Product description
Reusable freeze bag protection cassettes are designed to protect single-use pharmaceutical bags during freezing, frozen storage and transportation. The rigid metal enclosure supports the bag, tubing and process connections and helps reduce the risk of mechanical damage at very low temperatures.
The cassette is individually configured around the specific bag, tubing layout and connectors. Standard configurations can accommodate single-use bags from approximately 5 mL to 2 L, with larger sizes available for custom applications.
Technical overview
Flexible single-use bags and tubing become more vulnerable to mechanical stress when frozen. A rigid protection cassette provides external support to the assembly and limits movement during freezing, storage, handling and transport.
Internal form elements can be designed around the bag and fluid-path geometry to secure the container, tubing and connectors. This is particularly relevant for assemblies incorporating larger sterile connectors or other components that require defined positioning.
The reusable metal construction is suitable for pharmaceutical environments and can be cleaned between uses. Aluminum, stainless steel and electropolished stainless-steel configurations are available.
Operating principle
The single-use bag assembly is placed inside the rigid cassette before freezing. Internal contours and retaining features position the bag, tubing and connectors so that movement is restricted during handling and transportation.
As the product freezes, the cassette provides mechanical support around the flexible assembly. This helps protect the bag and connection points from impact, vibration and uncontrolled movement while the product is in a frozen and potentially more fragile condition.
Depending on the freezing process, the cassette can be supplied with openings in the housing to increase airflow around the bag or with a closed housing where additional enclosure is preferred.
The flat cassette geometry is suitable for conventional freezer storage and can also be configured for use with plate-freezing equipment.
Material options
Freeze bag protection cassettes are manufactured from metal rather than disposable polymer materials. Available constructions include:
- Aluminum
- Stainless steel
- Electropolished stainless steel
Standard surfaces can be supplied cleaned and degreased, while electropolished surfaces are available where a more refined stainless steel surface is required.
The appropriate material should be selected according to handling, cleaning, freezer environment, required durability and site-specific operational requirements.
Available micron ratings
Not applicable. A freeze bag protection cassette is a mechanical handling and storage component and does not contain filtration media. It therefore has no micron or pore-size rating.
If the associated single-use assembly contains filtration components, filter membrane and micron rating are specified separately as part of the fluid-path configuration.
Design and construction
Each cassette is configured around the required single-use bag and its associated tubing and connection technology. The internal geometry can therefore be adapted to the actual assembly rather than relying on a universal cavity.
Bag size range
Standard configurations are suitable for bag volumes from approximately 5 mL up to 2 L.
Typical supported volumes include:
- 5 mL
- 50 mL
- 100 mL
- 250 mL
- 500 mL
- 1 L
- 2 L
- Larger or custom bag sizes on request
Temperature capability
The cassette is designed for pharmaceutical freezing applications at temperatures down to approximately −85°C and below. Suitability of the complete system must also consider the bag film, tubing, connectors and frozen product.
Perforated and closed designs
Two principal housing concepts can be considered depending on the freezing and transport process.
Perforated or slotted housings allow increased air circulation around the bag and can support efficient heat transfer during freezing.
Closed housings provide a more enclosed cassette construction and can help prevent materials such as dry-ice granulate from entering the cassette during transport.
Bag, tubing and connector protection
Internal contours can be designed to locate the bag and secure tubing and process connections. This helps prevent components from moving freely within the cassette during freezing, storage and transportation.
Configurations can also accommodate relatively large sterile connectors and other fluid-path components where sufficient internal space and mechanical protection are required.
Technical construction details
| Bag volume range | Approx. 5 mL to 2 L, larger sizes on request |
| Temperature | Down to approximately −85°C and below |
| Materials | Aluminum, stainless steel |
| Surface | Cleaned and degreased; electropolished option available |
| Sheet thickness | Approx. 0.5–2.0 mm |
| Dimensional tolerances | According to DIN ISO 2768-cK |
Identification and handling options
Cassettes can be individually laser marked with identification such as part numbers or QR codes. Sealing options can also be incorporated where required for handling or traceability.
Dedicated freezer inserts, racks, holders and transport systems can also be developed to accommodate multiple cassettes within a common storage or logistics system.
Typical applications
Freeze bag protection cassettes are intended for pharmaceutical and biotechnology processes where frozen product must be stored or transported in flexible single-use bags.
- Drug substance freezing
- Frozen drug substance storage
- Frozen pharmaceutical intermediate storage
- Cell and gene therapy processes
- Vaccine storage
- Cryogenic and low-temperature process handling
- Single-use freeze bag protection
- Frozen product transportation
- Dry ice transportation
- Plate freezer applications
- Conventional freezer storage
Key benefits
- Mechanical protection: provides a rigid enclosure around flexible single-use bags, tubing and connectors.
- Low-temperature capability: designed for pharmaceutical applications at approximately −85°C and below.
- Application-specific design: the internal geometry can be configured around the actual bag assembly and connection layout.
- Connector protection: internal contours can accommodate and secure larger sterile connectors and other fluid-path components.
- Reusable metal construction: aluminum and stainless-steel cassettes can be cleaned and reused.
- Different freezing concepts: perforated and closed housing configurations are available.
- Flexible freezer integration: the flat design can be considered for conventional freezers and plate-freezing systems.
- Identification options: laser marking with part numbers or QR codes can be incorporated.
Configuration and quotation
Freeze bag protection cassettes are normally configured around the actual bag assembly rather than selected only by nominal bag volume. Bag dimensions, tubing routing and connector geometry all influence the final cassette design.
For technical configuration and quotation, provide the following information where available:
- Bag manufacturer or bag drawing
- Nominal bag volume
- Filled bag dimensions
- Bag film construction where relevant
- Tubing dimensions and routing
- Connector types and dimensions
- Required minimum storage temperature
- Freezing method
- Conventional freezer or plate freezer
- Storage and transport method
- Dry ice transport requirement
- Preferred cassette material
- Perforated or closed housing
- Surface-finish requirement
- Laser marking or QR-code requirement
- Rack or multi-cassette handling requirement
- Prototype quantity
- Estimated annual demand
Where no existing cassette design is available, a bag drawing or physical bag assembly can provide the starting point for developing a suitable protection system.