Method for production of a female embossing tool, a female embossing tool, and an embossing module equipped therewith

Abstract

A method for production of a female embossing tool intended for embossing a sheet element: provide a female embossing tool with an outer layer made of a material with shape-memory type properties, and the outer face of the layer has no recesses; provide a male embossing tool with an outer face with at least one protuberance corresponding to at least one desired embossing relief that is to be formed on the sheet element after embossing; and cooperation of the male embossing tool with the female embossing tool such that the outer layer of the female embossing tool undergoes a plastic deformation which creates at least one recess of a shape complementary to the protuberance(s) of the male embossing tool.

Claims

1. An embossing tool set comprising a female embossing tool and a male embossing tool for embossing sheet elements configured to form packagings, the female embossing tool comprising: a first outer layer comprised of a material with shape-memory type properties; and the male embossing tool comprising: a second layer including at least one protuberance and configured to deform the first outer layer of the female embossing tool to create at least one recess of a shape complementary to the protuberance of the male embossing tool, such that the female embossing tool with the first outer layer in the deformed state together with the male tool with the second outer layer emboss the sheet elements when the sheet elements pass therebetween.

2. The female embossing tool according to claim 1, wherein the material is selected from at least one of shape-memory metal alloys and polymer materials with shape-memory type properties.

3. The female embossing tool according to claim 1, wherein the tool is flat and forms a tool for a platen press.

4. The female embossing tool according to claim 1, wherein the tool has a cylindrical outer revolution face on which the material is located such that the tool forms a rotating female embossing tool on the outer revolution face.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be better understood and its various advantages and characteristics will appear more clearly from the description below of a non-limitative exemplary embodiment, with reference to the attached diagrammatic drawings in which:

(2) FIG. 1 is a diagrammatic view of a folder-gluer machine viewed from the left side relative to the direction of transport of cardboard cut-outs to be embossed,

(3) FIG. 2 illustrates an example of a pair of male and female embossing tools, with a female embossing tool produced according to the invention,

(4) FIGS. 3 to 10 show steps in production of a first female embossing tool according to the invention, its use, then its adaption to another profile in order to produce the second embossing tool which is different from the first embossing tool.

DESCRIPTION OF PREFERRED EMBODIMENTS

(5) FIG. 1 depicts a folder-gluer, illustrating a possible application of the invention. In this example, cardboard cut-outs arrive in the folder-gluer via the inlet E and are discharged in the form of folded boxes at the outlet S, and are processed along the transport path of the cardboard cut-outs. The transport direction is indicated by arrow F. The folder-gluer comprises successively, from the inlet E to the outlet S, a feed station 10, a breaker module 20, a module 30 called the “embossing module”, a folding module 40 and a reception station 50.

(6) The function of the embossing module 30 is to mechanically imprint a relief onto the cardboard cut-outs passing through the folder-gluer, by means of the pair of rotating tools 5 and 6. Such relief forms may for example constitute fold lines for future folding at these lines, or Braille characters thus printed, or graphic characters in relief for decorative purposes.

(7) FIG. 2 illustrates an example of a pair of tools 5 and 6 according to the invention. The tools 5 and 6 comprise a rotating male embossing tool 5, and a rotating female embossing tool 6. The male tool 5 comprises a cylinder having a peripheral surface which is studded with one or more pins or protuberances 41. The female tool 6 comprises a cylinder having a peripheral surface which is imprinted with recesses or depressions 42. The male embossing tool 5 has a form and dimension and protuberance compatible with the form, dimension, and recesses of the female embossing tool 6. During Braille printing, the pins 41 penetrate into the thickness of the cardboard to form Braille characters.

(8) Advantageously, the pins 41 and the recesses 42 are carried by respective plates 43, 44 in the form of a strip wound around the respective cylindrical tool 5, 6 to form the outer face.

(9) According to the invention, the plate 44 of the female tool 6 is made from shape-memory material.

(10) The material is selected from shape-memory metal alloys, for example type CuAlNi, CuZnAl and NiTi, polymers with shape-memory type properties, for example expanded PVC or TPU, or others.

(11) However, the male tool 5 is still made by means of a metal plate 43 such as a strip or plate of solid steel, machined to produce on its surface the desired protruding relief consisting of dot-like or linear, continuous or discontinuous protuberances of greater or lesser extent, etc.

