Cross-cutting device

Abstract

The invention relates to a cutting device and method for cutting prefabricated transverse seal seams of a tube composed of plastic film and filled with food, particularly soft cheese, wherein each transverse seal seam of the continuously supplied film tube to be processed separates one portion of the food from the next portion. The device comprises a rotating knife holder provided with at least one knife blade 22, and wherein the knife blade 22 acts on a counter bearing 4 when cutting a transverse seal seam, wherein said knife holder has a heating element for heating the knife blade 22 in a targeted fashion.

What is claimed is: 
     
         1 . A cutting device for cutting pre-fabricated transverse seams of a plastic-film sleeve that is filled with food, whereby each transverse seam of the film sleeve to be processed and continuously fed separates one portion of food from the next portion, wherein the device comprises:
 (a) a rotatable knife holder having an axis of rotation and equipped with at least one cutting blade and one receiving part per cutting blade to receive the cutting blade, whereby the cutting blade has a cutting edge parallel to the axis of rotation and wherein the cutting blade extends from the axis of rotation,   (b) the cutting blade is mounted on the receiving part such that the cutting edge extends beyond the receiving part and   (c) a rotatable roller having a roller surface located proximate to, and having an axis of rotation parallel to the axis of rotation of, the rotatable knife holder,   
       wherein 
       the receiving part comprises a heating element for heating the cutting blade and 
       the rotatable knife holder and the rotatable roller are configured to cause the cutting edge of the cutting blade of the rotatable knife holder to strike the surface of the rotatable roller when the rotatable knife holder is rotated, whereby the surface of the rotatable roller ( 4 ) engages with, and bears against, the cutting blade such that the cutting edge of the cutting blade and the rotatable roller roll off against each other during rotation of the rotatable knife holder. 
     
     
         2 . The cutting device according to  claim 1 , wherein each cutting blade is held elastically on the rotatable knife holder in the cutting direction. 
     
     
         3 . The cutting device according to  claim 1 , wherein the rotatable knife holder has a cylindrical cross-section and is equipped with multiple cutting blades. 
     
     
         4 . The cutting device according to  claim 1 , wherein each receiving part comprises a support surface for the cutting blade having a hole for a heating element, the cutting blade rests on the support surface and the heating element is arranged in the hole. 
     
     
         5 . The cutting device according to  claim 4 , wherein
 each receiving part is a separate component mounted on the rotatable knife holder and   the rotatable knife holder comprises (a) at least one radially oriented guideway for holding each receiving part and (b) springs positioned between each radially oriented guideway and each receiving part for pressing the receiving part in a direction radially outward from the axis of rotation.   
     
     
         6 . The cutting device according to  claim 4 , wherein each receiving part is an integral part of the knife holder. 
     
     
         7 . The cutting device according to  claim 6 , wherein each cutting blade has a rectangular cross-section. 
     
     
         8 . The cutting device according to  claim 6 , wherein the rotatable knife holder has a splined shaft cross-sectional profile and comprises clamping claws for clamping each cutting blade onto the knife holder such that each cutting blade is in the plane of a secant relative to the surface of the rotatable roller. 
     
     
         9 . The cutting device according to  claim 1 , wherein the rotatable knife holder is provided with a sensor to measure temperature and/or with a cooling system. 
     
     
         10 . A method for cutting pre-fabricated transverse seams of a plastic-film sleeve that is filled with food, whereby each transverse seam of the film sleeve to be processed and continuously fed separates one portion of the food from the next portion, the method comprising:
 providing a cutting device according to claim I having a rotatable knife holder having at least one cutting blade and a rotatable roller;   passing the plastic-film sleeve that is filled with food having pre-fabricated transverse seams between the rotatable knife holder and the rotatable roller;   heating said cutting blade with a heating element within said receiving part to a temperature between about 80° C. and about 130° C., which is lower than a melting temperature of the plastic-film sleeve;   rotating the rotatable knife holder so that the cutting blade moves in the same direction as the plastic-film sleeve when proximate to the plastic-film sleeve;   synchronizing contact between the cutting blade edge and the surface of the rotatable roller with the presence of a pre-fabricated transverse seam of the plastic-film sleeve at the same location; and   striking against the surface of the rotatable roller with said cutting blade during rotation of the knife holder, whereby a pre-fabricated transverse seam of the plastic-film sleeve is cut by said cutting blade.   
     
     
         11 . The method according to  claim 10 , wherein the plastic-film is polypropylene. 
     
     
         12 . The method according to  claim 10 , wherein each cutting blade has a cutting edge and the total length of the cutting edge of the cutting blade is shorter than the transverse seam, so that film arms remain, or a perforated seam is produced, after the cutting blade strikes against the surface of the rotatable roller. 
     
     
         13 . A method for cutting pre-fabricated transverse seams of a plastic-film sleeve that is filled with food, whereby each transverse seam of the film sleeve to be processed and continuously fed separates one portion of the food from the next portion, the method comprising:
 providing a cutting device having a rotatable knife holder having at least one cutting blade and a rotatable opposing bearing wherein the rotatable knife holder and rotatable opposing bearing are configured so that the cutting blade strikes the rotatable opposing bearing when the rotatable knife holder is rotated;   passing the plastic-film sleeve that is filled with food having pre-fabricated transverse seams between the rotatable knife holder and the rotatable opposing bearing;   rotating the rotatable knife holder so that the cutting blade moves in the same direction as the plastic-film sleeve when proximate to the plastic-film sleeve;   synchronizing contact between the cutting blade edge and the surface of the rotatable roller with the presence of a pre-fabricated transverse seam of the plastic-film sleeve at the same location;   striking against the surface of the rotatable roller with said cutting blade during rotation of the knife holder, whereby a pre-fabricated transverse seam of the plastic-film sleeve is cut by said cutting blade,   wherein the cutting blade is heated to a temperature between about 80° C. and about 130° C.   
     
     
         14 . The method according to  claim 13 , wherein the plastic-film is polypropylene. 
     
     
         15 . The method according to  claim 13 , wherein each cutting blade has a cutting edge and the total length of the cutting edge of the cutting blade is shorter than the transverse seam, so that film arms remain, or a perforated seam is produced, after the cutting blade strikes against the surface of the rotatable roller.