CONTINUOUS INKJET PRINTING

• US 20100321449A1
• Filed: 09/09/2008
• Published: 12/23/2010
• Est. Priority Date: 10/04/2007
• Status: Active Grant

• Current Assignee: Eastman Kodak Company
• Original Assignee: Eastman Kodak Company
• Inventors: Rieubland, Sarah, Clarke, Andrew
• Granted Patent: US 8,186,784 B2
• Time in Patent Office: Days
• US Class Current: 347/73
• CPC Class Codes: B41J 2/03 by pressure

Abstract

A continuous inkjet method in which liquid passes through a nozzle, the liquid being jetted comprising one or more dispersed or particulate components and where the particle Peclet number, Pe, defined by

$\mathrm{Pe}=\frac{1.25{\phi }_T·d_{\mathrm{eff}}^3\sqrt{{\mu }_S}}{\mathrm{kT}}\sqrt{\frac{\rho U^3}{x}}$

is less than 500 and where the effective particle diameter, d_eff, is calculated as

$d_{\mathrm{eff}}={\left(\frac{{\int }_0^{\infty }d^3\phi \left(d\right)d}{{\int }_0^{\infty }\phi \left(d\right)d}\right)}^{1/3}$

where Φ(d) is the volume fraction of the particles or components of diameter d (m) and where Φ_T is the total volume fraction of dispersed or particulate components, μ_S is the viscosity of the liquid without particles (Pa.s), ρ is the liquid density (kg/m³), U is the jet velocity (m/s), x is the length of the nozzle in the direction of flow (m), k is Boltzmann'"'"'s constant (J/K) and T is temperature (K). The present invention limits the magnitude of flow induced noise generated by particulate components in the ink to maximise the efficiency of drop formation and to minimise adverse interactions with the nozzle.

Claims

1. A continuous inkjet method in which liquid passes through a nozzle, the liquid being jetted comprising one or more dispersed or particulate components and where the particle Peclet number, Pe, defined by

2. The method of claim 1 wherein said Peclet number is less than 250.

3. The method of claim 1 wherein the jet velocity, U, is greater than about 20 m/s.

4. The method of claim 1 wherein the length of the nozzle, x, is less than about 10 micrometers.

5. The method of claim 1 wherein the liquid viscosity, μ

_S, is less than about 10 mPa·

s.

6. The method of claim 1 wherein the effective particle size, d_eff, is less than about 125 nanometers.

7. The method of claim 1 wherein the total volume fraction of dispersed or particulate components, Φ

_T, is less than 0.25.

8. The method of claim 1 wherein the continuous inkjet nozzle is formed via a MEMs technology.

9. The method of claim 1 wherein a perturbation to the liquid jet is generated by a heating element.

10. The method of claim 1 wherein droplets are sorted for printing and non-printing by means of a flow of gas.

11. The method of claim 1 wherein said dispersed or particulate component contains one of or a composite of a latex, a pigment, a metal particle, an organic particle, an inorganic particle, a dye, a monomer, a polymer, a dispersant, a surfactant.

20. The method of claim 1, wherein the product of effective particle diameter, d_eff, of said components and the cube root of the total volume fraction, Φ

_T of particulate or dispersed components is less than 95 nanometers.

12. A method of continuous inkjet printing in which liquid passes through a nozzle and wherein the liquid being jetted comprises one or more dispersed or particulate components and wherein the product of effective particle diameter, d_eff, of said components and the cube root of the total volume fraction, Φ

_T, of particulate or dispersed components is less than 95 nanometers, the effective particle diameter, d_eff, being calculated as

13. The method of claim 12 wherein the product of effective particle diameter, d_eff, of said components and the cube root of the total volume fraction, Φ

_T, of particulate or dispersed components is less than about 60 nm.

14. The method of claim 12 wherein the product of effective particle diameter, d_eff, of said components and the cube root of the total volume fraction, Φ

_T;

of particulate or dispersed components is less than about 40 nm.

15. The method of claim 12 wherein said dispersed or particulate component contains one of or a composite of a latex, a pigment, a metal particle, an organic particle, an inorganic particle, a dye, a monomer, a polymer, a dispersant, a surfactant.

16. The method of claim 12 wherein the continuous inkjet nozzle is formed via MEMs technology.

17. The method of claim 12 wherein a perturbation to the liquid jet is generated by a heating element.

18. The method of claim 12 wherein droplets are sorted for printing and non-printing by means of a flow of gas.

19. The method of claim 12 wherein the total volume fraction of dispersed or particulate components is less than 0.25.