the wear part of the seal is separate from the spring part the shape of the wear part and the material from which it is made can be optimized without changing the stiffness of the spring part because of the way in which the spring part is attached spring plate 21 does not have to be bent and this facilitates design and construction and reduces costs wear part 20 is the only part that requires replacement because the wear part of the seal designed in accordance with the present invention is made of plastic it can also replace seals used on a roll shell that has no wire cloth thereby making it easier and less expensive to add or remove the wire cloth which of course is only required when there are short fibers in the pulp suspension the seal designed in accordance with the present invention also conforms better with the roll and is thus better able to return fibers that have slipped past the doctor blade and continue to move along the roll shell moreover the seal permits the roll to be backed up i e rotated in the reverse direction and because of its geometry the seal also provides greater resistance to vat pressure peaks the seal designed in accordance with the present invention also makes it possible to provide a novel wear indicator which issuer a warning signal when wear part 20 have been worn down to a certain dimensions at which replacement is necessary in accordance with the present invention wear indicator 27 comprises two electrical leads 28.