US20140075884A1 - Induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products - Google Patents

Induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products Download PDF

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Publication number
US20140075884A1
US20140075884A1 US14/115,171 US201214115171A US2014075884A1 US 20140075884 A1 US20140075884 A1 US 20140075884A1 US 201214115171 A US201214115171 A US 201214115171A US 2014075884 A1 US2014075884 A1 US 2014075884A1
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US
United States
Prior art keywords
inductive element
sealing device
packaging material
tube
edge
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US14/115,171
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English (en)
Inventor
Fabrizio Sighinolfi
Andrea Babini
Pietro Monari
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tetra Laval Holdings and Finance SA
Original Assignee
Tetra Laval Holdings and Finance SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tetra Laval Holdings and Finance SA filed Critical Tetra Laval Holdings and Finance SA
Assigned to TETRA LAVAL HOLDINGS & FINANCE S.A. reassignment TETRA LAVAL HOLDINGS & FINANCE S.A. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: BABINI, ANDREA, MONARI, PIETRO, SIGHINOLFI, FABRIZIO
Publication of US20140075884A1 publication Critical patent/US20140075884A1/en
Abandoned legal-status Critical Current

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/36—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B51/00—Devices for, or methods of, sealing or securing package folds or closures; Devices for gathering or twisting wrappers, or necks of bags
    • B65B51/10—Applying or generating heat or pressure or combinations thereof
    • B65B51/22—Applying or generating heat or pressure or combinations thereof by friction or ultrasonic or high-frequency electrical means, i.e. by friction or ultrasonic or induction welding
    • B65B51/227—Applying or generating heat or pressure or combinations thereof by friction or ultrasonic or high-frequency electrical means, i.e. by friction or ultrasonic or induction welding by induction welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/36—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction
    • B29C65/3604—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the type of elements heated by induction which remain in the joint
    • B29C65/3644—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the type of elements heated by induction which remain in the joint being a ribbon, band or strip
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/36—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction
    • B29C65/3604—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the type of elements heated by induction which remain in the joint
    • B29C65/3656—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the type of elements heated by induction which remain in the joint being a layer of a multilayer part to be joined, e.g. for joining plastic-metal laminates
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/36—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction
    • B29C65/3668—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the means for supplying heat to said heated elements which remain in the join, e.g. special induction coils
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/02—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure
    • B29C65/34—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement"
    • B29C65/36—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction
    • B29C65/3672—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the composition of the elements heated by induction which remain in the joint
    • B29C65/3676—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the composition of the elements heated by induction which remain in the joint being metallic
    • B29C65/368—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor by heating, with or without pressure using heated elements which remain in the joint, e.g. "verlorenes Schweisselement" heated by induction characterised by the composition of the elements heated by induction which remain in the joint being metallic with a polymer coating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
    • B29C65/4805—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding characterised by the type of adhesives
    • B29C65/481—Non-reactive adhesives, e.g. physically hardening adhesives
    • B29C65/4815—Hot melt adhesives, e.g. thermoplastic adhesives
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
    • B29C65/50—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
    • B29C65/50—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like
    • B29C65/5042—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like covering both elements to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C65/00—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor
    • B29C65/48—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding
    • B29C65/50—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like
    • B29C65/5092—Joining or sealing of preformed parts, e.g. welding of plastics materials; Apparatus therefor using adhesives, i.e. using supplementary joining material; solvent bonding using adhesive tape, e.g. thermoplastic tape; using threads or the like characterised by the tape handling mechanisms, e.g. using vacuum
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/01—General aspects dealing with the joint area or with the area to be joined
    • B29C66/05—Particular design of joint configurations
    • B29C66/10—Particular design of joint configurations particular design of the joint cross-sections
    • B29C66/11—Joint cross-sections comprising a single joint-segment, i.e. one of the parts to be joined comprising a single joint-segment in the joint cross-section
    • B29C66/112—Single lapped joints
    • B29C66/1122—Single lap to lap joints, i.e. overlap joints
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/432—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms
    • B29C66/4322—Joining a relatively small portion of the surface of said articles for making tubular articles or closed loops, e.g. by joining several sheets ; for making hollow articles or hollow preforms by joining a single sheet to itself
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/49—Internally supporting the, e.g. tubular, article during joining
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/72—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined
    • B29C66/723—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered
    • B29C66/7232—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered comprising a non-plastics layer
    • B29C66/72321—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered comprising a non-plastics layer consisting of metals or their alloys
