CA1280266C - Water-dispersible synthetic fiber - Google Patents
Water-dispersible synthetic fiberInfo
- Publication number
- CA1280266C CA1280266C CA000506113A CA506113A CA1280266C CA 1280266 C CA1280266 C CA 1280266C CA 000506113 A CA000506113 A CA 000506113A CA 506113 A CA506113 A CA 506113A CA 1280266 C CA1280266 C CA 1280266C
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- Canada
- Prior art keywords
- fiber
- water
- filaments
- dispersible
- polyester
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- D—TEXTILES; PAPER
- D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
- D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
- D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
- D21H13/10—Organic non-cellulose fibres
- D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- D21H13/24—Polyesters
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Mechanical Engineering (AREA)
- Textile Engineering (AREA)
- Artificial Filaments (AREA)
- Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
ABSTRACT
Water-dispersible polyester fiber of cruciform cross-section to promote dispersibility, and so better uniformity, more opacity, good permeability and an attractive flannel-like hand to the resulting wet-laid fabrics.
Water-dispersible polyester fiber of cruciform cross-section to promote dispersibility, and so better uniformity, more opacity, good permeability and an attractive flannel-like hand to the resulting wet-laid fabrics.
Description
12~30216~i TITLE
NEW WATER-DISPERSIBLE SYNTHETIC FIBER
TECHNICAL FIELD
5~hi invention concerns new water-disper~ible synthetic polymer fiber, particularly of poly(ethylene terephthalate), and its preparation.
9AC~GROUND OF INVENTION
There has been increased ;nterest in recent years 10 in water-di6persible synthetic fiber, e~pecially of polyester. Such water-di~persible fiber i~ used in various non-woven applications, including paper-making and wet-laid non-woven fabrics, so~etimes as part of a blend, often with large amounts of wood pulp, or fiberglas~, but 15 also in applications requiring only polyester fiber, i.e., unblended with other fiber. This use, and the requirements therefor, are entirely different from previous more conventional use as tow or ætaple fiber for conver~ion into tsxtile yarns for eventual use in woven or 20 knitted fabrics, because of the need to di~perse this fiber in water instead of to convert the fiber into y~rns, e.g., by processes such as carding, e.y. in the cotton 6ystem. It i6 this requirement for water-dispersibility that distinguishe~ the field of the invention from 25 previous, more conventional polyester staple fiber.
~ ost ~uch water-dispersible polye~ter fiber i6 of poly(ethylene terephthalate), and i~ prepared in essentially the ~ame general way as conventional textile polye~ter staple fiber, except that most water-dispersible 30 polyester fiber is not crimped, whereas any polyester staple fiber for use in textile yarns is generally crimped while in the form of tow, before conversion into staple -2- 12 ~ 66 fiber. ~hu~, waterdi6persible polyester fiber has generally been prepared by melt-spinning the polyester into filaments, combining the filaments to form a tow, drawing, applying a suitable coating to impart 5 water-dispersible properties, generally in the ~ame way as ¦ a fini~h is applied to a tow of conventional textile ! filaments, and then, generally without any crimpin~ (or with imparting only soms mild wavy undulations in ~ome ca~es to provide extra bulk and a three-dimen~ional 10 matrix), converting the tow into staple. Some prior polyester staple fiber has been prepared in uncrimped form, e.g. for use as flock in pile fabrics, but for such use, water-dispersibility has not been required.
Polyester fibers are naturally hydrophobic, so it 5 i5 necessary to apply to the polye~ter a euitable coating, a~ disclosed by Ring et al. in U.S. Patent No. 4,007,083, ~awkins in U.S. Patent No~. 4,137,181, 4,179,543 and 4,294,883, and Viscose Suisse in British Patent No.
958,350, to overcome the inherent hydrophobic character of 20 the polyester fiber without creating foam or causing the fibers to flocculate. It is this coating that has distinguished water-di~persible polyester fiber from more conventional polyester ~taple fiber, rather than any inherent characteristic feature of the polyester it~elf, 25 or of its shape, ~uch as the cross-~ection. ~eretofore, so far as i8 known, the cross-~ection of all commercial water-di~persible polye~ter fiber has been round. Indeed the cross-~ection of mo~t commercial polye~ter staple fiber has generally been round, because this has been 30 preferred.
Although, hitherto, most ~ynthetic polymeric water-dispersible fiber ha~ been formed of polyester, being inexpensive and plentiful, increasing amount~ of polyolefins and polyamides are beginning to be used for 35 water-dispersible fibers, and so the invention is not ~3~ ~ 2 80 ~ 6~
limited only to polyesters, but covers other synthetic polymers.
SUMMARY OF INVENTION
According to the present invention, there i~
provided new synthetic polymer water-dispersible fiber, especially polyester fiber, characterized in that the fibers are of cruciform cross-section.
A cruciform cross-section has been used heretofore for other polyester fiberæ, as described herein. Other than the cross-section, the water-dispersible fiber of the invention may be e sentially similar to prior water-dispersible polyester or other synthetic polymer fibers, although the advantages described hereinafter may provide the opportunity for additional modifications. The invention will be described hereinafter with ~pecial reference to polyester fiber, although it will be recognized that other synthetic polymers, such as polyamides and polyolefins, may also be used.
The fibers of the invention may be made conveniently by melt-spinning and drawing polye~ter filAments of appropriate denier per filament (dp~), and applying thereto a suitable coating to impart water-disper6ible characteristics. The filaments ~re then generally cut into staple of whatever length is desired 25 for the end-use contemplated.
