Medical Device Link.

FORM-FILL-SEAL

Material costs for form-fill-seal (FFS) packaging are rising, partly because of the rising cost of petroleum. Downgauging is one way to drive down costs, but that move challenges the machinery.

The Powerpak from Tiromat can handle elastic materials, if needed.

Switching to a lower-gauge material for FFS packaging promises cost savings. New materials make it possible to downgauge the bottom web without sacrificing the required physical properties, such as puncture resistance and formability.

“Different resins have come out over the past few years, and we’ve blended and processed these resins to develop new lower-gauge bottom webs,” says Craig Livingston, vice president, business development, for Rollprint Packaging Products Inc. (Addison, IL). “In many cases we’re downgauging the existing bottom webs 30% or more, depending upon the application,” he adds. “Downgauging from 6 to 4 mil, or from 4 to 2.8 mil, is now possible for many customers.”

Running the lowest-gauge materials can present challenges for FFS equipment, however. “We can run very extensible webs. We add drive systems to the machine to enhance performance with some very elastic materials,” says Keith Barnes, area sales manager for Tiromat Medical Packaging, a division of CFS (Frisco, TX). “It’s a lot easier to deal with it up front on a new piece of equipment,” he cautions. “Retrofitting some of the older equipment can be done, but presents additional challenges.”

And “the time to evaluate new materials is when you bring in a new machine,” advises Vin Faherty, product manager for packaging for Harpak Inc. (Easton, MA), makers of the Hooper N2500 FFS machine. “Once a system has been validated, customers rarely want to make a change. But when you bring in a new piece of equipment, FDA requires revalidation.”

To form deep-draw packages, Harpak uses radiant heating on its FFS machines.

Preparation can go a long way. Mike Lynch, director of sales for Multivac Inc. (Kansas City, MO), says building in flexibility to allow future downgauging and testing with other materials is a priority. “We have single preheat, double preheat, sandwich preheating, plug assist, forming with vacuum, forming with air, heat above forming, etc. All of these options address various web-gauge issues. We discuss these options with our customers before building a new piece of equipment. Although it is easier to address these options on a new machine, we retrofit these features into many of our machines every year.”

Rick Crane, vice president–technical marketing and new business development for J-Pac LLC (Somersworth, NH), says J-Pac’s Doyen Medipharm equipment “can run and process substrates that a lot of other equipment is not capable of handling.” J-Pac, a contract packager of sterile medical disposable devices, bought Doyen Medipharm, a manufacturer of FFS machinery, in 2004. He attributes this capability to its approach to web control and tensioning control. The most extreme challenges are perhaps products that are themselves run as webs. An example is an edible film, such as the Theraflu strip. “Running those films consistently without any breakage requires special continuous-motion systems that Doyen creates,” emphasizes Mark Hefford, a business development manager for J-Pac.

“All the products that are cutting edge seem to have an active ingredient,” Crane explains. Manufacturing and packaging these products may require applying a medicament to a substrate, through either coating or polymerization. “We’ve worked with hydrocolloids, hydrogels—very difficult-to-handle, dimensionally unstable webs,” he adds.

Advanced Concept Innovations is a start-up contract FFS packager that opened in February 2006 in Lakeland, FL. Anthony Soria, president, says the key to flexibility on his three FFS machines, all from different manufacturers, is tooling expertise. One workhorse machine, he says, “can go from a 25- to 30-mil PETG or PVC rigid through 25- to 30-mil HIPS, but it can also go down as low as 8-mil PVC or even 100-gauge PE nylon laminate, or a nylon coextruded material, for a flexible web. These machines are highly versatile, but you have to know how to set them up and how to design the tooling,” he explains.

Topas has developed a five-layer PETG/COC/PETG for FFS applications.

UNCOATED TYVEK OR PAPER

Coated Tyvek is one of the priciest options for top-web rollstock. Many companies are therefore searching for alternatives to it.

