US 3273329 A
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Description (OCR text may contain errors)
Sept. 20, 1966 sc 3,273,329
TEXTILE YARNS Original Filed July 25, 1963 Ill INVENTOR Fnm'enn in United States Patent 3,273,329 TEXTELE YARNS Frederick Scragg, Mobberley, England, assignor to Ernest Seragg & Sons Limited, Macclesfield, England Original application July 25, 1963, Ser. No. 297,510, new Patent No. 3,199,284, dated Aug. 10, 1965. Divided and this application Feb. 23, 1965, Ser. No. 434,257 Claims priority, application Great Britain, July 26, 1962, 28,710/ 62 5 Claims. (Cl. 57140) The present application is a division of my US. patent application Ser. No. 297,510, filed. July 25, 1963, now U.S. Patent No. 3,199,284, entitled Process for Making Yarn From a Thermoplastic Strip.
The present application relates to textile yarns.
It is well known that during the manufacture of a textile yarn from a plurality of relatively short fibers, such as cotton, it is necessary to draft or align the fibers into a sliver and then to twist the sliver, the twist being for the purpose of imparting strength to the sliver and binding the fibers together. Such a yarn has a relatively soft handle if the turns per inch are not excessive, which is to say if the yarn is not tightly twisted, and the softness and air-retaining properties are modified not only 'by the degree of twist but also by the length of the ends of the fibers which protrude from the yarn. Because of the protrusion of these ends, however, it has been found that in a loosely twisted yarn some of the fibers tend to pull out of the yarn and to pill. Similar results occur with yarns constructed from modern synthetic filaments, and, in fact, pilling occurs more readily with such filaments since their surfaces are usually smoother than those of fibers derived from natural sources.
Attempts have been made to produce non-pilling yarns having characteristics similar to those, for example, of a spun yarn such as cotton or wool, by applying a continuous crimp to the filaments of the yarn made from a continuous synthetic material. Such yarn, however, more particularly if made by twist crimping, tends to be highly elasticized, which is to say its extension under a relatively small tensioning force is excessive, although the bulk of the yarn may be satisfactory. Thus, although pilling is, of course, prevented with such yarn, the fact that the yarn possesses a series of radially extending kinks or loops provide the disadvantage that the material tends to catch on the fingers as well as to be excessively elastic and to elongate far too readily and easily for many purposes.
It is thus an object of the present invention to provide a synthetic yarn from a thermoplastic material which will not have the extreme elongation capability of conventional twist-crimped yarn and which at the same time will be nonpilling.
A further object of the present invention is to provide a yarn which not only cannot be elongated excessively and will not pill, but in addition which has a bulk and feel very similar to that of natural spun yarn.
In accordance with the present invention, there is provided a textile yarn which consists of an elongated twisted thermoplastic strip which is formed with a plurality of piercings distributed therealong and which has a plurality of free projecting portions distributed along the yarn and projecting from the exterior surface thereof as well as embodied in the interior thereof.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:
FIG. 1 illustrates a portion of a thermoplastic strip which has been slit in accordance with one of the steps of the process of the present invention;
FIG. 2 illustrates the strip of FIG. 1 after it has been drawn in accordance with a further step of the process of the present invention;
FIG. 3 shows a portion of the strip of FIG. 2 after it has been transversely expanded and broken according to further features of the present invention; and
FIG. 4 is an illustration of a portion of the yarn of the present invention.
Referring to FIG. 1, there is fragmentarily illustrated therein a strip of thermoplastic filament-forming material such as nylon, and in accordance with the invention the strip 1 has been pierced at closely-spaced locations so as to be provided with a plurality of slits 2 in a manner similar to that used in the manufacture of expanded metal, or by the use of rotary knives. The strip 1 must be made of a material which is capable of being drawn, and inasmuch as most filament-forming materials are thermoplastic, the drawing should be in the case of a thermoplastic material be carried out with the use of suitably heated drawing apparatus. However, in the case of non-thermoplastic material the drawing can be carried out without any heating of the material.
