Film Packaging Apparatus and Method

Abstract

A film packaging apparatus, operating on a flow of products movable along a feed direction and apt to package each product into a respective wrapping of heat-sensitive film, includes: a transversal sealing unit, having a heat sealer and a sealer receiving element, apt to seal transversal portions of the film transversally to the feed direction, an actuator with mechanical drive element for moving the heat sealer and the sealer receiving element in the direction of the flow; and a control unit, which controls the actuator so that, at a sealing section of the path of the products along which the heat sealer produces the sealing of the transversal portions of film, the speed of the heat sealer element and sealer receiving element in the direction of the flow is constant and equal to the speed of the flow of products.

1 - 34 . (canceled)  
     
     
         35 . A film packaging apparatus, operating on a flow of products movable along a feed direction and apt to package each of said products into a respective wrapping of heat-sensitive film, comprising: 
 a transversal sealing unit, which in turn comprises: 
 heat sealer means, apt to seal transversal portions of the film transversally to said feed direction and along a sealing section of the path of the products; and  
 first driving means, apt to move said heat sealer means according to said feed direction, said first driving means comprising an actuator and mechanical drive means interposed between said actuator and said heat sealer means; and  
   a control unit, apt to control said actuator of said first driving means so that, at said sealing section, the speed of said heat sealer means in said feed direction is substantially equal to the speed of the flow of products.    
     
     
         36 . The apparatus according to  claim 35 , wherein said control unit is apt to control said actuator of said first driving means so that the speed of said heat sealer means at said sealing section is substantially constant.  
     
     
         37 . The apparatus according to  claim 35 , wherein said mechanic drive means of said first driving means is based on a connecting rod-crank kinematic motion.  
     
     
         38 . The apparatus according to  claim 35 , wherein said transversal sealing unit comprises also second driving means, distinct from said first driving means and apt to move said heat sealer means in a direction substantially orthogonal to said feed direction.  
     
     
         39 . The apparatus according to  claim 38 , wherein said second driving means comprises a respective dedicated actuator.  
     
     
         40 . The apparatus according to  claim 35 , wherein said heat sealer means comprises at least one heat sealer element and at least one corresponding sealer receiving element, the overall arrangement being such that, in said sealing section, the transversal portions of film to be sealed are arranged between said elements.  
     
     
         41 . The apparatus according to  claim 40 , wherein said first driving means is apt to move said heat sealer element and said sealer receiving element according to said feed direction.  
     
     
         42 . The apparatus according to  claim 40 , wherein said transversal sealing unit comprises also second driving means, distinct from said first driving means and apt to move said heat sealer means in a direction substantially orthogonal to said feed direction, and wherein said second driving means is apt to simultaneously move said heat sealer element and said sealer receiving element in opposite senses.  
     
     
         43 . The apparatus according to  claim 42 , wherein said second driving means comprises a rocker arm mechanism connected to said heat sealer element and sealer receiving element.  
     
     
         44 . The apparatus according to  claim 40 , wherein said transversal sealing unit comprises also second driving means, distinct from said first driving means and apt to move said heat sealer means in a direction substantially orthogonal to said feed direction and comprising a respective dedicated actuator, and wherein said control unit is apt to control said dedicated actuator of said second driving means so that the relative speed (v S/C ) of at least said heat sealer element with respect to said flow of products movable along a feed direction at said sealing section is substantially nil.  
     
     
         45 . The apparatus according to  claim 40 , wherein said transversal sealing unit comprises also second driving means, distinct from said first driving means and apt to move said heat sealer means in a direction substantially orthogonal to said feed direction and comprising a respective dedicated actuator, and wherein said control unit is apt to control said dedicated actuator of said second driving means so that the relative speed (v S/C ) of said heat sealer element and of said sealer receiving element with respect to said flow of products movable along a feed direction at said sealing section is substantially nil.  
     
     
         46 . The apparatus according to  claim 40 , wherein said transversal sealing unit comprises also second driving means, distinct from said first driving means and apt to move said heat sealer means in a direction substantially orthogonal to said feed direction and comprising a respective dedicated actuator, and wherein said control unit is apt to control said dedicated actuator of said second driving means so that during a backward stroke of the sealing the relative distance between said sealer receiving element and heat sealer element remains substantially constant.  
     
     
         47 . The apparatus according to  claim 40 , comprising means for adjusting the working height of said heat sealer element and/or sealer receiving element in a direction substantially orthogonal to said feed direction.  
     
