‘Groovy’ Innovation at German Cabinet Plant

Market leader Miele, a producer of high-end cabinets, replaces its dowel construction with unique new V-grooving, ‘glue hinge’ technology to achieve mass customization.

By Helen Kuhl

Miele’s Folding System line starts with an IMA AS700 saw that cuts panels to length and applies the bar code that directs operations down the line. The entire automated process can be viewed from a gantry above.  

When a company like Miele — a European leader in the production of complete high-end kitchens, from appliances to cabinets — decides to change its casework production methods completely, one can imagine that it is a significant task. Such was the case three years ago when Germany’s second largest cabinet manufacturer switched from dowel construction to using unique new technology, a “Folding System” from IMA.

Working in partnership with the German machinery manufacturer, Miele invested $6 million and was given two years’ exclusive use of the new system, which produces a miterfold box using polyurethane glue as the “hinge.” The virtually operator-free automatic line at Miele, which stretches roughly 300 feet, combines a variety of specialized double-end tenoners, edgebanders, conveyors, processing centers and hardware insertion equipment to produce a complete cabinet, including hardware, at the rate of 350 or more per 7-hour shift.

The new system also helps Miele achieve mass customization in a fast, efficient manner. It is as practical to produce lots of one as to do multiples: A tall pantry cabinet can be followed down the line by a standard case, followed by a specialty cabinet designed to house an appliance, with no loss of efficiency. Today, the entire line of Miele cabinets is being produced in this manner with great success and virtually no effect on the outside appearance of the casework.

Bird’s-Eye View Shows Unique Process

At the Miele cabinet plant in Gutersloh, Germany, the entire process can be viewed from a gantry above and, to help interested customers easily understand the process, the catwalk features samples of panels showing different stages of completion.

The new Folding System begins as half-size or full-size panels arrive via conveyor from a panel saw, where they have been cut to a width that corresponds to the final case depth. An IMA AS700 saw cuts panels to length and applies the bar code that guides operations down the line. The saw is equipped with a measuring device to measure the size of the strips; there is no offal because all the panels are connected together.

Panels move next to a Torwegge double-end tenoner, then to a boring and grooving machine, which cuts grooves for the glue “hinges” and also drills a small hole into the back through which the polyurethane glue will be injected into the grooves. The machine has a sensing unit to ensure that the drill bit is making a precise connection. All this happens at a speed of 240 feet per minute.

Panels then pass through a cleaning machine, with brushing and dust collection, before going to the machine which injects the polyurethane glue into the hole. The glue, supplied by Dorus, can be made in any color to match the various cabinet colors offered by Miele. The polyurethane strips also can be made bigger or smaller, depending on how strong a PU “hinge” is needed.

At this point, there is a buffer area in the conveyor line. In the event of a stoppage down the line, up to 900 panels can be stored there for as long as needed.

More Machining, Then Edgebanding — All Operator-free

After leaving the buffer area, the system continues with panels passing through a group of specialized IMA machines that do double-end tenoning, grooving for the back cabinet wall and application of edgebanding. It also does any special cutting required, such as cut-outs for ovens, which typically are housed in cabinets in Europe and Asia.

Miele’s showroom shows several examples of its cabinetry. This vignette is the Avant Garde line.  

For the front edgeband, where the cabinet meets the door, Miele uses a special product that includes a bumper. This softens the door closing and, more importantly, acts as a seal to ensure that steam, dust, etc., cannot enter the cabinet. Miele also applies a thin edgeband on the back edges of panels to ensure water-resistance. After these operations, there is another buffer area where panels can be removed from the line, if necessary.

The next machine in the line is an IMA through-feed processing center, which features Wiesel IMA patented technology for clamping and positioning of panels. This machine applies edgebanding to the cross sides; it also does any additional required grooving and boring, whatever may be needed for custom designs. The machine has drilling and routing units to do machining from the bottom as well as the top.

When panels leave this processing center, they are cleaned again and pass through another buffer area before being conveyed to another Torwegge, which V-grooves the panels. Next, an MAW Nottmeyer installs hardware, such as drawer slides and shelving pins. Most of the hardware is fed automatically to the machine from storage bins on the catwalk above.

Throughout the entire system to this point, no operator has been required to touch the panel unless there is a problem or unless supplies, such as edgebanding materials or glue, have had to be replenished.

Samples show how panels are grooved on the front side and a small hole is drilled in the back. This is the hole through which polyurethane glue is injected into the grooves.  

On to the Assembly Room

Panels leave the machine room, travelling automatically down the line to a first-stage buffer area in the assembly room.

The first machine in this area applies white glue into three of the four V-grooves and into the groove for the back panel. This equipment also does outside boring required for the cabinet’s mounting hardware, at a speed of roughly 600 feet per minute.

It is here that the first operator touches the cabinet, placing the cabinet backs into the grooves and applying any hardware that cannot be mounted automatically. The cabinet is folded, glue is applied into the fourth corner and the case is placed into a high-frequency case clamp, which cures the white glue. Curing takes between 20 and 60 seconds.

Cabinets are further finished with the addition of any final hardware items, such as lighting, and then move up an elevator to an upstairs conveyor, which takes them to the shipping department. The entire Folding System line is designed to provide an up-time of 85 percent minimum; it is manned by only five operators, plus two as back-ups. The entire processing time, from feeding the strip into the line, manufacturing the complete case (in a lot size of one), to finally entering the shipping area is only minutes.

Such an innovative installation was possible because of the strong cooperation in its development between Miele and IMA, says Frank Meyrahn, IMA’s director of sales for Asia and North America. Miele was totally committed to making a complete switch from a European-style dowel construction to the Folding System, he says.

“Miele did it because it is the leanest manufacturing you can get and it provides total quality control,” Meyrahn adds. “Miele is a market leader. This new system is part of its quality and its design.”

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