Originally Published MPMN November 2001

PRODUCT UPDATE

Medical-Grade Packaging Papers Take on Spunbonded Olefin

High-strength, high-barrier papers may reduce manufacturing costs

In order to be considered for use in medical packaging, a material must possess a number of characteristics. It must be compatible with commonly used sterilization processes. It must provide a strong barrier to bacterial penetration. It must run smoothly on a variety of packaging equipment without creating static electricity that could attract airborne particles. It must have a smooth surface that enables clear graphics. It must not break down in moist or wet conditions. It must be clean peeling—opening a package shouldn't trigger the release of fibers that could threaten a clean environment. And of course it should be strong enough to resist tearing.

Traditionally, manufacturers in need of a high-strength, high-barrier, breathable material for their medical form-fill-seal packaging and lidding needs have turned to spunbonded olefin, made by DuPont Medical Packaging. Spunbonded olefin, known as Tyvek, is manufactured by using heat and pressure to bond very fine continuous filaments of high-density polyethylene (HDPE) together. It is chemically inert, naturally white, and contains no binders or fillers.

Because it meets or exceeds medical standards, Tyvek has long dominated the sterile medical device packaging industry. However, cost has been a factor for some manufacturers in using this product, leading them to turn to less-expensive medical-grade papers for packaging applications that don't require the highest quality materials.

While acceptable for some uses, papers have drawbacks that make them less desirable in sterile packaging. These include a susceptability to tearing, especially in moist or wet conditions, reduced barrier properties, and a tendency to release fibers when opened.

Paper alternatives show strength

Recently, though, advances have been made in paper formulations. Two suppliers now offer papers as alternatives to spunbonded olefin. These new products offer many of the characteristics of spunbonded olefin, but are available at a lower cost.

"The main reason for the lower cost is that paper has more competition than spunbonded olefin," says Kimball Mancke, president and chief operating officer of Bomarko Medical Packaging. "When a new product is developed and has no competition, the price remains at a high level until more alternatives become available. This is the change we're experiencing in the marketplace today."

Two puncture-resistant, medical-grade papers from Bomarko Medical Packaging exhibit strength and barrier properties. Through the use of high-performance coatings, the TA100 and TA115 products provide a fiber-free peel with consistent coating transfer.

"Of course there are products that need the qualities of spunbonded olefin; however, there are many soft or smooth products that can be packaged in a different substrate without incurring the expense of spunbonded olefin," says Mancke. "Bomarko Medical Packaging offers TA 100 and TA 115, which are specifically intended for use with products that need high-performance protection at a sensible cost."

Both grades of paper are suitable for a range of packaging applications including form-fill-seal and lid stock. Typical items packaged include gloves, gauze, soft or smooth products, flat packs, and products with low-definition packaging needs that do not require overengineered spunbonded olefin.

Another medical packaging company, Kimberly-Clark Technical Paper, offers a high-strength, high-barrier reinforced paper that incorporates a proprietary polymer. Impervon seals directly to a wide variety of multilayer films, is easily printable, and provides a high internal bond strength that resists tearing in many medical packaging applications. It is engineered to perform on form-fill-seal, rotary, platen, shuttle, pouch-making, and bar-sealer equipment and offers high opacity, drapability, and printability.

All three papers work effectively with commonly used sterilization methods.

DuPont has also stayed on top of the cost-cutting trends among manufacturers. The company has designed Tyvek 2FS as a lower-cost alternative to medical-grade Tyvek. This lower-basis-weight style of spunbonded olefin is designed specifically for less-demanding flexible packaging applications.

The opaque, white material provides high print contrast and easily makes bar codes readable. A TiO₂ additive makes 2FS resistant to the formation of transparent seals. It can reduce material costs because it has a low basis weight and high strength. This combination enables the design of cost-effective packages that process with high yield and survive the distribution environment with few product returns.

Susan Wallace

Copyright ©2001 Medical Product Manufacturing News