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US-RE50879-E1 - Method for extruding and labelling a cylindrical product

Abstract

The method for extruding and labeling a packaging tube comprises the following successive steps: a) forming a partially or totally tubular label from a film in a shaper; b) inserting the label into a calibration element; c) extruding a tubular body at the concave-face side of the label in an extrusion head; d) bringing the outer face of the extruded tubular body into contact with the concave face of the label. In the method, the label comprises at least one layer of which the melting temperature is at least 20° C. higher than the melting temperature of the extruded tubular body. A first pressure difference is formed in the extruded tube with an air jet.

Inventors

  • Jacques Thomasset
  • Eduardo Rey

Assignees

  • AISAPACK HOLDING SA

Dates

Publication Date
20260505
Application Date
20240508
Priority Date
20160913

Claims (17)

  1. 1 . A method of extruding and labeling a packaging tube by an extrusion-labeling line comprising the steps of: (a) forming a partially or totally tubular label from a film in a shaper; (b) introducing the tubular label into a calibration element; (c) extruding a tubular body on a side of a concave face of the tubular label in from an extrusion head; and (d) bringing an external face of the extruded tubular body into contact with the concave face of the tubular label to produce a labelled packaging tube, by creating a first pressure difference between an interior and the external face of the extruded tubular body by an air jet, the first pressure difference generated by a first floating plug arranged downstream of the shaper that , wherein the first floating plug at least partially obstructs an escape of air via the interior of the tubular body, wherein the first floating plug is not mechanically attached along a direction of a movement of the extrusion, and being wherein the first floating plug is at a fixed position where the extruded tubular body is solidified, and wherein the first floating plug is retained at said fixed position by a magnetic force while the extruded tubular body is moved downstream past the first floating plug.
  2. 2 . The method as claimed in claim 1 , wherein the first pressure difference is also generated by a controlled escape of air from an upstream side of the shaper via the extrusion head.
  3. 3 . The method as claimed in claim 1 , wherein the first floating plug is located after a device for pulling on the packaging tube.
  4. 4 . The method as claimed in claim 3 , wherein the first pressure difference facilitates a pulling of the packaging tube performed by the device for pulling.
  5. 5 . The method as claimed in claim 1 , wherein a second plug is connected to the extrusion head during a starting phase.
  6. 6 . The method as claimed in claim 5 , wherein in the starting phase, the second plug is released from the extrusion head and transported by the moving of the packaging tube until the second plug abuts against the first floating plug.
  7. 7 . The method as claimed in claim 5 , wherein the second plug is movable along the direction of the movement.
  8. 8 . The method as claimed in claim 1 , wherein a second pressure difference is established between the interior and the exterior of the packaging tube, the second pressure difference created by a reduced pressure in a vacuum tank.
  9. 9 . The method as claimed in claim 1 , wherein step (c) is performed in the calibration element.
  10. 10 . The method as claimed in claim 1 , wherein the calibration element is cooled.
  11. 11 . The method as claimed in claim 1 , wherein the calibration element includes a contact surface that enables reduction of friction with the tubular label.
  12. 12 . The method as claimed in claim 1 , further comprising the step of: controlling a tension of the tubular label at an entry of the shaper.
  13. 13 . The method as claimed in claim 1 , wherein the tube undergoes a treatment to optimize roundness.
  14. 14 . The method as claimed in claim 1 , wherein edges of the tubular label are disposed end to end or edges of the tubular label overlap.
  15. 15 . The method of as claimed in claim 1 , wherein the tubular label includes two layers, one of the layers has a melting point that is at least 20° C. higher than a melting point of the extruded tubular body.
  16. 16 . The method of as claimed in claim 1 , wherein a magnetic sleeve is arranged to provide for the magnetic force to the first floating plug, the magnetic sleeve arranged around the extruded tubular body.
  17. 17 . The method of as claimed in claim 1 , wherein the tubular body is extruded by an extrusion nozzle of the extrusion head, and the air jet is provided by a blower slot of the blower rod and and is escaping via an escape channel situated between the extrusion nozzle and blower rod.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a United States national stage application of International patent application PCT/IB2017/055515 filed on Sep. 13, 2017 that is designating the United States, and claims foreign priority to European patent application EP 16188491.1 filed on Sep. 13, 2016, the contents of both documents being herewith incorporated by reference in their entirety. TECHNICAL FIELD AND PRIOR ART The invention is situated in the field of tubes or cylinders, and more particularly in the field of packaging tubes for liquid or viscous products, such as toothpastes and creams, the skirt of which is obtained by extrusion of material. Flexible packaging tubes generally have two distinct parts, namely a flexible cylindrical body or skirt connected to a head including a neck that is closed by a cap. The skirt of the tube is obtained either by extrusion of a tubular body or by welding of a multilayer film that is rolled up to form this tubular body before welding it edge to edge or with an overlap. A number of methods exist for adding and fixing a tube head to the end of a previously extruded skirt. The tube head may be compression or injection molded and conjointly welded to the skirt by an overmolding process. Another method consists in prefabricating the tube head by injection or compression molding and then assembling the tube head to the skirt by welding. The tube formed in this way is then decorated at the level of the skirt, notably by the end user of the tube, and printing techniques are routinely used to add the required decoration. When the skirt is obtained by extrusion of a tubular body, the printing operation is carried out before or after the assembly of the skirt and the tube head. This printing operation has a number of disadvantages linked to the fact that the printing is not carried out flat but on the tubular geometry of the skirt. This generally leads to a process of greater complexity and consequently costly equipment, lower production rates, and reduced flexibility of the manufacturing process. The lack of flexibility of printing machines leads for example to reworking operations for complex decorations such as screenprinting or a hot decoration process. In order to overcome the difficulties of decoration by printing, one alternative method consists in applying a preprinted adhesive label to the tube. The label, which is associated with a support film generally made of PET, is separated from the support upon application to the external surface of the tube. The label is precoated with a sticky adhesive that bonds the label to the surface of the tube. The adhesive layer is protected by the support film before application of the label to the tube. For example, the method disclosed in the patent application WO 2007/092652 consists in applying a thin label that is not suck to a support film before use. In this method, the operation of coating or of activation of the adhesive layer takes place at the moment of application of the label to the surface of the tube. A variant of this method consists in applying the adhesive layer to the label at the moment of application. Another variant consists in applying the adhesive layer to the surface of the tube before application of the label. The method described in WO 2007/082652 has a number of disadvantages, however. The addition of an adhesive layer by coating at the moment of application of the label or the addition of an activation step makes the manufacturing process more complex, in particular when applied on a line for continuous tube extrusion (FIG. 2 of WO 2007/092652). Another disadvantage lies in the very short activation time of the adhesive layer that this method requires, which can lead to a restricted and costly choice of adhesives. Another disadvantage is situated at the level of the packaging: the label that is added to the surface of the tube is not an integral part of the wall of the packaging. The edges of the label are sometimes visible or detectable by touch and compromise the decorative and esthetic properties of the packaging. The patent application EP 0 457 561 describes a method and a device for the making up of extruded tubular bodies having a laminated surface film. This method consists in forming a first tubular body from a film, extruding a liner inside said tubular body, drawing the liner radially, pressing the liner against the tubular body. This method has a number of disadvantages. A first disadvantage is linked to the fact that the liner must be extruded inside the tubular body formed by the film. This operation requires a tube diameter sufficiently large to place in the tube the tools necessary for the extrusion and radial drawing of the extruded liner. The method proposed in this prior art does not enable the production of tubes of small diameter and in particular of tubes with a diameter less than 35 mm. EP 0 457 561 also proposes internal calibration of the diameter of the tube