|Publication number||US3156085 A|
|Publication date||Nov 10, 1964|
|Filing date||Sep 24, 1959|
|Priority date||Sep 24, 1959|
|Publication number||US 3156085 A, US 3156085A, US-A-3156085, US3156085 A, US3156085A|
|Inventors||William H Jamieson|
|Original Assignee||Du Pont|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (19), Referenced by (17), Classifications (13)|
|External Links: USPTO, USPTO Assignment, Espacenet|
10, 1964 w. H. JAMIESON 5 CONTINUOUS COMPQSITE POLYESTER FILAMENT YARN Filed Sept. 24, 1959 3 Sheets-Sheet 1 FIG. I
INVENTOR WILLIAM H. JAMIESON ATTORNEY Nov. 10, 1964 w. H. JAMIESON 3,156,085
File d Sept. 24, 1959 3 Sheets-Sheet 2 FIG.30 FI6.3b FIG.4a FIG.4b
FI6.5a FIG. 5b
1964 w. H. JAMIESON 3,156,085
TINUOUS Filed Sept. 24, 1959 3 Sheets-Sheet 3 Fl6.90 Fl6.9b FIG. I00
FIG. IOb cz$3 FIGJG FlG.lIb
I I I /I/yM FIG. '20 FIG. 2b
INVENTOR WILLIAM H. JAMIESON 3,156,085 CONTINUQUS COMPOSITE POLYESTER lFILAMENT YARN William H. Jamieson, Newark, Del., assignor to E. I.
du Pont de Nemours and Company, Wington, Del,
a corporation of Delaware Filed Sept. 24, 1959, Ser. No. 841,988 6 Claims. ((31. 57140) This invention relates to composite polyester yarns and the process for manufacturing said yarns. More particularly, this invention relates to composite polyester yarns which have a highly uniform appearance in the form of dyed fabrics.
Synthetic linear condensation polyesters, and particularly the linear terephthalate polyesters, have attracted high commercial interest for many uses owing to their high tenacity, flexibility, crease resistance, low moisture absorption, and other valuable properties. Among such polyesters are polyethylene terephthalate and poly(phexahydroxylylen terephthalate). However, one difiiculty has been associated with the polyesters in that the affinity of the polyester fibers for dyes changes markedly with variations in processing conditions. The sensitivity of the polyesters to varying conditions is such that even quite minor fluctuations in the process are sufiicient to cause noticeable changes in the dye aflinity of the fibers. In commercial production, it is frequently observed that n'on-uniformities occur sporadically within a single filament, or that one filament is continuously non-uniform wth respect to the average. These non-uniformities are observed as light or dark streaks in dyed fabrics and are regarded as highly objectionable.
Attempts have been made to solve the problem of non uniform-ities in various ways. In general, attention has been focused on greater control of process variables such as polymer composition and molecuar weight, temperature during the spinning and orientation steps, and ten sion applied during the various steps. However, due to the inherent difiiculty of .the problem, these attempts have not met with complete success.
It is, therefore, an object of this invention to provide polyester yarns which have a uniform appearance in the form of dyed fabrics. Another object is to provide such yarns by a process which is less sensitive to small fluctuations in process conditions than processes used heretofore. Other objects of this invention will appear here inafter.
Surprisingly, it has now been found that when filaments of different cross section are spun together and forwarded as a single filament bundle, the yarn so formed has a uniform appearance in the form of a dyed fabric. When the dyed yarn is observed under magnification, it is seen that the individual filaments have varied shades of color. However, as seen :by the unaided eye, the overall appearance of the fabric is quite uniform. The yarn of which the fabric is made is also slightly more bulky than conventional continuous filament yarn of homo geneous cross section, and this also contributes to the desirable appearance of the fabric.
