MXPA99007869A - Industrial fibers with sinusoidal cross sections and products made therefrom - Google Patents

Abstract

The present invention relates to industrial fibers and products made therefrom and more specifically to industrial polyester fibers and products made therefrom. The fibers comprise a synthetic melt spun polymer having a relative viscosity about 24 to about 42, a denier of about 4 to about 8, a tenacity of about 6.5 grams/denier to about 9.2 grams/denier, and a sinusoidal shaped cross section normal to a longitudinal axis of the filament, the cross section having an aspect ratio of about 2 to about 6.

Description

INDUSTRIAL FIBERS WITH TRANSVERSAL SINUSOIDAL SECTIONS AND PRODUCTS MANUFACTURED FROM THEMSELVES BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to industrial fibers and products made therefrom, and more specifically to industrial polyester fibers and products made therefrom. 2. Description of the related art Industrial fibers (ie, high strength) and multi-filament yarns are well known, and include 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, and a toughness of about 6.5 grams / denier at approximately 9.2 grams / denier. These REF .: 30750 characteristics of relative viscosity, denier and tenacity distinguish, in part, the yarns described that are considered to have "industrial properties" of the yarns for garments of polyester of lower relative viscosity and lower denier, and in consequence, of resistance (ie, tenacity) significantly lower. Industrial polyester yarns have these properties, and the processes for producing the yarns are described in US Pat. No. 3,216,187 to Chantry et al. It is also known to prepare industrial polyester yarns of varied shrinkage by a continuous process involving spinning, hot drawing, hot-stretching, interlacing and winding the yarn to form a package in a coupled process. U.S. Patent 4,003,974 to Chantry et al. describes such a continuous coupled process for making polyethylene terephthalate multiple filament yarns 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, comprise the differentiating characteristics of the yarns with "industrial properties". U.S. Patent 4,622,187 to Palmer discloses a continuous coupled process for making very low shrink polyester yarns of about 2%, with other properties suitable for industrial multi-filament yarn applications. Each of the patents mentioned above describe filaments or filament yarns made of filaments having circular cross sections normal to their longitudinal axes. For use in garment applications, it has been proposed to use fibers that do not have circular cross sections with resistance less than that required for industrial applications. However, to date, all commercial industrial fibers have circular cross sections. In fact, the inventors are not aware of prior art describing an industrial polyester multiple filament yarn having a denier range of multiple filament yarn from about 600 to about 2000 with filaments other than those of round cross section. An object of this invention is to provide industrial fibers, industrial filament yarns and fabrics with improved cover power which reduces the weight of a fabric made of the yarns per unit area, without significantly reducing the industrial properties thereof. These and other objects of the invention will be apparent from the following description.

BRIEF DESCRIPTION OF THE INVENTION The invention relates to an industrial filament, comprising a synthetic melt-spun polymer having a relative viscosity of about 24 to about 42, a denier of about 4 to about 8, a tenacity of about 6.5 grams / denier to about 9.2 grams / denier, and a sinusoidal shaped cross section normal to the longitudinal axis of the filament, the cross section having a dimensional ratio of about 2 to about 6. The invention is further directed to industrial multi-filament yarns, fabrics and other products using industrial filaments as described herein.

BRIEF DESCRIPTION OF THE DRAWINGS The invention can be more fully understood from the following detailed description thereof in connection with the accompanying drawings described as follows. Figure 1 is a schematic enlarged view, illustrating various measurement parameters, of an industrial filament cut normal to its longitudinal axis showing a sinusoidal shaped cross section, according to the invention. Figure 2 is a schematic enlarged view of a first filament tile arrangement shown in Figure 1, in an industrial wire cut normal to its longitudinal axis. Figure 3 is a schematic enlarged view of a second tile arrangement of the filaments shown in Figure 1 in an industrial wire cut normal to its longitudinal axis. Figure 4 is a schematic enlarged view of the prior art arrangement of filaments having round cross-sectional shapes in an industrial wire cut normal to their longitudinal axis. Figure 5 is a schematic enlarged view of an industrial wire cut normal to its longitudinal axis according to the present invention. Figure 6 is a schematic enlarged view of one embodiment of a fabric according to the present invention. Figure 7 is a view of a row orifice in a row for spinning the filaments shown in Figure 1. Figure 8 is a cross-sectional view, generally along line 8-8 of the row shown in Figure 7 in the direction of the arrows.

Figures 9A and 9B illustrate an extended sinusoidal shaped spin hole and an extended sinusoidal shaped cross section of a filament formed by spinning polymer through the extended sinusoidal shaped spinneret hole. 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 a hollow bilobate shaped die hole and a hollow bilobate cross section of a filament formed at spinning the polymer through the hollow bilobed shaped die orifice. Figures 12A and 12B illustrate a hollow oval shaped die hole and a hollow oval cross section of a filament formed by spinning the polymer through the hollow oval shaped die orifice. Figures 13A and 13B illustrate a swath hole formed of flat ribbon and a cross section of flat ribbon of a filament formed by spinning polymer through the die orifice formed of flat ribbon. Figures 14A and 14B illustrate a circular shaped die hole and a circular cross section of a filament formed by spinning polymer through the circular shaped die hole.

