Automation Spurs Customization for European Window Manufacturers.
AT ITS HIGHEST LEVEL, composite panel processing has evolved into an entirely hands-off process. The development of automation for solid wood machining has lagged behind, though, because of the lack of uniformity of the wood pieces. The variable dimensions of solid wood blanks make precise machining a challenge.
But solid wood is now getting its turn. Three European window manufacturers, Ego Kiefer and Biene Fenster of Switzerland and Italy's Sudtirol Fenster, have succeeded in automating their plants. Each produces product from fingerjointed and solid wood blanks of varying dimensions. While each took a different approach in the details of their machining lines, all three share automatic tool changeover and positioning and hands-off conveyorization of parts from one machine to the next.
They have also embraced the idea of "mass customization," producing lots of as few as one window at a time to meet the needs of a single customer, rather than long production runs. In doing so, they have maintained high production levels and short lead times, and since each line requires only a few workers to operate, minimized labor requirements.
All three companies purchased their lines from Delmac Group SpA, the Italian parent company of Delmac Machinery Group, based in Greensboro, NC. Delmac engineered each line using custom machines built by its companies, Gabbiani-GDG, SAG and Busellato.
Delmac hosted a tour of these companies last November. (See sidebar, page 87). Representatives from 10 U.S. wood product manufacturers attended with an eye toward increasing the level of automation in their own plants.
While the trend is still developing in the United States, the European market demands product specifically tailored to a client. As a result, all three lines share traits to help them meet these needs. Each company runs single-window job runs, and each line has the capability to add windows into any position on the production list for almost instant production.
Big Numbers from a Small Company
A single-operator line produces parts for 80 windows a day at Biene Fenster.
BIENE FENSTER, based near Lucern, Switzerland, has made fast production of single windows, rather than long runs of stock items, its specialty. The company's offerings vary by size, thickness and number of panes of glass.
The company has about 50 employees and produces about 80 windows per day. Biene's machining line, installed in 1997 for about $1.7 million, is completely hands-off. No human touches a part between the time the operator inserts wood and the same operator stacks the machined parts.
The line's computer directs the action, working off an electronic cutlist. First, a chop saw cuts long fingerjointed stock down to approximate size, expelling the waste wood and returning longer unused pieces to the operator for later use. Parts are then held on a SAG conveyor that acts as a staging area while the next machine does its work.
A rotating arm picks up on part at a time and carries it through a GabbianiGDG unit that combines single-end tenoner and saw. During the first pass, one end is tenoned. The arm then rotates.
Parts at this point are still longer than their final length. The rotating arm is what allows the line to cut them accurately. It grabs parts off-center, at the mid-point of their final length. As a result, when the arm rotates, the part is in position so only the excess length will be cut. The machine then tenons the second end as the arm carries the part back to the conveyor.
After tenoning, a Gabbiani-GDG machine applies the side profiles. A return conveyor carries parts back to the operator, who loads them on a cart for assembly and finishing.
Adding Assembly into the Mix
Sudtirol Fenster's line goes a step beyond, putting out completed windows instead of parts.
NEAR BOLZANO, in the Italian Alps, Sudtirol Fenster's line produces 300 windows per shift. The line requires six people to operate, more than either Ego Kiefer or Biene, but its scope goes beyond those lines to include window assembly. Instead of just parts corning off the line, the blanks that enter are transformed into completed window frames.
First, cut-to-length blanks pass through a Gabbiani-GDG machine that cuts and sands a profile in one corner. The machine splits that corner off from the rest of the part for use later on in the window's moulding.
After inspection, which occurs as parts are being conveyed without stopping the line, each part runs through a Gabbiani double-end tenoner. The machine adjusts itself for length automatically. A third Gabbiani-GDG machine cuts the inside profiles to hold panes of glass.
At the next station, a SAG machine conveys each part in an serpentine pattern. Robots spray glue on both ends of each part before it travels to assembly.
Two employees assemble each window frame on a Casolin clamp as parts come out of the gluing station. When finished, another conveyor carries the frames to another Gabbiani-GDG machine.
This one profiles the outside of each frame, one side at a time. One person operates the machine, inserting one frame after another. After one edge is cut, the machine has an arm that carries the frame to a return conveyor while rotating it 90[degrees]. The operator re-inserts each frame as it comes back until all four edges are profiled, when he puts the frame onto another conveyor.