FIG. 2 shows the condition of the strip 1 after it has been drawn. It will be noted that not only has the width of this strip decreased while the length thereof has correspondingly increased, but in addition the slits 2 have become elongated and in this Way formed into the longer slits 3 while at the same time the widths of the portions 4 located between the elongated parallel longitudinally extending slits has also diminished, so that the slits are located closer together in FIG. 2 than they are in FIG. 1. The drawing step is important for the production of a yarn according to the invention inasmuch as each individual filament of an artificial yarn has a diameter on the order of 0.0006 inch and therefore it would be extremely difiicult to pierce a sheet of material which itself has a thickness of 0.001 inch or less with a pattern or" slits so closely spaced that the material without any drawing could be made into a yarn. With the use of the drawing step, however, in which the material may be extended from four to twenty times its length before drawing, depending upon the nature of the material which is used for the strip and the drawing temperature, it is clear that the slits can be spaced at substantial distances from each other and a thicker material can be used for the initial slitting step, while the final dimensions of the individual filamentary structures may be of the desired order. It is to be noted, however, that the dimensions of the strips and slits shown in the drawings are illustrative only and that in fact a much greater draw is pos sible than that which has been shown in FIG. 2 as com pared to FIG. 1.
FIG. 3 illustrates the condition of a portion of the strip after two further operations have been performed thereon subsequent to the drawing. The first operation is an expanding operation in which the strip is pulled transversely so as to be transversely expanded and thus made to resemble expanded metal with the openings therein extending substantially in longitudinal direction of the strip and such openings having adjacent opening portions, as is apparent from FIG. 3. This transverse expanding operation is preferably carried out continuously, and a device similar .to a tenter may be employed for this purpose, suitably modified with respeet to dimensions. Thereafter, a further operation is effected, according to which some of the filamentary structures are broken as indicated by transversal slots at the regions 5 in FIG. 3, connecting adjacent opening portions, while other fila- 'mentary structures, as illustrated at the regions 6 in FIG. 3, remain unbroken. Thus, it will be seen that portions of the strip which separate adjoining slots or piercings thereof i.e. adjacent opening portions are broken, as indicated at 5. This breaking of the strip may be brought about by subjecting the strip to continuous or interrupted blasts of very high pressure air from minute air jets, or by bombarding the strip with a sand blast. The particles in the blast may be edged as in the case of sand, or they may be spherical and made of metal or glass, and the piercing may be assisted by heating the particles so that severance of the filamentary structures is effected cleanly.
Finally, the entire structure which has been treated as illustrated in FIGS. l3 and described above is given a continuous twist as shown in FIG. 4, the unbroken strip portions 6 having a twist applied to them while the broken projecting portions 5 may project slightly from the surface of the yarn giving the yarn a hairy, soft feel. Other broken projecting portions may project inwardly and be trapped between the continuous, unbroken portions of the yarn, thus giving the yarn a certain amount of bulk.
Although it is indicated in FIGS. 1 and 2 that the piercing of the strip is carried out in a series of parallel lines, this feature is not essential. The strip may be pierced with a series of holes in predetermined positions as by the use of combs with multiple needles, or by piercing at random, in which case the piercing may be elfected with an air jet carrying particles which pierce the material as a result of the velocity imparted to the particles by the air jet. If such pierced strips are highly drawn it will be found that the holes pierced therethrough become elongated into slits 3 as shown in FIG. 2, and the result is a yarn as illustrated in FIG. 4.
Preferably, all of the operations are carried out in a continuous manner, the piercing, expanding, breaking and twisting operations following one another in a single machine, although several machines located in such a way that the yarn-forming material passes continuously from one to the other may be used. Alternatively, the pierced, drawn or broken material may be wrapped on bobbins after each operation if it is found that such winding and storage is desirable, and the present invention is intended to cover both the Continuous and discontinuous processes of manufacture.
Although the invention has been described in connection with a nylon strip, it is to be understood that any filament-forming material such as that known under the trade name Terylene or polypropylene, or any cellulosebased material such as cellulose diacetate which is thermoplastic, may be employed and the process applies equally to such suitable materials.