The use of a cruciform cro6s-~ection for the water-dispersible fiber of the invention has, ~urprisingly, been found to promote dispersibility, in comparison with a round cross-section, and this imparts to 30 the resulting wet-laid fiber~ better uniformity, more opacity, good permeability, and an attractive flannel-like hand as will be seen in the Example.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 shows a cruciform cross-section for a 35 stylized fiber according to the invention.
~2~0Z6~
Figure 2 shows a typical spinneret orifice for spinning fil~ments of the invention.
DISCLOSURE OF THE INVENTION
As indicated above, a cruciform cro~ ection has already been used for more conventional polyester staple fiber, that has been spun into filaments and drawn, cut, converted into spun yarn, and used in woven or knitted fabrics. Such fiber had the water-dispersible characteristics required for this invention. Similarly, 10 polyester filaments having a cruciform cross-~ection are alread~ known from Lehmicke U.S. Pat. No. 2,945,739, which discloses a process for melt-spinning polyamide and polyester filaments of, inter alia cruciform cross-6ection, and woven and knitted fabrics from staple 15 fibers, and from Jamisson U.S. Pat. No. 3,249,669, which discloses a process for making a multifilament yarn of polyester filament6 of various cro6s-sections, including a cruciform cross-section. Oriented polyester filaments o non-round cross-section have also been described by 20 Frankfort et al. in U. S. Pat. Nos. 4,134,882 and 4,195,051, having been prepared by spinning at a very high speed (6,000 ypm), which high speed could al60 be used to prepare oriented polyester filaments of cruciform cross-section as a substrate for applying thereto a uitable coating to impart water-di~persible characteristics, ~nd thereby obtaln water-dispersible fiber according to the invsntion. None of this art concerns the field of the present invention. ~owever, the polye6ter filamentary ~ubstrates for making the 30 water-di8persible fiber of the invention may be prepared by the techniques described therein, or by appropriate modifications of these or other known techniques of making polyester filament~ of non-round cross-section.
The prior art references disclose parameters for a 35 cruciform cross-~ection and Figure 1 is essentially as shown therein.
_5_ 12~Z6~
Th6 preparatlon of the polye~ter ~taplæ Xiber otherwi~e conventlonal, involving th~ 6tep~ of melt-splnning polymer into filament~, collecting the filaments ~nto a tow, drawinq the tow, ~nd ~pplying a ~uitable coating water-dispersible to impart characteri~tic~. If low ~hrinkage i~ de~ired, the drdwn ~ilament~ are ~enerally annealed.
Selection of ~n appropriate coating to promote w~ter-di~persibility i~ lmportant, and more of ~ueh coating i6 generally required than for compar~ble weight~
of ~iber of round cros6-æectio:n o~ lar dpf, because of the larger 6urface area of the periphery of the cruciform cross-~ection. It i~ especially important to provide qood boundary lubrication properties. For thi6 re~60n, an 15 ethoxylated coa~ing i~ preferred.
Suitable coating~ are disclo6ed ~n ~awkln6, V. S.
Pat. No~. 4,13~ ,179,543 and 4,294,883 disclosLng ~ use of . _ .a syn~hetic copolyester.. o~ poly(ethylene terephthalate) unit6 and poly(oxyalkylene) of groups derived from a 20 poly(oxyalkylene~ glycol having an average molecul~r weight in the ranqe of 300 to 6,000, ~ di~clo6ed, e.g. in McIntyre, ~t al. V.S. Pat. No6. 3,416,952, 3,557,039 and 3,619,269, referred to there$n; other u6eful ~egmented copolye~ter6 ar~ disclosed ln Raynolds U.S. Patent No.
25 3,981,807; all the~e disclosures are lncorpor~t~d her~ln --by reference.
Such polyester fiber i~ generally prepared f$r~t in the ~orm of ~ continuous filamentary uncrimped tow or, if extra bul~ i6 required, and a more three-dimen6ional 30 matrix, the filament~ may be provided with mild wave-like undulations by a mild crimping-type proce~s, and the uncrimped or ~ildly wave-like filament6 are cut t~ the desired cut len~th, $.e. to form the water-dlspersible ` -6- 1~8~6~
fiber, which is generally ~old in the ~orm of bales, or other packages of cut fiber. Suitable cut lengths are generally from about 5 to about 90 mm tl/4 to 3 inches), generally up to 60 mm (2-1/2 inches), and of length/diameter (L/D) ratio from about 100:1 to about 2000:1, preferably about 150:1 to about 2000:1, it being an advantage of the invention that good performance has been obtainable with preferred water-dispersible fiber of the invention with ~n L/D ratio higher than we h~ve ¦ 10 considered satisfactory with prior art water-dispersible polyester fiber. For instance, machine manufacturers have generally recommended that the L/D ratio not exceed 500:1, and many operators have considered even this figure unrealistically high. A suitable denier per filament is generally from ~bout 0.5 to about 20. The coating i~
generally present in amount about 0.04 to about 1.0~ of the weight of fiber (OWF~), it being an advantage that smaller amounts may generally be used than we have i considered satisfactory according to the prior art.
There is al60 provided ~ process for preparing such water-dispersible polyester fiber, comprising the steps of melt-spinning the polyester into filaments of cruciform oros~-section, forming a tow of such filaments, drawinq, and then coating the filaments in the tow with 25 ~uch synthet~c copolyester, and, at an appropr~ate time, converting 6uch coated filaments into staple fiber.
The coatIng is preferably cured on the filaments by heating the coated filaments, or the resulting staple fiber, if desired, to a temperature of about 100 to about 30 190 to improve durability.
The invention is further illustrated in the ~ollowing Example, in which all parts and percentages are by weiqht, unless otherwi~e indicated, and OWF is tsolids) "of weight of fiber". Reference is made to several 35 measurements of yarn properties, such as tensile ~7~ ~2~6~
properties (tenacity and elongation-to break), which are measured according to the methods described in Frankfort et al. U.S. Patent No. 4,134,882. It will be understood that other conditions can be used e.q., other designs of orifice, 6uch as are shown in the art.
