Clamshell Improves Suture-Wire Packaging

Employed by surgeons to pass sutures through ligaments, cartilage, and bone, suture wire has historically been difficult to package using traditional trays because the stiffness of the wire complicates the coiling process. But those days are over. In response to this difficulty, Perfecseal has developed a new type of medical package that eases the suture-wire coiling process, reduces assembly time, and facilitates the removal of the wire in the operating room.

Constructed from thermoformed PETG, Perfecseal's clamshell package design features a flap that extends over the product cavity when it is folded over and snapped into place, according to Tad Kinyon, the company's project engineer. Extending only over approximately 50% of the product cavity, this flap enables the assembler to feed the suture wire in from the top of the package in a wrapping motion. Alternatively, the wire can also be fed in from an end opening with the option to change to the top-feed method if the wire becomes stuck. Lastly, a third flap is folded over to protect the tip of the product. At the time of use, the clamshell can be opened easily by means of a thumb tab on this third panel, enabling end-users to access the head of the suture wire and remove it.

This design also features a continual trim around the entire package, eliminating the need for a separate die cut in the center of the package to create the coil cavity, Kinyon remarks. A separate die cut would create a material slug that must be removed, making the part more expensive. The narrow opening between the trimmed center and the outer perimeter of the package allows for the continual trim and also provides a path for the product tip to be placed and contained.

"This technology," Kinyon says, "is suitable solely for products that have a spring to them, such as a stiff wire. If you try coiling such a wire in a normal thermoform tray, it wants to come out unless there's something stopping it. That's what our design provides." And the more tightly the stiff and springy wire can be coiled, the smaller the package can be.

In contrast to this design, current suture-wire packaging utilizes a crush cut through a molded channel, Kinyon comments. This cut forms when the trim die crushes a vertical side wall to the level of the horizontal trim plane. Current packaging also requires that a Tyvek lid be sealed to the tray, leaving an opening at the point of the crush cut that leads to the circular cavity at the center for housing the wire. "In the previous packaging design, the secondary operation of sealing Tyvek to a tray increases costs," Kinyon says. "And the crush-cutting operation to form a channel creates rough edges and burrs that can cut through sealed sterile pouches or snag gloves."

Because of its novel design, Perfecseal's clamshell was selected as the winner of the 2011 DuPont Packaging Innovation Award. While its ability to prevent wire from springing out during the insertion process sold the idea to Arthrex, the company for whom the clamshell was originally conceived, any manufacturer of springy wire could benefit from this package design, Kinyon notes.

Perfecseal
Oshkosh, WI
www.perfecseal.com