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1. (WO1991006600) THERMALLY BONDABLE FABRICS, PREPARATION AND USE
Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

1. A process for preparing a fabric, which fabric is either thermally bonded or bondable, from filaments including thermoplastic fine denier
discontinuous staple fibers having an average denier per filament in a range of from 0.1 to 15 d.p.f., and having filament lengths up to 30 cm. , and in which the staple fibers are prepared from a meltspun blend of linear ethylene polymers:

characterized in that the polymer blend in the staple fibers has a Q value above 4.5, wherein Q is defined as weight average molecular weight divided by number average molecular weight, as determined by gel permeation chromatography.

2. A process for preparing a fabric, which fabric is either thermally bonded or bondable, from filaments including thermoplastic fine denier
discontinuous staple fibers having an average denier per filament in a range of from 0.1 to 15 d.p.f., and having filament lengths up to 30 cm. , and in which the staple fibers are prepared from a meltspun blend of linear ethylene polymers:

characterized in that the polymer blend in the staple fibers has an I10/I2 value of at least 7, wherein 110 is determined by ASTM D-1238(N) conditions, and 12 is determined by ASTM D-1238(E) conditions.

3. The process of Claims 1 or 2 wherein an c- unbonded fabric prepared thereby is capable of being
thermally bonded to give a stronger fabric, as
determined by normalized strip tensile strength, over a broader range of thermal bondirrg temperatures, than an otherwise identical process used to prepare a
10 comparative product wherein the polymer blend in the
staple fibers in the comparative product has either a Q value in a range of from 3.5 to 4.0 or an I10/I2 value in a range from 6.0 to 6.5.

15 4. The process of Claim 1 wherein the
polymeric blend in the staple fibers has a Q value in a range from 5.5 to 10.

5. The process of Claim 2 wherein the
20 polymeric blend in the staple fibers has an I10/I2 value in the range from 10 to 20.

6. Thermally bonded fabric prepared by the process of Claims 1 or 2, wherein the thermally bonded

25 fabric has a normalized strip tensile strength of at
least 3,000 grams.

7. The thermally bonded fabric of Claim 6
wherein the polymeric staple fibers comprise a polymeric

30 blend is an in-situ blend formed during polymerization of the polymer; and the thermally bonded fabric has a normalized strip tensile strength of at least 3,600
grams .

8. The thermally bonded fabric of Claim 7
having a normalized strip strength of at least 3,700
grams.

-. 9. Polymeric fibers including discontinuous staple fibers suitable for use in the process of Claims 1 or 2.wherein the polymer has an I10/I2 value of at
least 7 and the polymer is a btend of

10 (A) at least one high molecular weight
linear ethylene polymer having a MI value less than 25 grams/10 minutes and a density above 0.91 grams/cm^, and

(B) at least one low molecular weight

1C- linear ethylene polymer having a MI above 25 grams/10 minutes and a density above 0.91 grams/cπ .

10. The staple fibers of Claim 9, having an average denier per filament in a range of from 0.1 to 15

20 d.p.f., and being homofilaments.

11. A polymer blend suitable for use in
preparing the polymeric fibers of Claim 9 characterized in that the polymer blend has an I-|o /l2 value of at

25 least 7 as determined by ASTM D-1238(N) and (E)
respectively and further wherein the blend is formed by blending (A) and (B) in appropriate weight ratios
wherein

30 (A) is at least one high molecular weight linear ethylene polymer having an MI measured in
accordance with ASTM D-1238(E) (190°C/2.16 kg) less than 25 g/10 minutes and a density above 0.91 g/cπ ; and,

(B) is at least one low molecular weight

35
linear ethylene polymer having a MI measured in accordance with ASTM D-1238(E) (190°C/2\16 kg) greater than 25 g/10 minutes and a density above 0.91 g/cπ .

12. The blend of Claim 11 wherein the ratio of the high molecular weight linear ethylene polymer and low molecular weight linear ethylene polymer is
sufficient to provide a blend having an MI value in the range of 0.1 to 40 grams/10.minutes and a density in the range of 0.94 to 0.96 grams/cπ .

13. The blend of Claim 11 wherein at least one of the linear ethylene polymers comprises a copolymer of ethylene with at least one C3~Ci2 olefin.