Example The following fiber&, Fiber A, a compari~on of round cross section, and Fiber N, a fiber of the invention of cruciform cros~ section, were both spun from 10 poly(ethylene t~rephthalate) of intrinsic viscosity 0.64, containing 0.3% Tio2 as a delusterant.
Fiber A was spun at 1600 ypm into filaments with conventional radial air quenchinq using a 900 hole ~pinneret, with round holes 0.015 inche~ in diameter ~nd 15 capillary length of 0.030 inches, a 270C block, and polymer throughput 68.2 pounds/hour. Denier per filament was 3.67. Fiber A was then oriented by running over a set of feed rool~ at 29.3 ypm, followed by a set of draw roll~
at 80.0 ypm, and delivered to a conveyer by puller rolls 20 at 80.1 ypm. Between feed roll sections the filaments were treated in a 45C water bath. Between feed and draw rolls the rope w~s sprayed with water at 9BC. Between draw ~nd puller roll~ a commercial water-dispersible coating (50/50 mixture of pota~ium ~alt of mono and 25 diacid phosphate ~sters of lauryl alcohol/tallow alcohol ethoxylated with 25 ~ole~ of ethylene oxide) was applied.
The filaments were then relaxed free in ~n oven at 150C
for 6 minutes.
Fiber N was produced in a similar manner to Fiber 30 A excep~ that 625 filaments of 3.22 dpf and cruciform cro~6-section were ~pun through capillaries as shown in Figure 2, with block temperature 273C, and throughput 42.9 pound6/hour. -Roll 6peeds for the orientation were feed roll~ 32.1 ypm, draw rolls 80.2 ypm and puller rolls 3579.2 ypm, and a somewhat higher level of water-dispersible -8- ~ ~8~Z6~
coating wa~ used to offset approximately 57% higher surface area of the cruciform cross-section.
The properties of the drawn coated filaments are compared in Table 1.
Ta'ole_1 Sample A N
Cross-section Round cruciform dpf 1.47 1.5 coating OWF(~) 0.4 0.44 Boil-off shrinkage(%) 1.0 0 Dry heat shrinkaye (196C) (~) 2.45 3.6 Tenacity at break (g/d) 4.5 4.8 Elongation at break(%) 42 26 Tenacity at 2% elonyation(g/d) 0.93 0.93 ~oth types were cut to form water-di6persible i fiber of 1/4, 3/8, 1/2 and 3/4 inch cut lengths and were tested on an inclined wire Fourdrinier machine. Fibers were dispersed for three minutes in a s~all pulper at 0.75% consifitency (lbs. fiber per 100 lbs. slurry, or furni~h). The cylindrical nulper wa~ approximately 3 feet in dii~,meter by 6 feet deep. Fibers were then mixed with unrefined sulphite pulp to form a 50% polye,ter blend and diluted to 0.1~ consistency in a 10 cubic meter stock tank. This stock was further diluted in the headbox of -the machine to 0.0143% consistency and ~ormed into ia 0.5 meter wide wet lay nonwoven fabric at 20 ~eters/minute. A
~priay of an acrylic binder, Acronyl 240D was spray applied at the end of the Fourdrinier wire. The fabric was then cured in a through air drier at 150C. Finished fabric weight averaged 40 grams/square meter.
Dispersion quality can be judged by the uniformity of the fabric produced from ia given sample. As cut length increases, the uniformity of the fabric can generally be -9- ~28~ 6 expected to suffer significantly. However, great advantages can result from using a longer fiber because the fabric tear strength increases, for example. In practice, therefore, a fabric producer will generally wish 5 to use the longe~t fiber that will meet his uniformity standards. Thus, a longer fiber with improved, or equivalent uniformity would be preferred.
The di6persion quality of fabrics from Fiber6 A
and N were rated as they were produced on the machine by 10 observing the fabrics as the water drained from them on the Fourdrinier wire6. Results of this comparison ~re in Table 2 and indicate good disper6ion for the cruciform in spite of its 57% greater surface area.
DISPERSION DESCRIPTION
ROUND CRUCIFORM
cu'r LENGTH I TEM A ITEM N
1/4 inch good dispersion good dispersion few log defects few log defects 3/8 inch some log defects good dispersion general quality not fair fabric cover 80 good as 1/4 inch (opacity) 1/2 inch fairly good dispersion normal dispersion 25 3/4 inch di6percion definitely very good di6persion poor, cover lower Standard physical propertie6 were mea,~ured for the set of fabrics at Herty Foundation, Savannah, GA.
Compared each time to Fiber A as 100%, Fiber N had the 30 following average properties:
-1 o ~28026~
Air Permeability, Gurley 112%
Opacity, ISO 2471 111%
Bulk, TAPPI T410 om-83 and T411 om-83 118%
Tensile Strength, TAPPI T494 om-81 100%
5 Tensile Stretch, TAPPI T49~ om-81 B5 Tear Strength, TAPPI T414 om-82 104~
On balance, Item N exhibi~ed advantaye6 in the important ~reas of higher permeability, opacity, bulk and 10 tear ~trength compared to the control at equivalent ten~ile strength with a small reduction in ~tretch. The cover advantage is important because less fiber can be used for a nonwoven fabric with similar performance characteri6tics, thereby saving material6 cost. The ~ 15 fabrics of Item N also have an attractive flannel-like ? hand.
j When used with the appropriate water-disper6ible coating in appropriate amount, the cruciform cross-section fiber of the invention has given a fabric with 20 6urprisingly good dispersion uniformity, and the properties indicated.
