Suction box cover for fourdrinier machines

This invention relates to a suction box cover for Four drinier machines and has for an object the provision of improvements in this art. One of the particular objects of the invention is to provide a suction box cover which furnishes a very long life to the screen which moves thereover; which will itself have a long life; and which is much less expensive than the better types of coverings now available. Patent No. 2,876,685 discloses the use of polytetra fluoroethylene (PTFE or" Teflon') for suction box covers. This is a great improvement over wooden covers in that it furnishes a much longer wear life of the screen wire material. However, it is very expensive and rela tively soft so that it wears away rapidly, thus increasing the cost. The loss of time and product in shutting down a Fourdrinier machine to replace either the screen or the suction box cover involves very considerable expense, say $10,000 or more, hence it is highly …