THERMAL TRANSFER PRINTING

• US 20190308433A1
• Filed: 05/29/2019
• Published: 10/10/2019
• Est. Priority Date: 11/30/2016
• Status: Active Grant

• Current Assignee: Landa Labs (2012) Ltd.
• Original Assignee: Landa Labs (2012) Ltd.
• Inventors: LANDA, Benzion, ABRMOVICH, Sagi, HAVIV, Amit, AKNIN, Ofer, VALDMAN, Yaakov, NAGLER, Michael
• Granted Patent: US 11,104,779 B2
• Time in Patent Office: Days
• CPC Class Codes: B05B 1/20 Arrangements of several outlets along elongated bodies, e.g. perforated pipes or troughs, e.g. spray booms spray booms for agricultural uses A01M7/0071; spray bars for treating roads E01C19/176; Outlet elements therefor
• CPC Class Codes: B05B 13/0207 the work being an elongated body, e.g. wire or pipe B05B13/0436, B05B13/0463 take precedence
• CPC Class Codes: B05B 13/0228 the movement of the objects being rotative B05B13/0242 takes precedence
• CPC Class Codes: B05B 14/30 comprising enclosures close to, or in contact with, the object to be sprayed and surrounding or confining the discharged spray or jet but not the object to be sprayed
• CPC Class Codes: B41J 11/0024 using conduction means, e.g. by using a heated platen
• CPC Class Codes: B41J 2/0057 where an intermediate transfer member receives the ink before transferring it on the printing material
• CPC Class Codes: B41J 2/447 using arrays of radiation sources B41J2/475 takes precedence
• CPC Class Codes: B41J 2/45 using light-emitting diode [LED] or laser arrays
• CPC Class Codes: B41M 2205/06 relating to melt (thermal) mass transfer
• CPC Class Codes: B41M 2205/10 Post-imaging transfer of imaged layer; transfer of the whole imaged layer
• CPC Class Codes: B41M 5/025 by transferring ink from the master sheet
• CPC Class Codes: B41M 5/0256 the transferable ink pattern being obtained by means of a computer driven printer, e.g. an ink jet or laser printer, or by electrographic means
• CPC Class Codes: B41M 5/03 by pressure
• CPC Class Codes: B41M 5/38221 Apparatus features
• CPC Class Codes: B41M 5/52 Macromolecular coatings
• CPC Class Codes: C01P 2004/04 obtained by TEM, STEM, STM or AFM
• CPC Class Codes: C01P 2004/50 Agglomerated particles
• CPC Class Codes: C01P 2004/61 Micrometer sized, i.e. from 1-100 micrometer
• CPC Class Codes: C01P 2004/62 Submicrometer sized, i.e. from 0.1-1 micrometer
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/19 : Oil-absorption capacity, e.g. DBP values
• CPC Class Codes: C08G 77/04 : Polysiloxanes
• CPC Class Codes: C08K 2201/005 : Additives being defined by their particle size in general
• CPC Class Codes: C08K 3/04 : Carbon
• CPC Class Codes: C08K 3/36 : Silica
• CPC Class Codes: C08K 5/5419 : containing at least one Si—C bond
• CPC Class Codes: C08K 5/544 : containing nitrogen
• CPC Class Codes: C08L 83/04 : Polysiloxanes
• CPC Class Codes: C09C 1/56 : Treatment of carbon black ; Purification
• CPC Class Codes: C09C 3/10 : Treatment with macromolecular organic compounds C09C3/006 takes precedence
• CPC Class Codes: C09D 7/66 : characterised by particle size
• CPC Class Codes: G03G 15/162 : details of the the intermediate support, e.g. chemical composition
• CPC Class Codes: G03G 15/326 : by application of light, e.g. using a LED array
• CPC Class Codes: G03G 15/342 : by forming a uniform powder layer and then removing the non-image areas
• CPC Class Codes: Y02P 70/10 : Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

Method and system for thermal transfer printing are disclosed. The system comprises a transfer member having an imaging surface on the front side, a coating station at which a monolayer of particles made of, or coated with, a thermoplastic polymer is applied to the imaging surface, an imaging station at which electromagnetic radiation (EM) is applied via the rear side of the transfer member to selected regions of the particles-coated imaging surface to render the particles thereon tacky within the selected regions, and a transfer station at which only the regions of the particles coating that have been rendered tacky are transferred to a substrate. The transfer member includes on its rear side a body transparent to EM radiation and on its front side an EM radiation absorbing layer, the imaging surface being formed on, or as part of, the absorbing layer.

Claims

1. A printing system for thermal transfer printing onto a surface of a substrate, the system comprising:

a) a movable transfer member having opposite front and rear sides with an imaging surface on the front side;

b) a coating station at which a monolayer of particles made of, or coated with, a thermoplastic polymer is applied to the imaging surface or at least a segment thereof;

c) an imaging station at which energy in the form of electromagnetic (EM) radiation is applied via the rear side of the transfer member to selected regions of the particles coated imaging surface to render the particles thereon tacky within the selected regions; and

d) a transfer station at which the imaging surface and the surface of the substrate, or respective segments thereof, are pressed against one another to cause transfer to the surface of the substrate of only the regions of the particle coating that have been rendered tacky,

wherein

(e) the rear side of the transfer member is formed of a body transparent to the EM radiation, and

(f) an EM radiation absorbing layer made of an elastomeric silicone is provided on the front side of the transfer member adjoining the transparent body, the imaging surface being formed on, or as part of, the radiation absorbing layer.