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/72—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined
    • B29C66/723—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered
    • B29C66/7232—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered comprising a non-plastics layer
    • B29C66/72327—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered comprising a non-plastics layer consisting of natural products or their composites, not provided for in B29C66/72321 - B29C66/72324
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
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    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/72—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined
    • B29C66/723—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the structure of the material of the parts to be joined being multi-layered
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
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    • B29C66/80—General aspects of machine operations or constructions and parts thereof
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    • B29C66/81411—General aspects of the pressing elements, i.e. the elements applying pressure on the parts to be joined in the area to be joined, e.g. the welding jaws or clamps characterised by the design of the pressing elements, e.g. of the welding jaws or clamps characterised by the surface geometry of the part of the pressing elements, e.g. welding jaws or clamps, coming into contact with the parts to be joined characterised by its cross-section, e.g. transversal or longitudinal, being non-flat
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    • B29C66/80—General aspects of machine operations or constructions and parts thereof
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    • B29C66/83413—Roller, cylinder or drum types cooperating rollers, cylinders or drums
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/84—Specific machine types or machines suitable for specific applications
    • B29C66/849—Packaging machines
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/87—Auxiliary operations or devices
    • B29C66/872—Starting or stopping procedures
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/80—General aspects of machine operations or constructions and parts thereof
    • B29C66/87—Auxiliary operations or devices
    • B29C66/874—Safety measures or devices
    • B29C66/8744—Preventing overheating of the parts to be joined, e.g. if the machine stops or slows down
    • B29C66/87441—Preventing overheating of the parts to be joined, e.g. if the machine stops or slows down by lowering or shutting down the power supply
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B51/00—Devices for, or methods of, sealing or securing package folds or closures; Devices for gathering or twisting wrappers, or necks of bags
    • B65B51/10—Applying or generating heat or pressure or combinations thereof
    • B65B51/22—Applying or generating heat or pressure or combinations thereof by friction or ultrasonic or high-frequency electrical means, i.e. by friction or ultrasonic or induction welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B51/00—Devices for, or methods of, sealing or securing package folds or closures; Devices for gathering or twisting wrappers, or necks of bags
    • B65B51/10—Applying or generating heat or pressure or combinations thereof
    • B65B51/26—Devices specially adapted for producing transverse or longitudinal seams in webs or tubes
    • B65B51/30—Devices, e.g. jaws, for applying pressure and heat, e.g. for subdividing filled tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B9/00—Enclosing successive articles, or quantities of material, e.g. liquids or semiliquids, in flat, folded, or tubular webs of flexible sheet material; Subdividing filled flexible tubes to form packages
    • B65B9/10—Enclosing successive articles, or quantities of material, in preformed tubular webs, or in webs formed into tubes around filling nozzles, e.g. extruded tubular webs
    • B65B9/20—Enclosing successive articles, or quantities of material, in preformed tubular webs, or in webs formed into tubes around filling nozzles, e.g. extruded tubular webs the webs being formed into tubes in situ around the filling nozzles
    • B65B9/2035—Tube guiding means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65B—MACHINES, APPARATUS OR DEVICES FOR, OR METHODS OF, PACKAGING ARTICLES OR MATERIALS; UNPACKING
    • B65B9/00—Enclosing successive articles, or quantities of material, e.g. liquids or semiliquids, in flat, folded, or tubular webs of flexible sheet material; Subdividing filled flexible tubes to form packages
    • B65B9/10—Enclosing successive articles, or quantities of material, in preformed tubular webs, or in webs formed into tubes around filling nozzles, e.g. extruded tubular webs
    • B65B9/20—Enclosing successive articles, or quantities of material, in preformed tubular webs, or in webs formed into tubes around filling nozzles, e.g. extruded tubular webs the webs being formed into tubes in situ around the filling nozzles
    • B65B9/22—Forming shoulders; Tube formers
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/10—Induction heating apparatus, other than furnaces, for specific applications
    • H05B6/105—Induction heating apparatus, other than furnaces, for specific applications using a susceptor
    • H05B6/107—Induction heating apparatus, other than furnaces, for specific applications using a susceptor for continuous movement of material
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/40—General aspects of joining substantially flat articles, e.g. plates, sheets or web-like materials; Making flat seams in tubular or hollow articles; Joining single elements to substantially flat surfaces
    • B29C66/41—Joining substantially flat articles ; Making flat seams in tubular or hollow articles
    • B29C66/43—Joining a relatively small portion of the surface of said articles
    • B29C66/431—Joining the articles to themselves
    • B29C66/4312—Joining the articles to themselves for making flat seams in tubular or hollow articles, e.g. transversal seams
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C66/00—General aspects of processes or apparatus for joining preformed parts
    • B29C66/70—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material
    • B29C66/71—General aspects of processes or apparatus for joining preformed parts characterised by the composition, physical properties or the structure of the material of the parts to be joined; Joining with non-plastics material characterised by the composition of the plastics material of the parts to be joined
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2705/00—Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
    • B29K2705/02—Aluminium

