MXPA98002820A - Improvements related to the identification of hue fibers - Google Patents

Abstract

The hollow fibers are distinguished by their hollow which is partially filled with a differentiating feature which is a protuberance of a characterizing polymeric material. This material can be the same or different from the one that constitutes the rest of the fiber. The protrusion is provided by proper adjustment of the yarn capillarity, ie, during extrusion to form the fib

Description

IMPROVEMENTS RELATED TO THE IDENTIFICATION OF HOLLOW FIBERS DESCRIPTION OF THE INVENTION This invention relates to improvements related to the identification of fibers that includes a novel method for making a hollow fiber with a characteristic by which it can be identified later, novel hollow fibers marked in this way to be identifiable, and with products and materials that include such marked fibers, especially filler fibers filling materials (often referred to briefly as "filler fibers") and with products, which include lint, fiber balls and other products comprising such labeled fibers and materials made therefrom, and processes and apparatus for obtaining such hollow fibers and your products and materials. Users of fiber manufacturers consistently demand excellence in the fibers provided by the manufacturer. In other words, the users of the manufacturers require that the properties of any particular fiber do not vary appreciably between batches of this fiber as different batches REF: 27160 are produced from that fiber for several years. However, the fiber manufacturer needs to be able to identify the fiber of different batches of production, and at the same time maintain the consistency and uniformity that customers require. A lot of notoriety has been given to the identification of fibers in criminology, for example, as a way to make murderers or other criminals subject to justice. However, manufacturers also have other more mundane and practical reasons for needing to identify the production of particular fiber batches. Thus, for a long time it has been desirable to find a cheap but effective system for identifying fibers. For example, previously, one method has been to add a chemical or nuclear marker to the fiber, but this method has been expensive and complicated and has disadvantages, since the ease with which a different manufacturer of fibers can add the same marker after the manufacture, and in this way confuse this system for identification. In particular, there has long been a need in an economical way to identify and differentiate flexible hollow fibers (especially hollow polyester fibers) which are rolled and used as a filler fiber in products such as fluff, fiber balls and other fiber materials. stuffing and stuffed items such as pillows, stuffed garments, blankets, cushions and bedding and similar furniture. Such crimped hollow fibers have a single continuous gap through the length of the fiber and include those described by Tolliver in U.S. Patent No. 3,772,137, which has a hollow content of about 13 percent to about 25 percent, and a frequency from about 2 curls to about 5 curls per centimeter (5-12 curls per inch), and a curling index of about 25 to about 35. As indicated, it is very important that any identifier system can not change the performance and properties of fibers. The present invention solves this need by identifying and differentiating hollow fibers by providing a visual identification marker in the cross-sectional configuration of the hollow fiber. This marker identifies the hollow fiber only visually, that is, without significantly affecting the operation of the fiber. Fibers with such a visual identification marker according to the present invention are often referred to as "identifying fibers" (or "identifying filaments").

The term "fiber" and "filament" are often used in the present in an inclusive manner, without meaning the use of one term should exclude the other. Accordingly, this invention provides a process for preparing hollow filaments of a synthetic polymer comprising the post-blending melt spinning stages of the synthetic polymer through spinning capillary holes segmented in an arc shape., which form a segmented periphery so that the remaining freshly spun fused streams alternate and form continuous hollow filaments having a continuous inner surface, and which are cooled to solidify the hollow filaments and, if desired, stretch the resulting solid hollow filaments and / or further processing, and / or converting into short fibers, characterized in that the molten polymer is also spun in a small amount through a separate small hole which is located within the segmented periphery so as to form a small protrusion which is identifiable visually on the inner surface of the hollow filaments. As indicated below, the resulting protrusion should desirably be small enough that the degree of irregularity (as defined herein) of the hollow cross-section of the hollow filament is less than 5%.

