Multi-roll calender

A multi-roll calender for producing a sheet of elastomeric material, comprising:

• (a) a calender frame;
• (b) a series of rolls, and means mounting the ends thereof in said calender frame, said rolls including an intake roll and a series of vertically superimposed rolls, said intake roll being spaced from the lowermost roll of said series of rolls so as to provide a roll gap, all of said superimposed rolls likewise being spaced from vertically adjacent rolls so as to provide variable roll gaps between each adjacent pair of rolls, said roll gaps following one after another in the direction of sequential movement of said sheet during formation thereof;
• (c) means associated with said rolls for sensing the pressure of the material in each roll gap of the calender;
• (d) means on opposite ends of certain of said rolls responsive to said sensing means for adjusting the width of each roll gap formed by adjacent rolls to cause the difference between the pressures in said gaps to be as small as is practicable, and
• (e) means for maintaining such pressures substantially constant.