Papers & Board

Abstract

The widespread use of cellulose as a dielectric material is due principally to its ability to be plasticised by water if given suitable mechanical treatment, and to the ability of the fibres so plasticised to bond to each other without the use of adhesives. By variation of the degree and type of mechanical treatment it is possible to obtain a very wide range of such properties as porosity, mechanical strength and intrinsic electric strength. This process, the traditional papermaking process, naturally lends itself more to the manufacture of continuous sheet materials, from which rigid solid shapes may be built up if necessary. However, for bulk solid insulation purposes it is frequently more convenient to use either separately manufactured paper or textile fabrics in conjunction with a thermosetting resin adhesive, most often phenol-formaldehyde.