According to another aspect, this invention provides as novel articles, hollow fibers which are of a synthetic polymer and which have a single continuous gap through the length of the fiber, an empty content of up to 30% and a hollow cross section that shows a characteristic polymeric material protruding into the single continuous gap from an interior surface of the single continuous gap, the hollow cross section having a degree of irregularity (as defined herein) of less than 5%. According to a further aspect, this invention provides as novel articles filling material of filling fiber comprising flexible hollow filling fibers, which are of a synthetic polymer, wherein each of the hollow filling fibers has a continuous gap only through the length of the fiber, and a hollow content of up to 30%, and in which the filler fiber filling material is identified by all or a predetermined proportion of the fibers having a hollow cross section that shows characteristic polymeric material protruding into the single continuous gap from a single continuous hollow surface, the hollow cross section has a degree of irregularity (as defined herein) of less than one. hollow cross-section of a hollow fiber in the direction in which the hollow cross-section has a protruding part protruding from the hollow fiber. of the hollow cross section from an interior surface and the degree of irregularity is calculated, as a percentage, by dividing the area of the projecting part by the sum of the area of the projecting part and the area of the hollow section (and multiply x 100 to obtain the percentage), • this definition differentiates between the area of a protruding part and the area of the hollow section (ie, the cross-sectional area of the gap). In accordance with other aspects described herein, filler fibers (and including articles filled therewith) are provided in which the filler fiber comprises flexible hollow fiber voids of synthetic polymer and in which, for example, by at least 10% by weight of the fibers have a unique continuous vacuum across the length of the fiber, and have a cross section which shows that the characteristic polymeric material protrudes from the wall (ie, from an inner surface of such a vacuum) within the vacuum, whereby the characteristic protruding polymer material differentially identifies the fiber of similar synthetic polymer fibers which do not contain any protruding polymer material but, which does not significantly differentiates the performance properties (as filler material) of the fiber with respect to similar fibers. Thus, according to the invention, the polymer material that protrudes from the inner surface of the single vacuum of a (first) fiber of a synthetic material is used to identify the (first) fiber and differentiate it from other hollow fibers of cross section similar and having similar operating characteristics to those of the first fiber (identified and differentiated), except, of course, that the other fibers do not have the polymer material protruding from the inner surface of the fiber wall. Hollow synthetic polymer fibers, which have a unique continuous vacuum across the length of the fiber, are also provided, wherein the cross section of the fiber shows that the characteristic polymer material protrudes from a wall of such a vacuum, so that the characteristic protruding polymer material differentially identifies the fiber as compared to similar synthetic polymer fibers which do not contain any protruding polymer material but which do not differ significantly in terms of performance properties of this fiber with respect to similar fibers . Other aspects include methods, appliances and products described herein. Preferred features include the use of polyester polymer, with material for the synthetic polymer of the fiber and / or the characteristic polymer material, and preferably for both. In most of the aspects, the filler fiber filling material and the hollow, curled and flexible filling fibers of the invention are conventionally prepared by methods known in the art, such as those mentioned herein. Preferred hollow fibers are prepared from polyester polymers, especially polyethylene terephthalate, and this preferred embodiment is described herein more particularly, for convenience, it should be understood that appropriate modification can be made by those familiar with the art. for other synthetic polymers such as polyamides or polypropylene, taking into account the differences, for example, under melting conditions and properties, such as melt viscosity. One such description of the art is U.S. Patent No. 3,772,137 to Tolliver which discloses hollow synthetic filaments and a capillary spinneret for spinning such filaments containing a single continuous vacuum of synthetic polymers, including polyesters, in Figures 1, 3. and 5 of it. Figures 1-4 are enlarged photographs of cross sections of filaments as they are spun, according to the invention, as described in the following. Figure 5 is an enlarged photograph of conventional hollow filament cross sections, as they are spun, according to the prior art. Figure 6 is an enlarged view of a capillary spinelet, taken observing the lower face of the spinerette for spinning preferred filaments of the invention, such as those of Figures 1-4. Figure 7 is an enlarged photograph showing preferred fibers of the invention, not only a cross section but also that the fibers are crimped as described hereinafter. With reference to Figure 6 of the accompanying drawings, which shows an enlarged view of a capillary spinneret for spun filaments of the present invention, it will denote the similarity to that of Figure 5 of Tolliver. The capillary is formed of four individual segments generally designated 11, 12, 13 and 14 in the form of peripheral grooves 19, 20, 21, 22 which are bent to form arcs-lu of an incomplete circle. In each of the peripheral slots 19, 20, 21 and 22, there are "tabs" 23 and 24, 25 and 26, 27 and 28, and 29 and 30, respectively, which are the enlarged ends of the slot to assist in the post-lucidity of the molten polymer that arises, to form the desired hollow solid filament, as is known in the art, such as in U.S. Patent No. 3,772,137 to Tolliver. An important and novel difference in Figure 6 herein (that the difference from Figure 5 of Tolliver) is to provide an orifice 40. The molten polymer extruded through the orifice 40 solidifies and coalesces in the inner wall of the hollow filament formed by post-coalescence of the molten polymer extruded through the slots 11, 12, 13 and 14 to form an identifying protrusion projecting into the vacuum of the internal wall of the identifying fiber. The relative location of the protrusion may vary along the length of the filament, as will be understood. The cross sections of such hollow identifier filaments, as they are spun, contain a unique vacuum, with polymer protruding from an internal wall in vacuum, which are shown in Figures 1-4, in which most of the sections cross sections clearly show the polymer that protrudes in a vacuum.

