US3126095A

US3126095A - Debundlized tow

Info

Publication number: US3126095A
Authority: US
Publication date: 1964-03-24
Anticipated expiration: 1981-03-24

Description

March 24, 1964 BALE 0F DEBUNDL/ZEO TOW (.0055 OR BROKEN F/LAMENT PRIOR ART row J. F. CAINES ETAL DEBUNDLIZED TOW Filed Jan. 9, 1961 asauuouze'o row JAMES F. C'A/NES RICHARD F. DYE/'7 JAMES KNOX PAN/V/LL JR.

INVENTORS ATTORNEYS United States Patent f nill, Jr., Kingsport, Tenn., assignors to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Jan. 9, 1961, Ser. No. 81,222 4 Claims. (Cl. 206--83.5)

This invention relates to tow particularly useful for the manufacture of tobacco smoke filters. More particularly, this invention concerns tow in a new form as in a substantially fully or partially debundlized state.

As well established in the filter industry, many tons of tow are used commercially for tobacco smoke filter manufacture as may be noted from Chemical and Engineering News of March 30, 1959, page 91. The tow heretofore used has largely been in the form of a relatively compact ribbon as removed from the package and as described in detail in Crawford and Stevens US. Patents Nos. 2,794,239 and 2,953,837. As indicated, such tow has been in the form of a relatively compacted bundle or ribbon of filaments and in making filters from such tow of the prior art it has been the practice to subject the tow to various preliminary treatments before feeding the tow into the garniture of the filter rod forming mechanism. Certain of these prior art preliminary treatments are disclosed in several US. patents as Smith US. 2,790,208, Bishop and Tichenor US. 2,843,881 and Crawford and Stevens 2,794,480. As will be observed from these prior disclosures on the preliminary processing of tow, the tow has been passed through tension rolls and the like to put the crimp out of registry, open up the tow and for other reasons. However, such tensioning of the tow in some instances may possibly tend to weaken the tow at the point of crimp or tend to reduce the angle of retained crimp.

Although the foregoing type of preliminary prior art treatment of the older tow is satisfactory and operative and a number of large scale commercial operations are carried out in accordance therewith, some manufacturers may not wish to install the above type of mechanical rolls or similar equipment or for other reasons may wish a tow material which may be more directly and easily converted into filters. Also, there appears tobe'some demand for a wider variety of continuous filaments of various chemical compositions. In addition, certain manufacturers may find the new tow of the present invention better suited for their manufacturing facilities. Therefore, it is apparent that the provision of a new form of tow which exhibits somewhat greater flexibility of utilization and otherwise possesses elements of convenience represents a highly desirable result.

After extended investigation we have discovered a new form of tow and the packaging thereof which tow form may be more directly converted into filters with fewer processing and apparatus requirements prior to filter rod formation. F v I V V This invention has for one object to provide tow in a new form useful for the more direct conversion into filterelernents. A particular object is toprovide a debundlized' tow in package form. A further object is to provide a new tow in package form from which the tow may be directly withdrawn to filter rod formation. Other objects will appear hereinafter.

In the broader aspects of our invention we have found that continuous filament tow as spun and crimped and as withdrawn from the crimper may, in accordance with the present invention, besubjected to a processing which we will term cylindrical blooming. The cylindrically bloomed tow is then directly packaged. We have found that the tow thus formed and packaged may be more 3,126,095 Patented Mar. 24, 1964 ice readily withdrawn from the package in that the cylindrical blooming of the present invention apparently causes any filaments which might protrude to become entangled with similar filaments in adjacent portions of the tow in the package. In other words, any filaments which might normally protrude, in the tow of the invention are tucked into suitable contact with the filaments in the same tow area. Therefore, the tow of the present invention may be quite readily withdrawn from the tow package. We have further discovered that the tow of the present in vention even though packaged still retains substantially all of it's contraction due to crimp and in the form of sufficient crimp resiliency to permit the formation of filter rods directly therefrom without the need of a' preliminary treatment with tension rolls or the like.

Expressed in another way, in the prior art whereas the filter tow as withdrawn from the crimper has been directly packaged, in contrast thereto and in accordance with the present invention there is interposed the cylindrical blooming feature of the present invention on the tow from the crimper before such tow is packaged to provide the debundlized tow of the present invention which is packaged.

Our invention will now be described in greater detail as follows.