14. The blend of Claim 13 wherein at least one of the linear ethylene polymers is a copolymer of ethylene and propylene or octene.

15. The blend of Claim 11 wherein the blend is a blend of discrete polymers.

16. The blend of Claim 11 wherein the blend is an in-situ blend formed during polymerization.

17. The blend of Claim 15 or 16 wherein the high molecular weight linear ethylene polymer is HDPE, having an MI value within the range between 0.1 and 25 grams/10 minutes and the low molecular weight linear ethylene polymer is HDPE having an MI value within the range between 25 and 300 grams/10 minutes.

18. The polymeric staple fibers of Claim 9 wherein the polymer is the blend of any of Claims 11 to 17.

19. A process for preparing t e polymeric
staple fibers of Claim 9 characterized by the steps of

(A) Melt-spinning the polymer of any of r. Claims 11 to 17 into meltspun filaments;

(B) Hauling off the meltspun filaments at a speed in a range of from 60 to 2,000 meters/minute;
and, optionally,
10 (C) drawing and/or crimping and/or
cutting the hauled-off meltspun filaments by
conventional means.

20. A process wherein molten linear ethylene

15 polymer fine denier staple fibers are spun at
commercially feasible throughput rates, optionally
followed by mechanical drawing to produce fiber sizes of from 0.1 to 15 denier/filament and used in making a web

20 or fabric, characterized by:

spinning a blend comprising

(A) at least one high molecular weight linear ethylene polymer having a MI measured in accordance with

25 ASTM D-1238(E) (190°C/2.16 kg) less than 25 g/10 minutes and a density above 0.91 g/cm^, and

(B) at least one low molecular weight linear ethylene polymer having a MI measured in accordance with

30 ASTM D-1238(E) (190°C/2.16 kg) greater than 25 g/10
minutes and a density above 0.91 g/cirH, forming linear ethylene polymer staple fibers having a Q value above
4.5,- wherein Q is defined as weight average. molecular rmr- weight divided by number average molecular weight, as determined by gel permeation chromatography.

21. The blend of Claim 20 wherein the ratio of the high molecular weight linear ethylene polymer and low molecular weight linear ethylene polymer is
sufficient to provide a blend having a MI value in the ran^e of 0.1 to 40 grams/10 minutes and a density in the range of of 0.94 to 0.96 grams/cm^.

22. The blend of Claim 20 wherein at least one of the linear ethylene polymers comprises a copolymer of

10 ethylene with at least one C3-C12 olefin.

23. The blend of Claim 22 wherein at least one of the linear ethylene polymers is a copolymer of
ethylene and propylene or octene.
15
24. The blend of Claim 23 wherein at least one of the linear ethylene polymers is LLDPE.

25. The blend of Claim 20 wherein the blend is 0 a blend of discrete polymers.

26. The blend of Claim 20 wherein the blend is an in-situ reactor blend formed during polymerization.

27. The blend of Claim 25 or 26 wherein the

25 high molecular weight linear ethylene polymer is HDPE, having a MI value within the range between 0.1 and 25 grams/10 minutes and the low molecular weight linear ethylene polymer is HDPE having a MI value within the

30 range between 25 and 300 grams/10 minutes.

28. The blend of Claim 25 or 26 wherein the high molecular weight linear ethylene polymer is HDPE, having a MI value within the range between 0.1 and 25 -jj- grams/10 minutes and the low molecular weight linear ethylene polymer is HDPE having a MI v&lue within the range between 25 and 300 grams/10 minutes.

AMENDED CLAIMS
[received by the International Bureau
on 5 April 1991 (05.04.91);
original claims 7 and 28 amended;
new claims 29-34 added; other claims unchanged (3 pages)]

I10 is determined by ASTM D-1238(N) conditions, and 12 is determined by ASTM D-1238(E) conditions.

3. The process of Claims 1 or 2 wherein an
unbonded fabric prepared thereby is capable of being
thermally bonded to give a stronger fabric, as
determined by normalized strip tensile strength, over a broader range of thermal bonding temperatures, than an otherwise identical process used to prepare a
comparative product wherein the polymer blend in the

10 staple fibers in the comparative product has either a Q value in a range of from 3.5 to 4.0 or an I10 I2 value in a range from 6.0 to 6.5.

