Relying on the Strengths of Rigid Trays
Medical device packagers are counting on trays not only to protect their products, but also to accommodate entire product lines, withstand certain sterilization methods, and lengthen product shelf life.
by Karen G. Beagley, Midwest Editor
In recent years, medical device companies have begun searching for packaging materials that have minimal impact on the environment as well as on their bottom lines. For some, this has meant using flexible bags and pouches rather than rigid trays. (See "Cutting Costs and, Literally, Corners", PMP News, February 1998.) But, despite the fact that most medical device companies are trying to keep their costs down in order to remain competitive, no mass exodus from the use of trays has occurred.
Oftentimes one thermoformer can handle every need of a medical device packager. Photo courtesy of Berkley Industries.
In fact, a recent market study shows that the worldwide demand for medical trays is actually increasing. According to the Cleveland-based market research firm The Freedonia Group, the demand for surgical, diagnostic, and other procedural kits within the healthcare sector should increase nearly 5% annually to total 2.9 billion units in the year 2000.
But medical companies are not only demanding more trays, they are demanding more from their tray suppliers. In addition to asking for reliable yet economical materials, packaging engineers are also seeking specialized trays that can serve as packaging for an entire product line, withstand certain sterilization methods, and provide a long product shelf life. Many material suppliers and tray thermoformers are providing just that.
Trays are typically made from one of the following materials or material combinations: aluminum foil or paperboard with sheets of acrylic, expandable and high-impact polystyrenes, high-density polyethylene, polyethylene terephthalate-glycol (PETG), polycarbonate, polyvinyl chloride, and barrier films. When the bottom web is formed and filled, it is sealed to a top web or flat lidding composed of plastic film, medical-grade paper, specialty foil, or spunbonded olefin.
The material a medical device manufacturer chooses depends on a number of factors. "The need for cost containment, continued quality and package integrity, and environmental reasons all figure into the material decision," says Boon Chew, regional business market manager of Eastman Chemical Co. (Kingsport, TN). Eastman's Eastar PETG copolyester can be put back into the recycling stream.
But manufacturers need materials to be more than just recyclable. Other issues that manufacturers take into account are whether the material can be incinerated with little effect on the environment. If it can't and is meant to be sent to a landfill, it must maintain its integrity to protect waste handlers against infectious waste. Many medical device manufacturers have even moved recycling upstream by working with coextruders who take back and recycle tray manufacturing scrap.
But the device maker's most important concern appears to be reducing cost. One way manufacturers can keep costs down is to use one style of tray for more than one product line. Explains Jimmy Ramos, senior buyer at Baxter Healthcare Corp. (Anasco, Puerto Rico): "We are standardizing many of our trays in order to use one type of tray for three or four different products. This will give us increased buying power when purchasing the trays."
Device manufacturers also depend upon material suppliers to offer economical materials. "Many medical device manufacturers are seeking cost reduction opportunities in their packaging process," says Mike Laprocido, director of sales and marketing of BP Chemicals (Cleveland). To help manufacturers find such opportunities, BP Chemicals markets Barex film, which features low specific gravity for better yields, does not require a silicone coating, and can be thermoformed.
Many thermoformers, including Perfecseal, both design and produce trays for medical products.
Packaging manufacturers can use calendered Barex film from Klöckner Pentaplast of America (Gordonsville, VA) to control material gauge. "The excellent flow characteristics and rigidity of Barex films coupled with the calendered sheet characteristics offer opportunities to not only down-gauge, but to reduce total package cost," adds Michael Ryan, Klöckner's product manager of Barex films.
Klöckner has also developed an alternative to standard PETG. "As an extension to our Pentamed PETG medical device films, we have developed GPETG," says Randy Scott, market manager for medical device films at Klöckner Pentaplast. "This is a PETG/APET/PETG coextrusion that provides sealability to Tyvek spunbonded olefin at a reduced cost over standard PETG film. This product is already established in Europe and is being tested by several customers in the U.S. market."
One way for device manufacturers to reduce packaging costs is to form design and development partnerships with tray manufacturers. Elvera Kearns, package associate at Osteonics (Allendale, NJ), explains that her firm relies heavily on its tray thermoformer. "It is almost as if they become our designers. We go to them with ideas on what we want and it becomes a give-and-take situation."
Osteonics isn't the only one counting on such a partnership. "We have found that instead of using three or four different thermoformers, medical device manufacturers are using a single source to form a partnership," says Dave Jacobs, director of new business development at Berkley Industries (La Mirada, CA). "They want a constant exchange of information whether it is done electronically, via CAD/CAM files, or by E-mailing purchase orders."
Such partnerships can even help medical device manufacturers get their products to market quickly. Says Dick Simmons, vice president of sales and marketing of Plastofilm Industries Inc. (Wheaton, IL): "Our customers want quicker product development—they want a prototype as soon as possible. This increases our role as a partner helping in all the development stages."
