MXPA99007863A - Spinnerets with diamond shaped capillaries - Google Patents

Abstract

The present invention relates to spinnerets for the melt extrusion of synthetic polymer to produce industrial filaments. The spinnerets comprise a plate having an assembly of capillaries through which the polymer is melt extruded to form the filaments. Each of the capillaries have an elongated diamond cross section normal to a longitudinal axis of the capillary.

Description

ROWS WITH CAPILARES IN THE FORM OF ROMBO BACKGROUND OF THE INVENTION 1 ^ Field of the invention This invention relates to swaths for the melt extrusion of synthetic polymers to produce fibers, and to products made therefrom, and more specifically with swaths for the melt extrusion of synthetic polymers to produce industrial polyester fibers, and products made with them. 2. Description of the related art Industrial fibers (ie, high strength) and multi-filament yarns are well known, including yarns comprising polyester. Such yarns have been manufactured and used commercially for more than 30 years. Industrial polyester fibers are typically made of poly (ethylene terephthalate) polymer, having a relative viscosity of about 24 to about 42, one denier per filament (dpf) of about 4 to about 8 (one dtex of about 4.4 to REF. : 30749 about 8.9) and a toughness of about 6.5 grams / denier (about 5.7 cN / dtex) to about 9.2 grams / denier (about 8.1 cm / dtex). These characteristics of relative viscosity, denier and tenacity distinguish, in part, yarns described as those having "industrial properties" of yarns for polyester garments of relatively lower viscosity and lower denier, and consequently of significantly lower strength (it is say, tenacity). Industrial polyester yarns have these properties, and processes for producing such yarns are described in U.S. Patent 3,216,187 to Chantry et al. It is also known to prepare industrial polyester yarns of various shrinkage by a continuous process involving spinning, hot drawing, heat relaxation, interlacing and winding the yarn to form a package in a coupled process. U.S. Patent 4,003,974 to Chantry et al. discloses such a continuous coupled process for making multiple filament yarns of polyethylene terephthalate having a maximum dry heat shrinkage of 4% and an elongation at break in the range of 12% to 20%. Combined with the relative viscosity, denier range and toughness mentioned above, these properties of shrinkage and elongation at break include the defining characteristics of the yarns with "industrial properties". United States Patent 4,622,187 for Palmer describes a continuous coupled process for making very low shrink polyester yarns of approximately 2% with other properties suitable for industrial multi-filament yarn applications. Each of the patents mentioned above describe filaments, or filament yarns made from filaments having circular cross sections, perpendicular to their longitudinal axis. For use in garment applications, it has been proposed to use fibers having cross-sections that are not circular with resistance less than that required for industrial applications. For example, GB 1,086,873 discloses textile filaments with cross sections shaped as rhomboids, such as diamonds, especially squares, and trapezoids such as comets. The holes for producing the diamond-shaped cross sections are in cross section. EP 0 364 979 A2 discloses a method for making nonwoven fabric for diapers containing polyolefin filaments having delta or diamond shaped cross sections, but does not disclose any means for making such filaments. However, until now, all commercial fibers have circular cross sections. In fact, the inventors know that no prior art discloses an industrial polyester multiple filament yarn having a multiple filament yarn of denier range of about 600 to about 2000 with filaments other than the one of round cross section. An object of this invention is to provide swaths for producing industrial fibers which in turn can be formed into industrial filament yarns and fabrics with improved coating power, which reduces the weight of the fabric made of the yarns per unit area, without significantly reducing the industrial properties of the same. These and other objects of the invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE INVENTION The invention relates to a row for the melt extrusion of a synthetic polymer to produce filaments, comprising a plate having a capillaries assembly through which the polymer is excised by melting to form the filaments; and each of the capillaries has a cross-section in the form of an elongated rhombus, perpendicular to the longitudinal axis of the capillary.

BRIEF DESCRIPTION OF THE DRAWINGS The invention can be understood more fully from the following detailed description thereof in relation to the accompanying drawings, which are described as follows. Figure 1 is a schematic enlarged view, illustrating various measurement parameters, of an industrial filament cut perpendicular to its longitudinal axis showing an elongated diamond-shaped cross-section, Figure 2 is an enlarged schematic view of the arrangement of filaments as shown in figure 1 in an industrial wire cut perpendicular to its longitudinal axis. Figure 3 is a schematic enlarged view of a prior art filament arrangement showing rounded cross-sectional shapes in an industrial wire cut perpendicular to its longitudinal axis. Figure 4 is a schematic enlarged view of an industrial wire cut perpendicular to its longitudinal axis. Figure 5 is a schematic enlarged view of one embodiment of a fabric. Figure 6 is a view of a row orifice in a row according to the invention for spinning the filaments shown in Figure 1.

Figure 7 is a cross-sectional view generally along line 7-7 of the row shown in Figure 6 in the direction of the arrows. 8A and 8B illustrate a first row orifice in the form of a double rhombus and a first cross-section formed in the form of a double rhombus of a filament formed by spinning the polymer through the first row orifice in the form of a double rhombus. Figures 9A and 9B illustrate a second row orifice formed in the form of a double rhombus and a second double rhombus cross section of a filament formed by spinning a polymer through a second row orifice formed in the form of a double rhombus. Figure 10 is a schematic illustration of a spinning machine for producing yarns comprising the filaments shown in Figure 1. Figures HA and 11B illustrate the row orifice in the "S" form and an "S" shaped cross section. of a filament formed by spinning polymer through the row hole in the shape of "S". FIGS. 12A and 12B illustrate a hollow bilobate-shaped spinneret hole and a hollow bilobar cross-section of a filament formed by spinning polymer through the spinneret in hollow bilobal form.

FIGS. 13A and 13B illustrate a hollow oval shaped die hole and a hollow oval cross-section of a filament formed by spinning polymer through a hollow oval-shaped spinneret hole. Figures 14A and 14B illustrate a die hole in the form of a flat ribbon and a cross section in the form of a flat ribbon of a filament formed by spinning polymer through the die hole in the form of a flat ribbon. Figures 15A and 15B illustrate a circular shaped die hole and a circular cross section of a filament formed by spinning polymer through a circular shaped die hole.

DESCRIPTION OF THE PREFERRED MODALITIES Through the following detailed description, similar reference numbers refer to similar elements in all figures of the drawings. The present invention is directed to a die for melt extrusion of a synthetic polymer to produce industrial filaments having a cross-section in the shape of an elongate diamond and products made therefrom including multiple filament yarns and fabrics. 1. Filaments For purposes of this document, the term "filament" is defined as a macroscopically homogeneous, relatively flexible body having a high proportion of length with respect to its cross-sectional area. In the present, the term "fiber" will be used interchangeably with the term "filament".

