Application

High-speed doors for pharma and cleanrooms

A cleanroom door is a high-speed door that separates cleanroom zones with short open times, a tight curtain and smooth, low-particle surfaces, keeping the pressure cascade and cleanroom class stable in the pharmaceutical industry, in laboratories and in healthcare.

A cleanroom door is a power-operated opening in the envelope of a controlled area that allows the movement of materials and people without compromising room conditions. Designed as a high-speed door, it typically opens at 1.5 to 3 m/s and closes immediately after each passage. The time window in which air and particles can move between two zones therefore remains very short. For material transport with pallet trucks, roll containers or forklifts, it is the practical alternative to a manually operated door in many cleanrooms.

High-speed doors for cleanrooms are not standard doors with a white curtain. They have to fit into the pressure cascade of the ventilation system, run with minimal abrasion and withstand regular wipe disinfection without damage. Frame, guides and covers are therefore usually made of stainless steel 304 (1.4301) or smooth coated surfaces, and the curtain of low-porosity PVC fabric without seams, pockets or open edges.

In the pharmaceutical industry, a pharmaceutical high-speed door is mainly found at material airlocks, between manufacturing and storage, at cold rooms for temperature-controlled medicinal products and at transitions to unclassified areas. In healthcare, such doors are used in the supply and disposal zones of hospitals, in the reprocessing of medical devices and in laboratories. Medical technology, electronics and semiconductor manufacturing and cosmetics production have comparable requirements. Related hygiene requirements in food production are covered on the page High-speed doors for the food industry.

Cleanroom classes are defined in ISO 14644-1 from ISO 1, the strictest class, to ISO 9; the decisive factor is the permitted number of particles per cubic metre of air. For the manufacture of sterile medicinal products, the EU GMP Guide additionally distinguishes grades A to D. High-speed doors for material traffic are used mainly in areas of lower cleanliness classes and at transitions to unclassified zones; whether a door is acceptable in a particular class is decided by the operator’s cleanroom and qualification concept.

Requirements in this application

• Short open times to maintain pressure between cleanliness zones
• Low leakage through guides and floor connection when closed
• Low-abrasion running without generating particles
• Smooth surfaces with few joints, suitable for wipe disinfection
• Resistance to cleaning agents and disinfectants
• Airlock-capable control with mutual interlocking
• Touch-free activation and traceable operation

Typical challenges at the door opening

The biggest problem at cleanroom door openings is the collapse of the pressure differential. Cleanrooms work with a pressure cascade: the cleaner room has a higher pressure than the adjacent one, and EU GMP Annex 1 gives a guidance value of at least 10 Pa between adjacent rooms of different grades. When a door opens, this difference equalises quickly, the directional airflow from clean to less clean breaks down, and particles can migrate against the intended direction. A slow door, or one that opens unnecessarily often because of false triggering, sets off pressure alarms that have to be investigated and documented as deviations. In laboratories handling biological agents or in the production of highly potent active ingredients, the principle is reversed: negative pressure keeps the substances in the room, and the door protects the surroundings.

Weak points that only become apparent in operation add to this. Open sections, horizontal ledges and gaps at the wall connection collect particles and are difficult to disinfect. Painted parts can flake off under aggressive disinfectants. A drive that starts abruptly creates turbulence in the room air, and a curtain that bulges under differential pressure and does not sit cleanly in the guide increases leakage. In healthcare and laboratories, there is also mixed traffic of staff, trolleys, bed transport and industrial trucks, which requires reliable safeguarding of the passage.

The right solution

For most cleanroom applications, an indoor high-speed door with a smooth PVC curtain and stainless steel frame is the right basis. The curtain runs in closed guides with sealing profiles, and the bottom edge closes with a flexible bottom seal. The shaft housing and drive are encapsulated and fitted with sloped covers so that no dust settles on top. Where the installation situation allows, the drive sits on the side of the lower cleanliness class or in the technical area.

Short cycles and the right control are decisive for maintaining pressure. A frequency inverter accelerates the curtain smoothly and brakes it under control, which reduces turbulence and abrasion. The hold-open time is set as short as the traffic allows. Between zones with high protection requirements, two doors are interlocked as an airlock so that both are never open at the same time. An adjustable delay between closing one door and opening the other gives the ventilation time to rebuild the pressure in the airlock.

Activation is touch-free: by radar motion detector with a narrowly set detection field, by induction loop for industrial trucks or by touchless proximity switch for staff. A light curtain and a safety edge safeguard the passage. Depending on the control, status signals such as door open, door closed and fault can be transferred to the building management system or the cleanroom monitoring system so that open times remain traceable. For cold and frozen storage of medicinal products, an insulated freezer door is also an option.

