Originally Published March 2000

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Autoclavable Motors Series Introduced

Brushless motors withstand more than 100 sterilization cycles

Motors traditionally used in such handheld devices as drills and surgical cutting tools cannot be autoclaved because of the steam and tremendous heat involved in the process. "If the motor isn't completely sealed, the grease inside can liquefy and flow out of the bearings," says Micro Mo Electronics Inc. (Clearwater, FL) vice president of advanced research and planning, Dr. Stephen O'Neil. "This will cause the bearings to rust and the internal parts to abrade because of the lack of lubrication."

To prevent such problems, Micro Mo has introduced a line of autoclavable brushless motors. Specially formulated high-temperature plastics, developed by a sister company of Micro Mo, as well as protected coils and a special lubrication system allow the motors to undergo a minimum of 100 sterilization cycles.

A line of motors launched by Micro Mo Electronics is fabricated from polymers formulated to withstand high temperatures.

According to O'Neil, "In the past you could buy one or two versions of an autoclavable motor, but this is the first time that a complete range of motors is available."

To provide high torque and acceleration, the motors are based on System Faulhaber ironless rotor technology, a design that uses powerful rare earth magnets.—Karim Marouf

High-MVTR Adhesive Combines Performance with Easy Removal

Withstands poststerilization processes

An adhesive from Avery Dennison has been designed with highly breathable characteristics for use in wound-care applications. The AD2000 adhesive was presented at the Medical Design & Manufacturing West exposition & conference in January.

Marketing research, which included focus group panels with clinicians from across the United States, revealed that users are looking for a "gentle adhesive system," according to Lori Weinstein, medical marketing manager of Avery Dennison Specialty Tape Division. "This involves developing a formulation that delivers adhesion performance to skin, offers gentle and easy removal, and withstands the sterilization process."

What sets this adhesive apart from competing products, says Weinstein, is the high moisture vapor transmission rate (MVTR), a measurement that gauges the ease with which an adhesive can be removed from the skin. Using the inverted method of measuring adhesives on a thin film, the adhesive was shown to have an MVTR of more than 3600 g/m²/day. The high rate allows the skin to breathe by letting moisture evaporate through the adhesive, thereby preventing skin maceration. According to Weinstein, "Nothing the competition offers has an MVTR this high."

Breathability is a key feature of Avery Dennison's new adhesive, which has a moisture vapor transmission rate of greater than 3600 g/m²/day.

The adhesive coating maintains an MVTR of 3164 g/m²/day after 25-kGy sterilization and 3097 g/m²/day after 50 kGy. The adhesive also features low peel adhesion and low loop tack values before and after sterilization, an important consideration when measuring how gentle the adhesive is on skin.

The adhesive coating provides a bacterial layer that helps to prevent infections. It can be supplied as either a stand-alone pressure-sensitive adhesive or in conjunction with a range of breathable, conformable facestocks, such as PUR film and a nonwoven.—David Bowen

Two-Layered Packaging System Features Enhanced Peel and Seal Characteristics

Can be used with a wide variety of substrates

Rexam Medical Packaging (Mundelein, IL) has recently received a patent for its Core-Peel technology for peelable systems. Core-Peel offers separate coextruded seal and peel layers for a wide variety of uncoated materials.

"What's so unique about Core Peel is that it's a two-layer peel system," says Jerry Bennish, global marketing director for Rexam. "Most systems have a single layer which peels and seals, and in that case you have to balance those characteristics, which is difficult." By having two separate layers, the sealability is made easier while the peel characteristics are also improved.

During the sealing process, the seal layer embeds itself into the fiber structure of porous medical packaging material such as paper or Tyvek. When peeled, the seal layer breaks through cleanly, forcing the peel mechanism into the peel-blend layer.

Technology developed by Rexam Medical Packaging allows the use of uncoated Tyvek in its two-layer system.

According to Joe Spitz, vice president of technology, "The most important aspect of Core-Peel is that it gives users the opportunity to form peel seals on a wide variety of substrates, including rigid plastics such as PETG and PVC."

The technology allows the use of uncoated Tyvek. Bennish explains, "Without Core-Peel, you have an option of using coated Tyvek, which is more expensive and does not have the same breathability. Or you can use uncoated Tyvek with a conventional peel system, but then your window of machinability is narrow, resulting in more scrap product."

Another benefit of Core-Peel is the use of three visual seal-continuity color contrasts, one before opening and two more on the opposing webs after opening. This allows users to see if the seal has been broken.

Rexam currently offers Core-Peel on its Integra Pack Tyvek pouches, providing a low-cost option for users who normally employ a heat-seal-coated Tyvek. Core-Peel is also available on coextruded forming webs, coextruded top webs, and various laminations.—Karim Marouf

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