Unwinder for as-spun elastomeric fiber

• US 6,676,054 B2
• Filed: 03/19/2002
• Issued: 01/13/2004
• Est. Priority Date: 03/23/2001
• Status: Expired due to Term

• Current Assignee: The Lycra Company, LLC
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Hicks, Dennis, Martin, Kenneth E., Heaney, Daniel J., Graverson, Jon P.
• Primary Examiner(s): Mansen, Michael R.
• Application Number:
  US10/100,811
• Publication Number:
  US 20030006331A1
• Time in Patent Office: 665 Days
• Field of Search: 242/131, 242/131.1, 242/128, 242/157.R, 242/418, 242/564.4, 242/566, 242/593
• US Class Current: 242/131
• CPC Class Codes: B65H 2701/319 Elastic threads
• CPC Class Codes: B65H 49/02 Methods or apparatus in which packages do not rotate
• CPC Class Codes: B65H 49/16 Stands or frameworks
• CPC Class Codes: B65H 51/32 Supporting or driving arrangements for forwarding devices
• CPC Class Codes: B65H 57/16 formed to maintain a plurality of filaments in spaced relation

Abstract

An over-end takeoff device (OETO) and a method for unwinding elastomeric fiber from a package are provided. The OETO includes a fiber guide spaced apart from the fiber package and disposed at an acute angle between 0° and 30° to the rotational axis of the package.

Claims

1. An unwinder comprising:

a) a frame;

b) a fiber package holder affixed to said frame;

c) a fiber package held on the fiber package holder about a rotational axis such that at least one fiber can unwind from said fiber package in a direction defining an acute angle with the rotational axis of the fiber package;

d) a driven take-off roll for unwinding said at least one fiber from the fiber package at a predetermined take-off rate;

e) a first fiber guide for directing said at least one fiber as said at least one fiber is unwound from the fiber package, said first fiber guide defining a fiber guide inlet orifice having a central axis and positioned on said frame such that;

i. a distance (d) from the first fiber guide to a front end of the fiber package facing said first fiber guide, measured on the line defined by the rotational axis of the fiber package, is equal to;

1) at least about 0.41 meter when said at least one fiber has tack greater than about 2 grams OETO and less than about 7.5 grams OETO;

or

2) from about 0.71 meter to about 0.91 meter when said at least one fiber has tack greater than about 7.5;

ii. an angle (θ

), defined by the intersection of imaginary lines corresponding, respectively, to the rotational axis of the package and the central axis of the fiber guide inlet orifice that is equal to;

1) 0°

to about 30°

when said at least one fiber has tack greater than about 2 grams OETO and less than about 7.5 grams OETO;

or

2) 0°

to about 10°

when said at least one fiber has tack greater than about 7.5 grams CETO.

2. The unwinder of claim 1 further comprising a second fiber guide positioned between said fiber package and said first fiber guide for directing said at least one fiber as said at least one fiber is unwound from the fiber package.

3. The unwinder of claim 2 further comprising a third fiber guide positioned between said first fiber guide and said driven take-off roll.

4. The unwinder of claim 3 further comprising a fourth fiber guide positioned between said third fiber guide and said driven take-off roll.

5. The unwinder of claim 1 wherein said first fiber guide comprises a grooved roll.

6. The unwinder of claim 1 wherein said first fiber guide comprises a circular guide having a wear-resistant surface for contacting the fiber.

7. The unwinder of claim 6 wherein said wear-resistant surface is the inner surface of an annulus.

8. The unwinder of claim 1 wherein said first fiber guide is a static guide.

9. A method for unwinding fiber from a fiber package comprising the steps of:

a. holding the fiber package about a rotational axis such that at least one fiber can unwind from the fiber package in a direction defining an acute angle with the rotational axis of the fiber package;

b. unwinding said at least one fiber from the fiber package at a controlled predetermined rate;

c. controlling the direction of said at least one fiber by passing said at least one fiber through a first static fiber guide having an orifice with a central axis that is perpendicular to the plane of the orifice; and

d. establishing the distance (d) from said first static fiber guide to a front end of said fiber package facing said fiber guide, measured on the line defined by the rotational axis of the fiber package, such that said distance (d) is equal to;

i. at least about 0.41 meter when said at least one fiber has tack greater than about 2 grams OETO and less than about 7.5 grams OETO;

or

ii. from about 0.71 meter to about 0.91 meter when said at least one fiber has tack greater than about 7.5;

e. setting an angle (θ

), defined by the intersection of imaginary lines corresponding, respectively, to the rotational axis of the package and the central axis of said first fiber guide such that said angle (θ

) is equal to;

i. 0°

to about 30°

when said at least one fiber has tack greater than about 2 grams OETO and less than about 7.5 grams OETO;

or

ii. 0°

to about 10°

when said at least one fiber has tack greater than about 7.5 grams OETO.

10. The method of claim 9 further comprising providing a second fiber guide positioned between said fiber package and said first static fiber guide for directing said at least one fiber as said at least one fiber is unwound from the fiber package.