DESCRIPTION OF THE PREFERRED MODALITIES Through the following detailed description, similar reference numbers refer to similar implements in all figures of the drawings. The present invention is directed to an industrial filament 10 having a transverse section 12 formed sinusoidal or "S" and products made therefrom which include yarns and fabrics of multiple filaments. 1. Filaments For purposes herein, the term "filament" is defined as a macroscopically homogeneous, relatively flexible body having a high length ratio with respect to the maximum width in its cross section. In the present, the term "fiber" will be used interchangeably with the term "filament".

A ^ Cross section With reference to Figure 1, the cutting of the industrial filament 10 normal to its longitudinal axis showing its sinusoidal shaped cross section 12 according to the invention is illustrated. The sinusoidal cross section 12 has a periphery 14 comprising, in a clockwise direction in Figure 1, a first convex end 16, a first concave edge 18, a first convex edge 20, a second convex end 22, a second concave edge 24 and a second convex edge 26. The first convex edge 20 is defined by, or substantially by a radius rl. Although not required, it is preferred that the second concave edge 24 is also defined by or substantially defined by the radius rl. The second convex edge is defined by or substantially by a radius r2. Although not required, it is preferred that the first concave edge 18 is also defined by or substantially defined by the radius r2. The radius rl may be different from the radius r2, but preferably rl is equal to or substantially equal to r2. The first and second convex ends 16,22 are on two distal sides of the periphery 14. The industrial section shape of the filament 10 can be described quantitatively by dimensional proportion (A / B). The term "dimensional proportion" has been given various definitions in the past. In the present, when applied to filament cross sections, the term "dimensional proportion" 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 a first portion 28 and a second point 30 at the periphery 14 of the cross section 12 of filament that is furthest from each other. The first dimension (A) can also be defined as the diameter of a smaller circle 32 which will include the cross section 12 of filament 10. The second dimension B is 2r, where r is the sum of the radius rl of the first edge 20 outer convex and the radius r2 of the second outer convex edge 26. In the sinusoidal cross section 12, neither the first dimension (A) nor the second dimension (B) extend completely within the cross section 12 of the filament 10. The dimensional proportion of the sinusoidal cross section 12 of the present invention is from about 2 to about 6, and preferably from about 2.5 to about 5. In a preferred embodiment illustrated in Figure 1, a portion of the sinusoidal line 34 bisects the cross section 12 with the end points placed on the first and second convex ends 16. , 22 of the cross section 12 which is less than a full circle of the period P of the sinusoidal line 34. However, industrial filaments with cross sections extending over a full cycle or more of the sinusoidal line 34 are within the scope of this invention. Figure 9B illustrates such a filament 100. In addition, preferably, each of the first convex outer edge 20 and the second convex outer edge 26 are less than half a cycle of the sinusoidal line 34. Preferably, the cross sections 12 consist entirely of curved or arched edges or surfaces, and not straight ones.

B. Polymers The filaments 10, 100 can be made from any and all types of synthetic polymers and mixtures thereof which are capable of being melt spun in 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 (for Carothers), 2,465,319 (for Whinfield and Dickson), 4,025,592 (for Bosley and Duncan) and 4,945,151 (for Goodley and Taylor). More preferably, the polyester polymer used to make the filaments should essentially be a 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 amide bonds of the polymer are bonded to two aromatic rings. Broadly used nylon polymers such as poly (hexamethylene adipamide) which is nylon 6,6 and poly (e-caproamide) which is nylon 6, and their 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 that can be used in the process of this invention are those described in U.S. Patents 5,077,124, 5,106,946, and 5,139,729 (each to Cofer et al.) And the polymer and polyamide combinations described by Gutmann in Chemical Fibers International, pages 418-420, volume 46, December 1996. Polymers and filaments 10,100, resulting from yarns and fabrics may contain the usual minor amounts of such additives as are known in the art, such as delustrants or pigments, stabilizers for light, stabilizers for heat and oxidation, additives to reduce static, additives to modify the capacity of the dye, etc. Also as is known in the art, the polymers must be of a filament-forming molecular weight for the purpose of spun-spinning in a yarn.

C. Relative viscosity Polymers having a relative viscosity of about 24 to about 42, preferably about 36 to about 38, have been found to have very good results as indicated in the examples below.

D. Denier Filaments 10,100 of the present invention have 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 "as is spun" from average deniers measured which include yarn termination and ambient humidity, as described herein.

E. Tenacity Filaments 10,100 of the present invention have a toughness of about 6.5 grams / denier to about 9.2 grams / denier and preferably a toughness of about 7.5 grams / denier to about 8.0 grams / denier.