A ^ Cross section With reference to Figure 1, there is illustrated an industrial filament cut 10 perpendicular to its longitudinal axis showing a cross section 12 in the form of an elongated diamond. The elongated diamond cross section 12 has a periphery 14 comprising, in a clockwise direction in Figure 1, a first substantially straight side 16, a rounded first obtuse corner 18, a substantially straight second side 20 , a first sharp rounded corner 22, a third side 24 substantially straight, a second corner 26 obtuse rounded, a fourth side 28 substantially straight, a second sharp corner 30 rounded. Preferably, all four sides 16, 20, 24, 28 are of equal or substantially equal length. The obtuse rounded ends 18,26 are on opposite sides of the periphery 14. Similarly, the sharp rounded ends 22,30 are on opposite sides of the periphery 14. The obtuse rounded ends 18,26 are described as "obtuse" placed connecting the sides (16.20 and 24.28 respectively) that form an obtuse angle between them. Similarly, the acute rounded ends 22, 30 are described as "acute" since they connect to the sides (20, 24 and 16, 28) forming an acute angle between them. The acute angles that define obtuse rounded ends 18,26 need not be the same, but preferably they are. Similarly, the acute angles defining sharp rounded ends 22, 30 need not be the same, but preferably they are. The cross-sectional shape of a filament 10 can be described quantitatively by its dimensional proportion (A / B). The term "dimensional proportion" has been given various definitions in the past. In this document, when applied to cross sections of filaments, the term "aspect ratio" is defined as the ratio of a first dimension (A) to a second dimension (B). The first dimension (A) is defined as a length of a straight line segment connecting first and second points on the periphery 14 of the cross section 12 of filament that is farthest from the other. The first dimension (A) can also be defined as the smallest circle diameter 32 that includes the cross section 14 of the filament 10. The second dimension (B) is a maximum width of the cross section 12 extending at right angles with respect to the straight line segment. In the elongated diamond cross section 12, the first dimension (A) and the second dimension (B) extend completely within and along the cross section 12 of the filament 10. The dimensional proportion of the elongated diamond cross section 12 is from about 2 to about 6, and preferably from about 3.5 to about 4.5. Industrial filaments with elaborate cross sections of multiple elongated cross-sectional areas joined together are within the scope of this invention. Figure 8B illustrates such filaments 800 formed of a first cross section 812 shaped with a double diamond having a pair of elongated diamond-shaped cross-sectional areas joined together at their sharp rounded corners. Figure 9B illustrates such filaments 900 formed of a second cross-sectional section 912 of double diamond having a pair of elongated cross-sectional areas joined together at their obtuse rounded corners.

B. Polymers The 10,800,900 filaments can be made from any and all types of synthetic polymers and mixtures thereof which are capable of melt spinning into filaments having industrial properties as specified herein. Preferably, the polymers are polyesters or polyamides. The polyester polymer is used in this application to refer to polyester homopolymers and copolymers which are composed of at least 85% by weight of an ester of a dihydric alcohol and terephthalic acid. Some useful examples of polyesters and copolyesters are shown in U.S. Patents 2,071,251 (to Carothers), 2,465,319 (to Whinfield and Dickson), 4,025,592 (to Bosley and Duncan), and 4,945,151 (to Goodley and Taylor). More preferably, the polyester polymer used to make the filaments should be essentially 2G-T homopolymer, ie poly (ethylene terephthalate). The nylon polymer is used in this application to refer to polyamide homopolymers and copolymers which are predominantly aliphatic, that is, less than 85% of the polymer's amide bonds are bonded to two aromatic rings. The widely used nylon polymers such as poly (hexamethylene adipamide) which is nylon 6,6 and poly (e-caproamide) which is nylon 6 and its copolymers, can be used according to the invention. Other nylon polymers which can be used advantageously are nylon 12, nylon 4,6, nylon 6,10 and nylon 6,12. Illustrative of the polyamides and copolyamides which may be used in the process of this invention are those described in United States Patents 5,077,124, 5,106,946, and 5,139,729 (for Cofer et al.) And the polymer and polyamide blends described by Gut. ann in Chemical Fibers International, pages 418-420, volume 46, December 1996. The resultant polymers and filaments 10,800,900, the yarns and the fabrics may contain customary minor amounts of such additives as are known in the art, such as delustrants or pigments. , light stabilizers, stabilizers against heat and oxidation, additives to reduce static, additives to modify the dyeability, etc. Also as is known in the art, the polymers must be of filament-forming molecular weight in order to be able to be melt-spun and become a yarn.C. Relative viscosity It has been found that polymers having a relative viscosity of about 24 to about 42, preferably about 36 to about 38, provide very good results as indicated in the following, in the examples.

D. Denier Filaments having a denier per filament (dpf) of from about 4 to about 8 (about 4.4 dtex to about 8.9 dtex), and preferably from about 6 to about 7.2 (about 6.6 dtex to about 8.0 dtex). These deniers are preferably deniers measured as described herein. Preferably, the deniers measured are average deniers measured "as they are spun" which include yarn termination and ambient humidity, as described herein.

E. Tenacity The 10,800,900 filaments have a toughness of about 6.5 grams / denier (about 5.7 cN / dtex) to about 9.2 grams / denier (about 8.1 cN / dtex) and preferably a toughness of about 7.5 grams / denier (about 6.6 cN / dtex) a approximately 8.0 grams / denier (approximately 7. i cN / dtex).

F. Other properties The 10,800,900 filaments have a dry heat shrink from about 2% to about 16% at 30 minutes at 177 ° C, and preferably a dry heat shrink from about 3% to about 13% at 30 minutes at 177 ° C. Filaments 10,800,900 have an elongation at break in the range of 16% to 29%, and preferably 17% to 28%.