Definitions

  • the present invention relates to an induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products.
  • Tetra Brik Aseptic registered trademark
  • a typical example of this type of package is the parallelepiped-shaped package for liquid or pourable food products known as Tetra Brik Aseptic (registered trademark), which is made by folding and sealing laminated strip packaging material.
  • the packaging material has a multilayer structure substantially comprising a base layer for stiffness and strength, which may be defined by a layer of fibrous material, e.g. paper, or mineral-filled polypropylene material; and a number of layers of heat-seal plastic material, e.g. polyethylene film, covering both sides of the base layer.
  • a base layer for stiffness and strength which may be defined by a layer of fibrous material, e.g. paper, or mineral-filled polypropylene material; and a number of layers of heat-seal plastic material, e.g. polyethylene film, covering both sides of the base layer.
  • the packaging material also comprises a layer of gas- and light-barrier material, e.g. aluminium foil or ethyl vinyl alcohol (EVOH) film, which is superimposed on a layer of heat-seal plastic material, and is in turn covered with another layer of heat-seal plastic material forming the inner face of the package eventually contacting the food product.
  • gas- and light-barrier material e.g. aluminium foil or ethyl vinyl alcohol (EVOH) film
  • packages of this sort are produced on fully automatic packaging machines, on which the tube is formed continuously from the web-fed packaging material. More specifically, the web of packaging material is unwound off a reel and fed through a station for applying a sealing strip of heat-seal plastic material, and through an aseptic chamber on the packaging machine, where it is sterilized, e.g. by applying a sterilizing agent such as hydrogen peroxide, which is subsequently evaporated by heating, and/or by subjecting the packaging material to radiation of appropriate wavelength and intensity.
  • a sterilizing agent such as hydrogen peroxide
  • the web of packaging material is then fed through a number of forming assemblies which interact with the packaging material to fold it gradually from strip form in a tube shape.
  • a first portion of the sealing strip is applied to a first longitudinal edge of the packaging material, on the face of the material eventually forming the inside of the packages; and a second portion of the sealing strip projects from the first longitudinal edge.
  • the forming assemblies are arranged in succession, and comprise respective roller folding members defining a number of compulsory packaging material passages varying gradually in section from a C shape to a substantially circular shape.
  • the second longitudinal edge is laid on the outside of the first longitudinal edge with respect to the axis of the tube being formed. More specifically, the sealing strip is located entirely inside the tube, and the face of the second longitudinal edge facing the axis of the tube is superimposed partly on the second portion of the sealing strip, and partly on the face of the first longitudinal edge located on the opposite side to the first portion of the sealing strip.
  • Packaging machines of the above type are known in which the first and second longitudinal edge are heat sealed to form a longitudinal seal along the tube, which is then filled with the sterilized or pasteurized food product, and is sealed and cut along equally spaced cross sections to form pillow packs, which are then folded mechanically to form respective parallelepiped-shaped packages.
  • the heat-seal operation comprises a first heating step to heat the second longitudinal edge without the sealing strip; and a second pressure step to compress the sealing strip and the longitudinal edges.
  • the first heating step melts the polyethylene layer of the second longitudinal edge, which transmits heat by conduction to the first longitudinal edge and the sealing strip, so as to melt the polyethylene layer of the first longitudinal edge and the heat-seal material of the sealing strip.
  • the tube is fed between a number of first rollers outside the tube, and at least one second roller inside the tube.
  • the first rollers define a compulsory circular passage for the tube of packaging material, and have respective axes in a plane transversal to the path of the tube.
  • the longitudinal seal may be formed by induction heat-sealing.
  • the packaging machine comprises a sealing device which is wholly arranged outside the tube.
  • the sealing device substantially comprises one or more inductive elements electrically fed by a high-frequency alternate current generator.
  • the alternate current flowing inside the inductive elements generates an alternate magnetic field flux which extends substantially transversal to the feeding direction of the tube.
  • This alternate magnetic field flux generates eddy currents in the aluminium layer to melt the heat-seal plastic material locally.
  • Sealing device is mounted above and is connected with the first rollers.
  • the portions facing the sealing device of the first and second edges have been heated by sealing device but not yet pressed.
  • the sealing device In order to heat seal these portions, the sealing device is lowered together with the rollers when tube is stationary. In this way, these portions are heated a second time and then compressed, when the tube is again vertically advanced.
  • an induction sealing device for heat sealing packaging material for forming a seal in a packaging material, as claimed in claim 1 .
