"The previous material was frequently brittle which often led to part breakage, and there were major inconsistencies in the electrostatic dissipation (ESD) performance," says J. Douglas Anderson, VP, Biomarine. "Because of this we were rejecting entire lots, costing us a lot of time, money and resources."
The company is now using Fraradex, a stainless steel-loaded polycarbonate, from SABIC's Innovative Plastics business unit (Pittsfield, MA). According to Anderson, it provides 25% higher impact resistance than neat polycarbonate.
ESD capability is important for the equipment, called rebreathers, to provide a grounding path for any static charge that can build up in a plastic resin, causing potentially deadly sparks. When the conductive property is compounded into the part, conductivity cannot be disrupted by surface scratches or nicks.
The matrix material for the rebreathers, Lexan EXL copolymer, is described by SABIC as offering superior impact and low temperature ductility, as well as enhanced processability, compared to standard polycarbonate grades. Grades based on non-brominated, non-chlorinated and flame retardant systems are now available.
In an effort to save on assembly costs, notch and snap-fit design were used in the new rebreather housing
Anderson adds: "Since we no longer have to worry about bad lots of material or excessive scrap, it's easier to meet our productivity, quality and cost control objectives."
The Biomarine BioPak 240R Revolution uses a Solid Core Scrubber carbon dioxide (CO2) scrubber design to eliminate the need to measure and refill CO2 absorbent and the potential for refilling errors.