Threads A yarn comprises a plurality (typically 140-192) of the industrial filaments 10,800,900 having a degree of cohesion. The 10,800,900 filaments in a yarn are preferably intermixed and entangled by means of an intermixing device or in some other way. An intermixing device and a process is described in U.S. Patent 2,985,995 and is suitable for use in the manufacture of the present yarns. During the spinning process, filaments 10,800,900 with elongated diamond cross sections 12,812,912 have a tendency to naturally entangle without the aid of an intermixing device. The term "yarn" as used herein includes continuous filaments and short filaments, but preferably continuous filaments. The 10,800,900 filaments are "continuous" which means that the length of the filaments constituting the yarn are of the same length as the yarn and substantially have the same length as other filaments in the yarn, in contrast to filaments in a yarn that is discontinuous which is often referred to as short filaments or cut filaments formed in longer yarns in a very similar way as are the natural yarns (cotton or wool). Due to the unique diamond-shaped cross section of the filaments 10, some of the filaments 10 in the yarn are typically placed in an arrangement in such a manner that the oblique ends 18,26 of the cross sections 12 in a first row 36 of the filaments 10 are near the acute ends 22,30 of the cross sections 12 of the filaments 10 in the rows 38,40 of the filaments 10 on both sides of the first row 36. As can be seen by comparing this tile arrangement illustrated in Figure 2 with the more compact arrangement of the industrial filaments of the prior art illustrated in Figure 3 which has substantially the same cross-sectional area as Figure 2, the tile arrangement of the filaments 10 with elongated diamond-shaped cross-sections 12 are denser (i.e., a smaller number of hollow areas 42). Furthermore, when comparing the tile arrangement in Figure 2, with the prior art arrangement in Figure 3, it can be seen that the tile arrangement of the filaments 10 with the sections cross-sections 12 in the form of an elongated rhombus provide greater covering power compared to the compact arrangement of the filaments with round cross sections. The term "covering power" means that the same volume or weight of filaments 10 with the elongate diamond cross sections 12 cover or extend a larger surface (from left to right in Figures 2 and 3) than the arrangement of the filaments with rounded cross-sections having equal or substantially the same areas of the elongated diamond cross-sections 12. Thus, tapering the outward shape of the filaments 10 with diamond cross sections 12 provides a set of filaments 10 with a tendency to disperse along the surface in a substantially uniform manner which increases the coverage power or the property when used, instead of filaments with round cross sections of similar construction and weight and having the same or substantially the same cross-sectional area per filament. Figure 4 is a schematic enlarged view of a portion of an industrial wire cut 44 perpendicular to its longitudinal axis. The tile arrangement illustrated in Figure 2 can be seen through the entire cross section of the yarn in Figure 4.

Cloth The yarns incorporating the filaments 10 produced from row 60 of the present invention can be formed into industrial fabrics. One such industrial fabric includes at least one of the industrial yarns with at least part of the industrial filaments. The filaments 10 produced according to the present invention can be used as yarns and converted, for example, by crimping into fabric patterns of any conventional design by known methods. In addition, these bodies can be combined with other known filaments to produce mixed yarns and fabrics. Fabrics woven or knitted from filaments 10 produced in accordance with this invention have improved coverage power and reduced weight compared to similar construction and weight fabrics made from round filaments having the same cross-sectional area per filament . In a embodiment illustrated in Figure 5, the woven industrial fabric 52 comprises a plurality of first industrial yarns 54 in a warp direction, a plurality of second industrial yarns 56 in a weft direction or corrugated filling when the first industrial yarns 54, and at least some of the first industrial yarns 54 and / or at least some of the second industrial yarns 56 comprising a plurality of the industrial filaments. Preferably, at least the first industrial yarns 54 or the second industrial yarns 56 comprise a plurality of the industrial filaments. In this preferred case, the fabric 52 can have a reduction in total weight of at least 7% compared to a fabric made entirely of yarns comprising other filaments which are essentially the same as the industrial filaments 10 except that the others filaments have circular cross sections. An interval for a weight reduction of fabric (compared to a fabric made entirely of yarns comprising other filaments which are essentially the same as industrial filaments, except that the other filaments have circular cross sections) is from about 5% to about fifteen%. In a second embodiment, the woven industrial fabric 52 comprises a plurality of first industrial yarns 54 in a warp direction, a plurality of second industrial yarns 56 or filling in a filling direction woven with the first industrial yarns 54, and at least some of the first industrial yarns 54 and at least some of the second industrial yarns 56 comprise a plurality of the industrial filaments. In this case, the fabric 52 can have a reduction in total weight of at least 10% compared to a fabric made entirely of yarns comprising other filaments which are essentially the same as the industrial filaments, except that the others filaments have circular cross sections. In this case, the range for reduction in weight of the fabric is from about 10% to about 30%. 4. Rows Figures 6 and 7 illustrate a die 60 for use in the melt extrusion of a polymer to produce industrial filaments having elongated diamond cross sections 12. The die 60 comprises a plate 62 having an assembly of holes, capillaries or holes 64 through which the molten polymer is extruded to form the industrial filaments. Figure 6 shows a bottom view of one of the holes, capillaries or holes 64 having a cross-sectional shape or section 66 of elongated rhombus, through the plate 62. In Figure 6, the elongated cross section 66 is perpendicular to its Longitudinal axis passing perpendicular through the drawing sheet. Figure 7 is a cross-sectional view generally along line 7-7 of row 60 shown in Figure 6 in the direction of the arrows. As illustrated in figure 7, each hole 64 has two sections: a capillary 66 in itself and a larger and deeper perforation conduit 70 connected to the capillary 66. The elongated diamond cross section 66 of the capillary 68 has a periphery 71 comprising, in one direction clockwise in Figure 6 and joined together, a first side 72 substantially straight, a first corner 73 obtuse, a second side 74 substantially straight, a first acute corner 75, a third side 76 substantially straight, a second corner 77 obtuse, a fourth side 78 substantially straight, a second acute corner 79 joined to the side 72 substantially straight. Preferably, all four sides 72, 74, 76, 78 are of equal or substantially equal length. The obtuse ends 73,77 are on opposite sides of the periphery 71. Similarly, the acute ends 75,79 are on opposite sides of the periphery 71. The obtuse ends 73,77 are described as "obtuse" since they are connected to the sides (72.74, and 76.78, resively) that form an obtuse angle between them. Similarly, the acute ends 75,79 are described as "acute" since they are connected to the sides (74,76 and 72,78, resively) that form an acute angle between them. The obtuse angles that define the obtuse ends 73,77 do not need to be the same, but preferably they are. Similarly, the acute angles that define the acute ends 75,79 need not be the same, but preferably they are. The cross-sectional shape 66 of the capillary 68 can also be described quantitatively by its dimensional proportion (A / B). In the present, when applied to cross sections of capillaries, the term "as ratio" is defined as the ratio of a first dimension (A) to a second dimension (B). The first dimension (A) is defined as a length of a straight line segment connected to a first point and a second point on the periphery 71 of the capillary cross section 66 that is further away from each other. The first dimension (A) can also be defined as the diameter of a smaller circle that will include the cross section 66 of the capillary 68. The second dimension B is a maximum width of the cross section 66 extending at angles to the segment of a straight line. In the elongated diamond cross section 66, the first dimension (A) and the second dimension (B) extend completely within and along the cross section 12 of the capillary 68. The dimensional proportion of the elongated diamond cross section 66 of the capillaries 68 of the present invention is from about 8 to about 26, and preferably from about 15 to about 20. The row 60 used in the production of filaments 10 of the present invention may be of any conventional material used in the construction of rows for spinning by fusion. Stainless steel is esally suitable. Each row 60 can have from one to several thousand individual holes 64. The distribution or arrangement of holes is carefully designed to keep the filaments properly separated, to allow each filament 10 to present the maximum unobstructed exposure to cooling air, and to ensure that all filaments 10 are treated in as equal a manner as possible. possible. The counter drilling conduit 70 can be formed by drilling. However, the capillaries 66 must be manufactured to precise dimensions such as with a laser capillary machine. The capillary shape 66 of the spinneret determines the shape of the spun yarn 10. The size of the individual filament 10 is controlled by the size of the capillary 66, the dosing rate and the speed at which the filaments 10 are extracted from the cooling zone and are typically set by rotational speed of the feed roller assembly, and not because of the capillary design itself. The cross section 12 of the filaments 10 is smaller than the actual size of the capillary 66 through which they are produced. Figures 8A and 8B illustrate a first diamond capillary 866 in a double diamond shape, and a first cross-section 812 in the form of a double diamond, of a filament 800 according to this invention formed by spinning the polymer through the first capillary 866 of a row in the form of a double diamond. Figures 9A and 9B illustrate a second double-row diamond-shaped capillary 966 and a second double-diamond-shaped transversal section 912 of a filament 900 according to this invention formed by spinning polymer through a second row capillary 966 in the form of a double rhombus.