F. Other properties The filaments 10,100 of the present invention have a shrinkage with dry heat of about 2% to about 16% at 30 minutes at 177 ° C, and preferably a shrinkage in dry heat of about 3% to about 13% at 30 minutes at 177 ° C. ° C. Filaments 10,100 of the present invention have an elongation at break in the range of 16% to 29%, and preferably 17% to 28%. 2 ^ Threads A yarn comprises a plurality (typically 140-192) of the industrial filaments 10,100 having a degree of cohesion. Filaments 10,100 in a yarn are preferably intermixed and entangled through an intermixing device or in some other way. A typical intermingling device and 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 10,100 with a sinusoidal cross section 12,112 have a tendency to intermingle naturally without the aid of an intermixing device. The term "yarn" as used herein, includes continuous filaments and short filaments, but preferably continuous filaments. The filaments 10,100 are "continuous" which means that the length of the filaments 10,100 constituting the yarn are the same length as the yarn and are substantially the same length as the other filaments in the yarn, in contrast to the filaments in a yarn which are discontinuous which are often referred to as short filaments or cut filaments formed on longer yarns in a very similar manner as found in natural filaments (cotton or wool). Due to the unique sinusoidal cross section 12 of the filaments 10, some of the filaments 10 in a yarn are typically placed in a first tile arrangement and in some position themselves in a second tile arrangement. In the first tile arrangement illustrated in Figure 2, the filaments 10 are positioned so that the ends 22 of a first set 36 of the filaments 10 are close, and aligned with the ends 16 of a second set 38 of the filaments 10. , so that the pairs of the first set 36 of the filaments 10 and the second set 38 of the filaments 10 are placed substantially along sinusoidal lines 40 not overlapping. This first arrangement of tiles provides a very dense arrangement with a minimum of gaps 42 between filaments 10. In the second tile arrangement illustrated in Figure 3, the filaments 10 are positioned so that the inner concave surfaces 24 of a first set 44 of the filaments 10 make contact with the inner concave surfaces 18 of a second set 46 of the filaments 10, the outer convex surfaces 20 of the first set 44 of the filaments 10 make contact with the outer convex surfaces 26 of the second set 46 of the filaments 10, so that the first set 44 of the filaments 10 and the second set 46 of the filaments 10 are placed in an immobilized arrangement. The second tile device provides a natural cohesion between the filaments 10. As can be seen by comparing the first tile arrangement illustrated in Figure 2, with the more compact arrangement of the industrial round cross-section filaments of the prior art which they are illustrated in figure 4 which have substantially the same cross-sectional area as those of figure 2, the first tile arrangement of the filaments 10 with the sinusoidal cross-sections are denser (i.e. they have smaller hollow areas 42) ). Furthermore, when comparing the first tile arrangement in Figure 2 and the second tile arrangement in Figure 3 with the prior art arrangement in Figure 4, it can be seen that the tile arrangements of Figures 2 and 3 provide a greater coating capacity compared to the arrangement of the filaments with rounded cross sections in Figure 4. The term "covering power" means that the same volume or weight of filaments 10 with the sinusoidal cross sections covers or extends over a larger surface (from left to right in Figures 2-4) than an arrangement of the same number of filaments with round cross sections having equal or substantially equal areas to the areas of sinusoidal cross sections. Thus, the elongated shape of the filaments 10 with sinusoidal transverse sections 12 provide a set of filaments 10 with a tendency to spread along the surface increasing the coverage power or property when used, instead of the filaments with cross sections rounds of similar construction and weight and having the same or substantially the same cross-sectional area per filament.

Figure 5 is a schematic enlarged view of a portion of industrial wire 50 cut perpendicular to its longitudinal axis according to the present invention. The tile arrangements illustrated in Figures 2 and 3 can be seen through the wire cross section in Figure 5.

