Method of steam treating low yield papermaking fibers to produce a permanent curl

• US 6,413,362 B1
• Filed: 11/24/1999
• Issued: 07/02/2002
• Est. Priority Date: 11/24/1999
• Status: Expired due to Fees

• Current Assignee: Neenah Paper Incorporated (Mativ Holdings, Inc.)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Hu, Sheng-Hsin
• Primary Examiner(s): ALVO, MARC S
• Application Number:
  US09/448,162
• Time in Patent Office: 951 Days
• Field of Search: 162/9, 162/68, 162/23, 162/24, 162/28, 162/4, 162/20, 162/21, 162/247
• US Class Current: 162/4
• CPC Class Codes: A61L 15/28 Polysaccharides or their derivatives A61L15/225 takes precedence
• CPC Class Codes: A61L 15/42 Use of materials characterised by their function or physical properties liquid bandages A61L26/00
• CPC Class Codes: C08L 1/02 Cellulose; Modified cellulose
• CPC Class Codes: D21B 1/36 Explosive disintegration by sudden pressure reduction
• CPC Class Codes: D21C 9/007 by mechanical or physical means
• CPC Class Codes: D21H 15/04 crimped, kinked, curled or twisted fibres

Abstract

Wood fiber morphology can be permanently altered by introducing a substantial kink, twist, curl, crimp or other curvilinear deformation into a wood fiber. Wood fibers are first Fiberized using mechanical treatment processes and then are subjected to super atmospheric temperature/pressure steam explosion processing. The fiber morphology becomes a permanent characteristic of the fiber which is not relaxed in time, by contact with other treatments or through use.

Claims

1. A process for the production of a fiber having a permanently modified fiber morphology, the process comprising:

(a) subjecting a low yield papermaking fiber having a yield of about 55 percent or less to mechanical deformation without substantial fiber breakage resulting in a curled fiber having a temporary curl index of at least 0.15;

(b) subjecting the curled fiber to a treatment with steam at super atmospheric temperature and pressure for a sufficient period of time to render the fiber curl permanent; and

(c) explosively releasing the super atmospheric steam, thereby further increasing the curl of the fiber;

wherein the fiber resulting from this process has a permanent curl index of at least 0.20.

2. The process of claim 1 wherein the fiber comprises a purified papermaking wood fiber or recycled papermaking wood fiber.

3. The process of claim 1 wherein the mechanical deformation comprises a hammermill process sufficient to deform the fibers without substantial fiber breakage resulting in a fiber with a curvilinear structure.

4. The process of claim 1 wherein the super atmospheric temperature comprises a temperature of about 130°

to 250°

C.

5. The process of claim 1 wherein the super atmospheric pressure comprises a pressure of about 40 psi to 405 psi.

6. The process of claim 1 wherein the sufficient period of time comprises a time interval of about 0.1 minute to 30 minutes.

7. The process of claim 1 wherein the fiber resulting from this process has a permanent curl index of about 0.2 to 0.35.

8. The process of claim 1 wherein the fiber resulting from this process has a permanent curl index of about 0.22 to 0.33.

9. The process of claim 1 wherein the fiber with a permanent fiber morphology is blended with a purified papermaking wood fiber at a ratio of about 1 part of the papermaking wood fiber per each 0.01 to 100 parts of the fiber with the permanent fiber morphology.

10. A process for the production of a fiber having a permanently modified fiber morphology, the process comprising:

(a) subjecting a low yield papermaking fiber having a yield of about 55 percent or less to hammermilling without substantial fiber breakage resulting in a curled fiber having a temporary curl index of 0.15 or greater;

(b) subjecting the curled fiber to a treatment with steam at super atmospheric temperature and pressure for about 0.5 minutes to about 20 minutes; and

(c) explosively releasing the super atmospheric steam, thereby further increasing the curl index of the fiber;

wherein the fiber resulting from this process has a permanent curl index of from about 0.22 to about 0.33.

11. The process of claim 10 wherein the fiber comprises a purified papermaking wood fiber.

12. The process of claim 10 wherein the super atmospheric temperature comprises a temperature of about 150°

to 220°

C. within a sealed continuous process container.

13. The process of claim 10 wherein the super atmospheric pressure comprises a pressure of about 40 psi to 230 psi within a sealed continuous process container.

14. The process of claim 10 wherein the subjecting the fiber with the curvilinear structure to a treatment with steam at super atmospheric temperature and pressure occurs for about 1 minute to about 10 minutes within a sealed continuous process container.

15. The process of claim 10 wherein the fiber with a permanent fiber morphology is blended with a purified papermaking wood fiber at a ratio of about 1 part of the papermaking wood fiber per each 1 to 100 parts of the fiber with the permanent fiber morphology.

16. A process for the production of a fiber having a permanently modified fiber morphology, the process comprising:

(a) subjecting a low yield papermaking fiber having a yield of about 55 percent or less to mechanical deformation without substantial fiber breakage resulting in a curled fiber having a temporary curl index of about 0.15 or greater;

(b) subjecting the curled fiber to a treatment with steam at super atmospheric temperature and pressure for a sufficient period of time to render the fiber curl permanent; and

(c) explosively releasing the super atmospheric steam, thereby further increasing the curl of the fiber about 100 percent, wherein the fiber resulting from this process has a permanent curl index of from about 0.3 to about 0.4.