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July 1, 2001

6 Min Read
Time-tested success formula


Figure 1. Oskar Lehmann (right) was 22 when he started OL Plastik, which celebrates its 40th anniversary in August. To Lehmann's left is Bernd Flakowski, production manager.

Increasing automation, mastering e-commerce, thinking globally, and the practice of leading the customer into new areas of development are considered relatively new strategies in the molding industry. Not so new is the idea of building on good part design. Yet, OL Plastik in Blomberg, Germany has not been shy about employing all four of these concepts, and the company's 40 years of success has proven that they work. 

Oskar Lehmann (Figure 1), who started the company when he was just 22, was already a trained moldmaker at the time. And while he has changed just about everything else over the years, he has never changed his belief that designing and building a top-quality mold is the best guarantee of on-time startup and long-term productivity. He says his main responsibility as a custom molder is to ". . . bring new technology to [our] customers." And a brief look at his current operation shows us that a creative mind coupled with a willingness to try new things is a formula for success. 

Capitalizing on the Product 
OL Plastik serves a variety of markets, including appliances, office and home furnishings, automobiles, retail and trade fair displays, electrical/electronics, and metalworking machinery. Capitalizing on its location in the heart of Germany's furniture industry between Hanover and Düsseldorf, the company offers a proprietary line of furniture-related products (see Figure 2). A 130-page catalog offers more than 5000 standard parts such as end caps, gaskets, connectors, glides, drawer slides, and metal/plastic combination adjustable feet (see Figure 3). Produced in-house, the products are stocked in a high-rack warehouse due to be expanded and automated in the near future. 



Figure 2. OL helped develop and build the molds for a multipart adjustable furniture leg that allows the owner to vary the height to fit an individual person and to compensate for uneven floors (right).

The company takes a proactive role in product development, often bringing the initial idea to the client. To stay on the leading edge in furniture design, for instance, OL added two-component machines and already has more than 300 multicomponent molds in-house. The most frequent combinations are TPU or TPE with PP or ABS to provide optimum adhesion for a growing variety of hard/soft parts. OL brings this technology to customers with suggestions for how best to use it. Lehmann expects multicomponent work to continue growing in all segments now that designers know its capabilities. 

The high volume of parts OL sells requires more than 1000 active tools. Just-in-time has become a fact of life in all of Lehmann's markets, including furniture, which means shorter press runs and more product changes. OL currently averages around 30 mold changes per day. A variety of materials are processed, with a total volume of more than 2000 metric tons/year. Around 500 tons is nylon, 400 tons styrene, 250 tons ABS, 200 tons each PC and PE, 100 tons of PP, and the rest TPU, TPE, PMMA, POM, and a few others. The company offers nearly 700 colors using its masterbatch system. 

No Technology Left Unturned 
Behind it all is a high degree of automation and up-to-date technology. OL Plastik went to 3-D CAD years ago to give itself and its customers an edge. It has continually updated its moldmaking technology, adding spark erosion, wire EDM, high-speed machining centers, and pretty much any other new technology that comes to mind. The 21 moldmakers on staff built more than 300 molds last year and will build that many or more this year. OL also has certified several outside moldmakers to handle overflow work. 

On the molding side, the technology investment is equally aggressive. OL's Blomberg plant has 26,000 sq m (280,000 sq ft) of manufacturing floor space and employs 120 people. There are 73 molding machines with 15 to 600 tons of clamp force and shot sizes from .1 to 1.1 kg (3.5 to 35.3 oz). Fifty of the machines are recent models from Krauss-Maffei. Ten machines from the Winner Series, for which OL Plastik was a pilot site, were delivered last year. For added flexibility, OL Plastik has an interest in a molding shop with 26 molding machines in Thuringia, located in Eastern Germany. 

At its Blomberg plant, most of the machines are part of production cells. Automation is supplied by Klocke, Kuka, and Wittmann working with Krauss-Maffei on the overall system design. 

Automation has become a key part of the company's insert molding operations. Robot handling systems feed inserts directly into the mold and perform part extraction. Production Manager Bernd Flakowski says the big benefit with inmold inserting is consistency in process control. Most products call for both high surface quality and very close tolerances. Inmold inserting supports that, while allowing finished parts to be checked at an ergonomic working height. 

IMM saw one cell where the robot positions six threaded inserts simultaneously into a six-cavity mold for overmolding a PE grip wheel. The screws are placed into a custom fixture and carried to the mold for secure placement. In an application making furniture feet with metal inserts, adding the robot eliminated three people on each of three shifts while doubling the output. 

Another specialty operation performed by OL is gas assist. The company installed its first gas-assist system in 1999 and now features the technology in its custom molding brochure. Gas is primarily used with a 110-ton C Series machine to make handles and office chair armrests that combine excellent rigidity, durability, and surface finish with weight reduction and material savings. Lehmann likes how gas allows for the use of a lower-tonnage machine to reduce costs. 



Figure 3. More than 5000 parts are listed in OL Plastik's catalog, including caps, gaskets, glides, adjustable furniture feet, and more.

After 40 years in the business, Lehmann's first concern is staying up with changes in the marketplace. The most important thing, he says, is to do the right thing at the right moment. Relationships with customers are important, but so are those with suppliers and employees. He considers training a must because people work better if they know not only what they are doing, but why. 

OL Plastik's revenue in 2000 was 17 percent higher than in 1999. The company is large enough to have good resources for its customers, yet small and nimble enough to change rapidly and try new things. For example, winters are cold in northern Germany, but OL Plastik has found a way to reduce its heating bills to near zero. The molder recycles the heat from the production machines into the plant, and since local regulations permit the tapping of underground geothermal heat, a number of shafts were sunk under the buildings to bring up the natural heat from below. 

Contact information
OL Plastik (Oskar
 Lehmann & Co. KG)
Blomberg, Germany
Carsten Lehmann
Phone: +49 (5236) 898-0

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