Matt Barnard, package product engineer at 3M's Dental Product Div. (St. Paul, MN), recently worked with Plastofilm to design a tray to hold a dental adhesive system. Plastofilm thermoformed a white styrene tray along with a smaller tray, also white styrene, that contains 48 thermoformed disposable mixing wells made of black HIPS. Rather than ship all of the disposable mixing wells in bulk, Plastofilm offered to package 48 mixing wells in each of two trays and to pack everything into 3M's refill folding cartons, eliminating repacking at the 3M plant. According to Barnard, "Plastofilm's willingness to accommodate our extra packing requirements has allowed us to be more efficient in our assembly process. Whatever we can do to reduce lead time, we will do. By working closely with our vendor in the prototype stage we have significantly reduced our lead times."
Plastofilm also worked with another client, PE Applied Biosystems, a div. of Perkin-Elmer (Norwalk, CT), to create a double-hinged clamshell tray to package high-performance liquid chromatography columns. The tray can hold cartridges measuring 3 cm and smaller, making it an interchangeable package for many different-size cartridges.
The package was designed by Perkin-Elmer's packaging engineer Albert Harris, whose main goal was to decrease the cost of packaging. But by placing a capped cartridge in a tray, he also eliminated the need to heat-seal each cartridge into its own pouch.
After the cartridges are placed into formed indentations, an arm that also has symmetrically formed indentations folds over and snaps onto the tray, holding the cartridges in place. The cover then folds over the tray, snapping onto the arm. A tab that is designed into the cover allows users to open and close the tray easily. The cover is designed to accommodate a tamper-evident label.
"It is important for us to use the tamper-evident label," says Ilze Birznieks, associate product manager at Perkin-Elmer. "It protects us from someone returning contaminated products, which we may inadvertently restock."
Plastofilm Industries' double-hinged clamshell tray can be opened and closed easily.
Jim O'Dierno, senior vice president at Prent Corp. (Janesville, WI), works with medical device companies to help them get their products to market quickly. "Our customers want things done quicker," he explains. "We take CAD files and electronically send them back and forth between ourselves and our customers to speed the process. It becomes an issue of speed to market—who can present their product first."
Such open communication has benefits. "This change in our working relationship gives us direct communication between our customers' designers and our designers," says John Rottunda, executive vice president of Perfecseal of North America (Mankato, MN). "All of this aids in accelerating the design process. We can deal directly with any question the customer has. We also spend time at the beginning asking questions such as whether they will use the tray for multiple products. The better a working relationship is, the greater chance for getting product to market faster."
The use of electronic technology not only strengthens the relationship between supplier and customer, but also saves the customer time and money. "What customers want is to cut their costs," says Jerry Bennish, business director for film and bag products at Rexam Medical Packaging (Mundelein, IL). "Electronic prepress, lead time within five days, and field technical service to help with their specifications all enable us to build a good working relationship, which will cut costs."
Adds Jeff Greenlief, Rexam's business director for coated and die-cut products; "The electronic prepress will reduce the use of service bureaus. We receive the files containing copy and artwork on disk or via modem and we can turn them into film for the final product. The service bureaus had been charging from $150—$200 per film."
Many manufacturers are also seeking trays that can provide other benefits. To help its customers meet the regulations on EtO sterilization, Cyro Industries (Rockaway, NJ) has developed a polymer that withstands sterilization. "Our customers are looking for films that can withstand 100% EtO sterilization because of the new guidelines affecting Freon use," says Steve Magaziner, Cyro's business manager. "Our XT Polymer acrylic-based multipolymer compounds offer superior heat distortion temperatures and good impact strength and resistance to plasticizer migration, and they can be sterilized by either EtO or radiation methods and still retain their properties."
To enhance its product line, Rexam Containers (Union, MO) is increasing its involvement in medical tray development. "This is to increase our synergies on a global medical market," says Rob McCoy, Rexam Containers' president and general manager. "We see an opportunity for barrier packaging with seven different layers. This could also increase the shelf life for the products." The seven layers would be a polypropylene or polyethylene layer, regrind layer, tie layer, EVOH barrier layer, tie layer, regrind layer, and polypropylene or polyethylene layer." Increasing the shelf life of packaged products is certainly appealing to medical device makers, who could benefit from selling large quantities of a particular product to hospitals without worrying about the integrity of the packages.
The need to keep costs down isn't making medical device companies abandon the use of trays, but it is making them demand more from their tray suppliers. Device packaging engineers are on the lookout for reliable and economical trays that can accommodate entire product lines, facilitate end use, withstand certain sterilization methods, and lengthen product shelf life. They are also looking for suppliers who are easy to work with, and are forming long-term partnerships with them. Through such partnerships, medical device manufacturers are getting their products to market faster than ever before.