Images courtesy of Porex
A medical technology company sought to develop a new container for surgical instruments that could be used in autoclave sterilization. Guangdong Xianfeng Medical Technology Co. Ltd had previously been offering containers that utilized single-use paper and textile filters for steam penetration during sterilization and to maintain sterility post sterilization. Because of some material limitations, the Chinese manufacturer reached out to Porex for help with developing a robust, reusable bacterial barrier as a cost-saving alternative, explained Jack Chan, Ph.D, global marketing director for Porex.
Guangdong Xianfeng Medical was also driven by new legislation and regulations emerging in China intended to improve patient outcomes and healthcare worker safety. “As a result, there is a tremendous need to deliver high-quality innovations for decontamination and sterilization for the medical device industry,” Chan told MD+DI. “Lifesaving and health betterment procedures often leave patients vulnerable to healthcare-associated infections (HAIs), especially when the instruments used in these procedures lack proper sterilization. In fact, about one in 31 hospital patients acquires a HAI on any given day as a result of poor cleaning or disinfecting practices around a surgical procedure at a healthcare facility.”
Porex suggested use of the Porex Virtek PTFE venting and filtering solution made from the company’s proprietary medical-grade sintered PTFE hydrophobic membrane. The filter consists of particles fused together through heat and pressure and does not require supporting layers (or a scrim), unlike expanded PTFE film. It allows high airflow for optimal venting during the autoclave sterilization process and features high bacterial filtration efficiency to maintain sterile integrity during transport and storage, the company explained in a statement.
“Generally, PTFE is a high-performance material with high temperature resistance and chemical resistance,” explained Chan. “The Porex sintered PTFE manufacturing process of Virtek results in an intricate network of open-celled, omni-directional pores, that is strong and durable. This offers a different level of performance, as the manufacturing process of the material begins as fine particles with a tight size distribution. The material then undergoes a forming and sintering process to create a bulk microporous structure. The process fuses the fine particles together while creating voids. The resulting porous structure is then skivedto a precisely controlled thickness. Ultimately, a durable, design-flexible 3D material that does not require a supporting layer (scrim) and has long-term value is created.”
Chan said that the Porex sterilization vent introduced a new concept to the market, which became known as a permanent, or “fit and forget,” filter. “The flexibility of Porex’s manufacturing processes provided a cost-saving alternative to traditional materials, along with substantial performance and convenience advantages,” said Chan.
Porex’s Virtek PTFE venting and filtering solution remains in place during sterilization. “The sterile container [shown below] is fitted with a robust, reusable sterilization filter that is engineered to improve the autoclave sterilization process and helps reduce the risk of infection to patients and healthcare workers alike,” said Chan. “The Porex Virtek PTFE venting and filtering solution vents the steam that sterilizes the instruments as well as blocks bacteria during subsequent storage until use in surgery.”
The PTFE typical thickness is 0.65 mm-1.00 mm, but it can be thinner, Chan said. “Its pore structure has minimal shrinkage at elevated temperatures and is safe to handle without risk of damage,” he said.
Chan added that the vent can be used for up to thousands of autoclave sterilization cycles without any performance degradation. “The filter has a printable surface, so the user can record the date it was sterilized and keep track of the number of sterilization cycles,” Chan said. “The robust 3D sintered pore structure enables the filter to be reused and improves cost, performance, and production efficiencies. It eliminates the need for single-use paper and textile filters, which are wasteful and ineffective vents for sterile containers.”