The cutting and slitting of paper

Abstract

Modern papermaking methods and paper user requirements place severe pressure on the converter in terms of paper cut quality and quantity. The future trends indicate continued and increasing use of paper and allied products, hence there is considerable advantage in securing a reliable and acceptable method for reducing paper from reel to more usable form.

Paper making and conversion methods are outlined. An attempt is made to illustrate the complexity of cut quality and to formulate some broad concept of the term. The local strain of paper subjected to tensile and shear loading is examined and a mechanism is put forward for the formation of dust and structural damage during and in association with cutting.

Shear cutting is examined in some detail; the relevant literature summarised and a series of practical experiments are described which illustrate how wear occurs and its effect on the cutting process. Razor, liquid jet and laser methods are examined as alternative techniques. It is concluded that their use is restricted to special applications where particular characteristics can be utilized. The literature concerning abrasive wear and paper as a wear medium is reviewed. It is concluded that significant improvements to slitter life can be made by changes in material specification and basic system design. The techniques used in the work could readily be used design. The techniques used in the work could readily be used in further practical experiments to examine paper and tool surfaces continuously in the field.