Machine for generating optically variable image elements

Patent metadata

Field	Value
Publication number	US-2023241881-A1
Application number	US-202118025495-A
Country	US
Kind code	A1
Filing date	Aug 18, 2021
Priority date	Oct 1, 2020
Publication date	Aug 3, 2023
Grant date	—

Abstract

In some examples, a machine for generating optically variable image elements on a substrate includes a printing substrate infeed and a printing unit including a printing mechanism by which a substrate guided on a transport path is printed with a coating agent containing magnetic or magnetizable particles. A device for aligning the magnetic or magnetizable particles includes a first alignment device in the transport path and a further alignment device arranged upstream therefrom. During normal operation, the further alignment device is fixed to a frame at the transport path. The further alignment device includes a plurality of magnets that are spaced apart from one another transversely to the transport direction and, during operation, remain stationary. The number of magnets included in the further alignment device correspond to a number of columns of image-producing print motifs or groups of image-producing print motifs around a circumference of a forme cylinder.

First claim

1 - 24 . (canceled)

25 . A machine ( 01 ) for generating optically variable image elements ( 03 ) on a substrate ( 02 ), comprising a printing substrate infeed ( 13 ), at least one printing unit ( 04 ) comprising at least one printing mechanism ( 11 ; 12 ), by which substrate ( 02 ) guided on a transport path through the machine ( 01 ) is printed and/or can be printed at least on a first side with a coating agent ( 06 ) containing magnetic or magnetizable particles, a product receiving system ( 27 ) used to receive the substrate ( 02 ) treated in the machine ( 01 ), and a device ( 07 ) for aligning magnetic or magnetizable particles contained in coating agent ( 06 ) applied to the side of the web-format or sheet-format substrate ( 02 ), which is provided in the transport path of the substrate ( 02 ) between the printing unit ( 04 ) and the product receiving system ( 27 ); the printing mechanism ( 11 ; 12 ) comprising, as the image-producing cylinder, a forme cylinder ( 14 ; 16 ) including a multiplicity of image-producing print motifs or groups of image-producing print motifs around the circumference, which on a circumferential length corresponding to the print image length are arranged in multiple columns, which are equidistantly spaced apart from one another transversely to the transport direction (T), and on a cylinder width corresponding to the print image width are arranged in multiple rows, which are equidistantly spaced apart from one another in the transport direction (T); the device for aligning magnetic or magnetizable particles (P) comprising a first alignment device ( 33 ; 33 ′), which is arranged in the transport path of the substrate ( 02 ) to be conveyed and, in the region of its side facing the transport path, comprises a plurality of magnets ( 44 ) so as to align, in each case in a surface area comprising a coating agent ( 06 ), at least some of the particles (P) contained in the coating agent ( 06 ) in order to generate image information; the magnets ( 44 ) of the first alignment device ( 33 ; 33 ′) serving alignment purposes and the substrate ( 02 ) to which the coating agent ( 06 ) containing the particles (P) is applied moving synchronously with respect to one another, at least on a section of the transport path, characterized in that the device for aligning magnetic or magnetizable particles (P) comprises at least one first further alignment device ( 42 ), which is arranged upstream from the first alignment device ( 33 ; 33 ′) in the transport path of the substrate ( 02 ) to be conveyed and which, during normal operation, is fixed to the frame at the transport path and, transversely to the transport direction (T), comprises a plurality of magnets ( 46 ) that are spaced apart from one another transversely to the transport direction (T) and, during operation, remain stationary in the device; the first further alignment device ( 42 ) comprising a number of magnets ( 46 ) that corresponds to the number of columns of image-producing print motifs or groups of image-producing print motifs around the circumference of the forme cylinder ( 14 ; 16 ), which are arranged in the transport path in such a way that the print motifs or groups of image-producing print motifs are at least in each case partially aligned with the lateral position of the magnets ( 46 ) of the first further alignment device ( 42 ) along the transport path.