The two cross sections in Figure 1 (at the left end of the middle horizontal row, and in the next horizontal row down, fourth from the left end) do not clearly show the polymer protruding into the gap, - we believe that these sections Cross-sectional filaments are actually similar, but that the protruding polymer can not be seen clearly, perhaps due to the way in which the cross sections of filament were cut and / or due to the angle of the photograph. In FIGS. 2-4, further enlarged photographs of cross sections of identifier filaments are shown, in which the protuberances can be clearly seen, and in which enlargements are indicated. Such identifiable filaments have an operation and properties as fillers comparable to those of similar conventional filaments in the art which do not contain a protruding polymer and which is shown in Figure 5. The filler fiber filaments are so thin that, without extension It is doubtful whether a person will be able to observe any vacuum in the cross section, or whether the filament is solid, hollow or with multiple voids, without being able to recognize if any void is partially filled with protruding polymer. In other words, without making extended cross sections and examining and comparing them, most people will be unable to determine a significant difference between filaments of the invention and conventional filaments of the technique. Thus, the object of the invention has been obtained. economically by using a different capillary spin to provide a different cross-sectional configuration internally, without altering the exterior of the filament or its operation. The operation of the novel fibers of the present invention is the same as that of similar fibers without any protrusion. The protrusion in a fiber according to the invention has no effect on performance (such as its volume properties) but is visually evident when a cross section is examined (enlarged), so that the fiber acts as an identifier (visual ) without affecting the operation. Although convenience may be shown to refer to the degree of irregularity, we preferred to avoid using an area-based relationship, because we prefer to make a protuberance that is visually similar to a sudden indication, since a larger wall section with gradual thickening is not so easy to observe visually, and thus would not be so desirable for the recent invention. However, we measure the degree of irregularity for the cross sections in Figures 1-4 herein, and they are only about 1.5%, that is, well below 5%. It will generally be desirable for the protrusion to extend significantly and detectably within the vacuum, ie, to an amount of about 5 or 10% of the average wall thickness of the filament and not more than 35% of the average wall thickness, considering previous. A lighter thickening of the wall is not detected as easily as a significant sudden indication. The important goal is to have a feature that is relatively easy to detect visually, especially when using the same polymer material. Tolliver describes empty contents of about 13 percent to about 25 percent for these hollow fibers, and such vacuum contents are suitable and useful for hollow fibers according to the invention, too. Hollow fibers with vacuum contents of 15-20 percent are especially useful for filler fiber purposes, and a wider range of vacuum contents of up to 30 percent can also be identified by providing a protruding material in accordance with the invention. The vacuum content is generally at least 10%, since a smaller amount may not provide much difference of solid fibers, but this will most likely depend on the end use desired for the fibers, since the thick wall can sometimes be more important than the empty content. It is not necessary to provide each filament (ie, 100%) with an identifier, but a regulated ratio (eg, at least about 10% by weight) of particularly identified filaments can be included, and recorded for a batch of fiber which is sold. However, all filaments can be provided with an identifier, if desired. In addition, although the filaments spun from a single polymer are less expensive, and generally preferred, so that the polymer material is the same in the protrusion as in the rest of the filament, different polymers, if desired, can be used. way that better identification is provided for groups or batches of fibers. As will be readily understood, the invention presents in itself many variations. For example, the number and pattern of protrusions in relation to the vacuum may vary, to some limited extent, keeping in mind that it is generally desirable to maximize the empty content to take advantage of the presence of the vacuum.

