Calender and method for controlling such a calender

Abstract

A calender includes a rotatable roller, and a belt co-acting with the roller with a determined belt pressure. At least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender. The calender also includes heating means for heating the fluid and/or the roller, control means for controlling the heating means and/or the belt pressure and/or the contact time, and a database for storing data. The control means are configured to control the heating means and/or the belt pressure and/or the contact time on the basis of at least one of the data contained in the database, before and/or during throughfeed of the material. A set with a plurality of such calenders and a method for controlling such a calender.

1 . A calender, comprising:
 a rotatable roller, which roller is hollow and thereby defines an internal space which can be filled at least partially or is filled at least partially with a heatable fluid, such as oil or air;   a belt, co-acting with the roller, with a determined belt pressure, wherein at least one material for feeding through the calender is situated between the roller and the belt for a determined contact time during throughfeed through the calender;   heating means for heating the fluid and/or the roller, which heating means are disposed in the internal space;   one or more control means for controlling the heating means and/or the belt pressure and/or the contact time,   characterized by a database in which at least one of the following data is stored, periodically:   a measured outer periphery temperature of the roller;   a measured fluid temperature;   the contact time;   the belt pressure;   a power of the heating means;   number of revolutions of the roller since the start of a calendering process;   at least one property of the at least one material being fed through the calender;   at least one property of a transfer paper being fed through the calender;   an ambient temperature;   an air humidity;   which calender is used;   a power of drive means of the calender;   at least one property of a belt of the calender,   and the one or more control means are further configured to control the heating means and/or the belt pressure and/or the contact time on the basis of at least one of the data contained in the database, before and/or during throughfeed of the material.   
     
     
         2 . The calender according to  claim 1 , wherein the control means are configured to determine before and/or during throughfeed of the material, on the basis of at least periodically recorded settings of the heating means and/or the belt pressure and/or the contact time of a plurality of prior calendering processes and on the basis of at least the at least one property of the same material, how the heating means and/or the belt pressure and/or the contact time must be set, and to control the heating means and/or the belt pressure and/or the contact time in the determined manner. 
     
     
         3 . The calender according to  claim 1 , wherein the control means are configured to control the heating means and/or the belt pressure and/or the contact time on the basis of the ambient temperature. 
     
     
         4 . The calender according to  claim 1 , wherein the database and the control means are connected or at least connectable to each other, wirelessly or via a computer network. 
     
     
         5 . The calender according to  claim 1 , wherein the control means are configured to control the heating means and/or the belt pressure and/or the contact time on the basis of average values when a connection with the database drops out. 
     
     
         6 . A set with a plurality of calenders according to  claim 1 , wherein the control means of at least one of the calenders are configured to control the heating means and/or the belt pressure and/or the contact time of that one calender on the basis of periodically registered data of calendering processes performed with the calenders of the set. 
     
     
         7 . The set according to  claim 6 , wherein said one calender is a calender of the set other than the calender of which the data are registered. 
     
     
         8 . A method for controlling a calender according to  claim 1 , which method comprises the following steps of:
 a) controlling the heating means and/or the belt pressure and/or the contact time by means of the one or more control means on the basis of at least one of the data contained in the database, before and/or during throughfeed of the material.   
     
     
         9 . The method according to  claim 8 , wherein step a) is performed by determining on the basis of at least periodically recorded settings of the heating means and/or the belt pressure and/or the contact time of a plurality of prior calendering processes and on the basis of at least the at least one property of the same material how the heating means and/or the belt pressure and/or the contact time must be set, and by controlling the heating means and/or the belt pressure and/or the contact time in the determined manner. 
     
     
         10 . The method according to  claim 8 , wherein step a) is performed by controlling the heating means and/or the belt pressure and/or the contact time on the basis of the ambient temperature. 
     
     
         11 . The method according to  claim 8 , comprising the steps of:
 b) observing that a connection with the database has dropped out; and   c) controlling the heating means and/or the belt pressure and/or the contact time by means of the one or more control means on the basis of average values while the connection has dropped out.   
     
     
         12 . The method according to  claim 8 , comprising the steps of:
 d) entering a material for feeding through the calender;   e) setting the heating means and/or the belt pressure and/or contact time on the basis of at least one property of the material entered in step d).   
     
     
         13 . The method according to  claim 12 , comprising the steps of:
 f) generating a signal when the calender is ready for throughfeed of the material entered in step d); and   g) feeding through the material after the signal has been generated.