NEWS
FOR IMMEDIATE RELEASE

GREENFIELD , Massachusetts USA - Omniflex, Inc., of Greenfield , Massachusetts USA , reports that increasing numbers of textile laminators and manufacturers of medical/surgical apparel are utilizing super-thin Transport ® -brand films to produce reasonably priced, waterproof-breathable textile composites that maximize comfort while protecting medical personnel from exposure to blood and other liquid contaminants. Additionally, they shield patients and staff alike from transfer of microorganisms. The physical structure and puncture resistance of these films allows them to act as viral and liquid barriers in surgical gowns, masks and other medical/surgical apparel. All Transport-brand films 0.5 mils (12 microns) and thicker meet ASTM-1670 and ASTM-1671 requirements for blood and blood-borne pathogens. In addition, their elasticity, suppleness and bondability to other polymers also makes them ideal for use in transdermal patches and protective coverings for wound dressings and casts.

The high moisture vapor transmission rates (MVTR) of these films, as well as their other physical properties, also make them well suited for use in cleanroom garments and high-performance apparel such as parkas, rain gear, gloves and footwear. Whatever the application, Transport-brand films provide outstanding breathability and liquid resistance to keep the doctor, nurse, hunter, climber or skier dry and comfortable inside their clothing, despite exterior conditions.

Made from thermoplastic polyurethane (TPU), copolyester and ether-amide polymers, Transport-brand films have physical characteristics that make them ideal for use in medical textile applications: good drape, quietness, puncture and chemical resistance, excellent stretch and recovery. Their inherent adhesive properties also provide very durable bonds between the outer fabric layer and any inner lining material to which they are laminated (they are compatible with most common adhesive laminating systems). That these films can endure multiple cleanings enhances garment reusability. At the same time, their reasonable cost permits the garments in which they are used to be designed as disposables, if desired. In either case, the films survive all commercial sterilization processes, such as autoclaving and EtO procedures.

In addition to medical textile applications, the high MVTR of Omniflex Transport-brand films make them ideal for performance apparel and footwear.

Omniflex produces Transport-brand films without the addition of lubricants or processing aids that might migrate to the film surface.  This results in laminations of extremely high durability.  These films also exhibit excellent abrasion and temperature resistance when compared to films produced from other common polymers, like polyethylene and polypropylene.

HOW TRANSPORT FILMS WORK TO PROTECT THE WEARER, KEEPING THEM DRY AND COMFORTABLE

To create a waterproof garment that is also breathable, allowing the wearer's perspiration vapor to escape, a medical garment manufacturer will typically employ a textile composite. This composite is created by a textile laminator who bonds a layer of waterproof-breathable film to a layer of fabric or nonwoven. In such two-ply products, the film has the durability and low-gloss finish to serve as either the exposed outer layer or the inner lining material. The manufacturer may also sandwich a layer of film between two layers of fabric or nonwovens to create a three-ply composite. Omniflex can tailor the formulation or surface characteristics of the film for a specific application while still maintaining good hand, drape or quietness.

Medical garment manufacturers can specify either of two basic types of waterproof-breathable film: monolithic or microporous. Both can usually provide a solid barrier that physically repels liquids, preventing moisture from passing through the textile composite to the inside of the garment. However, they are not equal in other critical areas.

As the name implies, microporous coatings and films contain microscopic pores or capillaries that permit vapor to escape. They are hydrophobic in that the surface energy of the membrane causes it to inhibit the flow of liquid back through the capillaries into the garment due to the small size of the pores. The continued water repellency of this construction, however, is dependant upon the size of the pores, the pressure at which liquid may be applied to the outside surface of the coating, as well as its resistance to contaminants that can break down the membrane's surface energy and, in some cases, actually allow the pore channels to wick moisture to the inside of the composite. In addition, these pores can disqualify such a film from use in applications requiring a viral barrier.

Conversely, Omniflex Transport brand films are monolithic, hydrophilic, and do not have pore capillaries or pinholes, making them excellent liquid and viral barriers. Their hydrophilic nature is what makes them breathable, actively attracting water vapor and absorbing it through the inside face of the membrane. It is then "transported" through the chemical matrix of the solid film to the outside surface via solid-state diffusion, where it evaporates upon exposure to the atmosphere. The amount of moisture and the speed with which it is able to move through such a monolithic, hydrophilic membrane is directly related to the thickness of the film used in the construction: the thinner the film, the more moisture can be transported and diffused on the exterior of the composite.