The invention is further illustrated in the following example, all parts and percentages are by weight, unless otherwise indicated. The coating levels (lubricants and finishes) applied to the filaments are OWF (with respect to the weight of the fiber), the relative viscosity (sometimes referred to as LRV) and the vacuum content (by volume, by the flotation method) they are determined by the methods mentioned in U.S. Patent No. 4,712,988 (Broaddus et al.). The volume measurements are the manner of operation of the filler fiber are generally determined and were generally determined by the method mentioned in Tolliver, US Pat. No. 3,772,137. The curl properties were also measured essentially as described by Tolliver.

EXAMPLE Fiber fillers of poly (ethylene terephthalate) spun yarns of relative viscosity of 20.4 are cut at a polymer temperature of 291 to 297 ° C at 1167 mpm (1277 ypm) through a spinneret with 363 capillaries, at an expense per capillary of 0.126 kg / hr (0.278 lb / hr) using holes as shown in figure 6. The filaments are assembled to form a relaxed stretched 922,000 denier cord. The rope is stretched in a conventional manner, using a drawing ratio of 3.5 x in a hot, wet spray drawing area maintained at about 95 ° C. The stretched filaments are crimped in a conventional padding box curler (8.9 cm in size (3.5 inches)) to a curling frequency of approximately 3.3 crimps per centimeter (8.5 crimps per inch) so that a support volume is obtained ( volume at 0.014 kg / cm2 (0.2 psi)) of approximately 15 mm (0.6 inches), and the curled cord relaxes in an oven at 180 ° C. The fiber has been lubricated before relaxing it with the finish containing about 1% silicon by fiber weight to provide an average friction of 0.30. A conventional antistatic overlay of approximately 0.07% by weight is applied. It is found that the fibers have an average void content of about 18% and a denier per filament of about 6. The outer periphery of the fiber is round and regular. The filaments as spun of the invention have cross sections as shown in Figures 1-4. The filaments contain unique continuous voids. In the interior peripheries of these voids there are protuberances which serve as an identification mark. As will be seen from the following comparison, the performance as filler material (in particular the volume properties) of these fibers of the invention as filler material are essentially similar to those of conventional fibers which are similar (except for the absence of outstanding material that acts as a visual identification mark).

