Rugged Case Combines Aesthetic and Technical Features

A rugged, small case for the Lifepak CR Plus portable automated external defibrillator is molded of Bayblend FR 110 resin, a polycarbonate/ABS blend from Bayer. By redesigning the case using Bayblend PC/ABS and polyurethane, the manufacturer, Medtronic Physio-Control, was able to mold-in features to reduce post-molding assembly, and solved a color stability problem of the previous case material.

The design features of the defibrillator case were challenging. Wire routing channels and mounts for the different components that snap fit into the case are molded in. The seals and bumpers are also integrated into the case, by overmolding polyurethane. The overmolded polyurethane adheres well to the Bayblend material, so no mechanical features are needed to hold the polyurethane.

The new design eliminates 59 additional parts that would otherwise need to be assembled into the case.

Dave Kosanke, senior process engineer for the case molder Accurate Molded Plastics, said using the Bayblend resin offered processing, cost and performance benefits. “It’s our choice of material — because of its easy moldability and excellent impact properties for field use. The case needs to be strong, and wall thicknesses are just 0.090 in.”

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