expensive to build, stamping companies sometimes tend to mass-produce the parts. Sometimes, however, runs number in the hundreds, especially if they are restoration projects. How does Irwin balance economy of scale and customization? Quick die changes (QDC) have been instrumental, a company spokesperson said.
Before the pressroom converted to QDC, it took about an hour and a half to change a die. The emphasis was on getting as much productivity as possible out of the die (see Figure 4). Since quick-die-change equipment has been installed, setup time has been reduced to six or seven minutes with two operators, from last piece to first piece. One operator changes the coil while the other operator changes the die.
That ability to change dies quickly makes it possible to perform short runs on several jobs a day and eliminate the need to store additional inventory.
Crashes. Years ago the pressroom was dealing with up to eight die crashes a month, a company spokesperson said. Now dies crashes occur less than four times a year. The problem has been resolved primarily through more extensive operator training. All the operators do their own setups, as well, so they're more aware of potential crash hazards.
Common Parts. Irwin Seating produces nearly 800 variations of its seating—some have rockers; others have flip-arms; others are mounted on risers; on some, the seats move; on others, only the backs move (see Figure 5). Some, such as end aisle seats, accommodate lights. Worship market seating is equipped with boxes for Bibles. Education market seating has tablets for writing; inclines vary, as well as upholstery colors and fabrics. Even so, the company has identified many of its components that are common to all or most seating. For those parts, progressive dies are built and stored. Even those components are stamped-to-order, however.
Specials. Irwin makes parts for restorations, which often require unusual configurations and small quantities. Specials are blanked on a laser and formed on a press brake or small hand die when the volume is not large enough to justify building a prog die.
The company has stayed current with its audiences by critiquing how it manufactures its components too.
For example, for many years its standard upright was blanked, formed, and assembled from six components and required 14 inches of weld. The foot on the bottom was a separate piece and was welded.The part has been redesigned to have fewer components and only 7 in. of welds.
Showcasing the company's completed projects often requires a poster-sized photo to view the sea of seats (see Figure 6). Some of the company's recent projects include the stadium seating for the New Jersey Devils, Miami Heat, and the Indianapolis Colts.
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