; From theoretical con6iderations, water-dispersible fibers of conventional round cross-6ection would have been expected to give more uniform disper6ion6, and, therefore, ~5 more uniform wet-l~id fabrics. Thi6 ~s bec~use the surface energy requlred to disper~e a fiber (or other article~) is given by:
Ener~y ~ (Surface Tension) X (Dispersed ~urface area -Undisper~ed surface area).
The undispersed fiber exists in logs or clumps of many hundreds of fibers, most of which are on the inside of the logs. Therefore the undi6persed surfa~e area is ~ negligible compared to the dispersed area, and the energy term can be expressed approximately as:
128 [)~66 Energy ~ (Surface Ten6ion~ X (Number of fibers) X
(Surface area of a fiber).
This energy term describes both the energy required to disperse the fiber, and the free energy 5 driving force for reagglomeration. Therefore, for any given coating, and fiber dpf, fibers with lower area would be expected to provide a more uniform dispersion, hence more uniform fabric. Ths minimum surface area per unit weight for a given fiber occurs when the cross-6ection is round, which would be expected, therefore, to be preferred.
¦ Surprisingly, however, these cruciform fibers, in spite of about 60% greater surface area gave more uniform fabrics. Without limiting the invention to any theory, th~ may result from the fiber'~ hydrodynamic shape, which may more effectively use the energy available in the mixer shear field.
.
.
NEW WATER-DISPERSIBLE SYNTHETIC FIBER
TECHNICAL FIELD
5~hi invention concerns new water-disper~ible synthetic polymer fiber, particularly of poly(ethylene terephthalate), and its preparation.
9AC~GROUND OF INVENTION
There has been increased ;nterest in recent years 10 in water-di6persible synthetic fiber, e~pecially of polyester. Such water-di~persible fiber i~ used in various non-woven applications, including paper-making and wet-laid non-woven fabrics, so~etimes as part of a blend, often with large amounts of wood pulp, or fiberglas~, but 15 also in applications requiring only polyester fiber, i.e., unblended with other fiber. This use, and the requirements therefor, are entirely different from previous more conventional use as tow or ætaple fiber for conver~ion into tsxtile yarns for eventual use in woven or 20 knitted fabrics, because of the need to di~perse this fiber in water instead of to convert the fiber into y~rns, e.g., by processes such as carding, e.y. in the cotton 6ystem. It i6 this requirement for water-dispersibility that distinguishe~ the field of the invention from 25 previous, more conventional polyester staple fiber.
~ ost ~uch water-dispersible polye~ter fiber i6 of poly(ethylene terephthalate), and i~ prepared in essentially the ~ame general way as conventional textile polye~ter staple fiber, except that most water-dispersible 30 polyester fiber is not crimped, whereas any polyester staple fiber for use in textile yarns is generally crimped while in the form of tow, before conversion into staple -2- 12 ~ 66 fiber. ~hu~, waterdi6persible polyester fiber has generally been prepared by melt-spinning the polyester into filaments, combining the filaments to form a tow, drawing, applying a suitable coating to impart 5 water-dispersible properties, generally in the ~ame way as ¦ a fini~h is applied to a tow of conventional textile ! filaments, and then, generally without any crimpin~ (or with imparting only soms mild wavy undulations in ~ome ca~es to provide extra bulk and a three-dimen~ional 10 matrix), converting the tow into staple. Some prior polyester staple fiber has been prepared in uncrimped form, e.g. for use as flock in pile fabrics, but for such use, water-dispersibility has not been required.
Polyester fibers are naturally hydrophobic, so it 5 i5 necessary to apply to the polye~ter a euitable coating, a~ disclosed by Ring et al. in U.S. Patent No. 4,007,083, ~awkins in U.S. Patent No~. 4,137,181, 4,179,543 and 4,294,883, and Viscose Suisse in British Patent No.
958,350, to overcome the inherent hydrophobic character of 20 the polyester fiber without creating foam or causing the fibers to flocculate. It is this coating that has distinguished water-di~persible polyester fiber from more conventional polyester ~taple fiber, rather than any inherent characteristic feature of the polyester it~elf, 25 or of its shape, ~uch as the cross-~ection. ~eretofore, so far as i8 known, the cross-~ection of all commercial water-di~persible polye~ter fiber has been round. Indeed the cross-~ection of mo~t commercial polye~ter staple fiber has generally been round, because this has been 30 preferred.
Although, hitherto, most ~ynthetic polymeric water-dispersible fiber ha~ been formed of polyester, being inexpensive and plentiful, increasing amount~ of polyolefins and polyamides are beginning to be used for 35 water-dispersible fibers, and so the invention is not ~3~ ~ 2 80 ~ 6~
limited only to polyesters, but covers other synthetic polymers.
SUMMARY OF INVENTION
According to the present invention, there i~
provided new synthetic polymer water-dispersible fiber, especially polyester fiber, characterized in that the fibers are of cruciform cross-section.
A cruciform cross-section has been used heretofore for other polyester fiberæ, as described herein. Other than the cross-section, the water-dispersible fiber of the invention may be e sentially similar to prior water-dispersible polyester or other synthetic polymer fibers, although the advantages described hereinafter may provide the opportunity for additional modifications. The invention will be described hereinafter with ~pecial reference to polyester fiber, although it will be recognized that other synthetic polymers, such as polyamides and polyolefins, may also be used.
The fibers of the invention may be made conveniently by melt-spinning and drawing polye~ter filAments of appropriate denier per filament (dp~), and applying thereto a suitable coating to impart water-disper6ible characteristics. The filaments ~re then generally cut into staple of whatever length is desired 25 for the end-use contemplated.
