US3335042A - Method of making straw-like article of nylon continuous filaments - Google Patents

Description

Aug. 8, 1967 c. M. IRWVIN METHOD OF MAKING STRAW-LIKE ARTICLE OF NYLON CONTINUOUS FILAMENTS Filed April 4, 1962 INVENTOR. (LA UDE M- IRWl/V ,J m. "I'M- E? ATTORNEy United States Patent 3,335,042 METHOD OF MAKING STRAW-LIKE ARTICLE OF NYLON CONTINUOUS FILAMENTS Claude M. Irwin, Pensacola, Fla., assignor, by mesne assignments, to Monsanto Company, a corporation of Delaware Filed Apr. 4, 1962, Ser. No. 185,031 3 Claims. (Cl. 156-161) This invention relates to the production of a straw-like article from nylon continuous filaments. More particularly, the present invention relates to a straw-like article made from parallel arranged multicontinuous filament nylon yarn bonded together by means of a treatment with a bond-inducing agent of a particular class and to a method of producing such article.

It is known to make artificial straw of viscose rayon by extruding a viscose spinning solution through an L- shaped orifice in a spinneret. Such product consists of a continuous heavy filament folded during spinning and resembles a silk-like straw. In some cases there have been disclosed multi-filament versions of this. Also, it is known to melt spin a narrow ribbon-like structure from nylon by using a slot of proper size and shape or by coalescing a plurality of melt spun filaments before they are solidified. In either of these known melt spinning procedures, a satisfactory narrow, flat strcuture is expensive and diflicult to produce. Extremely costly melt spinning spinnerets are required. Moreover, it is difficult to arrange enough slots in a conventional spinneret blank to render the melt spinning economically feasible.

It is an object of the present invention to provide as an article of manufacture a new and useful straw-like article from nylon continuous filaments.

It is another object of the present invention to provide a new and useful method of making an article simulating to some extent a straw and made from parallel arranged multicontinuous nylon filaments.

Other objects of the invention may become apparent from the following description.

In general, these objects are accomplished in the provision of a straw-like article or fillet composed of multicontinuous filament nylon yarn bonded together in a certain wayeThe yarn has a plurality of substantially straight individual continuous filaments disposed in a substantially parallel relation with respect to each other and preferably in a substantially parallel relation with respect to the long axis of the article. The article is elongated, narrow and flat, being laterally at least two times as wide as it is thick and is composed of at least two filaments. The longitudinal dimension of the narrow, flat article can be any suitable length. While there is no definite upper limit for the denier of the article with bands having deniers in excess of a million being contemplated, the denier of the article for practical reasons should be. at least 15. It is preferred that the yarn from which the article is made have little or no twist, although the yarn can exhibit some twist without adverse effect. The individual filaments are fused together by means of a treatment with a multihydroxybenzene compound. First, a suitable nylon yarn is formed. A fluent multihydroxybenzene, preferably in solution, is applied to the yarn. For convenience, the application of the benzene compound is made while the yarn is traveling longitudinally. Pressure of about 0.5 to 100 pounds per square inch and heat at about 50 to 250 C. are applied to the yarn shortly after the application of the multihydroxybenzene compound to unite the filamentary material at points along the length thereof and to induce evaporation and removal of the solvent of the multihydroxybenzene compound. The resultant straw-like structure possesses a coherency among the strands that is difiicult to overcome without the per- 3,335,042 Patented Aug. 8, 1967 ice formance of considerable work. Any residual bond-inducing agent on the structure is not obnoxious and does not appreciably interfere with the dyeability ofthe fabric. While the resultant straw-like structure can be used without further processing in the construction of fabric by braiding, plaiting, knitting, or weaving, additional but optional treatments may be employed, such as washing, applying a softening agent, or the like. Fabric made from the straw-like structure can be used in making hats, bags, shoe uppers, curtains, artificial grass, carpets, upholstery, etc.

The present invention will be further illustrated by reference to the drawing wherein:

FIGURE 1 is a schematic view of apparatus suitable for use in carrying out the method of the present invention;

FIGURE 2 is a perspective view of a straw-like structure of the invention; and

FIGURE 3 is a cross section of the structure shown in FIGURE 2.

