10. SILICONE/SALINE/IMPLANTABLE BREAST PROSTHESIS

A. Problem/Issue

An Implantable Medical Products Company were having issues with their breast prosthesis silicone curing and dipping process. The silicone would contain bubbles and would exhibit tachiness upon final cure. This would cause the testing for elongation to be inadequate. The dipping mandrels were also made of aluminum-making the bubbles hard to spot.

B. Analysis

We analyzed the environment and the technical specifications for the silicone cure. A humidity chart recorder was installed with two sensing points inside the room. A research effort yielded alternate materials for the dipping mandrels. Local contacts for teflon coating and polishing were contacted for options to the aluminum dipping mandrels. A comprehensive program was created and evaluated that would solve their quality issues.

C. Solution/Results

The steam humidity system was modified to lower the output of the steam so the humidity levels would not swing wildly in both directions. Another humidity controller was installed and programmed to anticipate when the setpoint would be reached and reduce output accordingly. A specially designed pouring/dipping station was installed to prevent air bubbles from originating in the dipping apparatus along with coated mandrels in a color that would help the operators pick out any bubbles. This enabled them to modify their technique to greatly lessen the possiblility of a bubble forming. The output increased greatly with a corresponding increase in elongation strength.