The use of a cruciform cro6s-~ection for the water-dispersible fiber of the invention has, ~urprisingly, been found to promote dispersibility, in comparison with a round cross-section, and this imparts to 30 the resulting wet-laid fiber~ better uniformity, more opacity, good permeability, and an attractive flannel-like hand as will be seen in the Example.
BRIEF DESCRIPTION OF DRAWINGS
Figure 1 shows a cruciform cross-section for a 35 stylized fiber according to the invention.
~2~0Z6~
Figure 2 shows a typical spinneret orifice for spinning fil~ments of the invention.
DISCLOSURE OF THE INVENTION
As indicated above, a cruciform cro~ ection has already been used for more conventional polyester staple fiber, that has been spun into filaments and drawn, cut, converted into spun yarn, and used in woven or knitted fabrics. Such fiber had the water-dispersible characteristics required for this invention. Similarly, 10 polyester filaments having a cruciform cross-~ection are alread~ known from Lehmicke U.S. Pat. No. 2,945,739, which discloses a process for melt-spinning polyamide and polyester filaments of, inter alia cruciform cross-6ection, and woven and knitted fabrics from staple 15 fibers, and from Jamisson U.S. Pat. No. 3,249,669, which discloses a process for making a multifilament yarn of polyester filament6 of various cro6s-sections, including a cruciform cross-section. Oriented polyester filaments o non-round cross-section have also been described by 20 Frankfort et al. in U. S. Pat. Nos. 4,134,882 and 4,195,051, having been prepared by spinning at a very high speed (6,000 ypm), which high speed could al60 be used to prepare oriented polyester filaments of cruciform cross-section as a substrate for applying thereto a uitable coating to impart water-di~persible characteristics, ~nd thereby obtaln water-dispersible fiber according to the invsntion. None of this art concerns the field of the present invention. ~owever, the polye6ter filamentary ~ubstrates for making the 30 water-di8persible fiber of the invention may be prepared by the techniques described therein, or by appropriate modifications of these or other known techniques of making polyester filament~ of non-round cross-section.
The prior art references disclose parameters for a 35 cruciform cross-~ection and Figure 1 is essentially as shown therein.
_5_ 12~Z6~
Th6 preparatlon of the polye~ter ~taplæ Xiber otherwi~e conventlonal, involving th~ 6tep~ of melt-splnning polymer into filament~, collecting the filaments ~nto a tow, drawinq the tow, ~nd ~pplying a ~uitable coating water-dispersible to impart characteri~tic~. If low ~hrinkage i~ de~ired, the drdwn ~ilament~ are ~enerally annealed.
Selection of ~n appropriate coating to promote w~ter-di~persibility i~ lmportant, and more of ~ueh coating i6 generally required than for compar~ble weight~
of ~iber of round cros6-æectio:n o~ lar dpf, because of the larger 6urface area of the periphery of the cruciform cross-~ection. It i~ especially important to provide qood boundary lubrication properties. For thi6 re~60n, an 15 ethoxylated coa~ing i~ preferred.
Suitable coating~ are disclo6ed ~n ~awkln6, V. S.
Pat. No~. 4,13~ ,179,543 and 4,294,883 disclosLng ~ use of . _ .a syn~hetic copolyester.. o~ poly(ethylene terephthalate) unit6 and poly(oxyalkylene) of groups derived from a 20 poly(oxyalkylene~ glycol having an average molecul~r weight in the ranqe of 300 to 6,000, ~ di~clo6ed, e.g. in McIntyre, ~t al. V.S. Pat. No6. 3,416,952, 3,557,039 and 3,619,269, referred to there$n; other u6eful ~egmented copolye~ter6 ar~ disclosed ln Raynolds U.S. Patent No.
25 3,981,807; all the~e disclosures are lncorpor~t~d her~ln --by reference.
Such polyester fiber i~ generally prepared f$r~t in the ~orm of ~ continuous filamentary uncrimped tow or, if extra bul~ i6 required, and a more three-dimen6ional 30 matrix, the filament~ may be provided with mild wave-like undulations by a mild crimping-type proce~s, and the uncrimped or ~ildly wave-like filament6 are cut t~ the desired cut len~th, $.e. to form the water-dlspersible ` -6- 1~8~6~
fiber, which is generally ~old in the ~orm of bales, or other packages of cut fiber. Suitable cut lengths are generally from about 5 to about 90 mm tl/4 to 3 inches), generally up to 60 mm (2-1/2 inches), and of length/diameter (L/D) ratio from about 100:1 to about 2000:1, preferably about 150:1 to about 2000:1, it being an advantage of the invention that good performance has been obtainable with preferred water-dispersible fiber of the invention with ~n L/D ratio higher than we h~ve ¦ 10 considered satisfactory with prior art water-dispersible polyester fiber. For instance, machine manufacturers have generally recommended that the L/D ratio not exceed 500:1, and many operators have considered even this figure unrealistically high. A suitable denier per filament is generally from ~bout 0.5 to about 20. The coating i~
generally present in amount about 0.04 to about 1.0~ of the weight of fiber (OWF~), it being an advantage that smaller amounts may generally be used than we have i considered satisfactory according to the prior art.
There is al60 provided ~ process for preparing such water-dispersible polyester fiber, comprising the steps of melt-spinning the polyester into filaments of cruciform oros~-section, forming a tow of such filaments, drawinq, and then coating the filaments in the tow with 25 ~uch synthet~c copolyester, and, at an appropr~ate time, converting 6uch coated filaments into staple fiber.
The coatIng is preferably cured on the filaments by heating the coated filaments, or the resulting staple fiber, if desired, to a temperature of about 100 to about 30 190 to improve durability.