As illustrated, a package of yarn 10 wrapped about bobbin 12 is provided as a convenient source of a bundle of nylon filaments 14. The bundle of filaments can be unrolled from the bobbin or withdrawn overend. Obviously, the bundle 14 can be advanced directly from a filamentforming machine involving spinning and drawing operations without any intermediate package being formed. The-movement of the bundle can be controlled by 'the use of a yarn forwarding device. As shown, a pair of driven nip-forming rolls 16 are operated at a predetermined peripheral speed to deliver the bundle of filaments at a controlled rate from the source of supply thereof. The bundle of filaments is then passed over and engages ,a wick material 18 which extends into a container 20 holding a supply of fluent multihydroxybenzene 22. The bundle is wet with the multihydroxybenzene. 1

In order to obtain the desired width and thickness relation for suitable straw, the bundle of filaments is flattened, if the bundle needs to be so-shaped. One way of flattening the bundle is to run the bundle across a snubbing surface such as provided by draw pin 24. As illustrated the bundle is wrapped one time around the pin which is nonrotatably mounted and may or may not be heated. To complete the fusing of the filaments together, the bundle next is passed around forwarding rolls 26 and 28 a plurality of times. One of the rolls is positioned at an angle with respect to the other for proper longitudinal advancement of the bundle along the rolls. One or both of the rolls can be suitably heated in a conventional manner. An electrical resistance means within the rolls can be conveniently used for this purpose. If additional lateral pressuring of the bundle is required, convention- .al means can be associated with the rolls to squeeze the bundle while it is being heated.

Next, the bundle of filaments which at this point in the process has assumed its straw-like appearance is to be taken up in an orderly manner. As illustrated, a traverse 30 is used to cause the bundle to be wrapped in a neat package 32 on a bobbin 34. As shown, the package is surface driven by a driven roller 36 in a conventional manner. Other suitable package building apparatus can be used.

In FIGURE 2 it is seen that the bundle of filaments after the thermochemical treatment is in the form of a thin, flat narrow strip but that the individual filaments have not lost their identity. The product possesses substantial longitudinal strength, as well as lateral strength.

In FIGURE.3 it is seen that the filaments are bonded together to form a thin, flat article.

Dihydroxybenzene bond-inducing agents which can be employed include resorcinol, hydroquinone, and pyrocatechol. The trihydroxybenzenes include pyrogallol, for

example. The agents are not limited thereto since derivatives of the foregoing specific compounds also can be used to develop a strong coherency between the individual nylon filaments. Ordinarily, the dihydroxybenzenes and trihydroxybenzenes are solids at room temperature; and for best results they are rendered fluent before being applied to the filaments in order that the filaments can be more uniformly coated therewith. The benzene compounds can be melted before application. However, the preferred procedure is to dissolve the compounds in a suitable volatile solvent. Dihydroxybenzenes and trihydroxybenzenes generally are readily soluble in water, common alcohols (methanol, ethanol, etc.) and ethers (dimethyl ether and the like). The benzene compounds dissolved in such solvents or other solvents can be conveniently applied to the bundle of filaments in a variety of ways. The compounds can be sprayed, brushed, rolled, padded or applied to the bundle of filaments in other similar ways. The addition of the compound can be uniform along the length of the bundle of filaments, or for economic reasons can be made only at certain spaced points along the length of the bundle.

It has been found that preferably a predetermined amount of the benzene compound is dissolved in methanol. A solution containing about to 80 percent dihydroxybenzene or trihydroxybenzene on a weight basis gives excellent results. The preferred concentration of the benzene compound in the solution is about 20 to 60 weight percent. The concentration of the benzene compound selected, as can be perceived, will depend on many factors huch as the methanol of application, the proportion of the liquid picked up by the bundle of filaments, the bundle, etc. The temperature of the benzene compound when applied to the bundle of filaments is not too important. It has been found that room temperature is quite satisfactory as long as the benzene compound is fluent when applied, although higher and lower temperatures can be employed.