“Over the past three years, our strong focus has been toward developing formable bottom webs that seal and peel to uncoated Tyvek. By coextruding the peelable sealant with the forming web and then sealing to uncoated Tyvek, considerable cost savings can be achieved,” explains Rollprint’s Livingston.

Rollprint is rolling out ClearForm T this fall for this purpose. It is a multilayer coextruded material designed to seal and peel cleanly from uncoated Tyvek as well as uncoated paper. The basic formulation will be 6 mil, but Rollprint can adjust the gauge from 2.5 up to 15 mil.

“Because of the coextrusion process, we are able to adjust the various properties within the film in order to accommodate the individual package requirements, such as deep draw ratio and enhanced puncture resistance,” Livingston explains.

Until now, when manufacturers tried to seal materials to uncoated Tyvek, they had to leave a “skirt” of unsealed material around the perimeter of the package to prevent fiber tear when the package was peeled. This skirt design was not workable on most FFS machinery, since the tooling is not designed to create such an unsealed area. ClearForm T requires no such skirt.

HEAVY-GAUGE OPTIONS

Research has made possible not only gossamer-thin, strong webs of the lowest possible gauges, but also ever-more-robust options on the heaviest-gauge end of the spectrum. These options include new foil laminates, polyesters, and COC.

“We’re seeing growing demand for heavier-gauge bottom webs, which we would consider rigid or semirigid as opposed to flexible,” Rollprint’s Livingston asserts. “These customers are looking for alternatives to buying a premade tray.” For such applications, Rollprint may supply 15-mil polyester that has been extrusion coated or laminated with a high-barrier film, he explains, and a barrier top web, such as a peelable foil or ClearFoil laminate.

Some trade-offs are necessary for the medical device manufacturer moving from a purchased preformed tray to a rigid or semirigid package formed in-line on FFS equipment.

“We can duplicate the functionality and geometry of the preformed tray,” says Fran Ventura, vice president, sales, Ossid division of Pro Mach (Rocky Mount, NC). “But aesthetically, it may not appear equivalent, because the walls may be thinner.” Another trade-off is how fast the material can be run on the machine, he adds. Heavier-gauge materials may require longer dwell times.

“We like to address that issue up front with the customers. We do a lot of prototyping and help them design a package that will pass their ship tests with the reduced wall thickness,” agrees Tiromat’s Barnes. “With the prototyping, they will see exactly what they are going to get for the final product off an FFS machine.”

Harpak’s Faherty adds, “We have kind of replicated what thermoformers do by having radiant heating on our machine. Radiant heating allows a much higher thermal profile to maximize performance of materials such as high-density polyethylene and polypropylene without decreased productivity.”

A new option for applications requiring high moisture barrier is rollstock containing cyclic olefin copolymer (COC). Paul Tatarka, in market development for Topas Advanced Polymers Inc. (Florence, KY), says Topas has developed a PETG/ COC/PETG five-layer rollstock. Multivac has thermoformed it successfully in R&D experiments. According to Tatarka, the work was done at Multivac’s Kansas City, MO, tech center. “Multivac did not know of the composition of the sheeting beforehand, but the information was disclosed to them during the trial,” he says. Also, “It is very possible that additional trials with PETG/COC/PETG were done by other companies and organizations without my knowledge.”

Topas is working with Plitek LLC (Des Plaines, IL), a converter, for custom extrusion, laminating, and die-cutting of COC films, some of which Plitek will be showcasing at Pack Expo International in Chicago. “Plitek is excited about the many applications for this material for medical device packaging because of its superior optical and barrier properties,” says John Moore, Plitek’s director of medical sales.

Radiant heat, Tatarka says, is not required for COC. “It’s a unique polyolefin in the sense that it is amorphous. This amorphous morphology, as opposed to a crystalline morphology, makes it possible to thermoform COC-containing film over a broader temperature range and enables the end-user to form very complex shapes and parts.”

Unlike some other high-barrier materials, Tatarka adds, COC-based material can be formed in deep-draw applications. “That’s where we see the unique fit and benefit for COC,” says Tatarka.