• Cloth The invention is further directed to industrial fabric 52 which includes at least one of the industrial yarns with at least part of the industrial filaments 10 according to the invention. The filaments 10 produced according to the present invention can be used as yarns and can be converted, for example, by weaving 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. Woven or knitted fabrics from the filaments 10 produced in accordance with this invention have an increased coverage power and a reduced weight compared to similar construction and weight fabrics made of round filaments having the same cross-sectional area by filament. In one embodiment illustrated in Figure 6, 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 fill or weft direction woven with the first industrial yarns 54 , and at least part of the first industrial threads 54 and / or at least part of the second industrial threads 56 comprise 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, except that the others filaments have circular cross sections. A range for fabric weight reduction (as compared to a fabric made entirely of yarns comprising other filaments which are essentially the same as the industrial filaments 10, except that the other filaments have circular cross sections) is from about 5% to Approximately 15%. In a second embodiment, the woven industrial fabric 52 comprises a plurality of first industrial yarns 54 in the warp direction, a plurality of second industrial yarns 56 in a weft fill direction with the first industrial yarns 54, and at least part of the yarn. the first industrial threads 54 and at least part of the second industrial threads 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, a range for fabric weight reduction using the yarns manufactured completely from the filaments 10 is from about 10% to about 30%. 4 ^ _ Rows Figures 7 and 8 illustrate a die 60 for use in the melt extrusion of a synthetic polymer to produce industrial filaments having sinusoidal cross-sections 12 according to the present invention. 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 7 shows a bottom view of one of the holes, capillaries or holes 64 having a sinusoidal shape or cross section 66 through the plate 62. In Figure 7, the sinusoidal cross section 66 is normal with respect to a longitudinal axis passing perpendicular through the drawing sheet, through a central point C of the holes, capillaries or holes 64. Figure 8 is a cross-sectional view generally along line 8-8 of row 60 shown in figure 7, in the direction of the arrows. As illustrated in Figure 8, each hole 64 has two sections. A capillary 68 itself and a larger and deeper counter-drilling conduit 70 connected to the capillary 68. The sinusoidal cross section 66 of the capillary 68 has a periphery 71 comprising, in a clockwise direction in the direction of 7 and joined together, a first end straight or substantially straight 72, a first concave edge 73, a first convex edge 74, a second end 75 straight or substantially straight, and a second concave edge 76, and a second edge 77 convex connected to the first end 72. The first convex edge 74 is defined by or substantially defined by a radius r3. Although not required, it is preferred that the second concave edge 76 is also defined by, or substantially defined by the radius r3. The second convex edge 77 is defined by, or substantially defined by a radius r4. Although not required, it is preferred that the first concave edge 73 is also defined by or substantially defined by the radius r4. The radius r3 may be different from the radius r4, but preferably r3 is equal or substantially equal to r4. Furthermore, it is within the scope of this invention that rl, r2, r3, r4 are all of different lengths, all of the same lengths or any combination of lengths. 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 the cross sections of the capillaries, the term "dimensional proportion" 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 a first point and a second point on the periphery 71 of the capillary cross section 66 that is furthest from each other. The first dimension (A) can also be defined as the diameter of a smaller circle enclosing the cross section 66 of the capillary 68. The second dimension B is 2r where r is the sum of the radius r3 of the first outer convex edge 74 and the radius r4 of the second convex outer edge 77. In the capillary sinusoidal cross section 66 none of the first dimension (A) nor the second dimension (B) extends completely within the cross section 66 of the capillary 68. The dimensional proportion of the sinusoidal cross-section 66 of the capillaries 68 of the present invention is from about 1.3 to about 6, and preferably from about 1.5 to about 2.5. In a preferred embodiment illustrated in Figure 7, a portion of the sinusoidal line 78 bisecting the cross section 66 with the end points placed on the first and second ends 72, 75 of the capillary cross section 66 is less than one cycle. complete of period P of sinusoidal line 78 However, capillary cross sections 66 that extend over a full cycle or more of sinusoidal line 78 are within the scope of this invention. Figure 9A illustrates such a capillary 164. Furthermore, preferably, each of the first convex outer edge 74 and the second convex outer edge 77 are less than half the cycle of the sinusoidal line 78. This reduces the opportunities for the ends 22, 28 to be joined together at a point in the cross section 12 of the filament during the spinning process, thereby reducing the opportunity for the cross section 12 of the filament to form two holes, as it is illustrated in figure 11B, or a hole in one end. The row 60 used in the production of filaments of the present invention can be of any conventional material used in the construction of rows for melt spinning. Stainless steels are especially suitable. Each row 60 may have one or several thousand individual holes 64. The distribution or arrangement of holes is carefully designed to keep filaments 10 with maximum unobstructed exposure for air cooling, and to ensure that all filaments 10 are treated as equal as possible. The counter-perforation 70 can be a round cross section and can be formed by drilling. However, capillaries 68 must be manufactured to precise dimensions such as with a laser capillary machine. The shape of the row capillary 68 determines the shape of the spun filament 10. The size of the individual filament 10 is controlled by the size of the capillary 68, the dosing rate and the speed at which the filaments 10 are extracted from the cooling zone and is typically set by the rotational speed of the feed roller assembly and not because of the capillary design itself. As such, the cross section 12 of the filaments 10 is smaller than the actual size of the capillary 68 through which it is produced. Figures 9A and 9B illustrate an extended sinusoidal shaped die capillary 166 and an extended sinusoidal shaped cross section 112 of a filament 100 according to this invention formed by spinning polymer through the extended sinusoidal shaped die capillary 166.

INDUSTRIAL APPLICABILITY The filaments, threads and fabrics of the present invention have uses on the market that include air bags for automobiles, industrial fabrics (architectural fabrics, signs, canvas, tents, etc.), fabrics for marine activities, cable for tires, cordage (laces), fabric, selvage fabrics, metallic rubber goods 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 proportion of the viscosity of a weight of 4.47 on the weight percent solution of the polymer in hexafluoroisopropanol containing 100 ppm sulfuric acid regarding the viscosity of the solvent at 25 ° C. Using this solvent, industrial yarns in the prior art, such as that of U.S. Patent 3,216,817 have relative viscosities of at least 35.

Denier: All parts and percentages are by weight, unless otherwise indicated. Denier is linear density and is defined as the weight number 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 used is deciTex (dTex) which is equal to 1/10 of 1 Tex. All thread deniers reported herein are nominal deniers unless otherwise indicated as 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. The industrial polyester yarns reported herein, have their yarn deniers determined by E. I. du Pont de Nemours and Company (Wilmington, DE) with a designed automatic cut and an instrument for denier determination by weight (ACW). This ACW instrument is commercially available from LENZING AG, Lenzing Technik Division, A-4860 Lenzing, Austria. The measured denier is by means of the ACW instrument method and is based on two observations per yarn package. These two observations are averaged. Therefore, the "measured" denier is an average denier. The length of the wire 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 meters x W (grams) / 22.5 meters where D = denier; and W = sample weight.

