The filter capsules are fully assembled, which reduces operator error and assembly costs. Another advantage is that the single-use filter capsules can be sterilized by gamma irradiation, eliminating the need for autoclave or steaming operations. Since the manifolded filtration train is used once, cleaning validation requirements as well as any infrastructure needed for a cleaning system are reduced or eliminated. These systems were designed for biopharmaceutical manufacturers that are concerned about cross-contamination of products. Haughney says there are about 100 of these systems in use.
HyClone, Logan, Utah, supplies cell culture and bioprocessing systems for applications in research and production. The company designed a new facility for processing bovine serum, a component in nutritional media for cell culture operations, with a disposable Pall system. This facility was commissioned in the first half of 2003 and the company is considering other applications.
Justin Hutchinson, market manager of bioprocess containers for HyClone, says the validation cycles for the disposable systems are different from those for traditional filtration systems. “It saves time and money,” he says.
HyClone was able to reduce the utility infrastructure of the new facility, thereby decreasing construction costs — Hutchinson estimates that the facility would have cost twice as much to build using a stainless steel system. “The biggest savings come by way of greatly reduced or eliminated water systems [e.g., deionized water],” says Hutchinson. The need for a boiler, clean steam generator and steam-in-place system (SIP — not needed when using pre-sterilized systems) were all eliminated, resulting in lower validation and qualification costs. Since the overall size of the facility was reduced, this translated into additional cost savings on a square-foot basis.
Haughney says the system has limitations since it will be hard to retrofit the disposable system to an existing hard-piped system with process control. “Our disposable systems can be used as backup or can be used to provide additional capacity for existing systems.” The filter capsules and media can be disposed of in the same manner as any filter media producers are currently using.
Pall is continually expanding its disposable offerings. Earlier this year the company introduced SupraCap 200, a disposable, encapsulated depth filter.
Figure 2. Pall's systems demonstrate the cost, time and safety benefits of single-use systems for multiple filtration processes. Cleaning and cleaning validation are eliminated, and so is cross-contamination of products.
No cleaning required
Decker Industries, Palm City, Fla., a division of Liquid Control Corp., introduced its ParaDyne mix head in late 1999 for processing two-component polyurethane foams and elastomers for making small molded parts, panel and radial air filters, or foam-in-place gaskets. The ParaDyne was developed in conjunction with Purolator, a division of Arvin, for processing polyurethane foam in an automotive air filter application. The mix head was designed to eliminate repeated solvent flushing, improve uptime and stop foam from dripping on the mold carriers. Purolator realized savings of more than $300,000 annually and an increase in uptime of 13%.
Mac Larsen, vice president for Liquid Control and general manager of the Decker division, says the ParaDyne was designed to use disposable dynamic mixers, thereby creating a neat and more cost-effective process for companies that employ continuous and discontinuous flow rates and mixing of two ingredients.
The ParaDyne uses disposable dynamic plastic mixers and, in some cases, static mix nozzles. The mix head has two internal recirculation valves that rotate to switch from circulation to dispense, which is actuated by system software. It also has a pull-back or snuff feature to keep materials from dripping after the correct amounts have been added to the mixture. This mechanism is actuated in timing with the valves.
The disposable parts can be treated as solid waste; Larsen expects these waste costs to be much less than those for waste solvent.
The ParaDyne can process flow rates between 1 cc/sec and 70 cc/sec and fluids with viscosities between 10 cP and 5,000 cP. The mixer operates at speeds between 500 rpm and 6,000 rpm.
Larsen says the ParaDyne has several process limitations, although most applications are within the mix head’s limitations. It cannot process fluids with viscosities higher than 30,000 cP. It also is not suggested for flow rates greater than 70 cc/sec and temperatures of more than 167°F (75°C).
Diane Dierking is senior editor for Chemical Processing magazine. E-mail her at firstname.lastname@example.org.