INDUSTRIAL APPLICABILITY The rows of the present invention produce filaments 10,800,900, which are manufactured with yarns 44 and fabrics 52 that have uses in the market that include air bags for automobiles, industrial fabrics (architectural fabrics, signage, tarpaulins, tents, etc.). ), marine clothes, tire ropes, cordage (ropes), thick cinterpia, selvedge fabrics, mechanical rubber articles and others.

TEST METHODS Temperature: All temperatures are measured in degrees Celsius (° C).

Relative Viscosity: Any relative viscosity (RV) measurement referred to herein is a dimensionless ratio of the viscosity of 4.47 by weight to a percent solution by weight of the polymer in hexafluoroisopropanol containing 100 ppm of sulfuric acid until the viscosity of the solvent at 25 ° C. Using this solvent, industrial yarns in the prior art, such as that of United States Patent 3,216,817, have relative viscosities of at least 35.

Denier: All parts and percentages are by weight, unless otherwise indicated. Denier is a linear density and is defined as the number of units of weight of 0.05 grams per 450 meters (Man-Made Fiber and Textile Dictionary, Hoechst-Celanese, 1988). This definition is numerically equivalent to the weight in grams per 9000 meters of the material. Another definition of linear density is Tex, the weight in grams of 1000 meters of material. Also widely used is deciTex (dTex), equal to 1/10 of 1 Tex.

All thread deniers reported herein are nominal deniers unless otherwise indicated when measured. As used herein, "nominal" denier means the proposed numerical value of denier. As used herein, "measured" denier is by the method of cutting a standard length of yarn and weighing. Industrial polyester yarns, reported herein, hold their yarn deniers determined by an automatic cut weight and denier (ACW) determination instrument designed by E. I. du Pont de Nemours and Company (Wilmington, DE). This ACW instrument is commercially available from LENZING AG, Lenzing Technik Division, A-4860 Lenzing, Austria. The measured denier is by the ACW instrument method based on 2 observations per bundle of yarn. These two observations are averaged. Therefore, the "measured" denier is an average denier. The length of the thread test sample is 22.5 meters and the sample length tolerance is +/- 1.0 cm. All weights of the ACW machine are within +/- 0.2 milligrams tolerance of certified standards used in the calibration of the machine. The calculations for denier are based on the equation: D = (9000 meter x W (grams) / 22.5 meters where D = denier; and W = sample weight.

For example, 22.5 meters of yarn length of a nominal denier sample 840 (933.3 nominal dtex) of yarn are cut and weighed by the ACW machine. This 22.5 meter sample must have a measured weight of 2.10 grams for nominal denier and denier for measured yarn which is identical to 840 denier (or 933.3 deciTex). Similarly, nominal denier 1000 (or dTex 1111) yarns reported herein must have a weight of 2.50 grams for the nominal denier and yarn measured to be identical and the nominal denier yarns 1100 (or 1222 dTex) have a weight of 2.75 grams per 22.5 meters so that the nominal denier and measured yarn is identical. In the prior art, the "measured" yarn denier has been reported in two ways. The first way is measured denier "as is spun", which includes yarn terminated at ambient humidity. Typically, our "nominal" 840 thread denier (yarn with 933.3 dtex) is denier 847 measured (dtex 941 measured) "how is it spun". The second way is the "measured" thread denier (dtex) and is reported as denier (dtex) of thread "measured" "as sold". The term "as sold" does not mean that the filaments, in fact, are sold or offered for sale.

Instead, it means that the yarn is prepared as if it were to be sold before the denier measurement.

Prior to the denier (dtex) measurement "as sold", the finished yarn is cleaned by washing and the standard moisture content of the yarn is balanced to 0.4%. The denier (dtex) of yarn measured "as sold" is, by definition, equal to the nominal denier or 840 (dtex or 933.3) in this case. All denier yarn "measured" (dtex) reported in this "as is spun", which means that the weight of the finished yarn and the ambient humidity are included in the calculation.

Tension properties: The tension properties for the yarns reported here are measured on an Instron voltage test machine (TTARB type). The Instron equipment extends a specified length of untwisted yarn to its breaking point at a given extension speed. Before the tension test, all the yarns are conditioned at 21.1 ° C and 65% relative humidity for 24 hours. The "extension" "and" burst load "are automatically recorded in the thread in a stretch-tension line.For all the yarn tension tests in the present, the sample length is 25 cm (10 inches) , the speed of extension is 30 cm / minute (12 inches / min) or 120% / minute and the speed of the stretch-tension diagram is 30 cm / minute (12 inches / minute).

Tenacity: The "tenacity" (T) of the yarn is derived from the load at the thread breakage. Tenacity (T) is measured using an Instron Model 1122 tensile tester which extends a 10-inch long sample of wire to its breaking point at an extension rate of 30 cm / min (12 inches / min) at a temperature of approximately 25 ° C. The extension and the load to the rupture are recorded automatically on a stretch-tension diagram by Instron. Tenacity is defined numerically by the burst load in grams divided by the measured denier of the original yarn sample.

