Wickert cleanroom presses: Key technology for elastomer processing

Wickert Maschinenbau is experiencing a significant increase in demand for specialized hydraulic presses for elastomer processing in cleanrooms. These systems are primarily used for producing closure systems for pharmaceutical packaging, in the manufacturing of bipolar plates for fuel cells, and for seals and machine components in semiconductor production.

The driving force behind this trend is the growing interest in high-quality packaging components for costly and sensitive medical substances. Additional cleanrooms are also required to meet the rising demand for personalized medicine, such as prefilled disposable syringes for self-medication. The COVID-19 pandemic already highlighted the importance of vacuum compression presses for manufacturing these products.

Cleanroom hydraulic presses are used, among other things, to produce pharmaceutical closure systems made of butyl rubber (IIR) and bromobutyl rubber (BIIR). They are also applied in the production of sealing foils for bipolar plates made of elastomers as well as valve membranes from polytetrafluoroethylene (PTFE) for chemical and medical applications. Rubber-metal composites for semiconductor production are likewise manufactured on these systems.

Customized solutions

Hydraulic presses from the world market leader for cleanroom presses are used in elastomer processing whenever the highest quality standards are required. They meet the most stringent demands for accuracy, temperature homogeneity, and process reliability in sensitive applications. In addition, they are designed to enable precise elastomer processing in cleanrooms up to air cleanliness class 6 according to ISO 14644-1.

Wickert designs and manufactures its systems predominantly as customized machines or in very small series according to customer requirements. Thanks to their modular design, they can be configured in a wide variety of ways.

They achieve processing temperatures up to 500 °C, press forces up to 100,000 kN, and parallelism tolerances of 0.025 mm/m. For the vulcanization of sensitive compounds, vacuum chambers with up to 990 mbar vacuum are used. This prevents air inclusions even with complex geometries and optimizes material utilization of costly compounds.

A central criterion is uniform temperature distribution in the mold. Modern multi-zone controls and closed-loop systems ensure that temperature deviations greater than ±1 K are avoided. At typical processing temperatures up to 230 °C, exceeding these tight tolerances can negatively affect vulcanization and lead to rejects. Absolute control of these key performance indicators (KPIs) is therefore the guarantee for consistently reliable quality.

Fully enclosed systems

The completely enclosed presses, clad in stainless steel, integrate seamlessly into cleanroom concepts. The use of auxiliary and lubricating agents is avoided wherever possible. If they are indispensable, only non-toxic and physiologically safe materials are used. Moving parts of the machines are designed so that no lubricants or auxiliary agents can escape, achieved with high-quality sealing and wiper systems.

The maintenance area, known as the grayroom, and the production area inside the cleanroom are strictly separated to prevent contamination. Hydraulic pumps, control cabinets, and electronic systems are located at the rear of the press, while the cleanroom side, where the compounds are processed, is reserved exclusively for production. The interior design of the press meets all requirements for easy cleaning, avoiding undercuts and dead corners where potential contaminants could accumulate.

Automation reduces particle load

For roughly half of all new systems delivered by Wickert, processes are partially or fully automated. Magnetic clamping plates enable rapid tool changes of ferromagnetic molds within minutes. Systems for automated release agent application ensure reproducible and consistent processes. This step takes place in the closed press area, and integrated aerosol extraction reliably prevents spray mist from contaminating the production space.

Mirrored human-machine interfaces (HMIs) on both the grayroom and cleanroom sides further reduce particle entry. This allows setup personnel to perform all necessary tasks during mold changes from the grayroom.

Monitoring according to GMP standards

Modern systems use KPIs and quality gates to detect faulty process parameters at an early stage. All relevant data is securely documented in accordance with Good Manufacturing Practice (GMP). An access-level matrix ensures that only authorized personnel can make changes to machine or recipe data. The “audit trail” function additionally records and logs all operator actions.

Multi-level presses in compact spaces

Fixed piping replaces conventional hose connections, eliminating the otherwise mandatory six-year replacement cycle. This reduces operating costs and increases machine availability. Since cleanroom space is scarce, space-optimized two-deck presses also provide a way to double production capacity within the same footprint.

More automation in the future

Wickert expects major advances in AI-assisted process monitoring and energy efficiency in the coming years. The company also anticipates that the shortage of skilled labor and the growing diversity of component variants will further drive demand for automation. Thanks to smart setup concepts, automation is becoming increasingly economical even for small batch sizes.

With continuous innovations and numerous retrofit options for existing systems, Wickert expects that hydraulic presses for elastomer processing under cleanroom conditions will continue to play a key role in the future.