The invention is further illustrated in the ~ollowing Example, in which all parts and percentages are by weiqht, unless otherwi~e indicated, and OWF is tsolids) "of weight of fiber". Reference is made to several 35 measurements of yarn properties, such as tensile ~7~ ~2~6~
properties (tenacity and elongation-to break), which are measured according to the methods described in Frankfort et al. U.S. Patent No. 4,134,882. It will be understood that other conditions can be used e.q., other designs of orifice, 6uch as are shown in the art.
Example The following fiber&, Fiber A, a compari~on of round cross section, and Fiber N, a fiber of the invention of cruciform cros~ section, were both spun from 10 poly(ethylene t~rephthalate) of intrinsic viscosity 0.64, containing 0.3% Tio2 as a delusterant.
Fiber A was spun at 1600 ypm into filaments with conventional radial air quenchinq using a 900 hole ~pinneret, with round holes 0.015 inche~ in diameter ~nd 15 capillary length of 0.030 inches, a 270C block, and polymer throughput 68.2 pounds/hour. Denier per filament was 3.67. Fiber A was then oriented by running over a set of feed rool~ at 29.3 ypm, followed by a set of draw roll~
at 80.0 ypm, and delivered to a conveyer by puller rolls 20 at 80.1 ypm. Between feed roll sections the filaments were treated in a 45C water bath. Between feed and draw rolls the rope w~s sprayed with water at 9BC. Between draw ~nd puller roll~ a commercial water-dispersible coating (50/50 mixture of pota~ium ~alt of mono and 25 diacid phosphate ~sters of lauryl alcohol/tallow alcohol ethoxylated with 25 ~ole~ of ethylene oxide) was applied.
The filaments were then relaxed free in ~n oven at 150C
for 6 minutes.
Fiber N was produced in a similar manner to Fiber 30 A excep~ that 625 filaments of 3.22 dpf and cruciform cro~6-section were ~pun through capillaries as shown in Figure 2, with block temperature 273C, and throughput 42.9 pound6/hour. -Roll 6peeds for the orientation were feed roll~ 32.1 ypm, draw rolls 80.2 ypm and puller rolls 3579.2 ypm, and a somewhat higher level of water-dispersible -8- ~ ~8~Z6~
coating wa~ used to offset approximately 57% higher surface area of the cruciform cross-section.
The properties of the drawn coated filaments are compared in Table 1.
Ta'ole_1 Sample A N
Cross-section Round cruciform dpf 1.47 1.5 coating OWF(~) 0.4 0.44 Boil-off shrinkage(%) 1.0 0 Dry heat shrinkaye (196C) (~) 2.45 3.6 Tenacity at break (g/d) 4.5 4.8 Elongation at break(%) 42 26 Tenacity at 2% elonyation(g/d) 0.93 0.93 ~oth types were cut to form water-di6persible i fiber of 1/4, 3/8, 1/2 and 3/4 inch cut lengths and were tested on an inclined wire Fourdrinier machine. Fibers were dispersed for three minutes in a s~all pulper at 0.75% consifitency (lbs. fiber per 100 lbs. slurry, or furni~h). The cylindrical nulper wa~ approximately 3 feet in dii~,meter by 6 feet deep. Fibers were then mixed with unrefined sulphite pulp to form a 50% polye,ter blend and diluted to 0.1~ consistency in a 10 cubic meter stock tank. This stock was further diluted in the headbox of -the machine to 0.0143% consistency and ~ormed into ia 0.5 meter wide wet lay nonwoven fabric at 20 ~eters/minute. A
~priay of an acrylic binder, Acronyl 240D was spray applied at the end of the Fourdrinier wire. The fabric was then cured in a through air drier at 150C. Finished fabric weight averaged 40 grams/square meter.
Dispersion quality can be judged by the uniformity of the fabric produced from ia given sample. As cut length increases, the uniformity of the fabric can generally be -9- ~28~ 6 expected to suffer significantly. However, great advantages can result from using a longer fiber because the fabric tear strength increases, for example. In practice, therefore, a fabric producer will generally wish 5 to use the longe~t fiber that will meet his uniformity standards. Thus, a longer fiber with improved, or equivalent uniformity would be preferred.
The di6persion quality of fabrics from Fiber6 A
and N were rated as they were produced on the machine by 10 observing the fabrics as the water drained from them on the Fourdrinier wire6. Results of this comparison ~re in Table 2 and indicate good disper6ion for the cruciform in spite of its 57% greater surface area.
DISPERSION DESCRIPTION
ROUND CRUCIFORM
cu'r LENGTH I TEM A ITEM N
1/4 inch good dispersion good dispersion few log defects few log defects 3/8 inch some log defects good dispersion general quality not fair fabric cover 80 good as 1/4 inch (opacity) 1/2 inch fairly good dispersion normal dispersion 25 3/4 inch di6percion definitely very good di6persion poor, cover lower Standard physical propertie6 were mea,~ured for the set of fabrics at Herty Foundation, Savannah, GA.
Compared each time to Fiber A as 100%, Fiber N had the 30 following average properties:
-1 o ~28026~
Air Permeability, Gurley 112%
Opacity, ISO 2471 111%
Bulk, TAPPI T410 om-83 and T411 om-83 118%
Tensile Strength, TAPPI T494 om-81 100%
5 Tensile Stretch, TAPPI T49~ om-81 B5 Tear Strength, TAPPI T414 om-82 104~
On balance, Item N exhibi~ed advantaye6 in the important ~reas of higher permeability, opacity, bulk and 10 tear ~trength compared to the control at equivalent ten~ile strength with a small reduction in ~tretch. The cover advantage is important because less fiber can be used for a nonwoven fabric with similar performance characteri6tics, thereby saving material6 cost. The ~ 15 fabrics of Item N also have an attractive flannel-like ? hand.
j When used with the appropriate water-disper6ible coating in appropriate amount, the cruciform cross-section fiber of the invention has given a fabric with 20 6urprisingly good dispersion uniformity, and the properties indicated.