Shrinkage by dry heat: Shrinkage by dry heat (DHS) is determined by exposing a measured length of wire under zero stress to dry heat for 30 minutes in a furnace that is maintained at the indicated temperatures (177 ° C for DHS177, and 140 ° C for DHS140) and when measuring the change in length. The shrinkages are expressed as percentages of the original length. DHS177 is what is most often measured for industrial yarns, we find that DHS140 provides a better indication of shrinkage that industrial yarns actually experience during commercial coating operations, although the precise conditions vary according to the patented processes.

EXAMPLES This invention will now be illustrated by the following specific examples.

COMPARATIVE EXAMPLE A Industrial polyester filaments with round or circular cross sections are produced according to the process described in U.S. Patent No. 4,622,187 to Palmer. More specifically, and with reference to Figure 10, the polyester filaments 80 were spun by spinning in a row 82 and solidified by passing them down inside a chimney 83 to become an undrawn multiple filament wire 84, which it advances to the drawing stage by the feed roller 85, the speed of which is determined by the spinning speed, ie the speed at which the solid filaments are extracted in the spinning step. The undrawn yarn 84 is advanced by passing the heater 86, to become the yarn 87 stretched by the drawing rollers 88 and 89, which rotate at the same speed that is greater than that of the feed roller 85. The drawing ratio and the ratio of the speed of the drawing rolls 88 and 89 to the feed roll 85, and is generally between 4.7X and 6.4X. The drawn yarn 87 is annealed and subjected to multiple passages between the drawing rollers 88 and 89 within the heated enclosure 90. The resulting yarn 92 is entangled to provide coherence as it passes through the interlacing jet 94. The interlacing jet 94 provides heated air so that the interlaced yarn 95 is maintained at an elevated temperature as it advances to the winding or winding roll 96 where it is wound to form a bundle of yarn. The interlaced yarn 95 relaxes because it is supercharged to the roll 96, i.e., the speed of the winding roll 96 is less than that of the rolls 89 and 88. A finish is applied in a conventional manner, not shown, which is generally applied to deflect the yarn 84 before the feed roll 85 and to Stretching the wire 87 between the heater 86 and the heated enclosure 90. The speed of the drawing roller is 2835 meters / min (3100 ypm). The properties are measured as described in the following. The process is still using a steam jet at 360 ° C for the heater 86, and a drawing ratio of 5.9X between the drawing roller 88 and the feed roller 85, the heating rollers 88 and 89 at 240 ° C. within an enclosure 90, overfeeding of the yarn 13.5% between the roller 89 and the winding roller 96, so that the speed of winding or winding is 2450 meters / min (2680 ypm), and using interlacing air at 310 kPa (45 pounds per square inch) (psi) and 160 ° C in jet 94. A nominal denier 840 yarn (nominal dtex of 933.3) is made, with 140 filaments and a relative viscosity of 37 using the process and apparatus described above . The yarn is made of filaments which are round or circular cross sections. The filaments are spun from polyester polymer (2GT) having 0.10% titanium dioxide as a delustrant, residual antimony catalyst at a concentration in the range of 300 to 400 parts per million, and small amounts of phosphorus in a range of 8 to 10 parts per million. The only additional additive provided intentionally is an "organic pigment" (toner) which is an anthraquinone dye, at a concentration of 1 to 5 parts per million. The yarn of round cross section produced in this way has a good balance of shrinkage and tension properties. The yarn produced has an average denier of 847 (average dtex of 941) measured "as it is spun". The denier interval measured is from 823 to 873 (914.4 dtex to 969.9 dtex). The thread has a tenacity of 7.9 grams per denier (7.0 cN / dtex) and an elongation at break equal to 28%. Shrinkage (DSH177) of the yarn is 3.1%. Table 1 summarizes the properties of this comparative example A. This comparative example shows the properties of a typical industrial wire of the prior art of Dacron ™ (without cross sections of round filament as illustrated in Figure 15B) sold by DuPont under The designation 840-140-T51 and is a low shrink yarn. This thread of the prior art is packaged together with the set of filaments illustrated by Figure 3.

COMPARATIVE EXAMPLE B Using exactly the same conditions as in Comparative Example A, except that a row with an enlarged capillary dimension versus the capillary dimension used in Example 1 is used, 1000 denier yarns are produced (nominal dtex of 1111) having 140 filaments with round cross sections, as shown in Figure 15B. The same shrinkage and tension properties are measured as for the yarns of comparative example A. The properties of this yarn of comparative example B are summarized in table 1. This comparative example B shows the properties of a typical industrial yarn of the prior art DacronTM sold by DuPont under the designation 1000-140-T51, a low shrink yarn.

COMPARATIVE EXAMPLE C Using exactly the same conditions as in Comparative Example A, except as indicated herein, nominal denier yarns 1000 (nominal dtex 1111) are produced having 192 filaments with round cross sections, as shown in Figure 15B. As in comparative example B, a row is used with an enlarged capillary dimension versus the capillary dimension used in Comparative Example A. The shrinkage and tension properties were different from the properties of the yarns of Comparative Example A by of altered process conditions: the supercharging speed between the roller 9 and the winding roller 14 is reduced to 5% so that the speed of the winding roller is 2693 meters / min (2945 yards per minute), and the temperature of interlaced air is at room temperature (ca 30 ° C) and slightly higher supply pressure, 344.5 kPa (50 pounds per square inch). These yarns have a tenacity of 8.9 grams per denier (7.9 cN / dtex), an elongation at break of 17.5% and a shrinkage by dry heat (DHS177) of 12.2%. Table 1 summarizes the properties of this comparative example yarn B. This comparative example B shows the properties of a typical industrial yarn of the prior art of Dacron ™ sold by DuPont under the designation 1000-192-T68, a shrink yarn. high.

COMPARATIVE EXAMPLE D Using exactly the same conditions as in comparative example C, except as indicated herein, nominal denier yarns 1000 (nominal dtex 1111) and 192 filaments were produced from rows with capillary shapes as shown in FIG. Figure HA. The resulting filaments have "S" shaped cross sections, as shown in Figure 11B. These threads have dry heat shrink properties which are measured equal to those of comparative example C. Table 1 summarizes the properties of this thread of comparative example D.

COMPARATIVE EXAMPLE E Using exactly the same conditions as in comparative example A, except as indicated herein, nominal denier yarns 1100 (nominal dtex 1222) having 140 filaments are produced. The filaments are produced from rows with capillary shapes as shown in Figure 14A and result in filaments with cross sections in the form of a flat ribbon as shown in Figure 14B. These threads have dry heat shrink properties which are measured in the same manner as in comparative example A. The properties of this thread of comparative example E are summarized in table 1.

