Raising the Barrier in Flexible Packaging

Newer, clear, high-barrier films offer cost-effective solutions for pouch packaging of sensitive drug and device products. As alternatives to foil structures, clear films enable end users to see the packaged product.
In addition, when foil is replaced by film, foil’s interference with vision systems, metal detectors, and RFID readers is eliminated, says Dhuanne Dodrill, president, Rollprint Packaging Products (Addison, IL).
 
“People like the idea of being able to visually see the product. End users can verify the correct product and size without opening the package and potentially compromising product sterility,” Dodrill says.
 
Rollprint Packaging has expanded its ClearFoil line of transparent high- barrier films with its recent launch of the ClearFoil X and ClearFoil Z films. ClearFoil Z increases moisture and oxygen barrier by a hundred fold compared with other ClearFoil products and the barrier properties typically found in non-foil structures. ClearFoil X provides ten times better barrier.
 
“We are seeing significant demand for these clear, high-barrier materials with ultra-high barrier properties. People had no choice before but to package in foil. This gives them another option, that allows product visibility,” Dodrill says.
 
The clear films are used in applications including medical devices that oxidize in the presence of oxygen and products such as absorbable sutures that lose tensile properties with exposure to moisture, Dodrill says.
ClearFoil X and Z feature aluminum oxide barrier coatings. The Al₂O₃ is buried between the polyester and a sealant layer to prevent any degradation of the barrier from scuffing and abrasion. ClearFoil Z barrier is 0.0008 g/100 in²-day for moisture, 0.0008 cm³ /100 in²-day oxygen. ClearFoil X’s barrier performance is 0.003 (moisture) and 0.004 (oxygen).
 
The films outperform thinner-gauge foils, in which foil barrier is compromised by pinholes. “At 1 mil, foil is basically pinhole free. The thinner you go below 1 mil, the more pinholes are likely to be present,” Dodrill says.
 
“Pinholes are not distributed evenly. Some areas may be pin hole free and other areas may have enough pin holes to impact the barrier. You have to build around the worst case scenario. For planning purposes for a 35-gauge foil (0.35 mil), you need to be thinking of 0.02 g/100 in²-day moisture vapor transmission, 0.03 cm³/100 in²-day for oxygen,” Dodrill says.
 
The clear films are comparably priced with foil, despite a perception that aluminum oxide and silicon oxide coated films are more costly, Dodrill says.
 
“Aluminum foil has to be protected because it will oxidize. This requires a layer on both sides of the foil. Our ClearFoil products don’t need the protective layer. They are often less expensive than foil or at least in the same ball park. The ClearFoil structures can be an excellent and cost-effective choice for achieving high barrier packaging goals,” Dodrill says.
 
Beacon Converters Inc. (Saddle Brook, NJ) provides the A60 coated clear high-barrier film. The structure features barrier coated polyester, with MVTR barrier of less than 0.005 g/100 in²-day and oxygen barrier less than 0.006 cm³/100 in²-day, says Alison Tyler, technical director.
 
“Some customers have favored a clear/clear solution but we have found also many like to use one side with foil and the other with the clear film. We pair the A60 with our A34 polyester and foil laminate. It provides the same kind of appearance as a traditional film/Tyvek pouch, but with the higher barrier. Marketing tends to like the product visibility,” Tyler says.
 
“Many devices with a drug component are UV sensitive. Foil provides an excellent barrier for these applications, but we can also address UV barrier with our clear films,” Tyler adds.
 
For safely packaging device/drug combination products, Perfecseal (Oshkosh, WI) has introduced an alternative to Barex sealant foil films.
 
Barex is used as the sealant layer in PerfecSeal’s PerfecPharm P618 high barrier laminate. The Barex lamination limits ingress of gases through the pouch and seal area. As the layer in contract with the product, Barex has excellent resistance to the absorption of the medication and flavors present in products such as oral film strips.
 
Developed and manufactured by Perfecseal, PerfecPharm P619 utilizes a polyester sealant-based (PET) film that offers performance and cost advantages over P618 in various applications.
“We saw an opportunity to provide a less-costly alternative to Barex. In some Barex structures, the packaging is more expensive than the product,” says Georgia Mohr, market development director, pharmaceutical segment, Perfecseal.
 
“(Also) it is not very accessible. There is only one production site in the world that makes the resin. Whereas, polyester resins are sourced from many manufacturers,” Mohr says.
“PerfecPharm P619 incoprates the polyester sealant film, which is readily available, is cost effective, and has a very broad sealing window,” she says.
“Barex requires a very high temperature to heat seal: a minimum of 300° F. When you require a high heat sealing temperature, there is the possibility you might compromise the drug that is being packaged.
“PerfecPharm P619’s broader heat seal curve produces a higher bond strength at a lower temperature as compared to P618. This wider sealing window promotes packaging machine efficiency,” Mohr says.
 
PerfecPharm P619 features comparable Barex properties in chemical resistance, toughness, stiffness, clarity, thermoformability, and moisture and oxygen protection. The structure contains an exterior layer of polyester, extrudate, foil, adhesive, and the PET sealant layer.
“Currently, PerfecPharm P619 is on stability with transdermal patches and oral film strips with excellent results thus far. PerfecPharm P619 also provides an alternative for packaging really hard to hold gels and creams, for which Barex has been the only solution,” Mohr says.
 
Beacon has developed a die-cut card solution for device components that in standard practice would never be put into flexible packaging. The system evolves the traditional die-cut card into a 3D wallet.
Beacon developed the wallet-style packaging for an orthopedic device the customer originally planned to package in a double thermoformed tray system, says Tyler.
 
“Heavy and sharp devices traditionally go into a thermoformed tray or a tray within a tray. The customer wanted a less expensive solution with a smaller foot print, which is not possible with a tray,” Tyler says.
The components are loaded into a flat, scored extruded high-density polyethylene card. Tabs on the card are folded and fixed in place to secure the pieces, and the wallet is pouched.
 
As a 3D package, the wallet unitizes the system, while dramatically reducing the footprint. The foot print is reduced because the the components are stacked vertically within the wallet. This also reduces the size of the secondary packaging.
 
 “The foot-print of the pouch is much smaller than a tray and because of the folding it is much smaller than a flat die cut card configuration would allow. You are using less material for the same performance, with smaller carbon footprint that also reduces shipping costs,” Tyler says.
The package prevents sharp edges from puncturing the pouch, and provides localized protection for sensitive part tips.
 
“As a relatively thick gauge white HDPE, the card has UV barrier characteristics. In lieu of a cap, you can build in localized area for UV protection,” Tyler says.