Aiming for Reduced Cost, Greater Performance

Manufacturers increasingly seek films with special high-barrier properties, and converters answer with aluminum oxide and silicon oxide films. Photo courtesy Oliver Medical.

As medical devices become more complex, so do the requirements for bags and pouches used to package them. Nowadays, packaging must not only be stronger, tougher, and resistant to harmful environments and conditions, but must also be more cost-effective for device manufacturers.

Packaging converters and film manufacturers are meeting the device manufacturers’ challenges with a multitude of new products with a surprising array of film and lamination configurations. With these new products have come added or enhanced properties for greater performance.

Features “customers are asking for in pouches right now are high barrier and low cost,” reports Kevin Zacharias, engineering program manager for Oliver Medical (Grand Rapids, MI). “Device manufacturers still want the quality and barrier properties, but they ask us what we can do about the cost. So we have to delve into alternative film structures as opposed to traditional foil structures. We get a lot of requests for high-puncture films, especially for devices that are large and bulky or have sharp components. So it really is a challenge to keep the price down on materials, since we are using thicker and more-expensive materials than the device manufacturer may be accustomed to using.”

Bag and pouch producers see change in the industry for customers that want films with special high-barrier properties. One area is better barriers for moisture and oxygen. “We see aluminum oxide and silicon oxide films being used more often for moisture and oxygen barriers,” Zacharias explains. “Certain medical devices are very sensitive to moisture and/or oxygen, which could make the device or its contents degrade over time. If the product involves a liquid drug, it is important to have a good moisture barrier incorporated in the pouch. In this scenario, the pouch is critical to maintaining drug concentration levels that are acceptable throughout the stated shelf life of the drug.”

Bag and pouch manufacturers are in agreement about the many requests they get from customers to minimize costs while maintaining high-performance. “For the past several years, there’s been a need to create stronger films at less cost,” insists Jesse Blake, marketing manager at Alcan Medical Flexibles (Chicago). “Whereas traditionally we would use Tyvek and a polyester and a polylaminate, we’re going to a biaxially oriented nylon to get more strength. And we’re focusing on the new high-performance plastomer resins that are coming out. We have to constantly figure out how to keep the gauge down, but increase the strength with more layers.”

Alcan Medical Flexibles has a new breathable gamma sterilization pouch out that was showcased at the Medical Design & Manufacturing West 2008 show in Anaheim, CA. “Our Altitude pouch will have a Tyvek label vent on one side of a polylaminate pouch for gamma sterilization,” says Blake. “It’s breathable, so it can be transported at high altitudes and still maintain a certain pressure differential to prevent blowouts. The vent will also allow for odor removal associated with gamma radiation. When you get into sterilization with EtO, there has been quite a bit of advancement in recent times. About five years ago, it would have taken five to seven days to fill a header bag and then flush it to get out all of the residuals. Now [companies] are doing real aggressive sterilization cycles where they can do it in 24 hours using faster-breathing uncoated Tyvek header bags.”

One representative from a pouch manufacturer mentions that paper-laminated pouches are one way to cut costs. “Tyvek is really tough to tear, so it can stand a lot more strain than a traditional paper-laminate pouch, but it costs a whole lot more,” says Ralph Basile, vice president of marketing at Healthmark Industries Company, Inc. (St. Claire Shores, MI). “Upgrading to a paper-laminate pouch can help. We have a high-end pouch that uses a heavier grade of paper, a thick, 5-ply polypropylene laminate, and three layers of elastomers. After sterilization, polypropylene laminates tend to weaken and then become more brittle. The elastomers are more elastic, so when they are sandwiched in between the laminates it keeps the whole package more flexible.”

Oliver Medical addresses customer demand for products with barrier properties at a reasonable cost by examining alternative film structures as opposed to traditional foil structures.