COMPARATIVE EXAMPLE F Using exactly the same conditions as in Comparative Example E, except as indicated herein, nominal denier yarns 1000 (nominal dtex 1111) having 140 filaments were produced from hair-shaped arrays as shown in Figure 14A . These yarns have filaments with cross sections in the form of a flat ribbon, as shown in Figure 14B. These threads have dry heat shrinkages which are produced according to the method described in Palmer, US Pat. No. 4,622,187, Example 1, Sample A, wherein a supercharging between the roller 9 and the winding 14 of 9.1% allows a winding speed of 2580 meters / min (2820 yards per minute) and an air interlacing at 344.5 kPa (50 pounds per square inch) of supply pressure and approximately 30 ° C which provides a dry heat shrink (DHS177) of 5.3% and a toughness of 8.4 grams per denier (7.4 cN / dtex). Table 1 summarizes the properties of this thread of comparative example F.

COMPARATIVE EXAMPLE G Using exactly the same conditions as in comparative example F, except as indicated herein, nominal denier yarns 1000 (nominal dtex 1111) having 140 filaments are produced from rows with capillary shapes as shown in Figure 12A . This yarn has filaments with hollow bilobal shaped cross sections, as shown in Figure 12B. Table 1 summarizes the properties of this thread from comparative example G.

COMPARATIVE EXAMPLE H Using exactly the same conditions as in Comparative Example A, except as indicated herein, nominal denier yarns 1000 (dtex nominal lili) are produced having 140 filaments from rows with enlarged capillary shapes, as shown in FIG. Figure 13A. This yarn has filaments with hollow disc-shaped cross-sections as shown in Figure 13B. Table 1 summarizes the properties of this thread from Comparative Example H.

COMPARATIVE EXAMPLE I Using exactly the same conditions as in comparative example A, except as indicated herein, nominal denier yarns 1000 (nominal dtex 1111) having 140 filaments are produced from rows with enlarged capillary shapes as shown in the figure HE HAS. This yarn has filaments with "S" shaped cross sections, as shown in Figure 11B. Table 1 summarizes the properties of this thread from comparative example I.

COMPARATIVE EXAMPLE J Using exactly the same conditions as in comparative example A, except as indicated herein, nominal denier 840 yarns (nominal dtex of 933.3) are produced having 140 filaments from rows with capillary shapes as shown in the figure HE HAS. This yarn has filaments with "S" shaped cross sections as shown in Figure 11B. Table 1 summarizes the properties of this thread from comparative example J.

COMPARATIVE EXAMPLE K Using exactly the same conditions as in comparative example C, except as indicated herein, nominal denier yarn 840 (nominal dtex 933.3) having 140 filaments is produced. The filaments are produced from rows with round capillary shapes as shown in Figure 15A and result in filaments with round cross sections as shown in Figure 15B. Table 1 summarizes the properties of this yarn from comparative example K. These comparative examples show the properties of a typical industrial yarn of the prior art Dacron ™ sold by DuPont under the designation 840-140, T68, a high shrink yarn.

COMPARATIVE EXAMPLE L Using exactly the same conditions as in comparative example A, except that a row with an enlarged capillary was used versus the capillaries used in comparative example A, nominal denier yarns 1100 (nominal dtex 1222) having 140 filaments with sections are produced round cross sections, as shown in Figure 15B. The same shrinkage properties were measured as for the yarns of comparative example A. The properties of this yarn of comparative example L are summarized in table 1. This comparative example shows the properties of a typical industrial yarn of the prior art Dacron ™ sold by DuPont under the designation 1100-140-T51, a low shrink yarn.

EXAMPLE 1 Using exactly the same conditions as in comparative example A, except that a row with a capillary was used as shown in figures 6 and 7, and the interlacing air is deactivated, a nominal denier yarn 840 is produced ( nominal dtex 933.3) of 140 filaments. This thread has filaments with a cross section in the form of an elongated diamond. A cross section of the yarn is reproduced schematically in Figure 4 from a microphotograph. The yarn produced has an average denier measured "as spun" of 848 (dtex average 942). The tenacity of the yarn is 7.5 grams per denier (6.6 cN / dtex), the breaking strength is 14.7 grams, the elongation at break of 26.9 percent, DHS177 of 2.7 and the interlacing is 2.7 nodes per meter. The filaments have an average aspect ratio of 3.9 determined by measuring 7 randomly selected filaments in a photomicrograph view of the cross section of the yarn set. Table 1 summarizes the properties of this thread of Example 1 illustrating the invention. This example shows that the properties of a yarn manufactured from filaments with enlarged cross-sections have industrial properties similar to those of the yarns of Comparative Examples A and J. This example further shows by comparison of Figure 4 with Figure 3, that the filaments of Example 1 have a closer or denser packing with less open space between adjacent filaments.

EXAMPLE 2 Except for a row with an enlarged capillary dimension, exactly the same conditions were used to prepare the yarns as in example 1. Nominal denier yarns 1000 (nominal dtex 1111) are produced with 140 filaments, which have filaments with the cross section of Figure 1 in elongated diamond shape. These threads have an average denier measured "as is spun" of 1009 (dtex average of 1121). The tenacity, interlacing and shrinkage are the same as in Example 1. These threads of Example 2 show properties similar to the threads of Example 1 and have a dimensional ratio of 4 on the basis of randomly selected filament measurements. This filament thread of elongated diamond cross section is a low shrink yarn. Table 1 summarizes the properties of this thread of example 2 illustrating the invention. This example 2 shows that the properties of the yarn of example 2 manufactured from filaments with enlarged cross-sections have industrial properties similar to that of the yarns of comparative examples B and I.

EXAMPLE 3 Using exactly the same conditions as in Comparative Example C, except as indicated herein, nominal denier yarns 1000 (nominal dtex 1111) and 192 filaments are produced in the cross-sectional form of Figure 1. The average denier measured "as it is spun" for these yarn packages is 1008 (average dtex of 1120). The properties of shrinkage by dry heat (DHS177) and tension are the same as in comparative example C, 12.2%. This strand of filament in enlarged cross section is a high shrink yarn. Table 1 summarizes the properties of this thread of example ~ 3 illustrating the invention. This example 3 shows that the properties of the yarn of Example 3 made from filaments with enlarged cross-sections have industrial properties similar to those of the yarns of comparative examples C and D.

