of the pulp sheet this increase is primarily due to the closer contact of the pulp fibers which results from the compression of the pulp sheet of course the degree of increase of this through thickness tensile strength in the pulp sheet will be dependent upon the fiber length of the pulp and other pulp characteristics thus depending upon pulp characteristics the desired pulp sheet compression will vary between 60 and 95 of the original pulp sheet thickness while still maintaining the 3 millimeter roll gap the lowering of surface tension due to the reduction of contact area between the pulp sheet and the drum together with the through thickness tensile strength increase for the pulp sheet in the areas of localized compression makes the doctor significantly more effective in removing the pulp sheet and achieving a clean drum fig4 is an enlarged sketch illustrating the closer fiber contact and some fiber orientation within the pulp sheet due to the compression note that the compressed areas 5 of the pulp sheet 1 are associated with lifted areas 25 also note that the doctor blade 10 is separated by a doctor gap 15 from the smooth porous filter surface 2 although shown here as a flat filter surface the filter configuration may be any of those types commonly used fig5 show an alternative design of the compressor 20 of the present invention here the vanes are 34 pizza.