; From theoretical con6iderations, water-dispersible fibers of conventional round cross-6ection would have been expected to give more uniform disper6ion6, and, therefore, ~5 more uniform wet-l~id fabrics. Thi6 ~s bec~use the surface energy requlred to disper~e a fiber (or other article~) is given by:
Ener~y ~ (Surface Tension) X (Dispersed ~urface area -Undisper~ed surface area).
The undispersed fiber exists in logs or clumps of many hundreds of fibers, most of which are on the inside of the logs. Therefore the undi6persed surfa~e area is ~ negligible compared to the dispersed area, and the energy term can be expressed approximately as:
128 [)~66 Energy ~ (Surface Ten6ion~ X (Number of fibers) X
(Surface area of a fiber).
This energy term describes both the energy required to disperse the fiber, and the free energy 5 driving force for reagglomeration. Therefore, for any given coating, and fiber dpf, fibers with lower area would be expected to provide a more uniform dispersion, hence more uniform fabric. Ths minimum surface area per unit weight for a given fiber occurs when the cross-6ection is round, which would be expected, therefore, to be preferred.
¦ Surprisingly, however, these cruciform fibers, in spite of about 60% greater surface area gave more uniform fabrics. Without limiting the invention to any theory, th~ may result from the fiber'~ hydrodynamic shape, which may more effectively use the energy available in the mixer shear field.
.
.
Claims (20)
1. Water-dispersible synthetic polymer fiber, characterized in that the fibers are of cruciform cross-section.
2. Fiber as claimed in Claim 1, of cut length from about 5 to about 90mm,and wherein the length/diameter ratio is from about 109:1 to about 2000:1.
3. Polymer filaments essentially as claimed in Claim 1, except that they are in the form of a continuous filamentary uncrimped tow.
4. Water-dispersible polyester fiber, characterized in that the fibers are of cruciform cross-section.
5. Fiber as claimed in Claim 4, wherein the denier is from about 0.5 to about 20.
6. Fiber as claimed in Claim 4, of cut length from about 5 to about 90mm.
7. Fiber as claimed in Claim 6, wherein the length/diameter ratio is from about 100:1 to about 2000:1.
8. Water-dispersible fiber as claimed in Claim 7, in the form of a package of cut fiber.
9. Water-dispersible fiber as claimed in Claim 1, in the form of a package of cut fiber.
10. Polyester fiber according to Claim 4, consisting essentially of poly(ethylene terephthalate).
11. Water-dispersible poly(ethylene terephthalate) fiber as claimed in Claim 4, wherein the fiber is essentially uncrimped, of cut length about 5 to about 90mm, of length/diameter ratio about 100:1 to about 2000:1, and of denier about 0.5 to about 20, and an ethoxylated water-dispersing coating is present in amount about 0.04 to about 1.0% of the total weight of the fiber.
12. Water dispersible fiber as claimed in Claim 11, in the form of a package of cut fiber.
13. Polyester filaments essentially as claimed in Claim 11, except that they are in the form of a continuous filamentary uncrimped tow.
14. Polyester fiber according to Claim 4, coated with a water-dispersing coating consisting essentially of segmented copolyester of poly(ethylene terephthalate) repeat units and poly(oxyalkylene) groups derived from a poly(oxyalkylene) glycol having an average molecular weight in the range of 300 to 6000.
15. Polyester filament essentially as claimed in Claim 14, except that they are in the form of a continuous filamentary tow.
16. Water-dispersible fiber according to Claim 1, wherein the cruciform cross-section is of proportions essentially as shown in Figure 1.
17. A process for preparing water-dispersible polyester fiber, comprising the steps of melt-spinning the polyester into filaments of cruciform cross-section, forming a tow of such filaments, drawing the tow, coating the filaments in the tow with a segmented synthetic copolyester of poly(ethylene terephthalate) repeat units and poly(oxy- alkylene) groups derived from a poly(oxyalkylene) glycol having an average molecular weight in the range of 300 to 6,000, and converting the coated filaments to fiber of cut length from about 5 to about 90mm.
18. A process as claimed in Claim 17, wherein the filaments are coated with the copolyester in amount about 0.04 to about 1.0% of their weight.
19. A process as claimed in Claim 17, wherein the coating is cured on the filaments by heating the coated filaments to a temperature of about 100°C to about 190°C.