26 . The machine according to claim 25 , characterized in that the first alignment device ( 33 ; 33 ′) is formed by a magnetic cylinder ( 33 ; 33 ′), which is arranged in the transport path of the substrate ( 02 ) to be conveyed and, in the region of its outer circumference, comprises the plurality of magnets ( 44 ).

27 . The machine according to claim 25 , characterized in that a drying and/or curing device ( 41 ) is arranged at the transport path so as to act on a point of the transport path still located in the active region of the first alignment device ( 33 ; 33 ′).

28 . The machine according to claim 27 , characterized in that the drying and/or curing device ( 41 ) is directed at a circumferential section, located in the transport path, of the first alignment device ( 33 , 33 ′) designed as a magnetic cylinder ( 33 ; 33 ′) and/or is implemented as a UV radiation dryer and/or as an LED dryer.

29 . The machine according to claim 25 , characterized in that the first further alignment device ( 42 ) serving pre-orientation purposes is arranged upstream from the first alignment device ( 33 ; 33 ′) in the transport path in such a way that the arrangement and alignment of the magnets ( 46 ), in the surface areas that encompass the image information to be generated, induce or can induce a homogeneous pre-orientation of particles (P), which have a non-spherical, flat shape, having a longitudinal axis extending in the direction of the longest extension, an axis extending perpendicularly thereto in the direction of the width, and a thickness extending with respect to both axes and being smaller compared to the length and width, at least with respect to a parallel progression of the longitudinal axis of the particles (P) which is projected in the substrate plane.

30 . The machine according to claim 29 , characterized in that the magnets ( 46 ) of the first further alignment device ( 42 ) that is arranged upstream from the first alignment device ( 33 ; 33 ′) are configured and oriented in such a way that, in a respective surface area encompassing the image information to be generated, particles (P) are biaxially aligned parallel to one another, both with respect to their axis extending in the longitudinal direction and in the transverse direction, so that a homogeneous optical impression arises across this surface area.

31 . The machine according to claim 29 , characterized in that magnets ( 46 ) of the first further alignment device ( 42 ) that is arranged upstream from the first alignment device ( 33 ; 33 ′) rest against respective stop means ( 59 ), as viewed in a direction perpendicular to the transport path, and/or are acted upon by one or more spring elements ( 62 ) with a force pointing in the direction of the substrate path, and/or that the magnets ( 46 ) of the first further alignment device ( 42 ) arranged upstream from the first alignment device ( 33 ; 33 ′) are held by way of respective connections ( 59 , 61 ; 67 ; 68 ) that are positively active in the direction of the transport path, which can be released by a movement of the respective magnet ( 46 ) having at least one movement component which is located in a plane extending parallel to the transport plane.

32 . The machine according to claim 29 , characterized in that the magnets ( 46 ) of the first further alignment device ( 42 ) arranged upstream from the first alignment device ( 33 ; 33 ′) are arranged at a linear transport path section and, at least on the side facing the transport path, have a planar shape that is elongated in the transport direction (T) or are arranged at a curved transport path section, which is formed by a circumferential section of a rotating transport means, and, at least on the side facing the transport path, have a curved shape that is elongated along the transport path.

33 . The machine according to claim 25 , characterized in that a filler piece ( 56 ) is provided, for which a magnet ( 46 ) of the first further alignment device ( 42 ) can be exchanged, and/or that a handle ( 63 ) is provided, which can pick up a magnet ( 46 ) of the first further alignment device ( 42 ) by way of magnetic forces.

34 . The machine according to claim 25 , characterized in that a second, further alignment device ( 43 ) serving simultaneous orientation purposes and comprising a plurality of magnets ( 4

Assignees

• Koenig & Bauer Ag

Inventors

• Kreps Edwin
• Thony Emmanuel

Classifications

• B41F19/005 Primary

  with means for applying metallic, conductive or chargeable material · CPC title

• B41F13/193

  Transfer cylinders; Offset cylinders {(attaching blankets B41F30/04)} · CPC title

• B41F23/0409

  Ultraviolet dryers · CPC title

• B41F33/0009

  Central control units · CPC title

• B41F13/0024

  Frames · CPC title