One of the biggest things happening right now, according to Basile, is radio-frequency identification (RFID). “It’s starting to be used in pharmaceutical packaging, and is slowly making its way to medical devices,” says Basile. “These are package tags that are meant to replace bar codes. With RFID an end-user can store more information on the tag than is possible on a bar code, things like date of manufacture, who inspected the item, what plant it was from, and the date of sterilization.”

Besides cutting costs, converters and film manufacturers must constantly be aware of how to increase bag and pouch performance for next-generation medical devices. “What we’re doing these days to make our high-performance products stronger is to use more multilayer nylon films for added strength, especially since companies are moving products from rigid into flexible packaging materials,” maintains Michael Barr, product manager of films and converted products at Amcor Flexibles (Mundelein, IL). “For high-performance converted products, we can add an aluminum oxide–coated polyester to the laminate in order to improve the barrier properties in the converted products.”

As far as peelability goes, Amcor Flexibles has proprietary peelability features in two of its products called CorePeel and RayOPeel. “These features can be added to customers’ films to allow the other material to peel fiber-free from an uncoated material, like uncoated Tyvek or paper,” says Barr. “Most importantly, the peelable features can be incorporated into the aluminum oxide–coated polyester in order to give the customer the desired additional performance, such as being able to withstand autoclave sterilization.”

This bag and pouch manufacturer uses design and engineering to make strong, high-performing products at minimal cost. “Our customers are asking us to design materials that are stronger than any materials available today, yet somehow they can’t cost more,” says Ed Haedt, vice president of marketing at Perfecseal Inc. (Oshkosh, WI). “So what we’ve done, as well as our competitors, is use film technology to extrude very strong layers in the middle of bag films, using materials like nylon to make materials stronger.”

Perfecseal has taken extrusion technology to its limits by using three or four layers of nylon in a seven-layer film and ending up with a composite that is stronger and lighter than monolinear, polyethylene materials. “We are able to reduce the thickness of the film by half and yet have a stronger film than we had before,” Haedt explains. “The net of it is that we can supply something that is stronger, yet meets, or is even lower than, existing material costs for simpler films.”

Using nylon in coextrusions has allowed Perfecseal to provide high-strength materials to vacuum-pack implants. “Our company has a huge advantage in this area because our parent company, Bemis, has a lot of expertise in vacuum packaging food products,” says Haedt. “Also, in vacuum packaging, you need some good gas barrier properties, since these implants often have a three- to five-year shelf life.”

One converter and material manufacturer said three things come to mind that customers are requesting more often: increased performance, automated roll-fed packaging, and more attention to particulate matter on packages. “We’re seeing more interest in puncture and abrasion resistance for flexible packaging for single pouches or outer pouches with a tray lid,” says Leslie Love, director of healthcare sales with TOLAS Healthcare Packaging (Feasterville, PA). “We’re seeing many customers being challenged to reduce costs. We have validated a material combination that utilizes a coated Tyvek/nylon structure that has solved many of these challenges for our customers.”

Love says that, for a number of years, there were limited choices of how a product could be packaged with high-tech automation. “Device manufacturers are either large volume and use form-fill-seal, or they’re small volume and can’t load pouches by form-fill-seal,” says Love. “We’ve seen some developments in the equipment side lately for pouches on a roll. What we’ve had to do is hold closer tolerances and roll tensions and turn out packages that work well with device manufacturers’ automated machinery.”

Customers continue to require packagers to reduce the amount of allowable particulates. “The reality is that a lot of [companies in] the device industry are shipping products to Japan, which has very strict inspection criteria,” Love explains. “What we’ve been doing to address that is a three-pronged approach. First, we work very closely with our film and foil suppliers to reduce particulate matter; second, we now have a large number of people performing additional visual inspections; and third, we have added antistatic, brush web vacuums to all of our slitting equipment and pouch machines and air-scrubbing equipment in the plant.”

Whether it is cutting costs, increasing performance, or innovating with new products, bag and pouch converters and manufacturers will have many challenges to deal with in the years to come as they adapt to a global marketplace that changes rapidly.

David Gaines is a freelance writer based in Collinsville, OK.