20. A process as claimed in Claim 19, wherein the filaments are coated with the copolyester in amount about 0.04 to about 1.0% of their weight.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US72134685A | 1985-04-09 | 1985-04-09 | |
| US721,346 | 1985-04-09 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1280266C true CA1280266C (en) | 1991-02-19 |
Family
ID=24897603
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000506113A Expired - Lifetime CA1280266C (en) | 1985-04-09 | 1986-04-08 | Water-dispersible synthetic fiber |
Country Status (11)
| Country | Link |
|---|---|
| EP (1) | EP0198401B1 (en) |
| JP (1) | JPS62502484A (en) |
| KR (1) | KR880002441B1 (en) |
| CN (1) | CN1005734B (en) |
| AT (1) | ATE44787T1 (en) |
| CA (1) | CA1280266C (en) |
| DE (1) | DE3664503D1 (en) |
| ES (1) | ES8800998A1 (en) |
| FI (1) | FI80078C (en) |
| IE (1) | IE57359B1 (en) |
| WO (1) | WO1986006112A1 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4731239A (en) * | 1983-01-10 | 1988-03-15 | Gordon Robert T | Method for enhancing NMR imaging; and diagnostic use |
| US5057368A (en) * | 1989-12-21 | 1991-10-15 | Allied-Signal | Filaments having trilobal or quadrilobal cross-sections |
| JP3056862B2 (en) * | 1991-12-27 | 2000-06-26 | 日産自動車株式会社 | New sound absorbing material |
| US6250948B1 (en) * | 2000-01-31 | 2001-06-26 | Avava Technology Corp. | Cylindrical front access connector |
| CN100462492C (en) * | 2006-01-20 | 2009-02-18 | 泉州海天轻纺有限公司 | Textile with ultraviolet resistant , hygroscopic and perspiratory function, and its preparation method |
| JP2017145527A (en) * | 2016-02-17 | 2017-08-24 | 日本製紙株式会社 | Wall paper |
Family Cites Families (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2945739A (en) | 1955-06-23 | 1960-07-19 | Du Pont | Process of melt spinning |
| US3156085A (en) * | 1959-09-24 | 1964-11-10 | Du Pont | Continuous composite polyester filament yarn |
| GB958350A (en) | 1963-02-18 | 1964-05-21 | Ass Elect Ind | Improvements in and relating to electric incandescent lamps |
| GB1088984A (en) * | 1963-06-05 | 1967-10-25 | Ici Ltd | Modifying treatment of shaped articles derived from polyesters |
| DE1635684A1 (en) * | 1963-07-24 | 1969-10-16 | Glanzstoff Ag | Process for the production of textile surface structures with a felt-like character |
| US3249669A (en) | 1964-03-16 | 1966-05-03 | Du Pont | Process for making composite polyester filaments |
| US3625754A (en) * | 1970-02-02 | 1971-12-07 | Beaunit Corp | Surface-modified polyester article |
| US3702260A (en) * | 1971-01-18 | 1972-11-07 | Beaunit Corp | Coated polyester fiberfill |
| DE2105681C3 (en) * | 1971-02-08 | 1975-10-02 | Bayer Ag, 5090 Leverkusen | Process for the production of aqueous fiber suspensions |
| US3981807A (en) | 1973-09-27 | 1976-09-21 | E. I. Du Pont De Nemours And Company | Durable textile treating adducts |
| US4007083A (en) | 1973-12-26 | 1977-02-08 | International Paper Company | Method for forming wet-laid non-woven webs |
| US4195051A (en) | 1976-06-11 | 1980-03-25 | E. I. Du Pont De Nemours And Company | Process for preparing new polyester filaments |
| US4134882A (en) | 1976-06-11 | 1979-01-16 | E. I. Du Pont De Nemours And Company | Poly(ethylene terephthalate)filaments |
| US4294883A (en) | 1976-08-19 | 1981-10-13 | Hoechst Fibers Industries, Div. Of American Hoechst Corporation | Staple fiber, finish therefor and process for use of same |
| US4179543A (en) | 1976-08-19 | 1979-12-18 | Hoechst Fibers Industries, Division Of American Hoechst Corporation | Staple fiber, finish therefor and process for use of same |
| US4297414A (en) * | 1978-07-07 | 1981-10-27 | Mitsui Petrochemical Industries, Ltd. | Reinforcing material for hydraulic substances and method for the production thereof |
| JPS5685436A (en) * | 1979-12-12 | 1981-07-11 | Toray Industries | Synthetic staple fiber mixture having animal wool like feeling and animal wool like yarn |
| JPS5881609A (en) * | 1981-11-04 | 1983-05-17 | Nippon Ester Co Ltd | Melt spinning method of ultrafine modified cross section yarn |
-
1986
- 1986-04-08 WO PCT/US1986/000685 patent/WO1986006112A1/en active IP Right Grant
- 1986-04-08 KR KR1019860700877A patent/KR880002441B1/en not_active IP Right Cessation
- 1986-04-08 JP JP61502273A patent/JPS62502484A/en active Granted
- 1986-04-08 IE IE905/86A patent/IE57359B1/en unknown
- 1986-04-08 CA CA000506113A patent/CA1280266C/en not_active Expired - Lifetime
- 1986-04-09 DE DE8686104816T patent/DE3664503D1/en not_active Expired
- 1986-04-09 AT AT86104816T patent/ATE44787T1/en active
- 1986-04-09 ES ES553822A patent/ES8800998A1/en not_active Expired
- 1986-04-09 CN CN86102459.1A patent/CN1005734B/en not_active Expired
- 1986-04-09 EP EP86104816A patent/EP0198401B1/en not_active Expired
- 1986-11-18 FI FI864687A patent/FI80078C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| EP0198401A1 (en) | 1986-10-22 |
| IE860905L (en) | 1986-10-09 |
| KR880700116A (en) | 1988-02-15 |
| DE3664503D1 (en) | 1989-08-24 |
| JPH0331804B2 (en) | 1991-05-08 |
| ATE44787T1 (en) | 1989-08-15 |
| ES8800998A1 (en) | 1987-12-01 |
| WO1986006112A1 (en) | 1986-10-23 |
| FI864687A0 (en) | 1986-11-18 |
| KR880002441B1 (en) | 1988-11-12 |
| CN86102459A (en) | 1986-10-08 |
| IE57359B1 (en) | 1992-08-12 |
| JPS62502484A (en) | 1987-09-24 |
| CN1005734B (en) | 1989-11-08 |
| FI80078B (en) | 1989-12-29 |
| FI80078C (en) | 1990-04-10 |
| EP0198401B1 (en) | 1989-07-19 |
| ES553822A0 (en) | 1987-12-01 |
| FI864687A (en) | 1986-11-18 |
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