2. The printing system of claim 1, wherein the transfer station comprises an impression cylinder positioned facing the front side of the transfer member so as to define a nip at which at least a segment of the imaging surface of the transfer member and at least a segment of the substrate surface are pressed against each other, and wherein the imaging station is configured and aligned to apply radiation to the rear side of the transfer member at and/or adjacent the nip, so that the rendering of the thermoplastic particles tacky, and the impression of the particles onto the substrate surface, occur substantially concurrently.

3. The printing system of claim 2, wherein the imaging station further comprises a transparent member facing the rear side of the transfer member at the nip, the transfer member sliding during operation between the transparent member and the impression cylinder, the EM radiation applied to the particles on the imaging surface passing through the transparent member.

4. The printing system of claim 3, further comprising a lubrication system configured to controllably release a lubricant to the rear side of the transfer member to lubricate the rear side as the transfer member slides over the transparent member.

5. The printing system of claim 3, wherein the transparent member is compressible.

6. The printing system of claim 3, wherein the transparent member is non-compressible, the printing system further comprising a pressure applicator having a compressible segment in contact with the rear side of the transfer member adjacently to the nip.

7. The printing system of claim 3, wherein the transparent member includes a surface disposed to contact at least in a portion thereof, a portion of the rear side of the transfer member, the surface having one or two rounded edges to facilitate for a lubricant at least one of entry in-between the surface and the rear side and exit from in-between the surface and the rear side.

8. The printing system of claim 3, wherein the transparent member includes a surface disposed to contact at least in a portion thereof the rear side of the transfer member, the surface having one or more grooves for directing traversal of a lubricant between the surface and the rear side.

9. The printing system of claim 1, wherein the radiation absorbing layer comprises sub-micron carbon black particles dispersed in a silicone material.

10. The printing system of claim 1, wherein the coating station constitutes a first coating station, the transfer station constitutes a first transfer station, and the transfer member constitute a first transfer member, the printing system further comprising a second coating station serving to apply a monolayer coating of polymeric particles differing from the particles applied by the first coating station, to a second transfer member that is pressed against the substrate at a second transfer station disposed downstream of the first transfer station in the path of the substrate.

11. The printing system of claim 10, wherein the particles applied to the second transfer member are transparent.

12. The printing system of claim 10, wherein the particles applied to the second transfer member adhere only to regions of the surface of the substrate having a polymer film that was applied at the first transfer station and that is still tacky.

13. The printing system of claim 1, further comprising a finishing station for applying a thermal treatment to a polymer film that was applied to the surface of the substrate at the transfer station or at a last transfer station if more than one transfer station is utilized.

14. The printing system of claim 13, wherein the finishing station includes a surface that contacts the polymer film applied to the substrate during the thermal treatment of the polymer film.

15. A method of thermal transfer printing onto a surface of a substrate, which comprises:

a) providing a movable transfer member having opposite front and rear sides with an imaging surface on the front side;

b) applying to the imaging surface a monolayer coating of particles made of, or coated with, a thermoplastic polymer;

c) applying EM radiation via the rear side of the transfer member to selected regions of the coated imaging surface to render the particles thereon tacky within the selected regions; and

d) pressing the imaging surface and the surface of the substrate, or respective segments thereof, against one another to cause transfer to the surface of the substrate of only the regions of the particle coating that have been rendered tacky;

wherein the rear side of the transfer member comprises a body transparent to the EM radiation, the transfer member further comprising a radiation absorbing layer made of an elastomeric silicone on the front side of the transfer member adjoining the transparent body, and the imaging surface being formed on, or as part of, the radiation absorbing layer such that the EM radiation reaches the imaging surface by passing through the transparent body.

16. The method of claim 15, wherein applying EM radiation and pressing the imaging surface and the surface of the substrate, or respective segments thereof, against one another, occur substantially concurrently.

17. The method of claim 15, wherein during the step of applying EM radiation, the EM radiation passes through a transparent member which faces the rear side of the transfer member, and wherein during the step of pressing, the transfer member slides over the transparent member.

18. The method of claim 17, further comprising controllably releasing a lubricant to the rear side of the transfer member to lubricate the rear side as the transfer member slides over the transparent member.

19. A transfer member for use in a printing system having the form of an endless belt or a drum and comprising a body transparent to electromagnetic (EM) radiation lying within a predetermined range of frequencies disposed on a rear side of the transfer member, a radiation absorbing elastomeric silicone layer opaque to the EM radiation adjoining the transparent body and disposed on or adjacent a front side of the transfer member, and a hydrophobic release layer formed on the front side of the transfer member, the release layer being in thermal contact with, or formed as part of, the radiation absorbing layer.

20. The transfer member of claim 19, wherein the radiation absorbing layer is composed of an elastomeric silicone having carbon black particles dispersed therein.