Method for making bicomponent fibers

• US 4,552,603 A
• Filed: 09/27/1982
• Issued: 11/12/1985
• Est. Priority Date: 06/30/1981
• Status: Expired due to Fees

• Current Assignee: Akzona Incorporated
• Original Assignee: Akzona Incorporated
• Inventors: Parker, James P., King, Charles L., Harris, Robert D. Jr.
• Primary Examiner(s): Czaja, Donald
• Assistant Examiner(s): Lorin, Hubert C.
• Application Number:
  US06/423,943
• Time in Patent Office: 1,142 Days
• Field of Search: 264/168, 264/171, 264/248, 264/DIG. 75, 264/342 R, 264/345, 264/291, 264/210.5, 264/289.6, 264/290.5, 264/174, 264/235.6, 428/296, 428/373, 428/474.9, 156/167, 156/181, 156/290
• US Class Current: 156/167
• CPC Class Codes: D01D 5/30 Conjugate filaments; Spinnerette packs therefor
• CPC Class Codes: D01F 8/06 with at least one polyolefin as constituent
• CPC Class Codes: D01F 8/14 with at least one polyester as constituent
• CPC Class Codes: D04H 1/54 by welding together the fibres, e.g. by partially melting or dissolving in combination with needling D04H1/485
• CPC Class Codes: E04B 2001/7687 Crumble resistant fibrous blankets or panels using adhesives or meltable fibres
• CPC Class Codes: Y10S 264/75 Processes of uniting two or more fibers
• CPC Class Codes: Y10T 428/2929 Bicomponent, conjugate, composite or collateral fibers or filaments [i.e., coextruded sheath-core or side-by-side type]

Abstract

Novel heat bondable bicomponent fibers useful in the production of nonwoven fabrics, as well as methods for the production of such fibers, are disclosed. The fibers comprise a latently adhesive component for forming interfilamentary bonds upon the application of heat and subsequent cooling, and another component, and are characterized by the fact that upon the application of heat sufficient to melt the latently adhesive component and subsequent cooling, a substantial shrinkage force appears in said other component only after resolidification of said latently adhesive component.

Claims

1. A method for producing a heterofilament of the type comprising a latently adhesive component for forming interfilamentary bonds upon the application of heat and subsequent cooling, and a fiber component consisting of polyester, said heterfilament being characterized by a thermomechanical response wherein, upon the application of heat sufficient to melt the latently adhesive component and subsequent cooling, shrinkage force greater than about 0.01 g/denier appears in said fiber component only after the resolidification of said latently adhesive component;

said method comprising the sequential steps of;

(a) spinning said fiber; and

(b) subjecting said fiber to a thermal conditioning treatment wherein said fiber is heated to a preselected temperature below the softening point of the lower melting component for at least a preselected time in order to bring about in said fiber the above described thermo-mechanical response.

2. The method of claim 1, further including the sequential step of drawing said fiber prior to said thermal conditioning treatment.

3. The method of claims 1 or 2, wherein said latently adhesive component is polyethylene.

4. The method of claims 1 or 2, wherein said latently adhesive component is polypropylene.

5. The method of claim 3, wherein said thermal conditioning treatment temperature falls within the range of from about 90°

C. to 120°

C. and wherein said treatment time falls within the range of from about 180 seconds to 300 seconds.

6. The method of claim 4, wherein said fiber is heated to at least about 300 seconds for at least about 140°

C.

7. The method of claim 2, wherein said fiber is wound subsequent to said drawing step.