| The shell of the Equa 2 work chair has an H-shaped cutout which lets the back and seat flex separately so the chair moves naturally with the sitter. The chairs come in three sizes and sport pneumatic seat height adjustments and arm rests that pivot up to 25° to give computer users comfortable forearm support. |
Equa 2 office chairs from Herman Miller now sport a one-piece shell made from 40% glass-reinforced nylon 6 (PA6). The Akulon Ultraflow PA6 boasts of long-term fatigue resistance and also molds with superior surface quality thanks to an ultrahigh melt flow, reports its maker DSM Engineering Plastics, Evansville, Ind., (www.dsmep.com). It reportedly has 80% better melt-flow properties than other highly reinforced nylons including PA66. This translates to reduced cycle times, more design freedom (including thin-walled parts), pleasing surface appearance, and lower molded-in stress. Parts made with the material reportedly process more easily with less warpage and are tougher.
The mechanical properties of the Ultraflow grade resemble those of standard Akulon PA6s. It has an Izod impact strength of 1.9 ft-lb/in. at 23°C, tensile and flexural strengths of 26.1 and 29.7 kpsi, respectively, and a 400*F heat-deflection temperature.
-- Jean M. Hoffman