For example, a length of 22.5 meters of yarn from a nominal denier yarn sample 840 is cut and weighed by the ACW machine. This 22.5 meter sample can have a measured weight of 2.10 grams for the nominal and measured yarn denier which is identical to 840 denier (or 933.3 deciTex). Similarly, the nominal denier 1000 (or 1111 dTex) yarns reported herein must have a weight of 2.50 grams for the nominal and measured yarn denier to be identical and the nominal denier yarns 1100 (or 1222 dTex) have a weight of 2.75 grams per 22.5 meters for nominal thread denier and measured to be identical.

The "measured" yarn denier has been reported in the prior art in two ways. The first way is denier measured "as is spun" which includes the yarn termination and the ambient humidity. Typically, our denier of 840"nominal" yarn is denier measured 847"as it is spun". The second way, the "measured" yarn denier is reported as the yarn denier "measured" as it is 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 measurement "as sold" the yarn finish is removed and the standard moisture content of the yarn is balanced to 0.4%. The yarn denier sold "as sold" is, by definition, equal to the nominal denier or 840 in this case. All "measured" yarn denier reported herein is "as is spun" which means that the weight of the yarn termination 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 "breaking load" of the yarn are automatically recorded in a tension / stretch trace. For all yarn tension tests in the present, the length of the sample is 25 cm (10 inches), the extension speed is 30 cm / min (12 inches / min) or 120% / minute and the chart of tension / stretch speed 30 cm / minute (12 inches / minute).

Tenacity: The "tenacity" (T) of the yarn is derived from the breaking load of the yarn. Tenacity (T) is measured using the Instron tensile tester model 1122 which extends a sample of yarn 25 cm (10 inches) long 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 load to the break are automatically recorded in a tension-stretched trace by the Instron equipment. Tenacity is defined numerically by the breaking load in grams divided by the measured denier of the original yarn sample.

Shrinkage to heat by drying: Shrinkage to heat by drying (DHS) is determined by exposing a measured length of wire under zero stress to dry heat for 30 minutes in a furnace 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. It is most often measured for DHS177 industrial yarns, we find that DHS140 provides a better indication of the shrinkage that industrial yarns actually experience during commercial coating operations, although the precise conditions vary according to the processes recorded.

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

COMPARATIVE EXAMPLE A Industrial polyester filaments with circular or circular cross sections are produced according to the process described in the United States patent 4, 622,187 for Palmer. More specifically, and with reference to Figure 10, the polyester filaments 80 were spun by melting from a die 82, and solidified as they passed down into a chimney 83 to become an undrawn multiple filament yarn 84, which is advanced to the drawing stage by the feed roll 85, the speed of which is determined by the spinning speed, i.e., the speed at which the solid filaments are removed in the spinning step. The undrawn yarn 84 is advanced by passing the heater 86, to become a stretched yarn 87, by the drawing rollers 88 and 89, which rotate at the same speed, which is greater than that of the feed roller 85. The draw ratio is the ratio of the drawing speed of the rollers 88 and 89 to the feed roll 85, and is generally between 4.7X and 6.4X. The drawn yarn 87 is annealed as multiple passages are made 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 roll 96 where it is wound to form a bundle of yarn. The interlaced yarn 95 relaxes because it is supercharged to the winding roll 96, that is, the speed of the winding roll 96 is less than that of the rolls 89 and 88. It is applied in a conventional manner, not shown, which is generally it is applied to the yarn 84 not stretched before the feed roll 85 and the yarn 87 stretched 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. inside the enclosure 90, the yarn 13.5% is supercharged between the roller 89 and the winding roller 96, so that the winding speed is 2450 meters / min (2680 ypm), and interleaving air is used at 3.1 kg / cm2 45 pounds per square inch (psi) and ci 160CC in the jet 94. A denier nominal thread 840, 140 filaments and of relative viscosity 37 is made, using the process and apparatus described in the foregoing. The yarn is made of filaments with 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 level in the range of 300 to 400 parts per million, and small amounts of phosphorus in the range of 8 to 10 parts per million. The only additive provided intentionally exterior is an "organic pigment or toner," which is an anthraquinone dye, the level of which is 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 "as is spun" denier measured at 847. The denier interval measured is from 823 to 873. The yarn has a tenacity of 7.9 grams per denier and an elongation at break equal to 28%. The shrinkage (DHS177) is 3.1%. The properties of this yarn from Comparative Example A are summarized in Table 1. This comparative example shows the properties of a typical industrial yarn of the prior art Dacron ™ (with cross sections of round filament as illustrated in Figure 14B) sold by DuPont under the designation 840-140-T51 and is a low shrink yarn. These packages of yarn of the prior art together with the filament assembly illustrated by figure 4.

