Apparatuses for producing optical effect layers

Patent metadata

Field	Value
Publication number	US-11065866-B2
Application number	US-201515328823-A
Country	US
Kind code	B2
Filing date	Aug 19, 2015
Priority date	Aug 22, 2014
Publication date	Jul 20, 2021
Grant date	Jul 20, 2021

Abstract

The apparatus and methods of the present disclosure relate to devices comprising spinning magnets driven by electric motors for use with printing or coating equipment. These devices and methods are for orienting magnetic or magnetisable pigment particles in an unhardened coating composition on a substrate. Specifically, these devices and methods are for producing optical effect layers. The apparatus comprises a holder, onto which is mounted a motor and a permanent magnet assembly. The motor is configured to spin the permanent magnet assembly. The holder is configured to be removably fixed to a base of a rotating magnetic cylinder (RMC) or a flatbed printing unit.

First claim

The invention claimed is:

1. An apparatus for producing an optical effect layer, comprising:
a holder, including surrounding sidewalls and an accommodating recess spatially defined by the surrounding sidewalls, along an axis the holder having mounted thereto in the accommodating recess:
a motor;
a permanent magnet assembly; and
a support configured to be removably fixed to the holder, wherein the support accommodates the permanent magnet assembly,
wherein the motor is configured to spin the permanent magnet assembly around the axis in the support, wherein the holder includes a bottom surface and a removable fixation on the bottom surface, the bottom surface is curved according to a curvature radius of a circumferential mounting groove of a rotating magnetic cylinder of a printing unit, and the removable fixation of the holder is configured to be removably fixed to the circumferential mounting groove of the rotating magnetic cylinder of the printing unit, wherein the axis is substantially perpendicular to the bottom surface of the holder;
wherein the holder includes a lower recess between the accommodating recess and the bottom surface, at least a part of the motor is disposed in the lower recess of the holder, and the motor includes a central hole to provide access to the removable fixation: and
wherein the permanent magnet assembly is removably fixed to the holder.

2. The apparatus of claim 1 , wherein the motor comprises a rotor part and a stator part, wherein the rotor part further comprises a recess, and the permanent magnet assembly is removably couplable to the recess via a rotation transmission shaft.

3. The apparatus of claim 1 , wherein the motor comprises a rotor part and a stator part, and wherein the rotor part is disposed within the cavity of the support and the stator part is located external of the support and electromagnetically coupled to the rotor part.

4. The apparatus of claim 3 , wherein a ring-shaped element that interacts with the magnetic field of the rotor part is disposed between the permanent magnet assembly and the rotor part.

5. The apparatus of claim 1 , wherein the permanent magnet assembly is fixed to the support by a bearing to allow for relative rotation therebetween.

6. The apparatus of claim 5 , wherein the bearing is a Conrad-type bearing.

7. A rotating magnetic cylinder comprising at least one of the apparatuses of claim 1 mounted to the rotating magnetic cylinder through the holder.

8. A method of making an optical effect layer on a substrate, the method comprising:
providing a substrate carrying a wet coating composition comprising magnetic or magnetizable pigment particles;
providing an apparatus according to claim 7 ;
orienting the magnetic or magnetizable pigment particles aggregately by way of a rotating magnetic field produced by spinning the permanent magnet assembly with the motor to produce the optical effect layer; and
hardening the coating composition.

9. A method for protecting a security item, such as a banknote, comprising the steps of:
i. applying a coating composition comprising magnetic or magnetizable pigment particles to a substrate;
ii. exposing the coating composition to a rotating magnetic field produced by the spinning permanent magnet assembly of an apparatus of claim 7 to substantially orient at least part of the magnetic or magnetic pigment particles aggregately to produce an optical effect layer;
iii. hardening the coating composition so as to fix the magnetic or magnetizable pigment particles in a substantially oriented state or oriented state.

10. A method of making an optical effect layer on a substrate, the method comprising:
providing a substrate carrying a wet coating composition comprising magnetic or magnetizable pigment particles;
providing an apparatus according to claim 1 ;
orienting the magnetic or magnetizable pigment particles aggregately by way of a rotating magnetic field produced by spinning the permanent magnet assembly with the motor around the axis to produce the optical effect layer; and
hardening the coating composition.

11. A method for protecting a security item, such as a banknote, comprising the steps of:
i) applying a coating composition comprising magnetic or magnetizable pigment particles to a substrate;
ii) exposing the coating composition to a rotating magnetic field produced by the spinning permanent magnet assembly of the apparatus of claim 1 to substantially orient at least part of the magnetic or magnetic pigment particles aggregately to produce an optical effect layer;
iii) hardening the coating composition so as to fix the magnetic or magnetizable pigment particles in a substantially oriented state or oriented state.

12. The apparatus of claim 1 , wherein the holder is configured to be removably fixed to the circumferential mounting groove of the rotating magnetic cylinder, and wherein the holder and support are configured to move together concomitantly with the rotating magnetic cylinder.

13. The apparatus of claim 1 , wherein the support is fixed so that the support is immovable relative to the holder.

14. The apparatus of claim 1 , wherein the motor is mounted inside of the holder.

15. The apparatus of claim 1 , further comprising a magnet holder comprising a recess in which the permanent magnet assembly is disposed, wherein the magnet holder is located between the permanent magnet assembly and the motor.

16. A method of modifying an existing rotating magnetic cylinder of a printing unit having non-spinable permanent magnet assemblies which are mounted to an accommodating recess of a holder along an axis, the method comprising;
removing one or more non-spinnable permanent magnet assemblies along the axis from the rotating magnetic cylinder of a printing unit; and
replacing them with one or more spinnable permanent magnet assemblies spinning around the axis, wherein the one or more spinnable permanent magnet assemblies are removably fixed to the accommodating recess of the holder,
wherein the holder includes a bottom surface and a removable fixation on the bottom surface, the bottom surface is curved according to a curvature radius of a circumferential mounting groove of the rotating magnetic cylinder, and the removable fixation of the holder is configured to be removably fixed to the circumferential mounting groove of the rotating magnetic cylinder of the printing unit, wherein the axis is substantially perpendicular to the bottom surface of the holder;
wherein the holder includes a lower recess between the accommodating recess and the bottom surface, at least a part of the motor is disposed in the lower recess of the holder, and the motor includes a central hole to provide access to the removable fixation.

Assignees

• Sicpa Holding Sa

Inventors

• Loginov Evgeny
• Schmid Mathieu
• Despland Claude-Alain
• Degott Pierre
• Muller Edgar

Classifications

• H01F7/0294

  Detection, inspection, magnetic treatment · CPC title

• H01F7/0247

  Orientating, locating, transporting arrangements · CPC title

• B41M3/14

  Security printing {(securities B42D25/29)} · CPC title

• B41F19/005 Primary

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

• B41F15/24

  for webs · CPC title