The Modern Paper-Making Machine

During the last two decades both the speed and width of paper machines have increased considerably. This has resulted in the adoption of many devices which prior to that time were still looked on with doubt. The increase in width and weight of the rolls of modern newsprint machines has made the removable wet end practically standard. Similarly the increase in speed has only been made possible by the use of the projection slice, suction couch, and press rolls, which are being fitted with success to machines of all types. The shells of suction rolls must be free from blowholes and this has entailed the use of centrifugal castings, and has been the means of developing their technique. A further development is the vacuum-forming paper machine, probably the most revolutionary modification of the Fourdrinier machine yet proposed. The two-wire machine gives a paper free from any wire mark, and recently a wire has been produced which goes some way towards the elimination of the wire mark. Electric drives arc nearly standard on all new machines.