  • the present invention relates to a method of forming a seal in a packaging material, as claimed in claim 11 .
  • FIG. 1 shows a packaging unit comprising a sealing device according to the present invention
  • FIG. 2 shows the sealing device of FIG. 1 in an operative condition
  • FIG. 3 shows the sealing device of FIGS. 1 and 2 from a different visual angle and with parts removed for clarity;
  • FIGS. 4 and 5 show respective additional steps of the operation of the sealing device of FIG. 1 ;
  • FIG. 6 shows the heat sealing device of FIGS. 1 to 5 , when disassembled
  • FIG. 7 shows a first side of some components of the sealing device of FIGS. 1 to 6 , when disassembled;
  • FIG. 8 shows a second side, opposite to first side, of the components of FIGS. 1 to 6 , when disassembled;
  • FIGS. 9 and 10 show schematically electrical circuits of the sealing device of FIGS. 1 to 8 in respective different configurations
  • FIGS. 11 and 12 are section along lines XI-XI and XII-XII respectively of FIG. 8 and show constant magnetic field lines generated by the sealing device according to the present invention
  • FIG. 13 shows some components of the packaging machine of FIGS. 1 and 2 ;
  • FIGS. 14 and 15 show the patterns of inducing and eddy currents in a known prior art inductive element and in an inductive element according to the invention respectively.
  • Number 1 in FIG. 1 indicates as a whole a packaging machine for continuously producing sealed packages 2 of a food product from a web 3 of packaging material, which is unwound off a reel 4 and fed along a forming path P.
  • Machine 1 preferably produces sealed packages 2 of a pourable food product, such as pasteurized or UHT milk, fruit juice, wine, peas, beans, etc.
  • a pourable food product such as pasteurized or UHT milk, fruit juice, wine, peas, beans, etc.
  • Machine 1 may also produce sealed packages 2 of a food product that is pourable when producing packages 2 , and sets after packages 2 are sealed.
  • a food product is a portion of cheese, that is melted when producing packages 2 , and sets after packages 2 are sealed.
  • the packaging material has a multilayer structure substantially comprising a base layer for stiffness and strength, which may be defined by a layer of fibrous material, e.g. paper, or mineral-filled polypropylene material; and a number of layers of heat-seal plastic material, e.g. polyethylene film, covering both sides of the base layer.
  • a base layer for stiffness and strength which may be defined by a layer of fibrous material, e.g. paper, or mineral-filled polypropylene material; and a number of layers of heat-seal plastic material, e.g. polyethylene film, covering both sides of the base layer.
  • web 3 is fed along path P by guide members 5 , e.g. rollers or similar, and successively through a number of work stations, of which are shown schematically: a station 6 for applying a sealing strip 9 (shown enlarged in thickness in FIG. 13 for the sake of clarity) to web 3 ; a forming station 7 for forming a tube 10 of packaging material; and a heat-sealing station 8 for forming a longitudinal seal 14 along tube 10 .
  • Seal 14 is continuous and extends along a direction A parallel to path P.
  • Machine 1 also comprises a fill device 12 for pouring the sterilized or sterile-processed food product continuously into tube 10 of packaging material; and a jaw-type forming assembly (not shown) for gripping, sealing, and cutting tube 10 along equally spaced cross sections to form a succession of packages 2 .
  • a longitudinal edge 11 , parallel to path P, of web 3 is first heated, e.g. by heat induction, to melt the plastic layer.
  • Web 3 has a longitudinal edge 15 opposite edge 11 and also parallel to path P.
  • a portion 16 ( FIG. 13 ) of strip 9 is first applied to the face of edge 11 eventually facing inwards of packages 2 , while a further portion 17 of strip 9 projects from edge 11 .
  • strip 9 is pressed onto longitudinal edge 11 , e.g. by means of rollers not shown.
  • sealing strip 9 is made of heat-seal plastic material.
  • Strip 9 prevents edge 11 from absorbing the food product once tube 10 and seal 14 of the tube are formed, and also provides for improving the gas-barrier performance and physical strength of seal 14 .
  • Station 7 comprises a number of forming assemblies 13 arranged successively along path P, and which interact gradually with web 3 to fold it into the form of tube 10 .
  • forming assemblies 13 comprise respective numbers of rollers defining respective compulsory packaging material passages, the respective sections of which vary gradually from a C shape to a substantially circular shape.
  • the axes of the rollers in each forming assembly 13 lie in a relative plane transversal, perpendicular in the embodiment shown, to path P.
  • Forming assemblies 13 gradually form tube 10 , so that edge 15 is located outwards of edge 11 with respect to the axis of tube 10 . More specifically, when forming tube 10 , strip 9 is located inside tube 10 , and the inner face of edge 15 is superimposed partly on portion 17 of strip 9 , and partly on the outer face of edge 11 ( FIG. 13 ).
  • Station 8 comprises a heating induction sealing device 30 for heating edge 15 and locally melting the polyethylene layer of edge 15 . Heat is transmitted by conduction from edge 15 to edge 11 and strip 9 , so as to locally melt the polyethylene layer of edge 11 and the heat-seal material of strip 9 .
