Non-impact printing method for applying compositions to webs and products produced therefrom
View Patent ↗A method is disclosed for application of compositions onto non-woven webs, such as paper webs. The present invention is also directed to products made from the process. In general, the method includes applying a composition to a non-woven web using a non-impact printer, such as an ink jet printer. The composition is applied, in one embodiment, as droplets that remain as discrete shapes on the substrate. In this manner, treated areas and untreated areas are formed on the web. Through this process, the water absorption and control properties of the web can be adjusted as desired while simultaneously treating the web with a composition that improves the physical and/or chemical properties of the web.
1. A process for applying a composition onto a nonwoven web comprising:
providing a nonwoven sheet, the nonwoven sheet comprising a paper web containing cellulosic fibers; and
non-impact printing a composition onto at least one side of the sheet using an ink jet printer, the composition being applied in an amount sufficient to improve the physical properties of the sheet or to be transferred to an adjacent surface during use of the sheet, the composition being deposited on the sheet in the form of discrete droplets, the droplets on the sheet having a diameter of less than about 3 mm, the composition being applied to the sheet in a discontinuous manner such that the sheet includes treated areas where the droplets reside and untreated areas, the treated areas comprising from about 5% to about 90% of the surface area of the at least one side, wherein the paper web after being printed with the composition has a wet out time of less than about 10 seconds.
2. The process as defined in claim 1 , wherein the composition is hydrophobic.
3. The process as defined in claim 2 , wherein the composition comprises a silicone.
4. The process as defined in claim 3 , wherein the silicone comprises:
wherein, x and y are integers such that at least one of x or y is >0, the mole ratio of x to (x+y) can be from about 0 percent to about 80 percent, and the R 1 –R 10 moieties can be independently any organofunctional group including C 1 or higher alkyl groups, ethers, polyethers, polyesters, amines, imines, amides, or other functional groups including the alkyl and alkyl analogues of such groups and including mixtures of said groups. composition is hydrophobic.
5. The process as defined in claim 1 , wherein the ink jet printer is a piezoelectric printer, a valvejet printer, or a thermal printer.
6. The process as defined in claim 1 , wherein the nonwoven sheet comprises multiple plies.
7. The process as defined in claim 1 , wherein the droplets have a diameter of less than about 200 microns.
8. The process as defined in claim 1 , wherein the droplets have a diameter of less than about 50 microns.
9. The process as defined in claim 1 , wherein the treated areas comprise from about 5% to about 60% of the surface area of the at least one side of the sheet.
10. The process as defined in claim 1 , wherein the nonwoven sheet comprises a bath tissue, a facial tissue, or a paper towel.
11. The process as defined in claim 1 , wherein the paper web has a basis weight of from about 10 gsm to about 80 gsm.
12. The process as defined in claim 1 , wherein the composition comprises a wax that is solid at room temperature and wherein the process further comprises the step of heating the composition prior to applying the composition to the sheet.
13. The process as defined in claim 1 , wherein the composition is applied to the sheet at an add on rate of from about 0.1% to about 10% by weight of the sheet.
14. A process for applying a composition onto a paper web comprising the steps of:
providing a paper sheet containing cellulosic fibers, the sheet having a basis weight of from about 10 gsm to about 80 gsm and having a bulk of at least about 2 cm 3 /g; and
non-impact printing a composition onto at least one side of the sheet using an ink jet printer, the composition being deposited on the sheet in the form of discrete droplets, the droplets on the sheet having a diameter of less than about 3 mm, the composition being applied to the sheet in a discontinuous manner such that the sheet includes treated areas where the droplets reside and untreated areas, the treated areas comprising from about 5% to about 90% of the surface area of the at least one side, the composition being applied to the sheet at an add on rate of from about 0.1% to about 10% by weight of the sheet, the paper sheet after being treated with the composition having a wet out time of less than about 10 seconds.
15. The process as defined in claim 14 , wherein the composition comprises a silicone.
16. The process as defined in claim 14 , wherein the droplets have a diameter on the sheet of less than about 50 microns.
17. The process as defined in claim 14 , wherein the composition comprises a wax.
18. The process as defined in claim 14 , wherein the paper sheet includes multiple plies.
19. The process as defined in claim 14 , wherein the composition is applied to the sheet while the sheet is moving using a plurality of ink jet printers.
20. The process as defined in claim 14 , wherein the ink jet printer is digitally controlled by a controller, the composition being applied to the sheet according to a pattern that has been programmed into the controller.
21. The process as defined in claim 20 , wherein the paper sheet includes a pattern of areas where the sheet has been densified, said controller being configured to apply the composition to the sheet in a pattern that matches the pattern of the densified areas.
22. The process as defined in claim 14 wherein the droplets prior to contacting the sheet have a volume of from about 5 picoliters to about 500 picoliters.
23. The process as defined in claim 14 , wherein the droplets are uniformly applied over the surface of the sheet.
24. A paper product comprising:
a paper sheet comprising pulp fibers, the paper sheet having a basis weight of from about 10 gsm to about 80 gsm and having a bulk of at least about 10 cc per gram; and
a composition applied to at least one side of the paper sheet, the composition comprising a chemical additive, the composition being applied to the sheet in the form of discrete droplets, the droplets forming treated areas on the sheet separated by untreated areas, the droplets on the sheet having a diameter of less than about 200 microns, the treated areas comprising from about 5% to about 90% of the surface area of the at least one side of the sheet, the composition being hydrophobic, the sheet after being treated with the composition having a wet out time of less than about 10 seconds.