In further detail, the filaments forming the tow of the present invention may be dry, wet or melt spun from suitable compositions. Preferably the filaments would be spun from a plurality of spinnerettes and the spun filaments from the desired number of spinnerettes associated to form the tow of the desired total denier. In general we prefer to dry spin'a suitable celluloseacetate spinning solutionand to uniformly collect the filaments from a plurality of the spinnerettes and otherwise proceed with uniform operations in order to obtain filaments that are uniform and free of variations in any particular quantity of tow product.

The shape of the spun filaments may be round, clover leaf, or of special configurations such as Y, Q or the like and sufiicient of such filaments would be gathered to form a tow of a total denier within the range of 20,000-100,000. However, we have found that for the debundlized tow of thepresent invention usually a denier within the range of 30,00070,000 is satisfactory and that the denier per filament may be within the range of 0.5-5.0. However, filaments up'to 16 D./F. may be utilized but are not neces sary for, the present invention.

The filaments as collected 1 to tow or the filaments as they emerge from each spinning cabinet are treated" with a suitable treating agent as described in the aforemen tioned Crawford and Stevens patents. The treated filaments, in the form of tow are then crimped uniformly and free of ,skips, as described in the aforementioned Patent No. 2,953,837. For the debundlized tow of the present invention it is generally preferred to have a crimp of greater than 10 c.p.i. inasmuch as we have found that such higher crimp may be satisfactorily utilized inasmuch as there is no substantial amount of roll tension or the like subsequently applied to the debundlized tow of the present invention when our new tow is directly formed into filters. In other words, since the new tow of the present invention may be directly formed into filters, In other words, since the new tow of the present inventiin may be directly formed into filters, there is'eliminated the possibility that substantial filament breakage can occur due to the high crimp as would be the circumstances if such high crimp material were subjected to roll tension treatment in accordance with many prior art procedures.

In accordance with the present invention, the tow emerging from the crimper and which preferably has a relatively high crimp which is uniform and free of skips is then subjected to the step which we have referred to the like to the filaments above as cylindrical blooming. Such cylindrical blooming is accomplished by passing the crimped tow through a circular jet of the construction shown in our copending U.S. application Serial No. 27,091, now Patent No. 3 ,099; 594, of which the present application is a continuation-inpart. The cylindrical blooming of the crimped tow, in order to produce the debundlized tow of the present invention, is accomplished with gas pressures and other process steps as follows:

A throat diameter from inch to one inch and an inlet nozzle diameter of A-Vz inch may be used although the A3 inch throat and inch inlet nozzle diameters are preferred. At linear speeds of LOGO-1,500 feet per minute, air pressure of -40 p.s.i.g. is applied to the jet to accomplish the degree of debundlizing desired for commercial use without subsequent additional processing.

We have found that such treatment not only debundlizes the crimped tow, but it accomplishes this without impairing the crimp. The tow thus cylindrically bloomed is then packaged in accordance with the following procedure which is generally outlined at this point.

After emergence from the cylindrical blooming jet the debundlized tow passes to the nip of feed rolls arranged so as to feed the tow into the baler at a uniform rate and, simultaneously, to traverse in two directions, at right angles to each other, in a horizontal plane. This latter results in the tow being placed in the bale in uniformly disposed layers so that it may be withdrawn without tangling. When the baler is filled, the tow therein is compressed and wrapped with suitable covering materials for protection during subsequent handling.

We have found that the package of tow formed as just described even though the tow is rather firmly packed in the package, now possesses features not possessed by prior art tow packages. For example, the tow of the present invention can be quite readily withdrawn from the package without tangling difiiculties which have sometimes been encountered with prior art tow packages. Apparently in the tow of the present invention the abovedescribed cylindrical blooming has acted upon any of the protruding filaments which might cause entangling to cause such protruding filaments to be tucked into the tow bundle and thereby become entangled with the filaments in the same tow area. The tow of the present invention may be withdrawn from the package and fed directly into the garniture of a filter rod forming device. Since the cylindrical blooming referred to above does not destroy or impair the crimp, as may certain mechanical treatments, the debundlized tow of the present invention has ample retention of crimp to permit the formation of satisfactory filter rods directly therefrom without the need of further mechanical processing as heretofore practiced or even the application of plasticizers, polymeric binders or before filter rod formation.

Accordingly, it is thought apparent from the foregoing that the debundlized tow of the present invention represents an advance in the elimination of the need for plasticizing (although plasticizing may be accomplished if desired and is preferred) and renders it possible to more readily prepare filters from filaments of other compositions heretofore presenting some difficulties of filter formation. In further detail, debundlized tow of the present invention may be made not only from cellulose ester filaments which are preferred but also from polyolefin, polyester, acrylics, modacrylics and regenerated cellulosic filaments which type of filaments in the past have not been used too extensively for filter formation in view of certain problems of making firm filters therefrom. Now that such difficulty has been minimized to various extents by the debundlized form of tow of the present invention, an extension of the use of different filaments in filter formation has been accomplished.