     
         48 . The apparatus according to  claim 47 , wherein said means for adjusting said working height comprises a respective dedicated actuator.  
     
     
         49 . The apparatus according to  claim 40 , comprising means for pre-heating said sealer receiving element.  
     
     
         50 . The apparatus according to  claim 40 , comprising means for heating said sealer receiving element and sensing means apt to control said heating means depending on the temperature of said sealer receiving element.  
     
     
         51 . The apparatus according to  claim 35 , comprising means for nearing opposed transversal portions of film at said sealing section.  
     
     
         52 . The apparatus according to  claim 51 , wherein said heat sealer means comprises at least one heat sealer element and at least one corresponding sealer receiving element, the overall arrangement being such that, in said sealing section, the transversal portions of film to be sealed are arranged between said elements and wherein said means for nearing opposed transversal portions of film is arranged at said heat sealer element and/or said sealer receiving element.  
     
     
         53 . The apparatus according to  claim 52 , wherein said means for nearing comprises at least a pair of elongate elements arranged each at one side of a respective heat sealer or sealer receiving element.  
     
     
         54 . The apparatus according to  claim 35 , comprising, upstream of said transversal sealing unit, a wrapping unit, wherein said film is positioned with respect to said flow.  
     
     
         55 . The apparatus according to  claim 35 , comprising, upstream of said transversal sealing unit, a longitudinal sealing unit, for sealing longitudinal portions of said film parallelly to said feed direction.  
     
     
         56 . The apparatus according  claim 35 , comprising means for drawing each packaged product, arranged downstream of said transversal sealing unit and driven by a dedicated actuator.  
     
     
         57 . The apparatus according to  claim 56 , wherein said means for drawing comprises a pair of opposedly arranged drawing rollers.  
     
     
         58 . The apparatus according to  claim 57 , comprising means for adjusting the relative positions of said drawing rollers along said feed direction.  
     
     
         59 . The apparatus according to  claim 35 , comprising first conveying means, apt to feed the products to be packaged to said transversal sealing unit, and second conveying means for providing the products to be packaged through said transversal sealing unit, wherein said first and second conveying means have independent actuators.  
     
     
         60 . The apparatus according to  claim 35 , comprising one or more position, speed and/or acceleration sensors arranged at said heat sealer means and apt to provide feedback signals to said control unit.  
     
     
         61 . A packaging method operating on a flow of products movable along a feed direction and apt to package each of said products into a respective wrapping of heat-sensitive film, comprising a step of transversal sealing, in which transversal portions of the film are sealed transversally to said feed direction and along a sealing section of the path of the products, said step being carried out by heat sealer means driven by first driving means, apt to move such heat sealer means according to said feed direction, such first driving means comprising an actuator and mechanical drive means interposed between said actuator and said heat sealer means, in said step of transversal sealing said actuator of said first driving means being controlled so that, at said sealing section, the speed of the heat sealing means in said feed direction is substantially equal to the speed of the flow of products.  
     
     
         62 . The method according to  claim 61 , wherein in said step of transversal sealing said actuator of said first driving means is controlled so that the speed of the heat sealer means at said sealing section is substantially constant.  
     
     
         63 . The method according to  claim 61 , wherein said step of transversal sealing provides that a heat sealer element and a sealer receiving element of said heat sealer means be moved both in a feed direction by said first driving means and in a direction substantially orthogonal to said feed direction by second driving means, distinct from said first driving means and provided with a dedicated actuator.  
     
     
         64 . The method according to  claim 63 , wherein said step of transversal sealing provides that said dedicated actuator of said second driving means be controlled so that the relative speed (v S/C ) of said heat sealer element with respect to said sealer receiving element at said sealing section is substantially nil.  
     
     
         65 . The method according to  claim 63 , wherein said dedicated actuator of said second driving means is controlled so that during a backward stroke of the sealing the relative distance between said sealer receiving element and said heat sealer element remains substantially constant.  
     
     
         66 . The method according to  claim 63 , providing a step of adjusting the working height of said heat sealer element and sealer receiving element in a direction substantially orthogonal to said feed direction.  
     
     
         67 . The method according to  claim 61 , providing, upstream of said step of transversal sealing, a step of wrapping, wherein said film is positioned with respect to said flow.  
     
     
         68 . The method according to  claim 61 , providing, upstream of said step of transversal sealing, a step of longitudinal sealing, for sealing longitudinal portions of said film parallelly to said feed direction.