Technological innovation can be dramatic; it can also be over-hyped (think Segway). Other times technical innovation comes with less drama, often the result of a couple of engineers and their product managers thinking deeply about how to make their design even better for users and those who authorize the purchase — more functional, easier to operate, simpler and cheaper to implement and maintain and so forth. Of course, this is the way of most companies in the business of creating and selling ubiquitous industrial technologies including Pepperl+Fuchs, who recently introduced a highly refined operator interface terminal (OIT) purpose-built for sterile, cleanroom pharma processing environments.
Without being overly remedial, a clean room’s primary function in Pharma is to assure a sterile production environment to prevent products from being contaminated. Further, regulators classify these environments and compel Pharma to follow their specific mandates to control particulate and microbial contamination and assure the public’s safety. The FDA recommends that the area immediately adjacent to the aseptic processing line meet, at a minimum, Class 10,000 (ISO 7) standards during production. Drug makers can also classify this area as Class 1,000 (ISO 6) or keep the entire aseptic filling room at Class 100 (ISO 5). An area classified at an air cleanliness level of Class 100,000 (ISO 8) is appropriate for less critical activities such as equipment cleaning.
IT'S THE PEOPLE
According to P+F, clean room workers are a clean room’s largest contamination source. “People generate particles in the form of lint, skin flakes, cosmetics and respiratory emissions,” says P+F’s Lou Szabo. “To prevent particulates and particles from settling and accumulating on equipment, housing finishes must be hard, polished and free of corners, crevices or seams where dirt and other unwelcome visitors like bacteria might collect.” Szabo notes that the OIT can be a flashpoint of contamination “because that’s where humans tend to spend the most time.” Szabo explains that OITs must be designed, first, to eliminate any feature that promotes the accumulation of contaminates and be able to withstand the rigors of aseptic cleaning. “Housings must resist high-pressure, high-temperature washdowns, including live steam and aggressive cleaning chemicals as well as simpler SOPs such as spray and wipe,” says Szabo.
Pepperl+Fuchs say a major pharmaceutical company with extensive biopharmaceutical operations (one that shall not be named), recently embarked on a program to expand their aseptic manufacturing space to meet demand for a new drug. Operations quality supported by information systems and process controls was a priority, says P+F, and their customer wanted these systems to be accessed by OITs in its Grade A and B spaces mounted flush with the surface of the new space’s modular walls with minimal protrusion from behind. Plant requirements, as well as lessons learned from the initial plant construction, called for two aseptically designed OIT panels in theses spaces: One to communicate with the DCS and a second to communicate with the manufacturing execution system (MES) in a virtualized environment. Additional terminals were also specified to provide access to company intranets and corporate applications such as email, as well as room status displays (RSD). Pepperl+Fuchs’ customer, as well as the firm engineering the new capacity, both wanted the installation and maintenance of the OITs to be more cost-efficient.
PANEL DESIGN'S INHERENT EFFICIENCY
According to Pepperl+Fuchs, the existing workstation’s installation cycle time was long — between six and eight hours per unit for Grade B and A spaces, respectively. “A good deal of time was spent aligning templates, drilling holes, aligning fixtures, affixing rear fixing plates, and finally, sealing all exposed seams with a silicone room temperature vulcanizing (RTV) elastomer sealant/encapsulant,” says Szabo, “This translates to one workstation installation per day, or in the case where 20 or more are being installed, a ‘critical path item’ in the project schedule.”
The company’s improved panel design incorporates some well-refined installation features. To start, the OIT requires mounting the enclosure shell to the studs in the wall. The unit is then secured from the inside of the enclosure shell with a torque-limited drill. As the screws are tightened, a clever spring-activated latch deploys and tightens against the rear of the modular wall. “The shell can be secured in two minutes,” says Szabo, then the integral FDA-grade silicone gasket forms an air/bacteria seal between the shell and wall.”
The company says the door is never removed from the shell, so no electrical connections are disrupted, minimizing commissioning time. Power and Cat5 connections are made, power applied, and the single vault-like hinge swings the door back in place and the latches set, pulling the door firmly against the second layer of the silicone gasket. In the process, an air/bacteria seal between the door and the shell is completed. “Clean rooms are expensive to design, construct and operate,” says Szabo, “and reducing labor-intensive installation time to under an hour and reducing maintenance time by at least 50 percent is certain to save CAPEX and OPEX.”