The mouldings that were cut at the first machine in the line are re-joined with the completed frame at the end. A worker miters the mouldings and places them inside the frame to keep them convenient for when the glass is inserted.
Ego Kiefer Builds Mountains of Production
A giant window manufacturer keeps its focus custom.
EGO KIEFER, headquartered in Altstatten in southeast Switzerland, is the nation's largest window manufacturer, with annual production totalling about 200 million Francs (US$138 million). Its three plants (facilities are also located in Geneva and Berlin) produce both solid wood and plastic windows, as well as architectural wood doors.
A year and a half ago, the company installed a $1.3 million automated line to machine wood window parts. The line includes more than 80 computer-controlled axes to apply machining, as well as fully automatic conveyorization between stations. It also joins with the finishing line, so blanks are transformed into finished parts ready for assembly with minimal human intervention.
Most of the company's blanks are fingerjointed plies of wood laminated together, but the company also produces higher-end windows from a single solid piece of premium wood. Each blank is cut to length before it enters the line.
After the operator loads parts into the line, they travel through a moulder, which profiles them and calibrates each piece to a known dimension. After sanding, parts move to a Gabbiani double-end tenoner for end machining.
Like the tenoner at Sudtirol Fenster, the tenoner adapts quickly to the specific part being processed. Both sides open and close to the precise length at 10 meters per minute, and a 20-inch extended spindle holds the tooling stacks.
After tenoning, a series of three machines bore, rout and profile the part's sides. A printer labels each part, and a final machine inserts staples that will be used to hang each part on the finishing line. The window elements are conveyed to an elevator that lifts them to the upstairs finishing line.
An operator hangs the machined parts on the finishing line's overhead hooks. The finishing machine, a five-head robotic sprayer from Delle Vedove, coats the parts with either a white lacquer or natural finish. The parts then dry for five minutes and cure for a half hour before an employee removes the staples.
Mass Customization in Action
The line produces 2,000 parts per eight-hour shift -- enough for 250 to 500 windows per day. (Each window has four to eight elements, depending on design.) Despite the large volume, however, any model can be and is made in lots as small as one. The line produces all of the parts for a single window together before moving on to the next window, so no two consecutive blanks receive the same machining.
The line's central computer stores the machining pattern for every part of every model of window the company makes. Working off an electronic cutlist, the computer automatically makes the changes in the line necessary for each part -- adjusting the width between the tenoner ends for part length, changing cutterheads and positioning the boring and drilling heads.
Since no two consecutive parts are identical, machining time for each varies. To cope with that fact, each conveyor station has three sections in a zigzag shape: two belts moving forward, separated by a horizontal belt. This allows parts to be held on the conveyor waiting for the next machine without stopping the machines behind them.
The automatic changeover and digitally stored production list gives the line flexibility. When the company receives rush orders for one of the windows in the computer, it can add them into the list and leapfrog them over other jobs in the queue. Even orders that don't get the rush treatment, however, take only two weeks from order to delivery.
The central computer monitor also functions as a troubleshooting center for the line. The screen shows the programmed and actual positions of every axis, so any out-of-alignment cutter can be found and corrected. Each individual machine's layout can also be viewed for troubleshooting or coding a new machining pattern.
U.S. Firms Tour European Plants
Delmac Machinery Group hosted a technology tour of five European woodworking companies from November 27 to December 1, 2000.
Representatives from ten U.S. manufacturers attended, viewing highly automated lines, most focusing on window production. The three plants featured in this story were part of the tour, as well as Cleaf, a panel laminator near Como, Italy, and On & Bonetti, a window manufacturer near Piacenza, Italy. The tour also visited the manufacturing facilities of Delmac, Busellato, Gabbiani and SAG.
The wood product manufacturers attending were: Arnt & Herman, P.A. Bet, Eggers Industries, Lincoln Wood Products, Merillat Industries, Millwork Specialists, Scherer Brothers, Simpson Mastermark Door, Weathershield and Wood Harbor.
For information on future Delmac tours, contact Gerri Bolton at (336) 854-1211.
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|Publication:||Wood & Wood Products|
|Date:||Feb 1, 2001|
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