Support or pressure roll for a paper roll winder

Abstract

A roll for selective use as either a support drum or as a rider roll in a winder for winding a traveling paper web into a relatively large diameter wound web roll has a body with an outer, elastomeric cover. The elastomeric cover includes a pattern, open to the surface, arranged such that the percent of volumetric void for a unit of cover volume is such that the effective hardness of the cover ranges between about 30 Shore “A” to about 55 Shore “A” where the roll is a support drum, and between about 40 Shore “A” to about 65 Shore “A” when the roll is a rider roll. In addition, the elastomeric material has an absolute hardness of about 65 Shore “A”, or less, for a support drum, and about 75 Shore “A”, or less, for a rider roll, and a Poisson's ratio of between about 0.47 to about 0.499.

What is claimed is:  
     
       1. A roll for use in a winder for a papermaking machine as a support drum for winding a traveling paper web into a wound web roll by maintaining supporting nip engagement therewith, the support drum comprising, in combination: 
       a shaft body member having an outer surface and a longitudinal axis;  
       a cover on the outer surface of the body member, the cover having an outer surface defining the cylindrical shape and surface of the support drum and comprising an elastomeric material having a Poisson's ratio of about 0.47, or greater, and an absolute hardness of about 65 Shore “A”, or less;  
       a pattern in the outer surface of the cover, the cover having a volumetric void open to the outer surface thereof and intermediate the pattern, the pattern arranged such that the percent of the volumetric void for a unit volume of an outer portion of the cover which includes the volumetric void and the pattern is such that the cover has an effective hardness of about 55 Shore “A”, or less;  
       whereby a nip instant center is created which is within the wound web roll  cover.  
     
     
       2. A roll for use in a winder as set forth in  claim 1 , wherein: the Poisson's ratio of the elastomeric material ranges from about 0.47 to about 0.499. 
     
     
       3. A support drum roll for use in a winder as set forth in  claim 1 , wherein: 
       the percent of the volumetric void for a unit volume of the cover, as defined in  claim 1 , is such that the effective hardness of the cover ranges from between about 30 Shore “A” to about 55 Shore “A”.  
     
     
       4. A support drum roll for use in a winder as set forth in  claim 1 , wherein: 
       the Poisson's ratio of the elastomeric material ranges from about 0.47 to about 0.499;  
       the percent of the volumetric void for a unit volume of the cover, as defined in  claim 1 , is such that the effective hardness of the cover ranges from between about 30 Shore “A” to about 55 Shore “A”.  
     
     
       5. A roll for use in a winder as set forth in  claim 1 , wherein: the pattern in the cover includes a plurality of grooves. 
     
     
       6. A roll for use in a winder as set forth in  claim 1 , wherein: the pattern in the cover is diamond shaped. 
     
     
       7. A roll for use in a winder as set forth in  claim 1 , wherein: the pattern in the cover includes a plurality of raised dimples. 
     
     
       8. A roll for use in a winder as set forth in  claim 1 , wherein: the pattern in the cover includes a plurality of recessed holes. 
     
     
       9. A roll for use in a winder for a papermaking machine as a rider roll to apply a pressure nip to a web roll being wound in the winder from a traveling paper web, the rider roll comprising, in combination: 
       a shaft body member having an outer surface and a longitudinal axis;  
       a cover on the outer surface of the body member, the cover having an outer surface defining the cylindrical shape and surface of the rider roll and comprising an elastomeric material having a Poisson's ratio of about 0.47, or greater, and an absolute hardness of about 75 Shore “A”, or less;  
       a pattern in the outer surface of the cover, the cover having a volumetric void, the pattern arranged such that the percent of the volumetric void for a unit volume of an outer portion of the cover which includes the volumetric void and the pattern is such that the cover has an effective hardness of about 65 Shore “A”, or less;  
       whereby an instant center is created which is within the wound web roll  cover.  
     
     
       10. A rider roll for use in a winder as set forth in  claim 9 , wherein: 
       the percent of the volumetric void for a unit volume of the cover, as defined in  claim 9 , is such that the effective hardness of the cover ranges from between about 40 Shore “A” to about 65 Shore “A”.  
     
     
       11. A rider roll for use in a winder as set forth in  claim 9 , wherein: 
       the Poisson's ratio of the elastomeric material ranges from about 0.47 to about 0.499;  
       the percent of the volumetric void for a unit volume of the cover, as defined in  claim 9 , is such that the effective hardness of the cover ranges from between about 40 Shore “A” to about 65 Shore “A”.