Requirement	Solution at the door	Benefit
Pressure retention	High opening and closing speed, short hold-open time	Pressure cascade remains largely stable
Low leakage	Curtain in closed guides, sealing profiles and bottom seal	Less transfer air when closed
Low particle generation	Low-abrasion running, soft start via frequency inverter	The door does not become a particle source itself
Cleanability	Stainless steel 304 or 316, smooth curtain, sloped covers	Wipe disinfection without dirt traps
Separation of two cleanliness classes	Two doors with mutual interlocking as an airlock	No direct connection between the zones
Hygienic operation	Radar, induction loop or touchless switch	No hand contact with the door
Traceability	Status signals to the building management system, technical documentation	Supports monitoring and qualification

Benefits for your operation

• Stable pressure cascade even with frequent material traffic
• Fewer pressure alarms and deviations caused by open doors
• Less particle ingress into the cleaner zone
• Fast, reproducible cleaning and disinfection
• High throughput despite airlock operation
• Less load on the HVAC system thanks to short open times
• Safe passage in mixed traffic of staff and industrial trucks

Planning and installation

Planning a cleanroom door starts with the ventilation and zoning concept, not with the door. Clarify early on with the cleanroom planners which cleanliness classes adjoin each other, which pressure differential is to be maintained and in which direction the air must flow. This determines the position and number of doors, whether an airlock is needed and the permissible residual leakage, which the ventilation system has to compensate as transfer air.

Structurally, a clean connection to the room envelope is what counts. Cleanroom doors are often installed in panel wall systems; frame and wall must then be joined tightly with as few joints as possible, and the connecting joints sealed with cleanroom-compatible sealant. The floor in the door area should be level so that the bottom seal makes full contact. Headroom and side room are often limited, because suspended ceilings and service lines run close above the opening; these dimensions therefore belong in the planning from the outset. Standard dimensions and notes on headroom are on the page High-speed door sizes.

The door is delivered direct from the factory and installed by your installer. When retrofitting during operation, installation itself is a contamination risk; it is planned with enclosure, dust protection and subsequent thorough cleaning and agreed with quality assurance. Installation is followed by a function test, adjustment of the control and, depending on the concept, qualification. Which documents are supplied with the door is described under Delivery and installation; further notes for specifiers are on the page for planners.

Regulations and standards

A high-speed door in a cleanroom is first and foremost a power-operated door: it is subject to the product standard EN 13241 and to the safety-in-use requirements of EN 12453, while EN 12635 covers installation and use. Inspection and maintenance follow the manufacturer’s instructions and the national workplace regulations in the country of installation. For the cleanroom itself, the classification of air cleanliness to ISO 14644-1 applies; in the manufacture of medicinal products, the EU GMP Guide also applies, whose Annex 1 covers the manufacture of sterile medicinal products and whose Annex 15 covers qualification and validation. In healthcare, national standards for ventilation in healthcare facilities set additional requirements.

Important for classification: neither ISO 14644 nor the GMP Guide certifies individual doors. What matters is that the room and its equipment demonstrably achieve the required conditions in qualification, typically structured as DQ, IQ, OQ and PQ. For this, you will generally need material specifications, a functional description, wiring diagrams, setting values and test reports for the door; clarify the scope in your enquiry. If flammable solvents are processed, explosion protection under ATEX must also be checked.

Cost-effectiveness

Cleanroom air is expensive because it is filtered, conditioned and supplied at high air change rates. Every unnecessary second of open time increases the demand for treated supply air and forces the ventilation to compensate for pressure drops; a fast-closing, tight door reduces this demand.

In the pharmaceutical industry, the follow-up costs of deviations weigh even more heavily: a pressure alarm caused by a door left open too long triggers investigations and documentation effort and, in the worst case, an interruption of production. Throughput matters too, because an airlock with slow doors slows down every material transport twice. What determines the investment in a cleanroom door is explained under High-speed door cost; you can put your door together in the configurator for indoor doors.

Recommended equipment

Typical sizes in this application: 2,000 × 2,500 mm to 3,500 × 3,500 mm. All common sizes are listed under High-speed door sizes.

Checklist for your enquiry

• Which cleanliness classes adjoin at the door (ISO 14644 class or GMP grade), and which side is the cleaner one?
• Which pressure differential is to be maintained, and are there areas with negative pressure, for example for containment?
• Single door or airlock: how many doors, how large is the airlock room, and what delay is needed between the doors?
• Which cleaning agents and disinfectants are used, is there room decontamination, and is stainless steel 304 or 316 required?
• Which types of traffic pass through the door (staff, trolleys, pallet trucks, forklifts), how often per hour and with what dimensions?
• Exact clear opening, available headroom and side room, wall construction and floor condition
• Which interfaces (building management system, access control, fire alarm system) and which documents for qualification do you need?
• How is the emergency opening handled in the escape and rescue concept, particularly with interlocked airlocks?

Suitable door types