In carrying out the process of the invention, a molten linear condensation polyester is extruded through a plurality of spinneret orifices of different shapes. The polymer streams are then quenched and oriented, and the filaments so formed are forwarded as a single filament bundle to a collecting device. The filaments assume essentially the shape of the orifice through which they are extruded. The forwarding speeds may be selected within a wide range, forwarding speeds in excess of about 300 yards per minute usually being employed. It is generally desired that the extruded filaments be'oriented to cause them to become tenacious. This may be done simply by winding the extruded filaments at very high rates of speed, e.g., at about 3000 to 5200 yards per minute, as described by Hebeler in U.S. Patent 2,604,689. Alternatively, the extruded filaments may be wound up in a yarn bundle and then oriented by cold drawing the yarn up to about five times its original length in one or more separate steps as disclosed by Whinfield and Dickson in U.S. Patent 2,465,319. Because the orientation of the yarn in the spinning step increases with spinning speed, the draw ratio required to reach a given level of of orientation in the yarn decreases as the spinning speed increases.
In referring to the fiaments as having different cross sections, it is meant that the cross sections should differ markedly. A convenient numerical parameter relating to the shape of the cross sections is the shape factor, which is defined by the equation Shape Factor=P A where P is the perimeter of the cross section and A is its area, measured in the same units of length. Thus, a circle has a shape factor of 4 pi or 12.6; a square has a shape factor of 16; and a rectangle, having long sides four times the length of its short sides, has a shape factor of 25.
In accordance with the present invention, it has been found that at least one species of filaments in the filament bundle should have a shape factor of at least about 18. Thus, round filaments may be combined with filaments having ribbon-shaped (elongated rectangular), Y- shaped, or cruciform cross sections having shape factors of at least about 18.
In the event that all of the filaments in the bundle have the same number of wel1-defined sides in cross section, i.e., have the same general cross-sectional configuration, the shape :factors of at least two species of filaments in the bundle should differ by a factor of at least 1.4. The term sides is intended to include curved surfaces. For instance, two varieties of cruciform filaments having shape factors differing by a factor of at least 1.4 may be combined in the same filament bundle; or two varieties of ribbon-shaped cross section filaments having shape factors differing by a factor of at least 1.4 may be used.
All of the cross sections may have essentially the same shape factor, provided that the shape factor is at least about 18 and the filaments differ markedly in cross-sectional shape. Preferably, in the latter case, at least two species of the filaments in the bundle should have cross sections having different numbers of well-defined sides. For example, Y-shaped cross section yarn may be used with a cruciform cross section yarn even though the two cross sections have the same shape factor. Similarly, a cruciform cross section filament and a ribbon-shaped cross section filament having the same shape factor may be used; or a cruciform cross section and a C-shaped cross section having the same shape factors may be used.
In accordance with the present invention, not more than about of any one species of the filaments in the filament bundle should have the same shape factor and cross-sectional configuration.
In a preferred embodiment of the invention, three or more different cross sections are used. In one particularly desirable embodiment, not more than about 25% of each of several different species is utilized; Although each filament cross section need not be different, a variety of cross sections in the filament bundle is conducive to better uniformity. Since the cross sections of the filaments are governed by the shape of the orifices in the spinneret, a variety of filament cross sections can be obtained in each bundle simply by varying the orifice cross sections in the spinneret. i
If desired, the filaments may be of different denier as well as of different cross section. However, it is preferred that the filaments be of substantially the same denier throughout the filament bundle. Through routine experimentation, the hole size for each orifice cross section appropriate for substantially equivalent polymer flow rates through the orifices may be determined. However, a simpler method of achieving this result is the use of a metering plate containing capillary holes aligned with the spinneret orifices. The diameter of the capillary holes in the metering plate are made sufficiently 1a; with respect to the spinneret orifices that most of the pressure drop across the metering plate and the spinneret occurs within the metering plate. The denier of the filaments is thereby controlled primarily by the metering plate; and when substantially uniform deniers are desired, the diameters of the orifices in the metering plate are made uniform.
The invention will be further illustrated by reference to the accompanying drawings, in which:
FIGURE 1 is a schematic representation of suitable apparatus for spinning polyester filaments;
FIGURE 2 is a diagrammatic cross-sectional view of the portion of the spinnig head of FIGURE 1;
FIGURES 3a through 12a are bottom views of spinneret orifices of various cross-sectional configuration; and
FIGURES 3b through 12b are cross sections of filaments spun from the corresponding orifices of FIGURES 3a through 1241.
