Claims
- 1. Yarns comprising fine polyester filaments of denier per filament (dpf) in the range 0.2 to 0.8, said polyester having a relative viscosity (LRV) in the range 13 to 23, a zero-shear polymer melting point (T.sub.M.sup.o) in the range 240.degree. C. to 265.degree. C., and a glass transition temperature (T.sub.g) in the range 40.degree. C. to 80.degree. C.; and said yarns having the following characteristics:
- (a) tenacity-at-7%-elongation (T.sub.7) in the range 0.5 to 1.75 gpd, such that the [(T.sub.B).sub.n /(T.sub.7)]-ratio is at least [5/(T.sub.7)], wherein (T.sub.B).sub.n is normalized tenacity-at-break;
- (b) elongation-at-break (E.sub.B) in the range 40% to 160%;
- (c) boil-off shrinkage (S) less than the maximum shrinkage potential (S.sub.m), wherein Sm=[(550-E.sub.B)/6.5]%;
- (d) maximum shrinkage tension (ST.sub.max) in the range 0.05 to 0.2 gpd, with a peak temperature T(ST.sub.max) in the range 5.degree. C. to 30.degree. C. above the glass-transition temperature (T.sub.g)
- (e) an average along-end filament denier spread (DS) of no more than 4%.
- 2. Yarns according to claim 1, wherein the boil-off shrinkage (S) is at least 12%, the elongation-at-break (E.sub.B) is in the range 80% to 160%, and the tenacity-at-7%-elongation (T.sub.7) is in the range 0.5 to 1 gpd.
- 3. Yarns according to claim 1, wherein said polyester filaments have a shrinkage differential (.DELTA.S=DHS-S) no more than +2%, and each of the boil-off shrinkage (S) and the dry heat shrinkage (DHS) is in the range 2% to 12%, and are such that the filament denier, after shrinkage, is no more than 1; and wherein the tenacity-at-7%-elongation (T.sub.7) is in the range 1 to 1.75 gpd, and the elongation-at-break (E.sub.B) is in the range 40% to 90%, and a post-yield modulus (M.sub.py) in the range 2 to 12 gpd.
- 4. Yarns according to claim 1 having the capability of being uniformly cold drawn, wherein said polyester filaments have a shrinkage differential (.DELTA.S=DHS-S) no more than +2%, and each of the boil-off shrinkage (S) and the dry heat shrinkage (DHS) is in the range 2% to 12%, and having a temperature of onset of cold crystallization T.sub.c (DSC) of no more than 105.degree. C. and an instantaneous tensile modulus at least 0.
- 5. Yarns comprising fine polyester filaments of denier per filament (dpf) after boil-off shrinkage in the range 0.2 to 0.8 dpf, said polyester having a relative viscosity (LRV) in the range 13 to 23, a zero-shear polymer melting point (T.sub.M.sup.o) in the range 240.degree. C. to 265.degree. C., and a glass-transition temperature (T.sub.g) in the range 40.degree. C. to 80.degree. C.; and said yarns having the following characteristics:
- (i) boil-off shrinkage (S) and dry heat shrinkage (DHS) in the range of 2% to 12%;
- (ii) Tenacity-at-7%-elongation (T.sub.7) at least 1 gpd, such that the [(T.sub.B)n/(T.sub.7)]-ratio is at least [5/(T.sub.7)], wherein (T.sub.B)n is normalized tenacity-at-break, and elongation-at-break (E.sub.B) in the range 15% to 55%;
- (iii) post-yield modulus (M.sub.py) in the range 5 to 25 gpd;
- (iv) an average along-end filament denier spread (DS) no more than 4%.
- 6. Yarns comprising fine polyester filaments of denier per filament (dpf) in the range 0.2 to 0.8 dpf, after boil-off shrinkage, said polyester having a relative viscosity (LRV) in the range 13 to 23, a zero-shear polymer melting point (T.sub.M.sup.o) in the range 240.degree. C. to 265.degree. C., and a glass-transition temperature (T.sub.g) in the range 40.degree. C. to 80.degree. C.; said yarns being bulky and having the following characteristics:
- (i) boil-off shrinkage (S) and dry heat shrinkage (DHS) in the range of 2% to 12%;
- (ii) tenacity-at-7%-elongation (T.sub.7) greater than 1 gpd, E.sub.B in the range 15% to 55% and post-yield modulus (M.sub.py) in the range 5 to 25 gpd.
- 7. Yarns according to claim 5 or 6, wherein said polyester filaments have a dynamic loss modulus peak temperature T(E".sub.max) of no more than 115.degree. C.
- 8. Yarns according to any one of claim 1, 5 or 6, wherein said polyester filaments have a relative disperse dye rate (RDDR) of at least 0.1.
- 9. Yarns according to any one of claims 1, 5 or 6, wherein said polyester filaments have a shape factor (SF) of at least 1.25.
- 10. Yarns according to claim 1 or 5, wherein said polyester filaments have an average along-end denier spread (DS) of no more than 2%.
- 11. Yarns according to any one of claims 1, 5 or 6, wherein said polyester contains in the range of 1 to 3 mole % of ethylene-M-sulfo-isophthalate structural units, wherein M is an alkali metal cation.
- 12. Yarns according to any one of claims 1, 5 or 6, wherein said polyester is essentially poly(ethylene terephthalate), composed of first alternating glycol structural units A, [--O--C.sub.2 H.sub.4 --O--], and di-carboxylate structural units B, [--C(O)--C.sub.6 H.sub.4 --C(O)--], modified with minor amounts of other structural units selected from the group consisting of glycol structural units A' and di-carboxylic structural units B', that differ from said first alternating glycol structural units A and di-carboxylate structural units B, such as to provide a polyester polymer with a zero-shear melting point (T.sub.M.sup.o) in the range 240.degree. C. to 265.degree. C., and a glass-transition temperature (T.sub.g) in the range 40.degree. C. to 80.degree. C.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 07/647,381 filed Jan. 29, 1991, now abandoned and also of application Ser. No. 07/860,776 filed Mar. 29, 1992, now abandoned as a continuation-in-part of application Ser. No. 07/647,371 filed Jan. 29, 1991, now abandoned.
US Referenced Citations (13)
Related Publications (1)
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Number |
Date |
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860776 |
Mar 1992 |
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Continuation in Parts (2)
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Number |
Date |
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647381 |
Jan 1991 |
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Parent |
647371 |
Jan 1991 |
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