Dye-sublimation inkjet printing for textile
Provided herein is an inkjet dye-sublimation ink composition that is formulated to interact with an immobilizing composition such that the ink composition coagulates on the surface of an absorptive substrate, thereby substantially limiting soaking of the ink composition into the substrate. Also provided are a printing process and a printing machine, wherein the ink composition is directly printed on the substrate concomitantly with the immobilizing composition, and thereafter undergo heat-pressing to afford a dye-sublimation transfer of the dye to the substrate, thereby forming an image which is characterized by sharp and well defined edges of the dyed areas.
1. A process of direct inkjet printing an image on an absorptive substrate using a dye-sublimation ink composition, comprising contacting at least a portion of the substrate with an immobilizing composition, printing the dye-sublimation ink composition directly on said portion of the substrate, and heating the substrate to thereby form the image on the surface of the substrate, wherein:
said substrate comprises fibers suitable for dye-sublimation printing;
said ink composition comprises a sublimable dye, a property-sensitive agent and a carrier, and said immobilizing composition comprises a property-adjusting agent and a carrier,
said ink composition is formulated to coagulate on said portion of the substrate upon contacting said immobilizing composition, thereby substantially preventing said dye-sublimation ink composition from soaking into the absorptive substrate,
said dye-sublimation ink composition is essentially devoid of a film-forming agent,
said immobilizing composition and said ink composition are each individually applied digitally on said portion of the substrate by a separate applicator selected from the group consisting of a nozzle and a printhead, and
said ink composition is applied on said substrate while said substrate is still wet with said immobilizing composition.
2. The process of claim 1 , wherein said property-sensitive agent is an alkali-soluble agent.
3. The process of claim 1 , wherein said property-adjusting agent is selected from the group consisting of an acid, a metal oxide and a divalent metal cation.
4. The process of claim 1 , wherein said immobilizing composition and/or said ink composition are each formulated for application from a printhead and characterized by at least one of:
a maximal particle size of less than 1 microns;
a dynamic viscosity at shear that ranges from 2 to 25 centipoises;
a printing temperature Brookfield viscosity less than 25 centipoises;
a surface tension that ranges from 24 to 32 mN/m; and
an electrical resistance of 50 to 2000 ohm per centimeter.
5. The process of claim 1 , wherein said immobilizing composition is formulated for application from a nozzle and characterized by at least one of:
a maximal particle size of less than 100 micron;
a dynamic viscosity at shear that ranges from 2 to 400 centipoises;
a room temperature Brookfield viscosity less than 400 centipoises;
a surface tension that ranges from 15 to 70 mN/m; and
an electrical resistance of 50 to 2000 ohm per centimeter.
6. The process of claim 1 , wherein said immobilizing composition and said ink composition are each individually applied digitally on said portion of the substrate concomitantly within a time period that ranges from 0.01 seconds to 15 minutes.
7. The process of claim 1 , wherein said heating is effected to a temperature that ranges from 140 to 220° C.
8. The process of claim 1 , wherein the substrate is an untreated substrate.
9. The process of claim 1 , wherein the substrate is devoid of said property-adjusting agent prior to said contacting.