COMPARATIVE EXAMPLE B Using exactly the same conditions as in Comparative Example A, except that an enlarged capillary dimension versus the capillary dimension used in Example 1 was used for the row, nominal denier 1000 yarns were made having 140 filaments with round cross sections, such as it is shown in figure 14B. The same shrinkage and tension properties as for the yarns of Comparative Example A were measured. 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 Dacron ™ 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 were produced having 192 filaments with round cross sections, as shown in Figure 14B. In contrast to Comparative Examples A and B, the row used has reduced capillary dimensions. The properties of shrinkage and tension were different from the properties of the yarns of Comparative Example A by means of altered process conditions: the supercharging speed between the roller 9 and the winding roller 14 is reduced to 5%, so that the winding speed of the roller is 2693 meters / minute (2945 yards per minute), and the interlacing air temperature is the ambient temperature (ca. 30 ° C) and slightly higher than the supply pressure, 3.5 kg / cm2 (50 pounds per square inch). These yarns have a tenacity of 8.9 grams per denier, an elongation at break of 17.5% and a shrinkage in dry heat (DHS177) of 12.2%. The properties of this comparative example yarn B are summarized in Table 1. 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 A, except as indicated herein, nominal denier yarns 1100 having 140 filaments are produced. The filaments are produced from rows with capillary shapes as shown in Figure 13A and result in filaments with cross sections formed in the form of a flat ribbon, as shown in Figure 13B. These yarns have dry heat shrink properties, which measure the same as in Comparative Example A. The properties of this yarn of Comparative Example D are summarized in Table 1.

COMPARATIVE EXAMPLE E Using exactly the same conditions as in Comparative Example D, except as indicated herein, nominal denier 1000 yarns having 140 filaments are produced from rows with capillary shapes as shown in Figure 13A and capillary size. slightly smaller than in Comparative Example D. These yarns have filaments with cross sections shaped as a flat ribbon, as shown in Figure 13B. These yarns have dry heat shrinkage which are produced according to the method described in Palmer, U.S. Patent 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 interlaced air at 3.5 kg / cm2 (50 pounds per square inch) of supply pressure and approximately 30 ° C, which provides a dry heat shrink ( DHS177) of 5.3%, and a tenacity of 8.4 grams per denier. 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 having 140 filaments are produced from arrays with capillary shapes as shown in Figure HA. This yarn has filaments with hollow bilobate shaped cross sections, as shown in Figure 11B. The properties of this thread of Comparative Example F are summarized in Table 1.

COMPARATIVE EXAMPLE G Using exactly the same conditions as in Comparative Example A, except as indicated herein, nominal denier yarns 1000 having 140 filaments are produced from rows with elongated capillary shapes, as shown in Figure 12A. This yarn has filaments with hollow disc-shaped cross-sections, as shown in Figures 12B. The properties of this thread of Comparative Example G are summarized in Table 1.

COMPARATIVE EXAMPLE H Using exactly the same conditions as in Comparative Example C, except as indicated herein, a nominal denier yarn 840 having 140 filaments is produced. The filaments are produced from rows with round capillary shapes as shown in Figure 14A and result in filaments with round shaped cross sections, as shown in Figure 14B. The properties of this yarn of Comparative Example H are summarized in Table 1. This comparative example shows that 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 I Using exactly the same conditions as in Comparative Example A except that the row used is of enlarged capillary versus the capillaries used in the yarns of Comparative Examples A of nominal denier 1100 are produced having 140 filaments with round cross sections as shown in Figure 14B. The same shrinkage properties are measured for the yarns of Comparative Example A. The properties of this yarn of Comparative Example I 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 thread of low shrinkage.

EXAMPLE 1 Using exactly the same conditions as in Comparative Example A, except as explained herein, nominal denier 840 threads are produced which have 140 filaments from rows with capillary shapes as shown in Figure 7. This yarn has filaments with "S" shaped cross sections, as shown in Figure 1. The properties of this yarn from Example 1 are summarized in Table 1 EXAMPLE 2 Using exactly the same conditions as in Comparative Example A, except as indicated herein, nominal denier yarns 1000 having 140 filaments are produced from rows with enlarged capillary shapes, as shown in Figure 7. This yarn it has filaments with "S" shaped cross sections, as shown in figure 1. The properties of this thread of example 2 are summarized in table 1.

EXAMPLE 3 Using exactly the same conditions as in comparative example C, except as indicated above, nominal denier yarns 1000 and 192 filaments are produced from rows with capillary shapes as shown in Figure 7. The resulting filaments have sections "S" shaped cross-sections, as shown in figure 1. These yarns have dry heat shrink properties which measure the same as in comparative example C. The properties of this yarn of example 3 are summarized in table 1 .

TABLE 1 THREADS Examples of the invention Table 1 summarizes the properties of the threads A to I of the comparative examples with threads 1, 2 and 3 of the example of the invention. 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 1 and the comparison is preserved substantially regardless of the shape in the cross section of the filament. The shaping filaments with sinusoidal cross section in the form of industrial polyester yarns are not different or substantially different from the prior art and other yarns of comparison with respect to these properties. The surprising and distinctive characteristics of the yarns of the invention are found in the properties of a fabric that incorporates the yarns with at least part of the filaments formed in sinusoidal cross section.

EXAMPLE 4 A fabric is constructed from the yarns of Comparative Example H in the warp direction with 7.7 threads / cm (19.5 threads or threads per inch (ppi)) and the threads of Example 3 in the fill direction with 8 threads / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric (comparative example O) is used and higher numbers are provided to visually indicate better coverage power. The properties for and the observations regarding this cloth are summarized in table 2.