TABLE 1. THREADS Examples Denier nominal Denier Denier No. / Tenacity Shrinkage Comparative ratio of yarn (dtex) filaments yarn medifilament g / den Dimensional d (dtex) (dtex / f) (cN / dtex)% A (Fig. 15B) 840 140 848 6.0 7.9 3.1 1 (933.3) (942) (6.7) (7.0) B (Fig.15B) 1000 140 1009 7.1 7.9 3.1 (1111) (1121) (7.9) (7.0) C (Fig.15B) 1000 192 1008 5.2 8.9 12.2 (mi) (1120) (5.8) (7.9) D (Fig.11B) 1000 192 1008 5.2 8.9 12.2 (mi) (1120) (5.8) (7.9) E (Fig.14B) 1100 140 1110 7.9 7.9 3.1 (1222) (1233) (8.8) (7.0) F (Fig.14B) 1000 140 1007 7.1 8.4 5.3 (1111) (1119) (7.9) (7.4) G ( Fig.12B) 1000 140 1007 7.1 8.4 5.3 2.1 (mi) (1119) (7.9) (7.4) H (Fig.13B) 1100 140 1110 7.9 7.8 3.1 1.6 (1222) (1233) (8.8) (6.9) I (Fig.11B) 1000 140 (1009) 7.1 7.5 2.7 (1111) (1121) (7.9) (6.6) J (Fig.11B) 840 140 (847) 7 1 7.5 2.7 (933.3) (941) (7.9) (6.6) K (Fig.15B) 840 140 847 6.0 8.9 12.2 (933.3) (941) (6.7) (7.9) L (Fig.15B) 1100 140 1110 7.9 7.9 3.1 (1222) (1233) (8.8) (7.0) Examples of the invention 1 (Fig.1) 840 140 848 6.0 7.5 2.7 3.9 (933.3) (942) (6.7) (6.6) 2 (Fig.1) 1000 140 1009 7.1 7.5 2.7 (1111) (1121) (7.9) (6.6) 3 (Fig.1) 1000 192 1008 5.2 8.9 12.2 (mi) (1120) (5.8) (7.9) Table 1 summarizes the properties of the yarns of the comparative examples A to L with the threads of the example of the invention 1, 2 and 3. The properties of the yarn of the invention, particularly those properties consistent with industrial applicability of the yarn, for example Tenacity and shrinkage are shown by means of this table I where the comparison is substantially preserved regardless of the cross-sectional shape of the filament. The filaments in the form of elongated diamond cross section in the form of industrial polyester yarns are not different or substantially different from those of the prior art and other yarns of comparison with respect to these properties. The surprising and differentiating features of the threads of the invention are found in the properties of the threads incorporating a fabric with at least some of the filaments in the form of an elongated diamond cross section.

EXAMPLE 4 A fabric is made from the yarns of Comparative Example K in the warp direction with 7.7 threads / cm or p / cm (19.5 threads or ppi). and the threads of Example 3 in the weft or fill direction with 8.3 p / cm (21 ppi). The fabric is visually classified to determine its ability to create weft yarn cover by an observer using a light box for backlighting of the fabric. A rating system 1-10 is used with a rating of l supplied to the control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power. Table 2 summarizes the properties and observations regarding this fabric.

COMPARATIVE EXAMPLE M A fabric is made from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and yarns of comparative example D in the weft direction with 8.3 p / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the weft yarn by an observer using a light box for back lighting of the fabric. A rating system 1-10 is used with a rating of l provided to a control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power. Table 2 summarizes the properties and observations regarding this fabric.

COMPARATIVE EXAMPLE N A fabric is made from the yarns of comparative example K in the warp direction with 7.7 p / cm (19.5 ppi) and yarns from comparative example E in the weft direction with 8.3 p / cm (21 ppi). The fabric is visually classified with respect to its ability to create weft yarn cover by an observer using a light box for back lighting of the fabric. A rating system 1-10 with a rating of 1 provided to the control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power is used. The resulting fabric is visually classified with respect to its coverage power. Table 2 summarizes the properties and observations regarding this fabric.

COMPARATIVE EXAMPLE O A fabric is made from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and the threads of comparative example F in the weft direction with 8.3 p / cm (21 ppi). The fabric visually classifies with respect to its ability to create weft yarn cover by an observer using a light box for back lighting of the fabric. A rating system 1-10 with a rating of 1 provided to the control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power is used. The resulting fabric is visually rated for its coverage power. Table 2 summarizes the properties and observations regarding this fabric.

COMPARATIVE EXAMPLE P A fabric is constructed from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and yarns of comparative example G in the weft direction with 8.3 p / cm (21 ppi). The fabric is visually classified to determine its ability to create coverage of the weft yarn by an observer using a light box for backlighting of the fabric. A rating system 1-10 with a rating of 1 provided to the control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power is used. The resulting fabric is visually classified for coverage. Table 2 summarizes the properties and observations regarding this fabric.

COMPARATIVE EXAMPLE OR A fabric is constructed from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and yarns from Comparative Example H in the weft direction with 8.3 p / cm (21 ppi). The fabric is visually classified with respect to its ability to create weft yarn cover by an observer using a light box for backlighting of the fabric. A rating system 1-10 is used with a rating of 1 provided to the control fabric (comparative example S) and higher numbers to indicate a visually better coverage power. The resulting fabric is visually classified to determine its coverage power. Table 2 summarizes the properties and observations regarding this fabric.

COMPARATIVE EXAMPLE R A fabric is constructed from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and the threads of comparative example 1 in the weft direction with 8.3 p / cm (21 ppi). The fabric is visually classified to determine its ability to create weft yarn cover by an observer using a light box for back lighting of the fabric. A rating system 1-10 is used with a rating of l provided to the control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power. The resulting fabric is visually classified with respect to its coverage power. Table 2 summarizes the properties and observations of this fabric.

COMPARATIVE EXAMPLE S A fabric is constructed from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and yarn from comparative example A in the weft direction with 8.3 p / cm (21 ppi). The fabric is visually classified with respect to its ability to create coverage of the weft yarn by an observer using a light box for back lighting of the fabric. A rating system 1-10 with a rating of 1 provided to the control fabric (comparative example S) and higher numbers provided to indicate a visually better coverage power is used. The resulting fabric is visually classified for coverage power. Tables 2 and 3 summarize the properties and observations regarding this fabric. TABLE 2. FABRIC CLASSIFICATIONS AND COVERAGE FOR: 7.7 warp yarns / c) X (8.3 weft yarns / cm) ((19.5 warp yarns / inch) X (21 weft yarns / inch)) FABRIC CONSTRUCTION Example ( warp X frame) Classification KX Coverage Commentary 3 10 The highest coverage capacity. Overfills the construction. Uniform appearance No gaps in the fabric.

M K X D 9.5 Coverage capacity higher than that of Example O. It overfills the construction in a way not seen in example N.

Uniform appearance No gaps in the fabric.

N K X E 9.5 Coverage capacity greater than that of Example O. Frame construction with frame interior of Example 4. Uniform appearance. No gaps in the fabric.

O K X F Greater coverage capacity than the example P. The construction of the weft fabric with weft raster of example 4. Uniformity slightly inferior to the example N. Without gaps in the fabric.

