Process for applying chemical papermaking additives to web substrate

• US 6,126,784 A
• Filed: 05/05/1999
• Issued: 10/03/2000
• Est. Priority Date: 05/05/1999
• Status: Expired due to Term

• Current Assignee: The Procter & Gamble Company
• Original Assignee: The Procter & Gamble Company
• Inventors: Vinson, Kenneth Douglas, Ficke, Jonathan Andrew
• Primary Examiner(s): Silverman, Stanley S.
• Assistant Examiner(s): Fortuna, Jose A.
• Application Number:
  US09/305,765
• Time in Patent Office: 517 Days
• Field of Search: 162/111, 162/112, 162/113, 162/135, 162/136, 162/158, 162/206-207, 162/164.1-164.3, 162/168.1-168.6, 162/183, 162/184, 162/185, 162/179, 156/183, 264/282-283, 428/211, 428/152-154
• US Class Current: 162/184
• CPC Class Codes: D21H 19/84 on both sides of the substrate
• CPC Class Codes: D21H 21/22 Agents rendering paper porous, absorbent or bulky
• CPC Class Codes: D21H 23/72 Plural serial stages only
• CPC Class Codes: D21H 25/08 Rearranging applied substances, e.g. metering, smoothing; Removing excess material

Abstract

A process for applying a chemical additive, such as a softener, to a fibrous web comprises the steps of: providing a fibrous web having a first side and a second side opposite to the first side; providing a chemical additive; depositing the chemical additive only to the first side of the fibrous web; causing the first side of the fibrous web to contact the second side of the fibrous web thereby partially transferring the chemical additive from the first side to the second side of the fibrous web such that both the first side and the second side of the fibrous web comprise the chemical additive in a functionally sufficient amount. Preferably, the step of causing the two sides of the web to contact comprises winding the web into a roll.

Claims

1. A process for applying a chemical additive to a fibrous web, the process comprising the steps of:

(a) providing a fibrous web having a first side and a second side opposite to the first side;

(b) providing a chemical additive;

(c) depositing the chemical additive only to the first side of the fibrous web;

(d) maintaining the chemical additive deposited onto the first side of the web in a transferable condition such that a ratio of an open time to a drop absorbency time less than 3.0;

(e) causing the first side of the fibrous web to contact the second side of the fibrous web thereby partially transferring the chemical additive from the first side to the second side of the fibrous web such that both the first side and the second side of the fibrous web comprise the chemical additive in a functionally sufficient amount.

2. The process according to claim 1, wherein the step (e) comprises transferal of the chemical additive from a first position on the first side of the fibrous web to a second position on the second side of the fibrous web, the second position being off-set from the first position relative to a plane of the web.

3. The process according to claim 2, further comprising a step of continuously moving the fibrous web in a machine direction.

4. The process according to claim 3, wherein the step (e) comprises continuously winding the fibrous web into a roll.

5. The process according to claim 4, wherein the second position on the second side of the fibrous web is off-set in the machine direction from the first position on the first side of the fibrous web.

6. The process according to claim 5, wherein in the step (e) the amount of the chemical additive transferred from the first side of the fibrous web to the second side of the fibrous web is such that a ratio R of a surface concentration SC2 of the chemical additive on the second side to a surface concentration SC1 of the chemical additive on the first side is at least 1:

4.

7. The process according to claim 6, wherein the ratio R is at least 1:

2.

8. The process according to claim 7, wherein the ratio R is about 1:

1.

9. The process according to claim 6, wherein the step (c) comprises extrusion coating, spray coating, print coating or any combination thereof.

10. The process according to claim 1, wherein in the step (b) the chemical additive is selected from the group consisting of softeners, emulsions, emollients, lotions, topical medicines, soaps, anti-microbial and anti-bacterial agents, moisturizers, coatings, inks and dies, strength additives, absorbency additives, binders, opacity agents, fillers, and combinations thereof.

11. The process according to claim 10, wherein the chemical additive is a chemical softener selected from the group consisting of lubricants, plasticizers, cationic debonders, noncationic debonders, and mixtures thereof.

12. The process according to claim 11, wherein in the step (e) the functionally sufficient amount of the chemical additive is at least 20 pounds per short ton.

13. The process according to claim 12, wherein the functionally sufficient amount of the chemical additive is at least 50 pounds per short ton.

14. The process according to claim 13, wherein the functionally sufficient amount of the chemical additive is at least 90 pounds per short ton.

15. The process according to claim 10, wherein the chemical additive is a strength additive selected from the group consisting of permanent wet-strength resins, temporary wet-strength resins, dry-strength resins, and mixtures thereof.

16. The process according to claim 10, wherein the chemical additive is an absorbency additive selected from the group consisting of polyethoxylates, alkylethoxylated esters, alkylethoxylated alcohols, alkylpolyethoxylated nonylphenols, and mixtures thereof.

17. The process according to claim 1, wherein the ratio of the open time to the drop absorbency time is less than about 1.0.

18. The process according to claim 17, wherein the ratio of the open time to the drop absorbency time is less than about 0.5.

19. A process for applying a chemical additive to a fibrous web, the process comprising the steps of:

(a) providing a fibrous web having a first side and a second side opposite to the first side;

(b) providing a softening composition selected from the group consisting of lubricants, plasticizers, cationic debonders, noncationic debonders, and mixtures thereof;

(c) depositing the softening composition only to the first side of the fibrous web in the amount of at least 0.05 gram of the softening composition per square meter of the web;

(d) maintaining the softening composition disposed on the first side of the fibrous web in a transferable condition such that a ratio of an open time to a drop absorbency time less than 3.0;

(e) continuously winding the fibrous web into a roll thereby causing the first side of the fibrous web to contact the second side of the fibrous web such that the softening composition disposed on the first side is partially transferred therefrom to the second side of the web, wherein the amount of the softening composition transferred from the first side to the second side of the fibrous web is such that a ratio of a surface concentration of the chemical additive on the second side to a surface concentration of the chemical additive on the first side is at least 1;

4.

20. The process according to claim 19, wherein in the step (a) at least the first side of the fibrous web comprises a first region and a second region, the first region being raised above the second region.

21. The process according to claim 20, wherein the step (c) comprises depositing the softening composition non-compressively to the first region of the first side of the fibrous web.

22. The process according to claim 21 wherein in the step (a) the fibrous web comprises a pattern-densified structure, the first region having a first density and the second region having a second density different from the first density.

23. The process according to claim 22, wherein the first density is lower than the second density.

24. The process according to claim 19, wherein the step (c) is conducted during the papermaking process.

25. The product according to claim 19, wherein the chemical softening composition comprises a quaternary ammonium compound.