convex surface in such a manner that disturbances which are present at the free liquid surface are increased conclusively a configuration of the pressure plate according to the patent cited above implies that the stock jet at its arrival at the sheet forming zone very probably has been broken up this will result in a paper reflecting the quality of the stock jet in close connection to the inflection point according to fig2 the stock jet is enclosed between the pressure plate and wire along the convex surface of the pressure plate the wire will press against the pressure plate and the stock jet lying therebetween the size of this pressure depends on the tensile stress t in the wire and the curvature radius of the wire which radius substantially corresponds to the curvature radius r 2 of the pressure plate this relation is described by the equation as follows as appears from fig2 the pressure measured along the entire length of the pressure plate agrees pretty well with the theoretical ones the pressure measured beneath the convex portion of the pressure plate corresponds substantially to the dewatering pressure the dewatering capacity of a pressure plate in a first approximation can be set proportionally to the dewatering impulse i according to equ2 where i dewatering impulse pa s p t size of the pressure pulse at time t pa the equation 3 can be developed according to equ3 where u w wire speed m s the dewatering capacity thus is proportional to the surface below the pressure curve according to fig2 experiences a o from papermaking with twin wire machines have shown that the uniformity of the paper depends.