Rule 41 Implications for Linerboard Producers, 1992 Engineering Conference Proceedings

A recent change in the guidelines for construction of containerboard boxes, known as Rule 41, is expected to significantly change the containerboard market over the next five years. Since the 1920s, the industry specifications for boxes under Rule 41 have been categorized by the maximum weight of the contents for given container dimensions, combined with bursting strength, puncture strength, and basis weight of liners and corrugating medium. Under the revised Rule 41 alternative, the maximum weight of contents versus outside dimension relationship is retained, but "edge crush strength" (or the compression strength of the combined board) takes the place of other requirements.

This change in Rule 41, combined with the global trend toward reduced packaging, presents alternatives for designing and constructing containers where equivalent stacking strength is provided while box weight is reduced. As a result, a share of the current linerboard market is expected to move away from basis weight commodity grades to high performance containerboard (HPC) products manufactured for their "edge crush strength" characteristics, The present standard linerboard basis weights for 42 (205) and 69 lb/l000 sq ft (337 g/m 2) could decline by as much as 20 percent. Additionally, both the kinds of fiber used and the operation of linerboard machines are expected to change.

This paper discusses Rule 41 revisions and its overall impact on existing paper machine operations. Conclusions include an economic model that examines the cost effectiveness of Rule 41 - related paper machine rebuilds as a function of paper machine width.