Method and apparatus for curing inks printed on heat sensitive absorbent article components

Patent metadata

Field	Value
Publication number	US-10843455-B2
Application number	US-201815911692-A
Country	US
Kind code	B2
Filing date	Mar 5, 2018
Priority date	Mar 7, 2017
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

Aspects of the present disclosure relate to methods and apparatuses for printing and curing energy curable inks printed on a substrate having an onset temperature Tonset (C°). The printing systems may include a printing station and a light source. During operation, the printing station deposits energy curable ink onto a first surface of the substrate to define a printed region, and the light source directs ultraviolet light onto the first surface of the substrate to define an illumination zone on the first surface of the substrate. The substrate is advanced in a machine direction to advance the printed region through the illumination zone to cure the energy curable ink. While the printed region advances through the illumination zone, the ultraviolet light heats the substrate from an initial temperature Tin (C°) entering the illumination zone to a maximum temperature Tmax (C°), wherein Tmax (C°)≤Tonset (C°).

First claim

What is claimed is:

1. A method for printing, the method comprising:
providing a substrate extending in a machine direction, the substrate comprising a first surface and an opposing second surface and defining a width in a cross direction;
depositing energy curable ink onto the first surface of the substrate to define a printed region;
directing ultraviolet light from a light source onto the first surface of the substrate to define an illumination zone extending for a length, L (m), in the machine direction on the first surface of the substrate;
advancing the printed region through the illumination zone;
curing the energy curable ink advancing through the illumination zone with ultraviolet light traveling from the light source, wherein a portion of the ultraviolet light travels through the substrate and away from the second surface of the substrate;
reflecting the ultraviolet light traveling from the second surface of the substrate back toward the second surface of the substrate; and
removing heat energy from the substrate.

2. The method of claim 1 , wherein removing heat energy further comprises partially wrapping the substrate onto a chill roll.

3. The method of claim 2 , wherein partially wrapping the substrate onto the chill roll further comprises positioning the second surface of the substrate onto an outer circumferential surface of the chill roll.

4. The method of claim 2 , wherein the chill roll is rotatable about an axis, and wherein advancing the printed region further comprises rotating the chill roll.

5. The method of claim 2 , wherein the chill roll comprises a reflective outer surface, and wherein the ultraviolet light traveling from the second surface of the substrate is reflected back toward the second surface of the substrate by the reflective outer surface of the chill roll.

6. The method of claim 1 , wherein removing heat energy from the substrate is performed while curing energy curable ink advancing through the illumination zone.

7. The method of claim 1 , wherein removing heat energy from the substrate is performed before curing energy curable ink advancing through the illumination zone.

8. The method of claim 1 , wherein the substrate comprises a nonwoven material.

9. The method of claim 1 , wherein the ultraviolet light comprises an intensity I (W/m 2 ) at the first surface of the substrate in the illumination zone, wherein the printed region comprises an ink basis weight, IBW (gsm), that requires energy, Ec (J/m 2 ), to cure the energy curable ink, and wherein the printed region is advanced through the illumination zone at a speed, S (m/s), such that [I (W/m 2 ) x L (m)/S (m/s)]≥Ec (J/m 2 )].

10. The method of claim 1 , wherein the ultraviolet light comprises a plurality of different wavelengths.

11. The method of claim 1 , wherein the light source comprises a plurality of LEDs arranged to extend for a length in the machine direction.

12. The method of claim 1 , wherein the energy curable ink comprises a first color and a second color, wherein the first color is different from the second color.

13. A method for printing, the method comprising:
providing a nonwoven substrate extending in a machine direction, the substrate comprising a first surface and an opposing second surface and defining a width in a cross direction, the substrate comprising a melting onset temperature T onset (C°);
depositing energy curable ink onto the first surface of the nonwoven substrate to define a printed region;
directing ultraviolet light from a light source onto the first surface of the nonwoven substrate to define an illumination zone extending for a length, L (m), in the machine direction on the first surface of the substrate;
advancing the printed region through the illumination zone at a speed, S (m/s), such that the ultraviolet light heats the nonwoven substrate from an initial temperature T in (C°) entering the illumination zone to a maximum temperature T max (C°), wherein T max (C°)<T onset (C°) in the illumination zone; and
curing the energy curable ink advancing through the illumination zone with ultraviolet light traveling from the light source.

14. The method of claim 13 , wherein the ultraviolet light comprises an intensity I (W/m 2 ) at the first surface of the nonwoven substrate in the illumination zone, and wherein the printed region comprises an ink basis weight, IBW (gsm), that requires energy, Ec (J/m 2 ), to cure the energy curable ink; and wherein [I (W/m 2 ) x L (m)/S (m/s)]>Ec (J/m 2 )].

15. The method of claim 13 , further comprising removing heat energy from the nonwoven substrate.

16. The method of claim 15 , wherein removing heat energy from the nonwoven substrate is performed before curing the energy curable ink advancing through the illumination zone.

17. The method of claim 15 , wherein removing heat energy from the nonwoven substrate is performed while curing the energy curable ink advancing through the illumination zone.

18. An apparatus for printing a substrate extending in a machine direction, the substrate comprising a first surface and an opposing second surface and defining a width in a cross direction, the apparatus comprising:
a supply of energy curable ink;
a printing station positioned to deposit energy curable ink from the supply onto the first surface of the substrate;
a curing apparatus for curing the energy curable ink on the substrate, the curing apparatus comprising: a light source positioned to direct ultraviolet light toward the first surface of the substrate at a location downstream in the machine direction from the printing station, wherein the ultraviolet light source comprises a wavelength and wherein a portion of the ultraviolet light travels through the substrate and away from the second surface of the substrate, and
a chill roll comprising an outer circumferential surface positioned to support the second surface of the substrate, wherein the chill roll is adapted to remove heat energy imparted to the substrate from the curing apparatus; and
a reflective device positioned to reflect the ultraviolet light traveling from the second surface of the substrate back toward the second surface of the substrate.

19. The apparatus of claim 18 , wherein the reflective device comprises an outer surface of the chill roll.

20. The method of claim 1 , wherein the substrate comprises a melting onset temperature T onset) (C°), and wherein the printed region is advanced through the illumination zone at a speed, S (m/s), such that the ultraviolet light heats the substrate from an initial temperature T in (C°) entering the illumination zone to a maximum temperature T max (C°), wherein T max (C°)<T onset (C°) in the illumination zone.

Assignees

• Procter & Gamble

Inventors

• Strasemeier John Andrew
• Yang Hui

Classifications

• B41F23/0483

  Drying combined with cooling · CPC title

• B41F13/02

  Conveying or guiding webs through presses or machines · CPC title

• A61F13/51496

  having visual effects · CPC title

• A61F13/15731

  Treating webs, e.g. for giving them a fibrelike appearance, e.g. by embossing · CPC title

• B41M7/0081

  using electromagnetic radiation or waves, e.g. ultraviolet radiation, electron beams · CPC title