PACKAGING METHOD AND UNIT FOR PRODUCING SEALED PACKAGES OF A FOOD PRODUCT POURABLE INTO A TUBE OF PACKAGING MATERIAL

• US 20110120059A1
• Filed: 08/07/2009
• Published: 05/26/2011
• Est. Priority Date: 08/09/2008
• Status: Active Grant

• Current Assignee: Tetra Laval Holdings & Finance SA (Tetra Laval Holdings BV)
• Original Assignee: Tetra Laval Holdings & Finance SA (Tetra Laval Holdings BV)
• Inventors: Poppi, Marco, Andreotti, Stefano, Donati, Andrea
• Granted Patent: US 8,919,081 B2
• Time in Patent Office: Days
• US Class Current: 53/451
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/7451 the severing tool and the welding tool being movable with respect to one-another
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/4312 for making flat seams in tubular or hollow articles, e.g. transversal seams
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/72321 consisting of metals or their alloys
• CPC Class Codes: B29C 66/72328 Paper
• CPC Class Codes: B29C 66/72341 for gases
• CPC Class Codes: B29C 66/7373 Joining soiled or oxidised materials
• CPC Class Codes: B29C 66/81419 and flat
• CPC Class Codes: B29C 66/81427 comprising a single ridge, e.g. for making a weakening line; comprising a single tooth
• CPC Class Codes: B29C 66/81431 comprising a single cavity, e.g. a groove
• CPC Class Codes: B29C 66/81457 comprising a block or layer of deformable material, e.g. sponge, foam, rubber pressing elements supported or backed-up by resilient material B29C66/8161
• CPC Class Codes: B29C 66/8221 Scissor or lever mechanisms, i.e. involving a pivot point
• CPC Class Codes: B29C 66/8222 Pinion or rack mechanisms
• CPC Class Codes: B29C 66/8225 Crank mechanisms
• CPC Class Codes: B29C 66/83543 cooperating flying jaws
• CPC Class Codes: B29C 66/8412 of different length, width or height
• CPC Class Codes: B29C 66/84121 of different width
• CPC Class Codes: B29C 66/8491 welding through a filled container, e.g. tube or bag
• CPC Class Codes: B29C 66/90 : Measuring or controlling the joining process
• CPC Class Codes: B29C 66/96 : characterised by the method for implementing the controlling of the joining process
• CPC Class Codes: B29K 2023/06 : PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/086 : EVOH, i.e. ethylene vinyl alcohol copolymer
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2305/02 : Aluminium
• CPC Class Codes: B29K 2711/123 : Coated
• CPC Class Codes: B29K 2995/0067 : non-permeable
• CPC Class Codes: B29L 2009/00 : Layered products
• CPC Class Codes: B29L 2031/7166 : Cartons of the fruit juice or milk type, i.e. containers of polygonal cross sections formed by folding blanks into a tubular body with end-closing or contents-supporting elements, e.g. gable type containers in general B65D5/06
• CPC Class Codes: B65B 51/306 : Counter-rotating devices
• CPC Class Codes: B65B 9/2049 : Package shaping devices acting on filled tubes prior to sealing the filling opening shaping or reshaping completed packages B65B61/24
• CPC Class Codes: B65B 9/207 : the web advancing continuously B65B9/22 takes precedence

Abstract

A method of producing a sealed package of a pourable food product involving feeding a tube of packaging material along an axis; moving a pair of first jaws and a pair of second jaws cyclically and alternately along sealing paths parallel to the axis, and along repositioning paths; moving the jaws, as they travel along the sealing paths, into a closed position in which the sealing members grip the tube and respectively form, at different times, a first and a second seal sealing the tube and defining respective opposite ends of the package; and moving the jaws, as they travel along the respective repositioning paths, into an open position, in which they are detached from the tube; acquiring a desired value of a quantity related to the package weight; and forming the second seal at a distance, which is a function of the value, from the first seal.

Claims

1. A method of producing a sealed package of a food product pourable into a tube of packaging material;

the method comprising;

feeding said tube along an axis;

moving at least one pair of first jaws and one pair of second jaws cyclically and alternately along respective sealing paths parallel to said axis, and along respective repositioning paths along which said first and second jaws move with respect to said tube;

said first and second jaws comprising first and second sealing members respectively;

moving said first jaws and second jaws, as they travel along the respective sealing paths, into a closed position in which the respective said first and second sealing members grip said tube and respectively form, at different times, a first and a second seal sealing the tube and defining respective opposite ends of said package; and

moving said first jaws and second jaws, as they travel along the respective repositioning paths, into an open position, in which said respective first and second sealing members are detached from said tube;

acquiring a desired value of a quantity related to the weight of a said package; and

forming said second seal at a first distance, which is a function of said value, from said first seal;

said first distance being measured parallel to said axis.

2. A method as claimed in claim 1, comprising generating, on the basis of said value, a first and second control scheme respectively controlling a first and second actuator assembly for respectively moving said first and second jaws parallel to said axis along said respective sealing paths;

said first and second control scheme being generated to position said first sealing members of said first jaws at said first distance from said second sealing members of said second jaws, at least during said step of forming said second seal.