COMPARATIVE EXAMPLE J A fabric is constructed from the yarns of comparative example H in the warp direction with 7.7 yarns / cm (19.5 ppi) and yarns from comparative example D in the fill direction with 8 yarns / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric is used (comparative example O) and the higher numbers are provided to visually indicate better coverage power. The resulting fabric is visually classified for coverage power. Table 2 summarizes the properties for and observations about this fabric.

COMPARATIVE EXAMPLE K A fabric is constructed from the comparative example H of yarns in the warp direction with 7.7 yarns / cm (19.5 ppi) and yarns from comparative example E in the fill direction with 8 yarns / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric is used (comparative example O) and the higher numbers are provided to visually indicate better coverage power. The resulting fabric is visually classified for coverage power. Table 2 summarizes the properties for and observations about this fabric.

COMPARATIVE EXAMPLE L A fabric is constructed from the threads of comparative example H in the warp direction with 7.7 threads / cm (19.5 ppi) and threads of comparative example F in the fill direction with 8 threads / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric is used (comparative example O) and the higher numbers are provided to visually indicate better coverage power. The resulting fabric is visually classified for coverage power. Table 2 summarizes the properties for and observations about this fabric.

COMPARATIVE EXAMPLE M A fabric is constructed from the yarns of comparative example H in the warp direction with 7.7 yarns / cm (19.5 ppi) and yarns of comparative example G in the fill direction with 8 yarns / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric is used (comparative example O) and the higher numbers are provided to visually indicate better coverage power. The resulting fabric is visually classified for coverage power. Table 2 summarizes the properties for and observations about this fabric.

COMPARATIVE EXAMPLE N A fabric is constructed from the yarns of comparative example H in the warp direction with 7.7 yarns / cm (19.5 ppi) and yarns of comparative example I in the fill direction with 8 yarns / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric is used (comparative example O) and the higher numbers are provided to visually indicate better coverage power. The resulting fabric is visually classified for coverage power. Table 2 summarizes the properties for and observations about this fabric.

COMPARATIVE EXAMPLE OR A fabric is constructed from the threads of comparative example H in the warp direction with 7.7 threads / cm (19.5 ppi) and threads of comparative example A in the fill direction with 8 threads / cm (21 ppi). The fabric is visually classified to determine its ability to create a cover of the filling yarn by an observer using a light box for backlighting the fabric. A classification system 1-10 with a rating of 1 provided to the control fabric is used (comparative example O) and the higher numbers are provided to visually indicate better coverage power. The resulting fabric is visually classified for coverage power. Table 2 summarizes the properties for and observations about this fabric.

TABLE 2. FABRICS AND COVER CLASSIFICATIONS TO: 7.7 warp yarns / cm (19.5 warp yarns / inch)) X (8 yarns fill / cm (21 yarns fill / inch)) FABRIC CONSTRUCTION Table 2 summarizes the covering properties of 7 sign fabrics constructed with the yarns of comparative example H in the warp of the fabric (7.7 warp yarns / cm (19.5 warp yarns per inch)) and a variety of fill yarns , including the invention, with 8 filler threads / cm (21 filler / inch threads). The example O is the control fabric. The control fabric, example 0 (= H X A) is visually rated for the fabric cover and assigned a grade of 1. The control is described by comments appropriate to this cover rating of 1 compared to 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 comprising the fabric allows some transmission of light when observed against a lighting box, but the appearance otherwise is uniform.

EXAMPLE 5 A fabric is constructed from the yarns of Comparative Example H in the warp direction with 7.7 threads / cm (19.5 ppi) and the threads of Example 1 in the fill direction with 8 threads / cm (17.8 ppi). Table 3 provides the comments comparing the cover power of this fabric with the other fabrics. In addition, the reduction in% by weight of this fabric compared to the weight of the fabric of Comparative Example O (control) is calculated and presented in Table 4.

EXAMPLE 6 A fabric is constructed from the yarns of comparative example H in the warp direction with 7.7 yarns / cm (19.5 ppi) and the yarns of example 2 in the fill direction with 6.2 yarns / cm (15.8 ppi). Table 3 provides the comments comparing the cover power of this fabric with the other fabrics. In addition, the reduction in% by weight of this fabric compared to the weight of the fabric of comparative example O (control) is calculated and presented in table 4.

COMPARATIVE EXAMPLE OR A fabric is constructed from the yarns of comparative example H in the warp direction with 7.7 yarns / cm (19.5 ppi) and the yarns of comparative example A in the fill direction with 8 yarns / cm (21.0 ppi). Table 3 provides the comments comparing the cover power of this fabric with the other fabrics.