Referring now to FIGURE 1, the lower portion of a spinning head is represented by reference numeral 11. Molten polymer metered to cavity 12 is extruded through orifices not illustrated forming filaments 13, 14, 15, and 16. The filaments are drawn away from the orifice by means of a pair of slightly axially skewed forwarding rolls 17 and 18, and are delivered as a single yarn bundle to windup package 19. The yarn is traversed onto package 19 by means of a reciprocating traverse guide 20.
Referring to FIGURE 2, the spinning head includes a spinneret plate 21 positioned in contact with a metering plate 22. Spinneret orifices 23, 24, 25, and 26 are aligned with metering orifices 10. A cupped distributor plate 27, containing a plurality of holes 28, is located upstream from metering plate 22. The upstream face of distribution plate 27 is in contact with screen 29. Retaining cap 30, which is threaded onto spinneret housing 31, secures the plates and screen in position. Pins 32 and 32 on spinneret plate 21 are recessed into holes in the bottom of metering plate 22 and serve to align the orifices in the two plates. Gasket 33 provides a seal between screen 29, cupped distribution plate 27, and housing 31. The cavity 34 in housing 31 is filled with a filtering medium such as sand.
Both the metering orifices and spinning orifices 23, 24, 25, and 26 have compound shapes. Orifices 10 consist of a capillary 35 and counterbore 36. The spinneret orifices consist of jets 37 and counterbore 38. The counterbores and capillaries are circular in cross section; however, the jets may have various shapes as illustrated in FIGURES 3a through 120. The jets of spinneret orifices 23, 24, 25, and 26 are shown in FIGURES 3a, 6a, 4a, and 8a, respectively. The counterbore crosssectional areas are several times larger than the corresponding capillary and jet cross-sectional areas.
FIGURE 3a illustrates a conventional orifice of round cross section, and FIGURE 3b illustrates the conventional, round cross section of a filament spun from this orifice.
FIGURE 4a illustrates a series of three round orifices spaced sufiiciently closely that the polymer streams extruded from the orifices coalesce at the spinneret face. The holes are arranged in a straight line to afford a variegated ribbon-like cross-sectional pattern in the coalesced extruded filament, as shown in FIGURE 4b.
FIGURE 5a illustrates an orifice having the shape of a maltese cross. The cross section of the filament spun from the orifice is shown in FIGURE 51;.
FIGURE 6a illustrates an orifice of cruciform cross section, formed by the intersection of two punched slots. The cross section of the fiber spun from the orifice is shown in FIGURE 6b.
FIGURE 7:: illustrates an orifice having the shape of a three-bladed propeller. The cross section of the filament spun from the orifice is shown in FIGURE 7b.
FIGURE 8a illustrates a series of five punched holes of diamond-shaped cross section spaced sufficiently closely that the polymer streams extruded from the orifices coalesce at the spinneret face. The holes are arranged in an arc to provide a variegated ribbon-like cross section in the coalesced extruded filament, as shown in FIGURE 8b.
FIGURE 9a illustrates an orifice having the shape of a six-legged star. The cross section of a filament spun from the orifice is shown in FIGURE 9b.
FIGURE 10a shows an orifice in the form of a twobladed propeller. FIGURE 10b illustrates the cross section of a filament spun from the orifice.
FIGURE 11a illustrates an orifice having six round holes spaced in zigzag relationship which provides the filament of zigzag cross section shown in FIGURE 11b.
FIGURE 12a illustrates a four crosstie, ribbon-type orifice which provides a filament having a cross-section of the type shown in FIGURE 12b.