3. A method as claimed in claim 2, wherein, at said generating step, at least said first control scheme is generated as the sum of at least a first addend dependent on said value, and a second addend independent of said value.

4. A method as claimed in claim 1, comprising adjusting a second distance, crosswise to said axis, between said second sealing members of said second jaws, on the basis of at least one of a first parameter relating to the viscosity of said food product, and a second parameter relating to the output rate of said packages, and after said first sealing members of said first jaws have formed said first seal, and before said second sealing members of said second jaws form said second seal.

5. A method as claimed in claim 4, comprising engaging first and second fasteners, fitted respectively to said first and second jaws, along respective end portions of the respective repositioning paths;

said adjustment of said second distance preceding the engagement of said second fasteners.

6. A method as claimed in claim 4, wherein said adjustment of said second distance comprises generating, on the basis of said at least one of said first and second parameter, at least a third control scheme controlling a third actuator assembly for moving said second jaws between said open and closed positions.

7. A method as claimed in claim 6, wherein, at said generation of said third control scheme, said third control scheme is generated as the sum of at least a third addend dependent on said at least one of said first and second parameter, and at least a fourth addend independent of said parameters.

8. A method as claimed in claim 6, wherein, at said generation step, said third control scheme is generated independently of said value.

9. A method as claimed in claim 7, wherein said fourth addend is generated to move said second jaws between said closed and open positions along a basic trajectory;

and in that said third addend is generated to correct said basic trajectory as said second jaws travel along at least the respective said end portions of the respective said repositioning paths.

10. A method as claimed in claim 7, comprising releasing said first and second fasteners before the respective said first and second jaws complete the respective said sealing paths;

and wherein said generation of said third control scheme comprises generating said fourth addend to press said second sealing members of said second jaws together, at least along end portions of the respective said sealing paths and after said step of releasing said second fasteners.

11. A software product loadable onto a processing unit of a packaging unit for producing packages, and which, when executed, implements the method as claimed in claim 1.

12. A packaging unit for producing sealed packages of a food product pourable into a tube of packaging material fed along an axis;

the unit comprising at least one pair of first jaws and one pair of second jaws, in turn comprising first and second sealing members respectively;

said first and second jaws being movable, in use, between a closed position, in which said first and second sealing members grip said tube and respectively form a first and second seal crosswise to the tube and defining opposite ends of said package and an open position, in which said first and second sealing members are detached from said tube;

said pairs of first and second jaws being movable cyclically and alternately along respective sealing paths, parallel to the axis along which they are set to the respective said closed positions, and along respective repositioning paths, along which they are set to the respective said open positions;

acquisition means for acquiring a desired value of a quantity related to the weight of said package;

a first and second actuator assembly for respectively moving said first and second jaws parallel to said axis; and

processing means for generating, on the basis of said value, a first and second control scheme controlling said first and second actuator assembly;

said first and second control scheme being generated, in use, to position said second sealing members at a first distance, dependent on said value, from said first sealing members, at least as said second sealing members form said second seal.

13. A unit as claimed in claim 12, wherein at least one of said first and said second control scheme is a sum of at least a first addend independent of said value, and a second addend dependent on said value.

14. A unit as claimed in claim 12, wherein said first and second jaws are fixed to respective slides running parallel to said axis;

and in that at least said first actuator assembly comprises;

a first servomotor controlled by said first control scheme; and

a member movable in accordance with a time scheme dependent on said first control scheme, and connected functionally to said first servomotor and said slide.

15. A unit as claimed in claim 14, wherein said first actuator assembly comprises a pulley connected angularly to an output member of said first servomotor, and a belt wound about said pulley;

said member being fixed to a branch of said belt.

16. A unit as claimed in claim 15, wherein said member is a first rod movable parallel to said axis.

17. A unit as claimed in claim 12, comprising a third and fourth actuator assembly for respectively moving said first and second jaws between the respective closed and open positions;

and in that, on the basis of at least one of a first parameter relating to the viscosity of said food product, and a second parameter relating to the output rate of said packages, said processing means generate a third and fourth control scheme controlling said third and fourth actuator assembly respectively;

said third and fourth control scheme adjusting a second distance, crosswise to said axis, between said second sealing members of said second jaws, after said first sealing members of said first jaws form said first seal, and before said second sealing members of said second jaws form said second seal.

18. A unit as claimed in claim 17, wherein said first and second jaws comprise respective first and second fasteners which are engaged along initial portions of said respective sealing paths and released along at least respective portions of the respective repositioning paths;

said processing means, in use, adjusting said second distance before said second fasteners are engaged.

19. A unit as claimed in claim 18, wherein at least said third control scheme is the sum of at least a third addend independent of said first and said second parameter, and a fourth addend dependent on at least one of said first and said second parameter.

20. A unit as claimed in claim 18, wherein said third control scheme is independent of said value.

21. A unit as claimed in claim 17, wherein at least said second actuator assembly comprises:

a second servomotor controlled by said third control scheme;

a movable second rod connected functionally to said second servomotor and movable parallel to said axis in accordance with a time scheme dependent on said third control scheme; and

two connecting rods, each hinged to said second rod and to an appendix of a respective first jaw.