Super-thin Transport-brand films are cast on polyethylene (left), polyester and paper (right) carriers in thicknesses as low as 0.2 mils (5 microns), thus maximizing moisture-vapor-transmission-rates of the textile composite in which they are used. The thinnest films are cast on carriers for ease of handling and application of adhesives, being extruded from a variety of grades of polyurethanes, copolyesters and ether-amides. If a viral barrier is required, films 0.5 mils (12 micron) or thicker must be specified. Thicker films can be produced without a carrier. The polymer type and grade depends on the hardness, elongation, MVTR or other performance characteristics required for the garment and its end-use (see Typical Physical Properties table below). Omniflex can extrude any of these three polymers into a solid, monolithic, hydrophilic membrane, maximizing breathability, liquid repellency and microbial resistance. The combination is a functional garment that protects the wearer while keeping him dry and comfortable in the most challenging circumstances.

ADVANTAGES OVER MULTIPLE-MEMBRANE CONSTRUCTIONS

Utilizing a single layer of waterproof-breathable Transport-brand polyurethane, copolyester or ether-amide film has advantages over textile composites that employ multiple membrane layers (i.e., TPU and PTFE/Teflon). The inherent durability of polyurethane films allow them to be used without the necessity of an additional protective liner, as is required when PTFE is the inner layer of a PTFE/TPU composite, thus reducing material costs. Additionally, garments made with single-film, waterproof-breathable composites are lighter and more compressible than multi-membrane alternatives. Finally, single-layer laminating technology is more cost efficient than that required for TPU/PTFE constructions, allowing finished garments to be produced and marketed at significantly lower cost - even as disposables.

ADDITIONAL PRODUCT OPTIONS OFFERED

In addition to the choice of base polymer - thermoplastic polyurethane, copolyester and ether-amide - manufacturers can specify a number of other product options. These super-thin films are cast onto polyethylene, polyester or paper carriers. Thickness can be specified from 0.2 to 6.0 mils (5-150 microns) for the best performing films, and in widths up to 68 inches (1.727 meters). Mid-performance waterproof-breathable films are also available without carrier in thicknesses of 0.8 mils (20 microns) or greater. Any of these films may also be enhanced with antibacterial, antifungal and antistatic packages. Surface finish offerings include gloss, smooth and matte.

WHO IS OMNIFLEX?

Since 1994, Omniflex has been a leader in the manufacture of super-thin, high-performance films from thermoplastic polyurethane and other difficult-to-extrude specialty polymers for use in critical apparel, medical, automotive and industrial applications using blown-film, cast-on-carrier and flat-die extrusion technologies. The company markets these films under the Transport ® and Vacuflex ® brand names. Omniflex sells globally to textile laminators, adhesive coaters and converters, the specialty films market and selected OEM's. In addition to a reputation for superior quality, Omniflex prides itself on having the organization, relationships and expertise to navigate the most complex global supply chains. The company can be contacted by surface mail: Omniflex, Inc., P.O. Box 1167 , Greenfield MA 01302 U.S.A. ; telephone: (413)772-3773; facsimile: (413)772-1005; e-mail: info@omniflexfilms.com ; worldwide web: www.omniflexfilms.com.

• Link to Omniflex Application Bulletin (pdf) of this article (600KB).

• Link to Textile World Magazine article on Omniflex Medical Films: http://www.textileworld.com/News.htm?CD=3230&ID=10311

Links to other Omniflex news stories

• Omniflex Films Now Available with Antibacterial Odor Control
• Omniflex Announces New Visual Inspection System
• Omniflex Forms Joint Venture: Etcetera LLC
• Omniflex Transport Brand Films Provide Viral and Liquid Protection in Waterproof-Breathable Medical Apparel
• DuPont & Omniflex Finalize Joint Sales Agreement for Active Layer Film
• Omniflex Opens Three Offices in Asia
• Omniflex Releases Two New Application Bulletins

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