(12) FIGS. 3 to 10 illustrate the process of production of a first female embossing tool according to the invention, its use for embossing a cardboard cut-out, and the method for production of a second female embossing tool with different relief from the first female embossing tool.

(13) To produce the first female embossing tool, a step comprises providing a first male embossing tool 5, including a plate 43 which defines a first protuberance 41 (FIG. 3). Another step comprises providing a female embossing tool 6 according to the invention, having a plate or outer layer 44 made from shape-memory material. The female embossing tool is shown in FIG. 3 in an undeformed starting shape, indicated by a smooth outer face.

(14) In a second following step (FIG. 4), the plate 43 is brought against the plate 44 (arrow A1, exerting a force such that the protuberance 41 penetrates into the plate 44 and creates a deformation in the form of a depression in the surface and in a portion of the thickness of the plate 44. This relative movement between the plate 43 and plate 44 is performed for example until the plate 43 and the plate 44 make contact on either side of the protuberance 41. By this deformation operation, performed for example at ambient temperature, a depression 42 is formed (FIGS. 4 and 5) in the surface of the female embossing tool 6 which is systematically and precisely complementary in shape to the shape of the protuberance 41 of the male embossing tool 5. The recesses 42 may also be formed under other conditions, depending on the material of the plate 44.

(15) Thus a first female embossing tool 6 is obtained which can now be used as often as required in cooperation with the first male embossing tool 5. Thus by bringing the two tools together (arrow A2) and then by compression of a cardboard cut-out 60 between the first female embossing tool 6, obtained by deformation, and the male embossing tool 5, a cardboard cut-out 60 is embossed and deformed into the shape of an embossment 61 in accordance with FIGS. 5 and 6.

(16) When the embossing operations of the specified series of cardboard cut-outs 60 are complete and it is necessary to switch to embossing another shape, a second female embossing tool is produced by firstly restoring the initial, smooth form of the surface of the plate 44. To this end, as shown in FIGS. 7 and 8, a step comprises bringing the female embossing tool 6 to a temperature high enough to exceed the transformation temperature of the shape-memory material constituting the plate 44. For example, the female embossing tool 6 is placed in an oven heated to this end, after removal of the pair of embossing tools 5 and 6. Application of heat by radiation is also proposed. In this way, the depression 42 is erased since the shape-memory material of the plate 44 resumes its initial form, namely a surface without recesses.

(17) This restoration to the starting form of the female embossing tool 6 allows a new series of deformations of cardboard cut-outs 60 to be applied in another shape and/or another relief. FIGS. 9 and 10 show a method for production of a second female embossing tool according to the invention.

(18) To produce the second female embossing tool, a step comprises providing a second male embossing tool 5′, the plate 43′ of which defines a second protuberance 41′ (FIG. 9) with a different shape from the first protuberance 41 (FIG. 3). Another step comprises providing the female embossing tool 6 resulting from the heating process described above, the plate 44 of which has a smooth outer surface (FIG. 9).

(19) Then, in a supplementary step (FIG. 10), the plate 43′ is brought against the plate 44 (arrow A3), exerting a sufficient force for the protuberance 41′ to penetrate into the plate 44 and to create a deformation in the form of a depression in the surface and in part of the thickness of the plate 44. This relative movement between the plate 43′ and the plate 44 is operated for example until the plate 43′ and the plate 44 make contact on either side of the protuberance 41′. By this deformation operation performed at ambient temperature, a depression 42′ is formed (FIG. 10) on the surface of the female embossing tool 6 which is systematically and precisely complementary in shape to the shape of the protuberance of the second male embossing tool 5′.

(20) Thus a second female embossing tool 6 is obtained which can now be used as often as required in cooperation with the second male embossing tool 5′.

(21) The invention also concerns a method of embossing a sheet element intended to form a packaging, in which the embossing operation for the sheet element is performed with a pair of embossing tools selected from those described in the present text.

(22) In the embossing methods described above, the sheet element is preferably a cardboard cut-out, either flat cardboard, corrugated cardboard or multi-layer cardboard with flat and corrugated cardboard.

(23) The present invention is not limited to the embodiments described and illustrated. Numerous modifications may be made without leaving the framework defined by the scope of the claims.