Absorbent material incorporating synthetic fibers and process for making the material

• US 20030084983A1
• Filed: 11/08/2002
• Published: 05/08/2003
• Est. Priority Date: 01/09/2001
• Status: Abandoned Application

• Current Assignee: EAM Corporation (PT Sinar Mas Group)
• Original Assignee: EAM Corporation (PT Sinar Mas Group)
• Inventors: Chinai, Kays, Rangachari, Krishnakumar
• Application Number:
  US10/290,614
• Publication Number:
  US 20030084983A1
• Time in Patent Office: Days
• US Class Current: 156/181
• CPC Class Codes: A61F 13/15203 Properties of the article, e.g. stiffness or absorbency chemical aspects A61L15/00
• CPC Class Codes: A61F 13/15642 by depositing continuous layers or pads of fibrous material on single sheets or webs
• CPC Class Codes: A61F 13/534 having an inhomogeneous composition through the thickness of the pad A61F13/538, A61F13/539 take precedence; homogeneous cores with tissue wrapping A61F13/53
• CPC Class Codes: A61F 2013/15016 for breast; pads for bras
• CPC Class Codes: A61F 2013/15357 Stiffness, e.g. Taber rigidity
• CPC Class Codes: A61F 2013/530218 followed by heat treatment
• CPC Class Codes: A61F 2013/530715 by the acquisition rate
• CPC Class Codes: B32B 5/26 another layer next to it also being fibrous or filamentary relative arrangement of fibres or filaments of different layers B32B5/12

Abstract

A process is provided for making a soft, high density, absorbent material with improved characteristics. A web is formed from material that includes a mixture of cellulosic fibers and synthetic polymer fibers. Then, the web is preferably compacted and embossed at an elevated temperature to further increase the web density and preferably to also create liquid-stable bonds between the synthetic polymer fibers and the cellulosic fibers in spaced-apart regions of the web.

Claims

1. A process for making an absorbent material comprising the steps of:

(A) forming a web of cellulosic fibers and synthetic polymer fibers; and

(B) moving said web between a pair of heated rolls to compact said web while maintaining each of said rolls at temperatures to form liquid stable bonds that (1) are located at least between said cellulosic fibers and said synthetic polymer fibers, and (2) are insufficient to create a web Gurley Stiffness of more than about 1500 milligrams.

2. The process in accordance with claim 1 in which step (B) includes (1) moving said web at a selected speed, (2) compacting said web under a selected compaction load to a density of between about 0.25 grams per cubic centimeter and 0.50 grams per cubic centimeter, and (3) maintaining each of said rolls at temperatures which are insufficient at said selected speed of web movement and said selected compaction load to melt a major portion of the total surface area defined by the exteriors of said synthetic polymer fibers.

3. The process in accordance with claim 1 in which step (B) includes maintaining each of said rolls at temperatures such that only a minor portion of the total surface area defined by the exteriors of said synthetic polymer fibers is melted.

4. The process in accordance with claim 1 in which step (A) includes

providing superabsorbent material as part of said web in an amount which is between about 10% and 60% by weight of said web;

providing said synthetic polymer fibers in an amount which is at least about 5% by weight of said web; and

forming said web substantially free of added chemical binders.

5. The process in accordance with claim 1 in which step (B) includes

embossing a pattern of surface indentations into one side of said web with one of said rolls while maintaining each of said rolls at a temperature of at least 120°

;

maintaining said selected speed of web movement at between about 30 meters per minute and about 300 meters per minute; and

maintaining said selected compaction load between about 28 newtons per millimeter of transverse web width to about 400 newtons per millimeter of transverse web width.

6. The process in accordance with claim 1 in which step (A) includes forming said web with a basis weight between about 100 grams per square meter and about 650 grams per square meter.