For assistance in a further understanding of the present invention reference is made to the attached drawing forming a part of the application.

.blooming treatment using a FIG. 1 is a perspective view of a bale of debundlized tow of the present invention showing the withdrawal of a tow end therefrom.

FIGS. 2 and 3 are detailed views on a greatly enlarged scale concerning the filament configuration and arrangement of the filaments making up this debundlized tow.

Referring to FIG. 1, as explained above, the debundlized tow of the present invention may be compacted into a'bale form designated over-all as 2. The bale thus compacted would generally be of a rectangular shape as shown. The compacting or compression of the tow into the bale, usually greater than 15 lbs. per cubic foot, preferably is such that a self-sustaining block or package is obtained which is more convenient in handling around a manufacturing plant. Notwithstanding such compacting of our debundlized tow, an end thereof 3 may be readily withdrawn from the bale package over guide 4 to whatever utilization of said tow end is desired.

Reference is now made to FIG. 2, concerning the enlarged view of a small number of the filaments making up the debundlized tow of the present invention. These filaments are designated 12, 13 and 14. Each of these filaments has crimp therein as indicated at 15, 16 and 17. As further apparent from FIG. 2, said crimp is out of registry. In addition, at certain zones or areas some of the filaments may be internally entangled or interlocked as depicted at 13.

Reference is now made to FIG. 3 which depicts on an enlarged scale a view of the filaments making up one of the prior art type tows. These filaments are designated 21, 22, 23 and 24. Crimp may be present as at 25 and 26, for example. However, it will be observed that this crimp is generally in registry.

A further understanding of our invention may be had from a consideration of the following examples which are set forth to illustrate certain of our preferred embodiments.

Example I In accordance with this example substantially conventional round type cellulose acetate filaments were spun from a conventional spinning solution of cellulose acetate, titanium oxide and acetone.

The filaments as withdrawn from the spinning cabinet were a denier of 3.3. They were Withdrawn to provide a draft of about 1.2. The filaments from 26 cabinets were gathered together to form a bundle or ribbon of filaments of a total denier of 66,000.

This ribbon of filaments which had been lubricated with a lubricant of principally mineral oil was very carefully crimped in accordance with the aforementioned Crawford and Stevens procedure to provide a crimped tow in which the crimp was uniform and free of skips. The crimp imparted to the filaments was of the order of 13 c.p.i. The crimped cellulose acetate filaments emerging from the crimper were then subjected to a cylindrical 73 inch diameter jet with a A inch inlet nozzle and 40 p.s.i.g. air pressure. The cylindrically bloomed filaments were then packaged as described above.

The package of debundlized tow in accordance with the present invention was subjected to various tests as follows with the following results. For example, it was found that the tow can be removed from the bale at a speed of 125 yards per minute without entanglement. It was also found that the average angle of retained climp was not greater than upon withdrawal.

Example II As in Example I, a cellulose acetate tow of 4.5 D./F., 50,000 total denier, X cross-section, was spun from a plurality of spinning cabinets at a draft of 1.4, gathered into a ribbon, crimped to 13 crimps per inch, and passed through a cylindrical blooming jet having a inch diameter throatand a 1 inch diameter inlet nozzle to which was introduced standard cubic feet of air at 32 p.s.i.g. The debundlized tow thus produced was subsequently withdrawn at a rate of 120 yards per minute without tangling and fed directly to the garniture of the filter rod making machinery, wherein it was formed into 90 mm. X 24.8 mm. filter rods. Rod properties were comparable with those of rods produced by cylindrically blooming conventional tow withdrawn from a bale and debundlized immediately prior to rod formation. The angle of retained crimp was 91.

