Ensinger: Semi-finished products for medical technology and semiconductor manufacturing

Material lock for cleanroom (Photo: Ensinger GmbH)

Testing of an extruded round bar (Photo: Ensinger GmbH)

Cleanroom at Ensinger in Nufringen (Photo: Ritterwand GmbH & Co. KG)

Cleanroom at Ensinger in Nufringen (Photo: Ritterwand GmbH & Co. KG)

Cleanroom at Ensinger in Nufringen (Photo: Ritterwand GmbH & Co. KG)

Before a plastic is approved for use in medical technology or the electronics industry, it must meet special requirements. In both sectors, it is crucial that the materials are nearly free of contaminants. Therefore, Ensinger is increasingly manufacturing product lines in cleanrooms. These include compounds, machined finished parts, as well as sheets and rods made from high-temperature resistant plastics.

After the completion of the expansion building in Nufringen, the semi-finished products division not only has a high-bay warehouse with modern logistics but also additional production areas and six new cleanrooms. Ensinger extrudes part of its thermoplastic specialty products for the medical and semiconductor industries here. The cleanrooms are classified according to DIN EN ISO 14644-1 Class 8 or EU-GMP Class D. With their 3-zone cascade principle, they meet the latest state of the art. The planning and implementation of the cleanroom technology were carried out by engineers and technicians from the specialist BC Technology.

Overpressure Ventilation

To prevent particles from entering the manufacturing process, Ensinger uses overpressure ventilation. The clean air enters the cleanroom with minimal turbulence and exits on the opposite side of the room. Especially the sensitive work areas and machines must not be contaminated. In the central production room, where the extruders are located, a higher air pressure prevails than in the adjacent zones of the cleanroom system. The overpressure ensures that dust can only flow out of the production room, not into it.

Double Safety

The raw material lock on the work level above the cleanrooms operates on the same cascade principle. To prevent the plastic granulate from coming into contact with particles from the surrounding air, Ensinger has installed additional laminar flow units here. The two zones of a lock chamber are separated by a glass sliding door. Displacement airflow ensures that no dust can enter the area where employees remove granulate sacks from packaging. On the other side of the sliding door, in the so-called glove box, the pressure of the outgoing, cleaned air is even higher. When filling the drying hopper, employees work with permanently installed gloves that reach through ports in the box.

It is obvious that suppliers of medical technology bear great responsibility, as deviations can directly affect patients' health. Plastic products manufactured by Ensinger for medical applications are therefore subject to strict quality assurance. The increasing requirements of this industry not only influence production conditions but also the further processing of semi-finished products: Sheets, round, and hollow rods extruded in various dimensions are cut to customer specifications in a cleanroom tent and then cleaned. With the help of an X-ray device, employees can safely detect all voids, contaminants, and other inclusions.

Before shipping or interim storage in the new high-bay warehouse, the extruded semi-finished products are shrink-wrapped and packaged in a cleanroom. Ensinger also performs these final two process steps in a cleanroom of ISO class 8. Thanks to the constant and controlled processing conditions, Ensinger can guarantee that no foreign particles enter the final product beyond a defined limit.