Sponsored By

March 1, 2001

6 Min Read
The ideal cleanroom: Build it and they will come


Multinational Wilden's cleanroom experience jump-started its new Swiss facility (above), where it fully assembles devices like the Novartis dry powder inhaler (below).


Wilden AG Schweiz, the rapidly growing Swiss operation of German-based multinational Wilden GmbH, is putting the final touches on a facility designed from the ground up for molding high-precision technical parts and for cleanroom production of molded parts and complex assemblies. To ensure the highest level of functionality, Wilden decided to augment its considerable internal strengths with outside expertise. 

When the predecessor company to this operation was acquired by Wilden in 1993, it was located in two buildings in Zug, about 10 miles from the present location in Küssnacht. Wilden had been expanding in the medical sector for some time, as well as in its other main market, complex technical parts. 

Jakob Speich, general manager of Wilden AG, says with a smile that the technical and medical parts are equally demanding, the only real difference being the cleanroom. Confident of its technological competence, Wilden goes after the most demanding medical applications, which it can handle from concept to finished or semifinished assembly, including the mold. 

Expanding Wilden's medical capacity in Switzerland made sense, says Speich. Many worldwide medical and pharmaceutical companies have headquarters and/or operations in this relatively small country. For example, Wilden AG is a prime supplier to Novartis and Roche, among others. Wilden briefly considered expanding its Zug plant (13,000 sq m), but the two-building facility was not optimal for a high-productivity cleanroom. Wilden moved into the new plant in Küssnacht late in 1998, formally created the company Wilden AG Schweiz, and quickly finalized the cleanroom plans. 

It Takes a Team 
Setting up a cleanroom takes a variety of talents, says Speich. Above all, it must be done by people with hands-on experience in that environment. Wilden's cleanroom facilities in Pfreimd, Germany have been in operation for more than 20 years, so practical experience was at hand. To ensure that its planners were not limited by their own thinking, Wilden enlisted the help of an outside firm. When it found ONI Wärmetrafo GmbH of Lindlar, Switzerland, the concept quickly took form. 

Wilden's approach toward cleanroom use is functional, so the building was designed from the inside out with a technical parts molding area and two medical molding/assembly cleanrooms. The first step was to create a process flow chart/machine layout. Next came an actual floor plan, followed by designs for utilities such as air, water, heat, and electricity to support the layout. 

Wilden uses heat from the machines to warm the building in winter, so particular attention was paid to areas that lacked a local heat source. Recycling heat from machines means Wilden uses less than 100 liters (26 gal) of heating oil per month to heat 30,000 sq m (323,000 sq ft) of floor space during the winter—and winters can be cold in Switzerland. 


The newest machines acquired to expand Wilden's cleanroom capacity are from Demag Ergotech. They are mounted on special feet that allow space for cleaning under the machines.

Of the 37 molding machines at Wilden, 20 of them (25 to 300 tons) make technical parts that do not require a cleanroom. In the first cleanroom to go fully operational, called the Yellow Room, there are nine machines of 25 to 150 tons. The room is at full capacity making all the parts for and assembling a dry powder inhaler unit for Novartis. The device is finished to the point that the manufacturer simply inserts the medicine and completes final packaging. 

Dry powder inhalers are a high-growth category in the medical market. Wilden began volume manufacturing of the Novartis unit a little more than a year ago. The volume, which is undisclosed for competitive reasons, has increased quickly and should be triple the original volume by this spring. An inhaler produced at a Wilden plant in Germany requires 40 presses to meet demand. 

In the second cleanroom, or Red Room, seven of the eight machines are from Demag Ergotech, including several of its advanced hybrid El-Exis models. This cleanroom produces cuvettes—sophisticated diagnostic devices with very close tolerances—for Roche. 

Each cleanroom has two types of entrances that provide different levels of access to the room.

Leveraging Infrastructure 
Part of the Wilden Group is a 100-person moldmaking facility in Wackersdorf, Germany. Since Wilden AG's business is predicated on volume output, it has a fair number of complex high-cavitation, hot runner molds. Most are made by Wilden's Wackersdorf operation. 

The same location also makes automation and parts handling systems. The custom-automated handling systems and robotics on the cleanroom machines are all designed, produced, and supported by Wilden. 

The workflow within the cleanrooms is logical and linear. Raw materials come in one end, travel to the molding area, move on to assembly, and exit the other end in sterile packaging. 

Each cleanroom has several entrances colored blue or white. Going through the blue entrance provides only limited room access and requires that you cover your shoes, hair, and hands. Going through the white entrance allows full access to the room and requires that you cover every part of your body and disinfect your hands before gloving. 


Central material handling and drying were an intrinsic part of Wilden's plan for the new cleanroom facility.

Both Wilden cleanrooms are officially listed as Class 100,000; in fact, they operate much closer to Class 10,000. The more established of the two is already classified as a microbiological room, meaning far fewer microbes in the air. The second cleanroom is approaching that level. Cleanroom air pressure is greatest in the center and diminishes toward the edges to help the air exit. Incoming air is thoroughly filtered. 

It is worth noting that the machines in the cleanroom are neither fully electric nor cleanroom specific. Speich says the Demag machines are clean by design, and this is easily proven as the rooms are frequently surveyed for contamination. 

Wilden AG's annual revenue from completed orders is rising, and when it reaches about 36 million Swiss Francs ($21.5 million), the plant will be at full capacity. The plan is to move applications to other Wilden plants that have capacity and/or expand this plant. 

Medical parts in general are a growing market, says Speich, and this segment requires a strong engineering presence and adequate manufacturing capacity. Wilden offers both. Clients want development support and advanced production technology. Yes, Speich says, price is an important issue; however, the need for consistent quality is extreme—people's lives depend on it. 

Contact information
Wilden AG Schweiz
Küssnacht, Switzerland
Jakob Speich
Phone: +41 (41) 854 0910
Fax: +41 (41) 854 0919
Web: www.wilden.de
E-mail: [email protected]

Sign up for the PlasticsToday NewsFeed newsletter.

You May Also Like