4. The process of Claim 1 wherein the
15 polymeric blend in the staple fibers has a Q value in a range from 5.5 to 10.

5. The process of Claim 2 wherein the
polymeric blend in the staple fibers has an Iιo/l2 value

20 in the range from 10 to 20.

6. Thermally bonded fabric prepared by the
process of Claims 1 or 2, wherein the thermally bonded fabric has a normalized strip tensile strength of at

2E least 3»000 grams.

7. The thermally bonded fabric of Claim 6
wherein the polymeric blend is an in-situ blend formed during polymerization of *tlϊe' olymer'; and the thermally

3Q bonded fabric has a normalized strip tensile strength of at least 3»6Q0 grams.

O

21. The blend of Claim 20 wherein the ratio of the high molecular weight linear ethylene polymer and low molecular weight linear ethylene polymer is
sufficient to provide a blend having a MI value in the range of 0.1 to 40 grams/10 minutes and a density in the range of 0.94 to 0.96 grams/cm^.

22. The blend of Claim 20 wherein at least one of the linear ethylene polymers comprises a copolymer of ethylene with at least one C3-C12 olefin.

23. The blend of Claim 22 wherein at least one of the linear ethylene polymers is a copolymer of ethylene and propylene or octene.

24. The blend of Claim 23 wherein at least one of the linear ethylene polymers is LLDPE.

25. The blend of Claim 20 wherein the blend is a blend of discrete polymers.

26. The blend of Claim 20 wherein the blend is an in-situ reactor blend formed during polymerization.

27. The blend of Claim 25 or 26 wherein the high molecular weight linear ethylene polymer is HDPE, having a MI value within the range between 0.1 and 25 grams/10 minutes and the low molecular weight linear ethylene polymer is HDPE having a MI value within the range between 25 and 300 grams/10 minutes.

28. The blend of Claim 25 or 26 wherein the high molecular weight linear ethylene polymer is LLDPE, having a MI value within the range between 0.1 and 25 grams/10 minutes and the low molecular weight linear ethylene polymer is HDPE having a MI value within the range between 25 and 300 grams/10 minutes.

29. A method of increasing the thermal bonding window of staple fibers made from linear polyethylene, characterized by blending high and low molecular weight linear polyethylenes, spinning into staple fiber and thermally bonding into fabric.

30. The method of Claim 29 wherein the high and low molecular weight linear polyethylene blend has a Ilθ/l2 value above 7.

31. The method of Claim 29 wherein the staple fiber has a thermal bonding window of 10°C.

32. The method of Claim 29 wherein the staple fiber has an average denier per filament in a range from 1 to 15 denier per filament.

33- The method of Claim 29 wherein the high molecular weight linear polyethylene is HDPE and the low molecular weight linear polyethylene is HDPE.

34. The method of Claim 33 further
characterized by carding the staple fiber into fabric before thermal bonding.

STATEMENT UNDER ARTICLE 19(1)

In response to the Transmittal of the International Search Report mailed on 06 February 1991, please add Claims 29-34 and amend Claims 7 and 28 as the enclosed full page replacements (in triplicate) describe.

The amendment to Claim 7 deleting the language "staple fibers comprise a polymeric" corrects
transcription errors recorded while drafting the
application. This correction is supported throughout the disclosure, but is particularly well supported on page 10, lines 9-19 and in Examples V and VI on page 23.

The amendment to Claim 28 deleting the term "HDPE" and replacing with the term "LLDPE" corrects an error discovered by Examiner during the International Search. The amendment to Claim 28 is supported in the
disclosure, for example, on page 15, lines 7-9 and demonstrated in Examples I, IX and X on pages 19, 26 and 27, respectively.

New Claim 29 is supported in the disclosure on page 7, line 30 through page 8, line 3, as well as in the Examples of the invention (such as Example VI as
contrasted with Comparative Example VII, pp. 23-25).

New dependent Claims 30 and 31 are supported in the disclosure on page 12, lines 11-25.

New dependent Claims 32 is supported in the
disclosure on page 8, lines 6-7.

New dependent Claims 33 and 34 are supported in the disclosure on page 30, line 13 through page 31, line 2.

Applicants believe that the new Claims are fully supported by the disclosure and respectfully request that these Claims be added to the above identified application.