Through the years, owing to the gradual expansion of the field of application of sterilization processes, which has made

them indispensable in many aspects of life, these machines have been entrusted with increasingly important responsibilities. However, perhaps because of limited standards issuing and legislation in this field, their relatively low cost or the scarcely diversified experiences of some manufacturers, these sterilizers have not benefited from the considerable technological evolution that has affected industrial machines, especially those used by the pharmaceutical industry, and have remained - so to speak - glorified pressure cookers. Although some manufacturers have proved their worth by offering different technical principles, on the whole small laboratory sterilizers were (and still are) purchased when limited financial resources do not allow, or do not justify, the installation of a more sophisticated machine.

In early 1994 Fedegari, aiming to devise o future generation of laboratory sterilizers, started a highly rewarding dialog with users and vendors in order to understand the main shortcomings or critical aspects observed through daily use of these machines.
Careful analysis showed demand for the following characteristics:
• fully automated operation
• process flexibility
• higher productivity
• low maintenance
• higher process performance
• better ergonomics
• limited cost

Using its vast experience, acquired by meeting the ever-increasing demands of pharmaceutical industries, Fedegari accordingly started to develop the prototypes of what can now be considered as the third generation of laboratory sterilizers, which is described here.
Even the external structure of the machines is altered with respect to the previous generation: the technical area meant to accommodate the actuators and the control equipment is in fact larger, in order to allow to install all the electrical, electronic and fluids piping devices required to perform the various processes.

Sterilizers of the FOB series, with the aid of suitable equipment options, can perform sterilizations of solids with initial vacuum and with final vacuum for drying the load; sterilizations of liquids in open or closed containers, with indirect cooling by means of on internal heat exchanger and a fan (with a magnetic-drive coupling) and sterile air counterpressure; sterilizations of high-pathogen loads with no external treatment of the infected effluents; chamber vacuum or pressure tightness tests; the Bowie & Dick test; monitoring and control of processes based on the F0 value, etc... The technical area now also includes a small independent electrical steam generator

which is equipped with a pump for automatically feeding the deionized water. Therefore, the steam required for the process is no longer produced inside the sterilization chamber or inside the jacket but is supplied constantly by the generator.
This solution offers significant advantages, such as reduction of bad odors and elimination of any corrosion triggering caused by stagnation of water, which may be contaminated by the leakage of product from the load, on the bottom of the sterilization chamber. If the user has steam available, this option can be eliminated.

The door for closing the chamber has also been completely redesigned: in order to reduce maintenance and increase operator safety, the door is conceptually identical to the doors of industrial sterilizers, without closure lever systems and with the now thoroughly tested dovetail pneumatic gasket, patented by Fedegari for its sliding doors. The safety of this solution is absolute, also by virtue of a system of mechanicainterlocks between the lid and the chamber which prevents opening in the presence of residual pressure.

The piping is entirely made of AISI 316L stainless steel and has been engineered in the same way as that of industrial sterilizers, using sanitary-type quick-couplings and pneumatic valves with a special PTFE membrane.
The lid gasket, like the pneumatic valves, is fed by a small electric air compressor, which is also located in the lateral technical area.
This option, too, can be eliminated if the user has compressed air available; compressed air is in any case indispensable to perform processes which include the above described forced cooling of the load.

From the point of view of process control, Fedegari has succeeded in achieving a high level of modularity, flexibility and performance also by using a PLC and appropriate sensors.
The process software has been designed by Fedegari, starting from the software developed a few years ago for controllers of the SUPERSPECTRA series.
By virtue of the computing power provided by the software of the PLC the operator can also choose to control the sterilization phase according to the of accumulated F0 value or to simply print it out; in any case, process documentation provides irrefutable evidence and ensures the necessary traceability.

By using appropriate security passwords, the user can customize the sterilization processes or create new ones to treat specific products. In addition to fully automated operation, this kind of software offers a series of operating safeties and alarms which cannot be obtained otherwise. Fedegari has also made provisions for connecting the sterilizer to remote controllers by means of an RS232 serial port; this allows the option of integrating the machines in any monitoring and control network.

Finally, Fedegari, with the aim of extending the application range of the machine, has developed a socalled "pass-through" version with a second door for unloading, equipped with all necessary functional interlocks with the loading door (mod. F0B2S).

Many other innovations, which would be lengthy to list here, have been introduced in sterilizers of the FOB series with respect to previous ones.
To appreciate in greater detail the remarkable potential offered by this new generation of sterilizers, you should contact our Sales Department or our local agents and dealers.