TQC SHEEN TB0180 Aber Oscillating Abrasion Tester
An optional kit is available to conduct the Bayer Abrasion Test on contoured lenses. This set-up involves testing a specimen against a control lens for comparative purposes.
Rigid specimens that are 100mm square and less than 12.5mm in thickness are mounted in a holder located in the bottom of a sand tray so the surface is flush within 1mm. The tray is filled to a uniform depth (e.g 12.5mm) with a standardized abrasive media such as quartz silica or alumina. A scotch-yoke drive system reciprocates the tray in a back-and-forth (to-and-fro) motion which causes the entire mass of the abrasive media to shift significantly within the tray. The oscillating movement of the abrasive media results in a random pattern of scratches which simulates normal everyday wear.
Test parameters can be altered with Taber's Oscillating Sand Abrasion Tester, and allow the operator to select the operating stroke length (6.5 to 150 mm) and speed(variable from 100 - 200 cycles per minute). ASTM F735 specifies the sand tray travels a distance of 100mm at a speed of 300 strokes per minute.
In addition to the dry abrasion test, the oscillating sand abrasion tester may be used with abrasive slurry to perform erosion tests. For this application, the optional 4inch deep tray is suggested along with a specimen tray cover. In place of the abradant, a slurry would be used (e.g. 50 -50 mixture of solids and distilled water). The abrasivity of the slurry is dependent on the concentration of the solids in the liquid vehicle, along with the characteristics of the solid particles (shape, hardness, size, and friability).