  • Station 8 also comprises a number of forming rollers 21 defining a compulsory circular passage for tube 10 ; and one or more rollers 22 for pressing portion 17 of strip 9 , and portion 16 of strip 9 and edge 11 onto the face of edge 15 inside tube 10 , so that the polyethylene layers of edges 11 , 15 and the heat-seal material of strip 9 blend completely to form the molecular bonds defining seal 14 of tube 10 .
  • rollers 21 are located outside tube 10 , and pressure rollers 22 inside tube 10 .
  • Station 8 also comprises an annular support 29 which surrounds tube 10 and support rollers 21 .
  • Sealing device 30 is, in particular, movable together with support 29 ( FIGS. 4 and 5 ) between a raised position and lowered position along a direction which is parallel to path P shown respectively in FIGS. 4 and 5 .
  • sealing device 30 comprises a pair of inductors 31 , 32 ; inductor 31 comprises a portion 35 facing inductor 32 and defining with inductor 32 a passage 28 for edge 15 , and a portion 36 ; sealing device 30 is selectively arrangeable in a first configuration, in which alternate currents flow within inductors 31 , 32 ; portion 35 of inductor 31 and inductor 32 are configured to generate a magnetic flux M 1 transversally to direction A, when sealing device is arranged in the first configuration; portion 36 of inductor 31 is configured to generate a magnetic flux M 2 having a main component transversal to path P, when sealing device 30 is arranged in the first configuration.
  • Sealing device 30 may be also selectively arranged in a second configuration, in which alternate current flows within portion 36 of inductor 31 only and no alternate current flows within inductor 32 and portion 35 of inductor 31 .
  • sealing device 30 When sealing device 30 is arranged in the second configuration, magnetic flux M 1 is not generated and portion 36 generates only magnetic flux M 2 .
  • Portion 36 of inductor 31 comprises legs 200 , 201 within which alternate current flows, in use, in opposite direction; leg 200 is configured to induce, in use, a portion 300 of eddy current (shown with a dashed line in FIG. 15 ) within an area 202 of edge 15 to be sealed onto strip 9 and edge 11 .
  • Leg 201 is configured to induce a portion 301 of eddy current within area 202 of edge 15 to be sealed onto strip 9 and edge 11 .
  • both legs 200 , 201 of portion 36 of inductor 31 are effective in inducing respective portions 300 , 301 of eddy current within area 202 .
  • substantially the whole eddy current induced by portion 36 of inductor 31 circulate within area 202 and close to the margin layers 500 at which a new reel of packaging material has been joined to an existing one ( FIG. 15 ), instead of circulating at a certain distance from the margin layers, as in the prior art cited in the introductory part of the present description ( FIG. 14 ).
  • seal 14 is formed as continuous along a direction C orthogonal to direction B.
  • legs 200 , 201 have a length along a direction B parallel to direction A and are nonsymmetrical relative to direction B.
  • Legs 200 , 201 face each other along a direction C, which is orthogonal to direction B and parallel to direction A.
  • Portions 35 , 36 define respectively the top and the bottom of relative inductor 31 .
  • edge 15 when edge 15 enters passage 28 , it is still detached from edge 11 and strip 9 (see FIGS. 2 and 3 in which strip 9 is not shown).
  • Edge 15 overlaps edge 11 and strip 9 as it is fed in front of portion 36 of inductor 31 .
  • Sealing device 30 substantially comprises ( FIGS. 2 , 3 and 6 to 8 ):
  • Body 40 , 41 are releasably connected to each other, in the embodiment shown through a plurality of screws.
  • Bodies 40 , 41 extend along relative axes B parallel to direction A and define therebetween passage 28 .
  • Body 40 is also connected to a plate 39 which is, in turn, fixed to support 29 ( FIG. 2 ).
  • each body 40 , 41 comprises ( FIG. 6 ):
  • an insert 38 of flux concentrating material for example ferrite
  • Support 44 comprises ( FIG. 7 ):
  • a bottom part 46 b cooperating, on one side, with a bottom part of relative insert 38 .
  • Support 45 is sandwiched between housing 43 and relative insert 38 .
  • Supports 44 ; 45 also comprise a pair of faces 48 a, 48 b; 49 a, 49 b opposite to each other ( FIGS. 7 and 8 ).
  • Faces 48 a, 48 b are arranged towards the packaging material of tube 10 and have respective upper parts which cooperate with plastic housing 42 , 43 ( FIG. 8 ).
  • Faces 49 a, 49 b are arranged towards insert 38 ( FIG. 7 ).
  • Support 44 substantially comprises ( FIG. 7 ):
  • a crossbar 53 orthogonal to relative axis B and which extends between arms 51 , 52 .
  • Crossbar 53 extends from the middle of arm 51 towards a bottom end of arm 52 .
  • arm 52 extends upwardly from crossbar 53 and for a length which is less than the half of the length of arm 51 measured along axis B.
  • Support 45 substantially comprises:
  • a crossbar 63 orthogonal to axis B and which extends between respective arms 61 , 62 .
  • Arm 62 protrudes from crossbar 63 on the opposite of arm 61 .
  • arm 62 extends upwardly from crossbar 63 and for a length which is less than the half of the length of arms 51 , 61 measured along axis B.
  • crossbars 53 , 63 measured orthogonally to axis B is substantially identical.
  • the length of arm 52 , 62 measured parallel to axis B is identical.
  • inductors 31 , 32 of each pair are embedded between two insulating layers.
  • Inductor 31 comprises ( FIGS. 7 and 8 ):
  • a serpentine 70 having a pair of opposite ends 75 , 76 ;
  • a top half 74 of serpentine 70 and serpentine 71 are arranged in top half 54 of arm 51 and form portion 35 of inductor 31 .
