High-Strength Plastics and Processes Provide A Strong Punch

High-performance materials such as filled nylons combined with exotic structural processes allow breakthroughs in mechanical design. Gas assist allows strong parts with good aesthetics —combined with reduced resin usage. A new twist is structural web gas assist, which allows delivery of very specific amounts of melt to difficult mold locations before gas is injected.

New Design Cuts Cost and Noise

Alloys of polycarbonate and ABS are workhorse engineering polymers for computer and medical equipment housings. The Homecare Oxygen Concentrator from Respironics uses the alloy to create a new design. The new model eliminates the need for an internal chassis and, at the same time, lowers cost, noise and parts count. Fewer parts also mean reduced maintenance costs. Typically, oxygen concentrators have been designed with a cosmetic outer shell and an internal structural frame. In this new model, made by Mack Molding, the air compressor hangs by springs, reducing space requirements and noise. A computer board hangs on a built-in hook when the cabinet is open and is supported by the front and rear enclosures when closed. The screwless design reduces assembly costs. Also, the front and rear enclosures of the cabinet support the sieve canister without using fasteners.

Structural Web Creates Unique Chair

Trey is a multi-function chair, floor rocker and table or stool. Key to its design is a structural web gas-assist process using glass-filled nylon, nylon, thermoplastic elastomer, ABS and polypropylene. Structural web allows the designer to incorporate large structural rockers into the chair. It also allows integration of the seat and back portion of the frame into one structural entity. As a result, assembly operations and parts were reduced. The process also allows the simultaneous molding of multiple parts of disparate sizes in one machine cycle. Structural web begins with a short shot, then delivers gas into the mold after melt injection. Gas pressure packs and holds the melt against the mold face to achieve quality part surfaces. This process is different from standard gas assist in that it provides melt delivery into difficult locations of the mold before gas injection. 

Watercraft Seat is Stylish and Strong

The combination grip and seat base for a personal watercraft improves stability and safety. The assembly must meet or exceed a 400-lb pull test. The design was a collaboration of Kawasaki engineers in Japan and Nebraska and at Innovative Injection Technologies in Iowa. The gas-assist process created a strong part while maintaining highly textured aesthetics. The weight of the grip/seat base assembly was cut by 10 percent. The basic final design in ABS accommodates stylish color schemes using molded-in color as well as painted and plated accessory trim. An olefin polymer was also used.