In general, the variations in dye receptivity of filaments of different cross section is observed most significantly when the filaments are composed of a linear condensation polyester. Preferably, in accordance with the invention, a linear terephthalate polyester is employed. By linear terephthalate polyester is meant a linear polyester in which at least about 75% of the recurring structural units are units of the formula wherein G represents a divalent organic radical containing from 2 to 12 carbon atoms and is attached to the adjacent oxygen atoms by saturated carbon atoms. Thus, the radical G may be of the form cH A CH where m is 0 or 1 and A represents an alkylene radical, a cycloalkylene radical, a bis-alkylene ether radical, or other suitable organic radical. The linear terephthalate polyesters may be prepared by reacting terephthalic acid or an ester-forming derivative thereof with a glycol, G(OH) where --G- is a radical as defined above, to form the bis-glycol ester of terephthalic acid, followed by polycondensation at elevated temperature and reduced pressure with elimination of excess glycol. Examples of suitable glycols include ethylene glycol, diethylene glycol, butylene glycol, decamethylene glycol, and cisor trans-bis-1,4-(hydroxymethyl) cyclohexane. Mixtures of such glycols may suitably be used to form copolyesters, or small amounts, e.g., up to about 15 mol percent, of a higher glycol may be used, such as a polyethylene glycol. Similarly, copolyesters may be formed by replacing up to about 25 mol percent of the terephthalic acid or derivative thereof with another dicarboxylic acid or ester-forming derivative thereof, such as adipic acid, dimethyl sebacate, isophthalic acid, or sodium 3,5-dicarbomethoxybenzenesulfonate.
Surprisingly, the novel yarns of the invention not only have a more uniform appearance than conventional yarns of homogeneous cross section but in fabric form they are also somewhat more bulky and have a more pleasing hand. This results in part from a differential response to heat treatment exhibited by linear terepbthalate polyester filaments of various cross sections, in which the changes in length of the various filaments when heated differ by amounts ranging up to several percent. After the filaments are heated, the longer filaments are disposed outwardly from the shorter filaments in the form of loops protruding from the axis of the yarn bundle. The greater bulk of the yarn bundle also results in part from the fact that filaments of different cross section generally do not pack together in the yarn bundle as closely as filaments of homogeneous cross section.
The following examples will serve to further illustrate the invention and are not intended to be construed as limitative.
Example I A 5-inch stainless steel spinneret plate is prepared containing ten different orifice cross sections. Each of the orifices is provided with a inch diameter counterbore section. The spinneret contains a total of 34 orifices, seven round orifices and three of each of the orifices having the configurations illustrated in FIGURES 4a through 12a.
Polyethylene terephthalate having an intrinsic viscosity of 0.53 and containing 0.3% TiO is spun at 296 C. from the orifices described above, using a metering plate having 9-mil capillary sections above the spinneret plate. The filaments extruded from the spinneret are collected as a single filament bundle. The filament bundle is wound up at a speed of 1200 yards per minute and it is found to have an as-spun denier of 240. The spun yarn is oriented by passing it from a feed roll maintained at 96 C. and operating at a peripheral speed of 150 yards per minute, thence to an unheated draw roll operated at a peripheral speed of 454 yards per minute, after which the yarns are wound on a conventional windup. The drawn yarns are found to have a denier of 96.8, a tenacity of 2.5 grams per denier, and an elongation of 30.3%.
The drawn yarns are woven into a taffeta fabric containing 90 ends per inch in the warp and 76 ends per inch in the filling. The fabric is dyed for four hours at 100 C. in a dye bath comprising 2% of l,4-diamino 2,3-dichloroanthraquinone, based on the weight of the fabric. A control fabric is prepared as just described except round filaments are utilized in lieu of the filaments of different cross-sectional shapes. The dyed fabric is observed to be more uniform in appearance than the control fabric prepared from the conventional, round cross section polyethylene terephthalate yarn. The fabric prepared frorn the yarn containing filaments of different cross section is also observed to be somewhat more attractive in appearance and to have a somewhat softer hand than the control fabric.
Example 11 A 3-inch stainless steel spinneret is fabricated containing forty-four inch diameter counterbores. rom 22 of the counterbores 15-mil diameter round holes are drilled, while from the other 22 counterbores cruciform orifices are prepared by punching two intersecting 4 x 34 mil slots from each counterbore section. Polyethylene terephthalate having an intrinsic viscosity of 0.53 and containing 0.2% Ti0 is spun at 295 C. from the spinneret, the filaments being wound up together as a single bundle at 1200 yards per minute. The yarn is oriented as described in the preceding example. The drawn yarn is found to have a denier of 61.0, a tenacity of 4.3 grams per denier, an elongation of 13.6%, and an initial modulus of 114 grams per denier. Individual round and cruciform filaments are teased out from the filament bundle and it is found that the round filaments have an average vibrational denier of 1.59 and an average shrinkage in 100 C. water of 9.8%, while the cruciform filaments are found to have an average vibrational denier of 1.55 and an average shrinkage of 9.12%.
