Process of preparing printing solution and making patterned cigarette wrappers
A process for making patterned cigarette wrapper includes the steps of: preparing a printing solution including the steps of: mixing at least water and a starch to form a starch mixture, heating the starch mixture to a temperature of at least about 180° F. preferably for at least about 30 minutes to release amylopectin and amylose, adding propylene glycol to the starch mixture, and mixing the starch mixture and propylene glycol to form a printing solution, wherein the solution is maintained and applied at elevated temperature (120° F. to 150° F.). The process also includes providing a base web of wrapper and applying the printing solution to the wrapper in a predetermined pattern.
1. A process for making patterned wrapper of a smoking article comprising the steps of:
preparing a printing solution including the steps of:
mixing at least water and a starch to form an aqueous starch solution;
heating the aqueous starch mixture to a temperature of at least about 180° F. for a time sufficient to release at least one of amylopectin and amylose;
adding propylene glycol to the aqueous starch mixture; and
mixing the starch mixture and propylene glycol to form a printing solution; and
providing a base web of wrapper;
applying the printing solution to the wrapper in a predetermined pattern; and
between said preparing step and said applying step, cooling to and continuously maintaining the printing solution at a temperature ranging from about 120° F. to about 150° F.
2. The process of claim 1 , wherein the mixing step includes incorporating oxidized starch.
3. The process of claim 1 , wherein the printing solution is applied to the wrapper at a temperature ranging from about 120° F. to about 150° F.
4. The process of claim 1 , wherein the viscosity of the printing solution ranges from about 16.5 seconds to about 19.5 seconds as measured by a Zahn #2 cup at 120° F.
5. The process of claim 1 , further including agitating the printing solution during the heating step.
6. The process of claim 1 , wherein the printing solution is applied to the wrapper in transversely extending bands.
7. The process of claim 1 , wherein the printing solution has a pH in the range of about 4 to about 5 after adding propylene glycol.
8. The process of claim 1 , wherein the base web has a transverse direction and wherein the predetermined pattern comprises generally parallel bands extending generally transversely on the base web.
9. The process of claim 1 , wherein the base web has a longitudinal direction and wherein the predetermined pattern includes a longitudinally extending stripe.
10. The process of claim 1 , wherein the base web has a transverse direction and a longitudinal direction and wherein the predetermined pattern includes a plurality of regions extending transversely and spaced longitudinally on the base web.
11. The process of claim 1 , wherein the printing process is selected from the group comprising gravure printing, flexographic printing, offset printing, inkjet printing, spraying, and die printing.
12. The process of claim 11 , wherein the printing process is gravure printing.
13. The process of claim 1 , wherein the printing solution is applied in at least a single pass to the base web.
14. The process of claim 1 , further including adding calcium carbonate to the printing solution.
15. The process of claim 14 , wherein the calcium carbonate is added to the printing solution after the heating and maintaining step and before the printing step.
16. The process of claim 1 , wherein the printing solution has a viscosity ranging from about 40 cP to about 60 cP after the cooling step.
17. The process of claim 1 , wherein during the maintaining step, the temperature is maintained for at least 30 minutes or more.
18. The process of claim 1 , wherein the at least water and oxidized starch are mixed at a temperature of about 75° F.
19. The process of claim 1 , wherein the oxidized starch mixture has a viscosity of about 50 cP to about 80 cP after the heating step.
20. The process of claim 1 , wherein the viscosity of the printing solution is about 16.5 seconds to about 19.5 seconds as measured by Zahn #2 cup at 120° F. at application to a base web.
21. The process of claim 1 , wherein propylene glycol is a stabilizing agent and wherein the propylene glycol is added in an amount of about 7% to about 10% by weight based on the weight of the cooked starch solution.
22. The process of claim 1 , wherein the printing solution when applied has a solids content of about 21%, the viscosity of the printing solution ranges from about 16.5 seconds to about 19.5 seconds as measured by a Zahn #2 cup at 120° F., and the printing solution is applied to a base web in a single pass.