MAXIMIZING THROUGHPUT AND UPTIME

“Over the years, everybody’s been pushing the limits of FFS machines to make them run as fast as possible,” points out Tiromat’s Barnes, “but they can only run so fast. Now the cost savings we’re looking for is uptime—increased productivity of the machine.”

“You can maximize the tempo of the machine by limiting the lift strokes of the machine, opening the dies only as much as you need for clearance, and building in servo-controlled accuracy for repeatability so that you can register and maintain cavity-to-seal dimensions, actual peel-seal dimensions, and cutting dimensions,” Harpak’s Faherty points out.

John Merritt, director, medical business development, for FFS equipment provider RapidPak, says, “Our patented use of servos to drive plugs, as opposed to the use of pneumatics as practiced by the rest of the industry, gives us precision positioning and the ability to accelerate and decelerate plug speed. The result is the ultimate in flexibility and process repeatability as well as good process control, since the operating parameters for the plugs are stored in the PLC.”

Supersizing the rollstock is an option. Increasing the outside diameter (OD) of the rolls is one way that manufacturers have thought of to maximize uptime, since bigger rolls mean fewer roll changes and reduced waste. To realize cost savings from this option, however, users must recognize and address hidden challenges that lurk behind this benefit.

Manufacturers are requesting larger-OD rolls primarily for bottom-web rollstock. The heavier the gauge of the material, the less linear footage a given roll yields. This means more roll changes for the bottom web than the top web. The weight of the larger-OD rolls, however, can be problematic.

“You have to have an automated process to do the autoloading, because if these heavy rolls are manually handled they can be damaged and, more importantly, someone could be hurt,” stresses Harpak’s Faherty. Secondary hoisting equipment for material handling is therefore a must.

“Many customers who are buying new equipment are asking for larger-OD rolls,” says Rollprint’s Livingston, “so obviously they are going ahead and buying secondary hoisting equipment.” A traditional roll for the bottom web, Livingston estimates, has an OD of 15 to 19 in. “We just had a customer ask us to go out to 24 in.”

Customization and quick changeovers may also help. Merritt says that RapidPak’s side-extractable tooling “eliminates the inconvenience of having to remove heavy tools out through the top of the machine. Just as importantly, it eliminates the need to have to cut the films to access tools, and subsequently to rethread them after tool changes. Having to remove tools out through the top takes a fair amount of time as well as wastes material. Another of our innovations, the use of servos for lifting tools, means optimal machine speeds can be attained. Vital parameters associated with lifting tools and coordinating tool movement with machine indexing are stored in the PLC by product code.”

However, “when cost justification or return on investment becomes marginal,” says Ossid’s Ventura, “it behooves the machine fabricator to come up with ways to tempt the customer to buy the machine. The single biggest way to do that is to add the capability to make more packages, more variations, to the machine. This flexibility in turn requires different sets of tools, which usually have to be removed and replaced, hence the emphasis on ‘quick changeovers.’”

More important than just a blanket belief that a machine offers quick changeovers is getting a machine customized to one’s own specific production requirements, Ventura points out. As an example, he cites a machine that Ossid built for a customer who needed three different index lengths, with three different output requirements.

“When we designed the tooling, we eliminated most of the heavy lifting of tooling in and out of the machine,” Ventura explains. The longitudinal knives, for example, remain in the machine, but they are on a novel pivoting shaft so that they flip out of the way when they are not needed.

Similarly, Multivac offers the option of mounting multiple tooling sets—sometimes two or three dies—simultaneously on its machines. Automatic depth adjustment is another option to minimize changeover, says Wilmer Caraballo, technical sales advisor in Multivac’s medical, consumer, and industrial division. “With a single die, we allow a customer to select the desired package depth on the human-machine interface; then the machine automatically changes the depth for that package,” he explains.

Echoing Ventura, Caraballo points out that this option is not for everybody. “If you don’t do a lot of changes and you have only one or two depths, then obviously you can save on the cost of the piece of equipment by doing it manually.”