TAPPI T 818Ring crush of paperboard (flexible beam method)
The ring crush test correlates with edgewise compression strength of paperboard. This method is intended for paperbaord between 0.28mm (0.011 in.) and 0.51mm (0.020 in) thick. IT may be used with less reliability for paperbaord as thin as 0.18,, (0.007 in.) and as thick as 0.76mm (0.030 in.) The short cpan compressiontest measures edgewise compressive strength over a broader rage of thickness.