The O2-RESQ System for providing immediate ventilation in cases of congestive heart failure and other respiratory distress includes a face mask with a soft, rounded elastomeric cushion that fits comfortably on the patient's face and is free of odor, according to manufacturer Pulmodyne, Inc.
The translucent cushion, or seal, is made of a custom-formulated compound in the Medalist range of medical-grade elastomers from Teknor Apex Company. The soft, 37 Shore A elastomer is over-molded onto the transparent front portion of the mask, which is made of a rigid terpolymer material.
Unlike many other elastomers and flexible plastics used in medical masks, Medalist elastomers are odorless, latex-free, and contain no phthalates, according to Lisa Charno, medical market manager for the Thermoplastic Elastomer Division of Teknor Apex.
Over-molding the Medalist elastomer provides strong adhesion to the rigid substrate and combines the different functions of the soft and hard components into what is in effect a single part. And there are other manufacturing advantages, according to Charno: "Many medical masks, including Pulmodyne's O2-RESQ model, incorporate undercuts in their design that present real challenges when the part is ejected from the mold," said Charno. "Because Medalist compounds set up rapidly in the mold and exhibit good tear strength, they make it possible for the mask to be pulled off the mold core without tearing or stretching."
Because the Medalist compound has a lower specific gravity than PVC (0.88 versus 1.13), it yields more parts per pound of compound and makes possible a mask seal that is 22% lighter than it would have been in PVC.
The Medalist program for medical manufacturers includes a range of 33 standard high-purity elastomer compounds along with a comprehensive body of tools and information for designers and processors. Compounds are available with Shore A hardness from 5 to 87 and include clear, translucent, and opaque formulations.