MARKET PLACE
No compromise
 |
Surgical instruments, drapes and medical implants are just a few of the medical products that require sterilisation after the packaging operation. Gas flushing the contents of the package with ethylene oxide (EtO) is a method that is frequently chosen. Tyvek nonwoven polyethylene (DuPont Medical Packaging, www.medicalpackaging.dupont.com) is often used for this application because it is permeable to EtO, yet water-, chemical-, tear-, puncture- and abrasion-resistant. But these advantages are offset by the high material cost that Tyvek brings to the packaging equation. However, it is now possible to operate the same sterilisation process using less Tyvek and thereby reduce the overall cost of the pack. A packaging solution developed by Multivac applies gas-permeable Tyvek to an easy-peel plastic film.
The window technique
 |
The technology is based on a thermoforming process. The flexible plastic film (mostly a polyamide–polyethylene laminate) and the Tyvek are combined with each other on a fully automatic, horizontal packaging line. The machine starts by cutting a window of a specified size out of the flexible upper web. The gas-permeable strip of material, in this case Tyvek, is then fixed over the opening and firmly sealed to the upper web by a sealing die. At the same time, the packaging machine thermoforms a pocket from the lower web, which can be a rigid or flexible material, into which the medical instrument or the sterile product is loaded. Because the pack pocket is open at the top, it is simple to load the product from above. The pack is then sealed securely to the upper web before being cut to specification. Little or no packaging material waste is reportedly generated in this process. Because it is crucial that the Tyvek window is placed at the required location, the exact position of the upper web is controlled by sensors and any deviations are corrected via an adjustment shaft. “Typically, in standard thermoformed packs the entire package top would have to consist of Tyvek,” says Markus Boeck, Medical Sales Manager, Multivac. “In this solution, the amount of Tyvek is reduced to yield cost savings of 60–80% being possible depending on the package; it is a particularly attractive option for large or voluminous sterile products.”
Branding via customisation
“Gas-permeable materials like Tyvek can be applied to practically any flexible film,” says Boeck. The many different plastic films available means that packages can be customised. The films are printable and the pack can be given a brand-specific design. Required manufacturer information can also be printed directly on the film, to eliminate the need for additional instruction leaflets.
The topsealing technology provides a strong sealing seam so that the product is protected reliably during transport and storage. The films available have easy-peel properties to ensure that no fibres or other particles detach to compromise the sterile contents on opening. There is a choice of opening method, including Chevron or thumb hole.
The next step
Two thermoforming machine models are currently available. One is a flexible, all-purpose machine for medium output, and the second offers reported speeds of up to 16 cycles per minute and additional functions for large outputs and unusual formats.
For more information, contact Markus Boeck, Multivac, Wolfertschwenden, Germany, tel. +49 83 34 601 46 92, e-mail: markus.boeck@multivac.de, www.multivac.com.