K X G Upper coverage capacity than in example Q. The construction of the weft fabric with a weft inferior to that of example 4. Some light gaps in the construction.

Q K X H 3 Only slightly better coverage than in Example R. There are some gaps in the construction and some lack of uniformity.

R K X L 2 Just slightly better coverage than "control" with gaps in the fabric.

S K X A (control) 1 Gaps well distributed in the construction of the fabric.

Table 2 summarizes the coverage properties of 8 signage fabrics constructed with the yarns of comparative example K in the warp of the fabric (7.7 warp yarns per cm, 19.5 warp yarns per inch) and a variety of weft yarns, which include the invention with 8.3 weft threads per cm (21 weft threads per inch). The example S is the control fabric. The control fabric, example S (= K X A) is visually classified with respect to its fabric coverage and assigned a grade of 1. The control is described by comments appropriate to this subjective coverage rating of 1 versus the other examples. The control fabric shows open fabric gaps which are well distributed through the fabric. The distribution of gaps or spaces between the threads that constitute the fabric allows some transmission of light when observed against a light box, but the appearance of another way is uniform.

EXAMPLE 5 A fabric is constructed from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and threads of example l in the frame direction with 7. 0 p / cm (17.8 ppi). Table 3 provides comments comparing the coverage power of this fabric with respect to other fabrics. In addition, the% reduction in weight of this fabric is calculated and compared with the weight of the fabric of comparative example S (control) and is presented in table 4.

EXAMPLE 6 A fabric is constructed from the yarns of comparative example K in the warp direction with 7.7 p / cm (19.5 ppi) and yarns from example 2 in the weft direction with 6.2 p / cm (15.8 ppi). Table 3 provides comments comparing the coverage power of this fabric with other fabrics.

COMPARATIVE EXAMPLE T A fabric is constructed from the yarns of Comparative Example K in the warp direction with 7.7 p / cm (19.5 ppi) and the threads of comparative example J in the weft direction with 7.0p / cm (17.8 ppi). Table 3 provides comments comparing the coverage power of this fabric with other fabrics.

COMPARATIVE EXAMPLE U A fabric is constructed from the yarns of comparative example K in the warp direction with 7.7 p / cm (19.5 ppi) (and yarns from comparative example I in the weft direction with 6.2 p / cm (15.8 ppi). Table 3 provides comments comparing the coverage power of this fabric with other fabrics.

TABLE 3. FABRICS AND COVERAGE CLASSIFICATIONS Control = S = KXA, (7.7 warp yarns / cm) X (8.3 weft yarns / cm) ((19.5 warp yarns / inch) X (21 warp yarns / inch)) Invention = K in warp, (7.7 warp yarns / cm) X (weft yarns indicated / cm) ((19.5 warp yarns / inch) X (weft yarns indicated / inch)) Construction Yarns of Fabric Threads (frame / frame / cm Comments dimbre X frame) inch 5 KX 1 17. 8 (7 .0) Slightly better coverage than control. Regular uniform appearance without gaps in the fabric.

K X 2 15.8 (6.2) Coverage slightly better than the control despite a reduced weft yarn in the fabric. Smooth uniform appearance without gaps in the fabric.

T K X J 17.8 (7.0) Coverage slightly better than the control. Uniform and smooth appearance without gaps in the fabric.

U K X I 15.8 (6.2) Coverage slightly better than the control. Uniform and smooth appearance without gaps in the fabric.

S K X A (Control) 21.0 (8.3) Uniform coverage with holes in the fabric well distributed.

In Table 3, the cover and appearance performance of 4 fabrics are summarized, examples 5 and 6 and comparative examples T and U, versus Example S of the control fabric. Examples 5 and 6 show that the coverage and appearance of a completely commercially satisfactory fabric are obtained from filament yarns of elongated diamond cross section, even when they occur in a reduced weft count, versus filament yarns of round cross section of denser corrugation. This result is surprising in view of the generally accepted strategy of using dense waves to obtain more coverage. However, the densest waves are produced with some additional expense. More weft yarns present in a wave slow down the weaving process since the weaving machine requires more time to introduce the weft yarns. This result of examples 5 and 6 demonstrates that a faster weaving process can be obtained since the weft yarn count is reducible to a property of constant appearance for the fabric. In addition, this reduced weft yarn count translates into savings in web weight versus higher higher raster counts.

EXAMPLE 7 The fabric is constructed from yarns of example 2 in the warp direction with 6.2 p / cm (15.8 ppi) and yarns from example 1 in the weft direction with 6.2 p / cm (15.8 ppi). The reduction in% by weight of this fabric versus the weight of the fabric of comparative example S (control) is calculated and is presented in table 4.

TABLE 4. REDUCTION IN THE WEIGHT OF THE FABRIC S = Control warp threads weft threads by% weight reduction Example per inch (threads inch (threads of versus control (S) warp per cm) weft per cm) s (= KXA) 19.5 21 n / a (7.7) (8.3) T (= KXA) 19.5 17.8 13.6 (7.7) (7.0) u (= KXI) 19.5 15.8 7.9 (7.7) (6.2) 5 (= KX 1) 19.5 17.8 13.6 (7.7) (7.0) 6 (= KX 2) 19.5 15.8 7.9 (7.7) (6.2) 7 (= 2 X 1) 15.8 15.8 > 17 (6.2) (6.2) It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (3)

CLAIMS Having described the invention as above, the content of the claims is claimed as property:

1. A row for the melt extrusion of a synthetic polymer, to produce filaments, including a plate having a capillary assembly through which the polymer is melt extruded to form the filaments, and which is characterized in that: one of the capillaries has a cross section in the form of an elongated rhombus, or substantially in the form of a rhombus, perpendicular to the longitudinal axis of the capillary, wherein the cross section has a dimensional proportion from about 15 to about 26, and where the dimensional proportion (AR) is defined as the ratio of a first dimension (A) to a second dimension (B) where the first dimension (A) is defined as the length of a straight line segment which connects the first and second points at the periphery of the filament cross section so that they are farthest from each other, and the second dimension B is the maximum width of the cross section extending at right angles to the straight line segment .

2. The row according to claim 1, characterized in that the cross section has a peripheral comprising, in a clockwise direction, and joined together, a first substantially straight side, a first obtuse corner, a second substantially straight side, a first acute corner, a third substantially straight side, a second obtuse corner, a fourth side substantially straight and a second acute corner, joined to the first side substantially straight.

3. The row in accordance the claim 1, characterized in that a pair of capillaries form a double diamond, or substantially a -rombo, formed capillary, and a filament a cross section shaped substantially in the form of a diamond, which is formed by spinning the polymer through a double diamond, or substantially in the shape of a diamond, shaped capillary.