The yarn is woven into a taffeta fabric containing 90 ends per inch in the warp and 76 ends per inch in the filling. The fabric is dyed for four hours at 100 C. in
6 a dye bath comprising 2% (based on the fabric weight) of a dye having the formula tional round cross section polyethylene terephthalate yarn prepared under the same conditions.
In addition to the procedures just described, the prod nets of this invention may also be prepared by combining filaments from different spinnerets. They may be used in continuous filament or staple yarn form.
The novel yarns of this invention may be advantageously used in a variety of fabric constructions. They may be dyed either prior to or after being knitted or woven into a fabric. They may be dyed usink known dyes for polyester yarns.
As many widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that this invention is not to be limited to the specific embodiments thereof except as defined in the appended claims.
1. Linear polyester yarn having a uniform appearance in the form of dyed fabrics comprising a plurality of continuous filamentary structures having a uniform cross section along their length, said yarn consisting of at least two species of filamentary structures having different cross-sectional shapes, the cross section of one of said species having a shape factor of at least about 18, not more than about 75% of any one of said species being present in said yarn, with the proviso that when the cross sections of said species have essentially the same number of sides the shape factor of one of said species be at least 1.4 times greater than that of the other species.
2. The yarn of claim 1 wherein said polyester is polyethylene terephthalate.
3. The yarn of claim 1 wherein the major portion of said filaments are round.
4. The yarn of claim 1 wherein at least three species of filaments are present in said yarn.
5. The yarn of claim 1 wherein all of said filaments have essentially the same denier.
6. A dyed fabric having a uniform appearance prepared from linear polyester yarn comprised of a plurality of continuous filamentary structures having a uniform cross section along their length, said yarn consisting of at least two species of filamentary structures having different cross-sectional shapes, the cross section of one of said species having a shape factor of at least about 18, not more than about 75% of any one of said species being present in said yarn, with the proviso that when the cross sections of said species have essentialy the same number of sides the shape factor of one of said species be at least 1.4 times greater than that of the other species.
References Cited in the file of this patent UNITED STATES PATENTS 1,964,659 Brumberger June 26, 1934 2,041,798 Taylor May 26, 1939 2,262,871 Whitehead Nov. 18, 1941 2,291,873 Brubaker Aug. 3, 1942 2,578,899 Pace Dec. 18, 1951 2,750,653 White June 19, 1956 2,804,645 Wilfong Sept. 3, 1957 2,816,349 Pamm et a1 Dec. 17, 1957 (Gther references on following page) 7 UNITED STATES PATENTS Smith Mar. 4, 1958 Jarrett June 10, 1958 Sutor June 23, 1959 Groornbridge eta1 Sept. 22, 1959 Holland June 7, 1960 Lehmicke July 19, 1960 3 Craig Nov. 15, 1960 Groombridge et a1 Ian. 24, 1961 Waltz Apr. 18, 1961 Bottorf May 8, 1962 FOREIGN PATENTS Great Britain Nov. 9, 1933
|Cited Patent||Filing date||Publication date||Applicant||Title|
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|US2041798 *||Dec 12, 1931||May 26, 1936||Celanese Corp||Production of artificial materials|