  • a bottom half 79 of serpentine 70 and serpentine 72 are arranged in bottom half 55 of arm 51 and form portion 36 of inductor 31 .
  • L-shaped portion 73 is arranged inside crossbar 53 and arm 52 of support 44 .
  • Portion 77 , 78 are parallel to each other and are arranged inside crossbar 53 .
  • Bottom half 55 of arm 51 is sloped relative to top half 54 of such arm 51 ( FIG. 3 ).
  • Inductor 32 comprises ( FIG. 8 ):
  • serpentine 82 which has an end 87 electrically connected to end 85 of serpentine 81 and an end 88 opposite to end 87 ;
  • Serpentines 81 , 82 are housed within arm 61 .
  • U-shaped portion 83 substantially comprises:
  • Stretches 89 a, 89 b, 89 c are respectively housed inside arm 61 , 62 and crossbar 63 .
  • Each serpentine 70 , 71 , 81 , 82 has a length along axis B of relative body 40 , 41 and extends, along its length, at varying distances from axis B of relative body 40 , 41 .
  • Each serpentine 70 , 71 , 81 , 82 comprises a plurality of repeated modules 100 identical and adjacent to each other.
  • Each module 100 substantially comprises ( FIG. 7 ):
  • arms 52 , 62 ; top half 54 of arm 51 and arm 61 ; and crossbars 53 , 63 face each other from opposite sides of passage 28 along relative direction C.
  • serpentine 71 , 82 ; top half 74 of serpentine 70 and serpentine 81 ; and L- and U-shaped portions 73 , 83 face each other from opposite sides of passage 28 along relative direction C.
  • Top half 74 of serpentine 70 and serpentine 81 are arranged on the same side (right side in FIG. 12 ) of serpentines 71 , 82 respectively.
  • Homologous points of top (bottom) half 74 ( 79 ) of serpentine 70 and serpentine 71 ( 72 ) are arranged at constant distance measured along relative direction C from each other.
  • homologous point of serpentines 81 , 82 are arranged at a first constant distance measured along relative direction C from each other.
  • Stretches 101 of leg 200 ( 201 ) are arranged at a second distance measured along direction C from stretches 102 of the same leg 200 ( 201 ).
  • This second distance is less than or equal to the first constant distance between legs 200 , 201 .
  • stretches 101 of leg 200 are interposed between stretches 102 of leg 201 parallel to direction B and are aligned with or even arranged on the opposite side of stretches 102 of leg 201 along direction C with respect to stretches 102 of leg 200 .
  • inductor 32 comprises:
  • Inductor 31 comprises:
  • an electric contact 94 electrically connected (as schematically indicated by the dashed line in FIG. 8 ) to a free end of portion 78 .
  • Electric contacts 91 , 93 are electrically connected to each other by using a conductive element (only schematically shown in FIGS. 9 and 10 ), when sealing device 30 is arranged both in the first and in the second configuration.
  • Electric contact 94 is electrically connected to a negative pole of a power/current generator 99 , when sealing device 30 is arranged both in the first and in the second configuration ( FIGS. 9 and 10 ).
  • Electric contact 90 is electrically connected to a positive pole of the power/current generator 99 , when sealing device 30 is arranged in the first configuration ( FIG. 9 ). Electric contact 90 is left open, when sealing device 30 is arranged in the second configuration.
  • Electric contact 92 is electrically connected to a positive pole of the power/current generator 99 , when sealing device 30 is arranged in the second configuration ( FIG. 10 ). Electric contact 92 is left open, when sealing device 30 is arranged in the first configuration.
  • Electric contacts 94 and 90 or 92 are, in the embodiment shown, electrically connected to the power/current generator 99 by using conductive bars.
  • inductors 31 , 32 define together with power/current generator 99 a closed electric circuit C 1 .
  • circuit Cl comprises serpentines 70 , 71 , 72 , serpentines 81 , 82 and U-shaped portion 83 ( FIG. 9 ).
  • portion 36 and L-shaped portion 73 of inductor 31 define a closed electric circuit C 2 ( FIG. 10 ).
  • circuit C 2 comprises L-shaped portion 73 , serpentine 72 and bottom half 79 of serpentine 70 .
  • serpentine 71 and top half 74 of serpentine 70 are no longer connected to the positive pole of power/current generator 99 and therefore no alternate current may flow therein.
  • inductor 32 is no longer electrically connected to the positive pole of power/current generator 99 and therefore no alternate current may flow therein.
  • Web 3 is unwound off reel 4 and fed along path P.
  • web 3 is fed by guide members 5 along path P and through successive stations 6 , 7 , 8 .
  • edge 11 is heated, and portion 16 of strip 9 is applied to the face of edge 11 eventually facing inwards of packages 2 . Once portion 16 is applied to edge 11 , portion 17 projects from edge 11 .
  • web 3 interacts gradually with forming assemblies 13 , and is folded to superimpose edges 11 , 15 and form tube 10 not yet sealed longitudinally.
  • assemblies 13 fold web 3 so that strip 9 is located inside the as yet unsealed tube 10 , edge 15 is located radially outwards of edge 11 and portion 17 with respect to the axis of tube 10 still to be sealed longitudinally, and edge 11 is located radially outwards of portion 16 of strip 9 .
  • Seal 14 is formed, in station 8 , by sealing to the inner face of edge 15 portion 17 of strip 9 and the face of edge 11 on the opposite side to portion 16 .
  • sealing device 30 heats edge 15 to melt the polyethylene layer; heat is transmitted by conduction from edge 15 to edge 11 and strip 9 to melt the polyethylene layer of edge 11 and the heat-seal material of strip 9 .