COMPARISON The above filler fiber is compared with current conventional lubricated hollow products (similarly about 1%) of the same denier (approximately 6) and an average empty content (about 18%), spun using conventional capillarity (as shown in Figure 6, but without the orifice 40, i.e., more or less as shown by Tolliver in Figure 5 of U.S. Patent No. 3,772,137), and similarly curled up to a curling frequency of approximately 3.4 crimps per centimeter (approximately 8.75 crimps per inch) to provide a similar support volume level of 15 mm (0.59 inches). These conventional filaments (as they are spun) have a cross section as shown in Figure 5. These cross sections are different from those of the invention in that they do not contain the identification tag of the fiber protruding from the inner wall towards the vacuum. In the above comparative test, when comparing the volume capacity of the filler fiber constituted of identifier fibers of the invention with the volume capacity of the filler fibers consisting of fibers of similar cross section except that the ride was free (it is say, without identifier), the curling of each fiber group was compared and carried out in the same padding machine under the same conditions (using the same speed, temperature profile and pressures). Figure 7 is an enlarged photograph of the crimped hollow fibers according to the invention, showing a hollow cross section that is somewhat similar to the (enlarged) photographs of Figures 1-4, except that more fibers can be seen so that this photograph can show that this fiber has actually been curled conventionally using such a quilting box. The hollow fibers of the invention can be processed into products such as fluff and fiber balls (sometimes referred to as groups) and can be further processed into pillows, stuffed garments, blankets and bedding and similar furniture, as described in the art, including what is specifically mentioned herein, and the technique such as LeVan, U.S. Patent Nos. 3,510,888 and 4,999,232 and various Marcus patents, including U.S. Patent Nos. 4,618,531, 4,783,364, 4,794,038, 4,818,599, 4,940,502 and 5,169,580 and U.S. Patent No. 5,088,140 (Belcher et al). Although, until now, most of the filling fibers are made of short fibers, as described above, there has been an increasing commercial interest in using tow with erased registration of continuous filaments as filling fibers, as described, for example, by Watson in U.S. Patent Nos. 3,952,134 and 3,328,850. Accordingly, the invention's application for filler fibers in the form of continuous lined filament lined fillers is also contemplated herein and the invention is not confined to short fibers and filler fibers made of short fibers. Additionally, as is well understood in the art, it has been commonplace to mix or stir fibers for use as filler material. Accordingly, it is contemplated that the filler fiber according to the invention may consist essentially entirely of identifying fibers according to the invention, or these identifying fibers may be mixed with other fibers; therefore, the filler fiber filling material can be identified by all or a portion of its fibers which are such identifying fibers. Filling fibers, as is well understood by those familiar with the art, is the abbreviation for a filler fiber filling material, or, more briefly, a filler fiber material, and refers to a bulky mass of filler. fibers used to fill articles, such as pillows, cushions and other furniture materials that include other bedding materials, such as sleeping bags, mattress padding, quilts, blankets, duvets and the like, and in garments such as parkas (coat with hood) and other isolated articles of clothing, woven or not. The curling is an important feature and provides the volume that is an essential requirement for the filling fibers. Generally, the fibers are crimped by mechanical means, usually in a quilting box curling iron, as described in Halm et al. in USP 5,112,684. Curling can also be provided by other means such as asymmetric cooling or using two-component filaments as reported, for example, by Marcus in USP 4,618,531 and USP 4,794,038, and in the literature mentioned herein so as to provide a "curly" spiral". As is well understood by those familiar with this technique.

It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, property is claimed as contained in the following:

Claims (9)

1. l. A process for preparing hollow filaments of a synthetic polymer, characterized in that it comprises the steps of post-coalescence melting of the synthetic polymer through capillary holes of segmented arc-shaped yarns forming a segmented periphery so that the resulting molten streams , freshly spun, coalesce and form continuous hollow filaments having a continuous inner surface, and cool to solidify the hollow filaments and, if desired, stretch the resulting solid hollow filaments and / or further process and / or convert to short fibers, the The process is characterized in that the molten polymer is also spun in a small amount through a separate small hole which is located within the segmented periphery so as to form a small protrusion which is visually identifiable on the inner surface of the hollow filaments.
2. 2. The process according to claim 1, characterized in that the synthetic polymer is polyester.
3. 3. The process according to claim 1 or 2, characterized in that the synthetic polymer is polyester and the molten polymer is also a polyester.
4. 4. The process according to claim 3, characterized in that the polyester of the molten polymer is the same as that of the synthetic polymer.
5. 5. Articles having hollow fibers of a synthetic polymer and having a single continuous vacuum through their length of the fiber, an empty content of up to about 30% and a hollow cross-section showing a characteristic polymer material protruding into the continuous vacuum Unique from an interior surface of the single continuous vacuum, the hollow cross section has a degree of irregularity (as defined herein) of less than 5%.
6. 6. Articles characterized in that they comprise a filler fiber filler material comprising curled and flexible hollow filler fibers that are of a synthetic polymer, wherein the hollow filler fibers have a continuous continuous vacuum across the length of the fiber, and a vacuum content of up to 30%, and wherein the filler fiber filling material is identified by all or a predetermined portion of the fibers having a hollow cross section showing a characteristic polymer material protruding into the Continuous vacuum from an interior surface of the single continuous vacuum, the hollow cross section has a degree of irregularity (as defined herein) of less than 5%.
7. 7. The articles according to claims 5 or 6, characterized in that the synthetic polymer is polyester.
8. 8. The articles according to any of claims 5, 6 or 7, characterized in that the synthetic polymer is polyester and the characterizing polymer material is also a polyester.
9. 9. The articles according to claim 8, characterized in that the polyester of the characteristic polymer material is the same as that of the synthetic polymer.