ABSTRACT
In a typical North American pressroom, two or three rolls out of every 100 may fracture in the press. In large pressrooms, this can translate to a number of breaks each night, with each break resulting in lost production time and wasted material. Because of tight production schedules, such failures can cause delivery delays, and ultimately circulation and advertising can suffer as a result. Pressrooms therefore care about the runnability of their newsprint, and they pass this concern on to their suppliers. Suppliers respond by modifying their furnish and papermaking conditions to produce stronger or tougher sheets. These modifications inevitably add to the cost base of the newsprint, and consequently suppliers are extremely interested in having a good means of predicting the runnability of their sheets so they can keep their costs to a minimum. The quest for a means of predicting newsprint runnability has been, in fact, one of the main driving forces for the study of fracture over the years. A comprehensive review of the runnability literature was published in 1995 by Farrell and McDonald [76]. A guide to troubleshooting runnability problems was published by Roisum [77].