  • edge 15 enters passage 28 and remains detached from edge 11 as it travels between inductor 32 and portion 35 of inductor 31 .
  • Edge 15 overlaps edge 11 and strip 9 , as it travels in front of portion 36 of inductor 31 .
  • Sealing device 30 is arranged in the first configuration, during the normal operation of machine 1 .
  • electrical contact 94 is electrically connected to the negative pole of generator 99 and electrical contact 90 is electrically connected to the positive pole of generator 99 ( FIG. 9 ).
  • closed circuit Cl is formed within inductors 31 , 32 and alternate current flows therein.
  • the alternate current flowing in circuit C 1 generates magnetic flux M 1 (directed substantially orthogonally to path P) and magnetic flux M 2 (directed substantially transversal to path P).
  • magnetic flux M 1 is generated by alternate current flowing within portion 35 of inductor 31 and within inductor 32 .
  • Magnetic flux M 2 is generated by alternate current flowing within portion 36 of inductor 31 .
  • Magnetic flux M 1 generates eddy current in the packaging material of edge 15 . This eddy current results, in turn, in the heating of edge 15 .
  • magnetic flux M 2 generates eddy current in the packaging material of edges 15 , 11 and strip 9 overlapped onto each other. This eddy current results, in turn, in the heating of edges 15 , 11 and of strip 9 .
  • leg 200 of portion 36 of inductor 31 induces portion 300 of eddy currents within area 202 to be sealed of edges 11 , 15 and strip 9 ;
  • leg 201 of portion 36 of inductor 31 induces portion 301 of eddy currents within area 202 to be sealed of edges 11 , 15 and strip 9 .
  • tube 10 is fed through the circular passage defined by rollers 21 , 22 .
  • Edges 11 , 15 and strip 9 are compressed between rollers 21 , 22 to blend the polyethylene layer of edges 11 , 15 and the heat-seal material of strip 9 , and so form the molecular bonds defining seal 14 of the finished tube 10 .
  • This region is the one that is arranged within passage 28 .
  • sealing device 30 is lowered together with support 29 of rollers 21 , 22 into the lowered position ( FIG. 5 ), when tube 10 is not advanced along path P.
  • sealing device 30 is arranged in the second configuration ( FIG. 10 ).
  • electric contact 92 , 94 are electrically connected respectively to the positive and negative poles of power/current generator 99 .
  • portion 36 of inductor 31 generates magnetic flux M 2 ; and portion 35 of inductor 31 and inductor 32 do not generate magnetic flux M 1 while portion 36 of inductor 31 generates the magnetic flux M 2 .
  • this region of edge 15 is sealed to edge 11 and to portion 16 of strip 9 substantially without any risk to be damaged by a repeated heating.
  • sealing device 30 is moved together with support 29 into the raised position.
  • the longitudinally sealed tube 10 is filled continuously with the pourable food product by device 12 , and is then fed through the jaw-type forming assembly (not shown) where it is gripped, sealed, and cut along equally spaced cross sections to form a succession of packages 2 .
  • sealing device 30 according to the present invention will be clear from the foregoing description.
  • inductors 31 , 32 are configured to generate magnetic flux M 1 transversally to path P, when sealing device 30 is in the first configuration.
  • magnetic flux M 1 generated by inductors 31 , 32 reaches at edges 15 , 11 higher values than the ones reached in the prior art solution described in the introductory part of the present invention.
  • the efficiency of the sealing device 30 is highly improved when compared with the previously known sealing device.
  • the constant-value lines of the magnetic field generating magnetic flux M 1 are symmetrical relative to the packaging material of edges 15 , 11 .
  • Sealing device 30 is also particularly advantageous in case that the operation of machine 1 stops, thus leaving a region of edges 15 heated by sealing device 30 but not pressed by rollers 21 , 22 .
  • sealing device 30 is moved together with support 29 in the lowered position and is therefore arranged in the second configuration.
  • portion 36 of inductor 31 can be excited independently from portion 35 of inductor 31 and from inductor 32 when sealing device 30 is in the second configuration, the previously heated but not-pressed region of edges 15 is not heated again. In this way, power/current source 99 no longer needs to be adjusted in order to avoid that the region is damaged by overheating.
  • inductors 31 , 32 comprise respective serpentines 70 , 71 , 72 and 81 , 82 .
  • serpentines 70 , 71 , 72 ; 81 , 82 highly improve the uniformity of the heat pattern and of the resulting seal 14 .
  • serpentines 70 , 71 , 72 ; 81 , 82 prevent the formation of a nodal line in the eddy current generated in edge 15 and the consequent formation of a cold channel in edge 15 .
  • This effect is mainly due to the fact that heat pattern generated by stretches 101 , 102 of serpentines 70 , 71 , 72 ; 81 , 82 overlap each other at edge 15 .
  • the uniformity of seal 14 is highly enhanced.
  • Support 44 , 45 and inductors 31 , 32 form a printed circuit board. This allows manufacturing inductors 31 , 32 shaped in very different way with a reduced impact on manufacturing cost.
  • sealing device 30 as described and illustrated herein without, however, departing from the scope of the present invention as defined in the accompanying Claims.
  • Sealing device 30 may also be used in station 6 for sealing portion 16 of strip 9 to the face of edge 11 eventually facing inwards of packages 2 .