|US2262871 *||May 4, 1938||Nov 18, 1941||Celanese Corp||Method of preparing textile materials|
|US2291873 *||Jul 14, 1939||Aug 4, 1942||Du Pont||Synthetic filament|
|US2578899 *||Oct 22, 1949||Dec 18, 1951||Du Pont||Superstretching polyester structures|
|US2750653 *||Jan 19, 1955||Jun 19, 1956||Eastman Kodak Co||Yarn structure|
|US2804645 *||May 12, 1953||Sep 3, 1957||Du Pont||Spinneret plate for melt spinning|
|US2816349 *||Nov 30, 1955||Dec 17, 1957||Du Pont||Fibers and fabrics|
|US2825120 *||May 11, 1954||Mar 4, 1958||Eastman Kodak Co||Synthetic filament|
|US2838365 *||Dec 21, 1955||Jun 10, 1958||Eastman Kodak Co||Dry spinning process|
|US2891277 *||Jun 24, 1953||Jun 23, 1959||Du Pont||Apparatus for melt spinning filaments which will coalesce|
|US2904953 *||Nov 9, 1955||Sep 22, 1959||British Celanese||Manufacture of voluminous yarns|
|US2939201 *||Jun 24, 1959||Jun 7, 1960||Du Pont||Trilobal textile filament|
|US2945739 *||Jun 23, 1955||Jul 19, 1960||Du Pont||Process of melt spinning|
|US2959839 *||May 18, 1955||Nov 15, 1960||Du Pont||Linear condensation polymer fiber|
|US2968834 *||Apr 22, 1957||Jan 24, 1961||British Celanese||Manufacture of voluminous yarns|
|US2979883 *||Aug 12, 1957||Apr 18, 1961||Du Pont||Composite yarn and process of producing bulked fabric therefrom|
|US3033240 *||Dec 19, 1958||May 8, 1962||Celanese Corp||Pile carpet|
|GB401160A *||Title not available|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US3249669 *||Mar 16, 1964||May 3, 1966||Du Pont||Process for making composite polyester filaments|
|US3315021 *||Jun 9, 1965||Apr 18, 1967||Snia Viscosa||Process for the production of crimpable composite synthetic yarns|
|US3623939 *||Jun 28, 1968||Nov 30, 1971||Toray Industries||Crimped synthetic filament having special cross-sectional profile|
|US3860679 *||Jan 29, 1973||Jan 14, 1975||Fiber Industries Inc||Process for extruding filaments having asymmetric cross-section|
|US4054709 *||Jul 17, 1975||Oct 18, 1977||Mikhail Nikolaevich Belitsin||Man-made fibre, yarn and textile produced therefrom|
|US4179875 *||Jun 14, 1978||Dec 25, 1979||Fiber Industries, Inc.||High tenacity, low denier poly(ethylene terephthalate) fibrillated tape yarn|
|US4182606 *||Jun 14, 1978||Jan 8, 1980||Fiber Industries, Inc.||Slit extrusion die|
|US4242075 *||Apr 26, 1978||Dec 30, 1980||Ngk Insulators, Ltd.||Extrusion dies for extruding honeycomb structural bodies|
|US4245001 *||May 7, 1979||Jan 13, 1981||Eastman Kodak Company||Textile filaments and yarns|
|US4472477 *||Jun 21, 1982||Sep 18, 1984||Eastman Kodak Company||Fracturable fiber cross-sections|
|US4505867 *||Aug 3, 1983||Mar 19, 1985||E. I. Du Pont De Nemours And Company||Process for polyester yarns|
|US4657501 *||Jan 16, 1986||Apr 14, 1987||Nabisco Brands||Apparatus for continuously depositing sorbitol sweetened hard candy|
|US4713289 *||Mar 27, 1986||Dec 15, 1987||E. I. Du Pont De Nemours And Company||Water-dispersible synthetic fiber|
|US6790797||Apr 12, 2000||Sep 14, 2004||Invista North America S.A.R.L.||Insulating and footwear system|
|US20060116041 *||Dec 9, 2004||Jun 1, 2006||Sun Isle Casual Furniture, Llc||Yarn having lateral projections|
|DE2803401A1 *||Jan 26, 1978||Jul 27, 1978||Eastman Kodak Co||Textilfaeden, verfahren zu ihrer herstellung sowie aus den faeden hergestellte garne|
|WO1986006112A1 *||Apr 8, 1986||Oct 23, 1986||E. I. Du Pont De Nemours And Company||New water-dispersible synthetic fiber|
|U.S. Classification||442/192, 57/248, 57/905, 264/209.1, 428/364, 428/397, 57/244, 264/177.13, 264/177.14|
|Cooperative Classification||D01D5/253, Y10S57/905|