It is necessary that the bundle of filaments picks up an amount of the benzene bonding agent sufficient to effect a strong coherency of the bund e of filaments. The amount of multi-hydroxybenzene applied to the bundle of filaments prior to heating can be varied within relatively broad limits, depending upon the thickness and weight of the structure, the nature and characteristics of the particular nylon filaments employed, the individual properties of the bond-inducing agent employed, the physical properties desired in the final straw-like structure, and so forth. Within the broader aspects of the invention from about 5 to 80 weight percent multi-hydroxybenzene can be added on a dry basis.

As above indicated, it is necessary to heat the bundle of filaments carrying the benzene bond-inducing agents in order to effect a strong cohesion of the filaments. Heating of the filaments at an elevated temperature is feasible by mean of radiation, convection, or conduction. Preferably, the heat is supplied to the bundle of filaments by contact with a heated surface supplied by a heated rotating yarn forwarding roll or rolls. In this heating step the temperature of the strands is raised to about 50 to 250 C., preferably 50150 C., this being below the melting point of the nylon filaments. While heated, the bundle of filaments is laterally pressed in order to effect a better cohesion of the bundle of filaments and to shape the bundle into a straw-like structure. This can be accomplished by pressing the bundle between two flat or rounded heated surfaces such as provided by nip-forming rolls. However, it is not essential that the bundle be compressed on both sides. Pressures of about 0.5 to 100 pounds per square inch are satisfactory, although pressures lesser or greater can be employed. The strength of the resultant structure generally rises up to a point where a higher pressure is used. Generally, excessive, temperatures and pressures ought to be avoided since they can induce an inferior product to be formed. However, prudent selection of optimum conditions to obtain the desired product is not difficult.

Finally, the resultant straw-like structure is cooled prior to any further operation that undesirably would disturb the individual filaments of which the structure is composed. The cooling can be quickly accomplished by directly applying a coolant thereto. However, merely allowing the strands to reach equilibrium with room temperature is quite satisfactory. After cooling, the resulting structure can be used in the construction of textile articles nomally made of straw or artificial straw.

The filamentsare composed of nylon. As is well known, nylon-is a long-chain synthetic polymeric amide which has recurring amide groups as an integral part of the main molecular chain, and which is capable of being formed into a filament in which the structural elements are oriented in the direction of the axis. Specific types of nylon from which the filaments can be manufactured include nylon-66 (polyhexamethylene adipamide), ny- Ion-6 (polymeric E-aminocaproic acid), nylon-610 (polyhexamethylene sebacamide), nylon-4, nylon-7, nylon-ll, etc., and various fiber-forming copolymers thereof.

The number of nylon filaments which can be bonded together by the practice of the present invention to obtain the straw-like structure can range from two to any suitable number of filaments including tow. The cross section of the filaments may be round, but the cross section can be multilobal, multifaceted or the like. A bundle of filaments wherein the filaments have a hexalobal cross section can be shaped into a very dense straw-like structure since the lobes of the filaments will nest into the concavities of adjacent filaments.

The following examples illustrate specific embodiments of the present invention. It is understood that the invention is not limited thereto. All parts and percentages in the examples are by weight unless otherwise indicated.

Example I A drawn continuous filament nylon-66 yarn composed of filaments and having a total denier of 840 was unwound from a bobbin by means of a pair of feed rolls at a rate of feet per minute. The yarn was moved across an applicator issuing an aqueous solution containing 33 weight percent resorcinol. The yarn then was passed 10 times around an internally heated feed roll maintained at 180 C., having a peripheral speed of 180 feet per minute. Between the applicator and the heated roll, the yarn is passed one time around a conventional draw pin to suitably flatten the yarn. The yarn leaving the feed roll was wound up on a bobbin in a conventional way. The resultant structure had a straw-like appearance and texture. The longitudinal strength of the structure was 8 grams per denier. The lateral strength was also excellent.

Example II Instead of employing nylon-66 yarn, nylon-6 yarn was used. The same procedure as set forth in Example I was followed. Similarly excellent nylon artificial straw was obtained.

Example III Instead of employing resorcinol, a 35 percent aqueous solution of pyrocatechol was employed as the bond-inducing agent. Otherwise, the same procedure as in Example I was followed. Similarly excellent nylon artificial straw was obtained.

