Press roll and press in a paper making machine

In a paper making machine, a press forming a press nip defining a press nip zone through which a web to be dewatered passes during operation of the paper making machine, comprising:

• a first press roll including an inner frame having an outer substantially cylindrical surface, an elastic layered structure applied entirely around and adhering to said outer surface of said frame, said layered structure including an elastic inner layer having a plurality of cavities formed therein, and an outer layer acting against an inner surface of a looped press felt passing through the press nip, said outer layer having a plurality of discrete passages formed therethrough, at least one passage communicating with each of said cavities, the volume of a passage being smaller than the volume of a respective cavity with which it is in communication;
• a second press roll in nip defining relationship with said first press roll forming a press nip zone therebetween, said second press coil having an elastic coating and a hollow face;
• and
• a pair of press felts passing through said press nip zone,
• said cavities and passages being constructed such that during operation said cavities are compressed together within the press nip zone to thereby widen the press nip zone and such that said cavities produce a negative pressure in the press nip zone following a central region of the press nip zone.