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Chemical & Material Sciences (AREA)
  • Composite Materials (AREA)
  • Package Closures (AREA)
US14/115,171 2011-05-05 2012-04-24 Induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products Abandoned US20140075884A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
EP11165020.6A EP2520416B9 (en) 2011-05-05 2011-05-05 Induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products
EP11165020.6 2011-05-05
PCT/EP2012/057452 WO2012150148A1 (en) 2011-05-05 2012-04-24 Induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products

Publications (1)

Publication Number Publication Date
US20140075884A1 true US20140075884A1 (en) 2014-03-20

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US14/115,171 Abandoned US20140075884A1 (en) 2011-05-05 2012-04-24 Induction sealing device for heat sealing packaging material for producing sealed packages of pourable food products

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US (1) US20140075884A1 (ko)
EP (1) EP2520416B9 (ko)
JP (1) JP2014513019A (ko)
KR (1) KR20140033075A (ko)
CN (1) CN103501982B (ko)
BR (1) BR112013027327A2 (ko)
WO (1) WO2012150148A1 (ko)

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US20170008225A1 (en) * 2013-11-29 2017-01-12 Tetra Laval Holdings & Finance S.A. An induction heating device
US20170174377A1 (en) * 2015-12-17 2017-06-22 Khs Usa, Inc. Magnetically operated sealing bar assembly for packaging machines

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EP3090861A1 (en) * 2015-05-05 2016-11-09 Tetra Laval Holdings & Finance S.A. Induction heating sealing device
EP3090860B1 (en) * 2015-05-05 2019-09-11 Tetra Laval Holdings & Finance S.A. Induction heating sealing device
WO2017089187A1 (en) * 2015-11-27 2017-06-01 Tetra Laval Holdings & Finance S.A. A sealing device with increased robustness
JP7169997B2 (ja) 2017-05-30 2022-11-11 テトラ ラバル ホールディングス アンド ファイナンス エス エイ 食品製品用パッケージの上部を密封するための装置及び食品パッケージを形成し充填するためのシステム
CN110944913B (zh) 2017-08-04 2021-07-20 利乐拉瓦尔集团及财务有限公司 将密封条带施加到包装材料卷材上的方法和设备
CN108357732B (zh) * 2018-03-27 2020-10-09 广州市铭慧机械股份有限公司 一种高频感应加热机构
JP2022500316A (ja) 2018-09-10 2022-01-04 テトラ ラバル ホールディングス アンド ファイナンス エス エイ チューブを形成するための方法並びにパッケージを形成するための方法及び包装機
JP7447123B2 (ja) 2018-09-11 2024-03-11 テトラ ラバル ホールディングス アンド ファイナンス エス エイ 密封されたパッケージを形成するためのパッケージ装置

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Publication number Priority date Publication date Assignee Title
US20170008225A1 (en) * 2013-11-29 2017-01-12 Tetra Laval Holdings & Finance S.A. An induction heating device
US20170174377A1 (en) * 2015-12-17 2017-06-22 Khs Usa, Inc. Magnetically operated sealing bar assembly for packaging machines
US10351283B2 (en) * 2015-12-17 2019-07-16 Khs Usa, Inc. Magnetically operated sealing bar assembly for packaging machines

Also Published As

Publication number Publication date
EP2520416A1 (en) 2012-11-07
BR112013027327A2 (pt) 2019-09-24
KR20140033075A (ko) 2014-03-17
EP2520416B1 (en) 2013-12-25
JP2014513019A (ja) 2014-05-29
EP2520416B9 (en) 2014-04-23
CN103501982A (zh) 2014-01-08
CN103501982B (zh) 2015-12-02
WO2012150148A1 (en) 2012-11-08

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