A relatively low twist is applied to the strip of FIG. 3 in order to form the yarn of FIG. 4, and this yarn has a natural yarn-like characteristic in that it is only slightly extensible and in that a plurality of filamentary free end portions protrude from the surface of the yarn. In addition, inasmuch as some of the broken ends of the yarn are folded in by the twisting of the yarn and act to hold the remaining filament portions apart, the result that air is trapped in the interstices of the plexus.
Before the yarn is twisted it may be heated to a point below its melting temperature, under a condition of very low tension, so that each filament portion may develop a series of random crimps, the resulting twisted yarn then having a very high proportion of air spaces compared with its total volume.
As was indicated above the piercing of the strip can be brought about by a comb or similar structure having a large number of needle points or alternatively by a blast of particles of metal or glass of suitable size which is directed against the material so that the particles pierce it, and these particles may be heated in order to assist the piercing of the thermoplastic strip.
Also, the required number of strip portions may be broken or cut by passing the drawn strip, if necessary in an extended condition, beneath a further jet of particles, the number and size of which are adjusted to break the required percentage of strip portions, or by an air jet, or even by abrasion as a result of brushing the strip.
Thus, with the process of the present invention there is produced a yarn as shown on an enlarged scale in FIG. 4 having the feel of a natural yarn while still having a desirable non-pilling characteristic and also having a very low extensibility.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of textile yarns differing from the types described above.
While the invention has been illustrated and described as embodied in textile yarns and process for the manufacture thereof, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended with the meaning and range of equivalence of the following claims.
What is claimed as new and desired to be secured by Letters Patent is:
1. A textile yarn consisting of an elongated strip of plastic material which is twisted and formed with a plurality of relatively closely spaced elongated openings surrounded and defined by uniformly spaced narrow strip portions, said openings having adjacent opening portions at least some of which are connected by transverse slots so as to form between said adjacent openings portions a plurality of free projecting strip portions which are distributed along said strip in a regularly recurring pattern and at least some of which are located at the exterior of the yarn projecting from the surface thereof.
2. A textile yarn consisting of an elongated strip of plastic material which is twisted and formed with a plurality of relatively closely spaced elongated openings extending substantially lonigtudinally of said strip, said openings being surrounded and defined by uniformly spaced narrow strip portions and having adjacent opening portions at least some of which are connected by transverse slots so as to form between said adjacent opening portions a plurality of free projecting strip portions which are distributed along said strip in a regularly recurring pattern and at least some of which are located at the exterior of the yarn projecting from the surface thereof.
3. A textile yarn consisting of an elongated strip of plastic material which is twisted and formed with a plurality of relatively closely spaced elongated openings extending substantially longitudinally of said strip, said openings being surrounded and defined by uniformly spaced narrow strip portions and having adjacent opening portions .at least some of which are connected by transverse slots spaced from the ends of said adjacent opening portions so as to form between said adjacent opening portions a plurality of free projecting strip portions which are distributed along said strip in a regularly recurring pattern and at least some of which are located at the exterior of the yarn projecting from the surface thereof.
4. A textile yarn comprising an elongated twisted fibrous structure which, in untwisted state, has the form of a two-dimensional lattice of uniformly spaced filaments which are integrally interconnected with one another at a first plurality of uniformly spaced positions arranged along said structure, and which are disrupted at a second plura y O positions also spaced in longitudinal direction of said structure and located intermediate respective ones of said first plurality of positions.
5. A textile yarn comprising an elongated twisted fibrous structure which, in untwisted state, has the form of a two-dimensional lattice comprising a first plurality of substantially parallel filaments and a second plurality of substantially parallel filaments inclined to said first plurality, said filaments being integrally interconnected with one another at a first plurality of uniformly spaced positions arranged along said structure and being disrupted in a regularly recurring pattern at a second plurality of positions also spaced in longitudinal direction of said structure.
References Cited by the Examiner UNITED STATES PATENTS Jacque 281.4 Bailey 281.4 Costa et all. 264280 White 281.4
Rasmussen 57157 White 57-34 MERVIN STEIN, Primary Examiner.
I. PETRAKES, Assistant Examiner.