TABLE 3. FABRIC ^ AND COVERAGE RATINGS Control = O = H X A, (7.7 warp yarns / cm (19.5 warp yarns / inch)) X (8 yarns fill / cm (21 yarns fill / inch) Invention = H in warp (7.7 warp yarns / cm (19.5 warp yarns / inch)) X (fill yarns indicated / inch)) In table 3, the cover and appearance of operation of the three fabrics, examples 5 and 6 and the control fabric of example 0 are summarized. Examples 5 and 6 show that a commercially satisfactory covering and fabric appearance is obtained from filament yarns in sinusoidal cross section, even when they are present in a reduced fill yarn count, versus filament filaments of section round cross section of denser tissue. This result is surprising in view of the generally accepted strategy of using dense fabrics to obtain more cover. However, denser tissues produce an additional expense. More filling yarns present in a fabric decrease the weaving process since the weaving machine requires more time to introduce the filling yarns. This result of Examples 5 and 6 demonstrates a faster weaving process that can be obtained since the count of fill yarns is reduced to a property of constant appearance for the fabric. In addition, this reduced fill yarn count translates into savings in fabric weight compared to higher yarn counts.

EXAMPLE 7 A fabric is constructed from the yarns of Example 2 in the warp direction, with 6.2 yarns / cm (15.8 ppi) and the yarns of Example 1 in the fill direction with 6.2 yarns / cm (15.8 ppi). The reduction in weight% of this fabric is calculated in comparison with the weight of the fabric of Comparative Example 0 (control) and is presented in Table 4.

TABLE 4. REDUCTION OF WEIGHT OF THE FABRIC O = control Those familiar with the art who have the benefit of the teachings of the present invention as set forth in the foregoing, can make numerous modifications thereto. These modifications are considered covered within the scope of the present invention as set forth in the appended claims. 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 (13)

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

1. An industrial filament, characterized in that it comprises a synthetic melt-spun polymer having a relative viscosity of about 24 to about 42, a denier of about 4 to about 8, a toughness of about 6.5 grams / denier to about 9.2 grams / denier, and a sinusoidal shaped cross section perpendicular to a longitudinal axis of the filament, the cross section has a dimensional proportion from about 2 to about 6.

2. The industrial filament according to claim 1, characterized in that the dimensional proportion is from about 2.5 to about 5. The industrial filament according to claim 1, characterized in that the dimensional proportion (AR) is defined as a proportion of a first dimension (A) with respect to a second dimension (B) where the first dimension (A) is defined as a length of the segmen a straight line connecting the first and second points on the periphery of the cross section of the filament that is farthest from the other, and the second dimension B is 2r where r is the sum of the radius rl of a first outer convex edge of the filament and the radius r2 of a second outer convex edge of the filament. 4. The industrial filament according to claim 1, characterized in that the polymer consists essentially of poly (ethylene terephthalate). 5. The industrial filament according to claim 1, characterized in that the denier is from about 6 grams to about 7.2 grams. 6. The industrial filament according to claim 1, characterized in that the toughness is from about 7.5 grams / denier to about 8.0 grams / denier. The industrial filament according to claim 1, characterized in that it comprises a dry heat shrink from about 2 to about 16% at 30 minutes at 177 ° C. 8. An industrial thread, characterized p > or comprising: a plurality of industrial filaments, each of the filaments comprising: a synthetic melt-spun polymer having a relative viscosity of about 24 to about 42, a denier of about 4 to about 8, a toughness of about 6.5 grams / denier at approximately 9.2 grams / denier, and a sinusoidal shaped cross section normal to the longitudinal axis of the filament, the cross section has a dimensional ratio from about 2 to about 6. The industrial yarn according to claim 8, characterized in that The filaments are placed in a tile arrangement so that the ends of the first set of filaments are close, and aligned with the ends of a second set of the filaments so that the pairs of the first set of the filaments and the second set of filaments are aligned. filaments are placed substantially along lines sinusoidal The industrial yarn according to claim 8, characterized in that the filaments are placed in a tile arrangement so that the inner concave surfaces of a first set of the filaments contact the inner concave surfaces of a second set of tiles. filaments, the outer convex surfaces of the first set of the filaments contact the outer convex surfaces of the second set of filaments, so that the first set of filaments and the second set of filaments are placed in an immobilized arrangement. 11. An industrial fabric, characterized in that it comprises: a plurality of first industrial threads in a warp direction; a plurality of second industrial yarns in a filling or weft direction woven with the first industrial yarns; and at least part of the first industrial yarns and / or at least part of the second industrial yarns comprise a plurality of industrial filaments, each of the filaments comprising: a synthetic melt-spun polymer having a relative viscosity of about 24 at about 42, a denier from about 4 to about 8, a toughness from about 6.5 grams / denier to about 9.2 grams / denier, and a sinusoidal shaped cross section normal to the longitudinal axis of the filament, the cross section having a dimensional proportion from about 2 to approximately 6. 12. The industrial fabric according to claim 11, characterized in that at least the first industrial yarns or the second industrial yarns comprise a plurality of industrial filaments, so that the cloth has a reduction in weight total of at least 7% compared to a fabric fa completely made of yarns comprising other filaments which are essentially the same as the industrial filaments, except that the other filaments have circular cross sections. 1

3. The industrial filament according to claim 11, characterized in that the first industrial yarns and the second industrial yarns comprise a plurality of the industrial filaments, whereby the cloth has a reduction in the total weight of at least 13% in comparison with 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.