Consumable Co-molded Plastics Challenge

We depend on advice from the experts, but there are occasions you have to confront a problem the old fashioned way. That's how we solved a plastics challenge when developing a consumable for the Neomatrix Halo™ breast cancer screening system.


Cup hand smallThe disposable component is a soft plastic cup (at left) used to collect nipple aspirate fluid for PAP-type cancer screening. There were some special requirements. We needed a biocompatible, low durometer plastic, which could be molded with thin walls in production quantities, and bondable to polypropylene (the primary plastic part in the consumable).  

Our advisers and molding vendors believed Kraton™ was only polymer that could work but there wasn't any information to confirm the assertion. They had not seen the plastics co-molded and were not willing to build molds to give it a try. It was up to our team, so we involved Mark Mossberg, our CAD/CAM specialist and plastics expert, who has been with Omnica nearly 20 years. 


We designed and built an aluminum mold prototype in our machine shop to learn more about the elastomer. It was an iterative process, and we quickly confirmed with our 28-ton Arburg that all-aluminum molds were best for molding this material. Typically, molders use steel for high-volume parts, but we knew aluminum's heat conductive properties would be the only substrate that would work in this case.  


We ran the prototype co-molded parts and learned enough about their characteristics to define a process that could be used for the high-volume consumable. Our team transferred the information to a molder we sourced, who successfully accomplished the job for Neomatrix.