Example IV Example V Instead of employing resorcinol, a 35 percent aqueous solution of pyrogallol was employed as the bond-inducing agent. Otherwise, the same procedure as in Example I was followed. Similarly excellent nylon artificial straw was obtained.

In the place of water for rendering the multi-hydroxybenzene fluent, methanol, ethanol and diethyl ether can be used. Moreover, the use of a solvent may be omitted entirely.

There are a number of advantages afforded by the practice of the invention. A nonwovcn, thin, fiat, narrow band or straw-like structure of nylon is provided. The procedure is simple and inexpensive. The straw-like structure can be braided, plaited or woven into articles of manufacture such as .bags, hats, etc. Other advantages may be noted.

It is not intended that the invention be limited solely to the details of the embodiments set forth above. It will be recognized that numerous modifications conforming to the spirit of the invention may be made. Therefore, it is intended that the invention be limited only by the scope of the following claims.

What is claimed is:

1. A process for producing a nylon straw-like article comprising:

(a) longitudinally forwarding a bundle of substantially untwisted nylon continuous filaments from a source;

(b) applying a 5-80 weight percent solution of a multihydroxybenzene compound as the sole essential material thereof to the filaments being forwarded;

(c) flattening the bundle of filaments by pulling same around a nonrotatably mounted snubbing surface; (d) wrapping said bundle containing said multi-hydroxybenzene compound around a heated yarn for- 5 warding means to heat the filaments at a temperature of about 59-250 C., said temperature being below the melting point of the filaments, and at a lateral pressure of 0.5 to 100 pounds per square inch; (e) cooling the filaments; and (f) taking up the resulting article in a uniform manner. 2. The method of claim 1 wherein the nylon is nylon- 66 or nylon-6.

3. The method of claim 1 wherein the multi-hydroxy- 15 benzene compound is resorcinol, pyrocatechol, hydroquinone, or pyrogallol.

References Cited UNITED STATES PATENTS 2,031,636 2/1936 Dreyfus 156180 2,188,332 1/ 1940 Carothers. 2,349,290 5/1944 Loughborough 117138.8 2,402,021 6/ 1946 Compton.

25 2,757,111 7/1956 Henderson 15453.6

3,024,589 3/ 1962 Vaughan. 3,042,569 7/1962 Paul 156-180 ALEXANDER WYMAN, Primary Examiner.

30 EARL M. BERGERT, Examiner.

R. J. ROCHE, R. H. CRISS, Assistant Examiners.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,335 ,042 August 8 1967 Claude M. Irwin It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 3, line 31, for "huch" read such line 31, for "methanol" read method column 6, line 6, for

"SQ-250 c." read 50-2s0 c. Signed and sealed this 1st day of October 1968c (SEAL) Attest:

EDWARD J. BRENNER Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer

Claims (1)

1. A PROCESS FOR PRODUCING A NYLON STRAW-LIKE ARTICLE COMPRISING: (A) LONGITUDINALLY FORWARDING A BUNDLE OF SUBSTANTIALLY UNTWISTED NYLON CONTINUOUS FILAMENTS FROM A SOURCE; (B) APPLYING A 5-80 WEIGHT PERCENT SOLUTION OF A MULTIHYDROXYBENZENE COMPOUND AS THE SOLE ESSENTIAL MATERIAL THEREOF TO THE FILAMENTS BEING FORWARDED; (C) FLATTENING THE BUNDLE OF FILAMENTS BY PULLING SAME AROUND A NONROTATABLY MOUNTED SNUBBING SURFACE; (D) WRAPPING SAID BUNDLE CONTAINING SAID MULTI-HYDROXYBENZENE COMPOUND AROUND A HEATER YARN FORWARDING MEANS TO HEAT THE FILAMENTS AT A TEMPERATURE OF ABOUT 59-250*C., SAID TEMPERATURE BEING BELOW THE MELTING POINT OF THE FILAMENTS, AND AT A LATERAL PRESSURE OF 0.5 TO 100 POUNDS PER SQUARE INCH; (E) COOLING THE FILAMENTS; AND (F) TAKING UP THE RESULTING ARTICLE IN A UNIFORM MANNER.

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