It can be seen from the above that we have provided a new debundlized tow which may be readily packaged but which has several advantages over prior art tow packages. One particular advantage is that the debundlized tow of the present invention may be fed directly to filter rod formation with little or no further mechanical treatment. This produces the corollary advantages of reduced space requirements, capital investment, maintenance cost, and labor requirements for filter production. Another advantage is that filters may be fabricated from materials other than those which may be partially solvated, and therefore bonded, wi'h plasticizers since the debundlized tow has ample retention of contraction and resilience due to crimp to permit the formation of satisfactory filter rods therefrom without the application of plasticers, polymeric binders, and the like.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. As a new article a bale of debundlized tow adapted for the manufacture of tobacco smoke filters therefrom, the bale of tow consisting of an expandable ribbon of more than 5,000 crimped continuous filaments of a denier per filament not greater than 16, the filaments being generally parallel and crimped to greater than crimps per inch and debundlized to put at least a substantial number of the crimps out of registry and impart internal coherency to said ribbon, the average angle of retained crimp in the filaments is at most 100, the ribbon of tow being traversed into the bale in two directions in a horizontal plane and a substantial plane and a substantial amount of any randomly protruding filaments are tucked into the tow ribbon and entangled with filaments in the same area of the same ribbon, the bale being further characterized in that it is compacted to the density of at least 15 lbs. per cubic foot and the debundlized tow readily withdraws from the bale due to the aforesaid entangling of the filaments in the same area of the same ribbon without pulling out of the bale adjacent tow ribbons.

2. In the new article of claim 1 the sub-combination comprising a segment of debundlized tow, said tow being characterized in that it consists of a ribbon of more than 5,000 crimped continuous filaments of a denier per fila ment not greater than 16, the filaments being generally parallel and crimped to greater than 10 crimps per inch, the average angle of retained crimp in the filaments being at most the debundlizing being such as to tuck any protruding filaments into said tow ribbon and the filaments are entangled at intervals with the filaments in the same area of the same ribbon, whereby the tow segment may be moved away from other tow segments without pulling up and materially disturbing said other segments.

3. The bale of claim 1 wherein the filaments making up the tow are of a non-circular cross-section and are of a cellulose acetate composition.

4. The bale of claim 1 wherein the filaments making up the tow are of a cross-section from the group consisting of X, Y and C cross-sections.

References Cited in the file of this patent UNITED STATES PATENTS 2,719,352 Slayter et a1. Oct. 4, 1955 2,790,208 Smith Apr. 30, 1957 2,794,239 Crawford et al June 4, 1957 2,828,752 Jackson Apr. 1, 1958 2,831,748 Finlayson et al. Apr. 22, 1958 2,908,045 Stevens Oct. 13, 1959 2,914,835 Slayter et al. Dec. 1, 1959 2,953,838 Crawford et al Sept. 27, 1960 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No, 3,126,095 March 24', 1964 James F Caines et ale It is hereby certified that error appears in the above numbered pat- I ent requiring correction and that the said Letters Patent should read as corrected below.

Column 4, line 65, for "climp" read crimp column 5, line 25, for "plasticers" read plasticizers column ,6, line 2, strike out "and a substantial plane Signed and sealed this 4th day ofAugust 1964B SEAL) Attest:

EDWARD J BRENNER Commissioner of Patents ERNEST W. SWIDER Attesting Officer

Claims

1. AS A NEW ARTICLE A BALE OF DEBUNDIZED TOW ADAPTED FOR THE MANUFACTURE OF TOBACCO SMOKE FILTERS THEREFROM, THE BALE OF TOW CONSISTING OF AN EXPANDABLE RIBBON OF MORE THAN 5,000 CRIMPED CONTINUOUS FILAMENTS OF A DENIER PER FILAMENT NOT GREATER THAN 16, THE FILAMENTS BEING GENERALLY PARALLEL AND CRIMPED TO GREATER THAN 10 CRIMPS PER INCH AND DEBUNDIZED TO PUT AT LEAST A SUBSTANTIAL NUMBER OF THE RIMPS OUT OF REGISTRY AND IMPART INETERNAL COHERENCY TO SAID RIBBON, THE AVERAGE ANGLE OF RETAINED CRIMP IN THE FILAMENTS IS AT MOST 100*, THE RIBBON OF TOW BEING TRAVERSED INTO THE BALE IN TWO DIRECTIONS IN A HORIZONTAL PLANE AND A SUBSTANTIAL PLANE AND A SUBSTANTIAL AMOUNT OF ANY RANDOMLY PROTRUDING FILAMENTS ARE TUCKED INTO THE TOW RIBBON AND ENTANGLED WITH FILAMENTS IN THE SAME AREA OF THE SAME RIBBON, THE BALE BEING FURTHER CHARACTERIZED IN THAT IT IS COMPACTED TO THE DENSITY OF AT LEAST 15 LBS. PER CUBIC FOOT AND THE DEBUNDIZED TOW READILY WITHDRAWS FROM THE BALE DUE TO THE AFORESAID ENTANGLING OF THE FILAMENTS IN THE SAME AREA OF THE SAME RIBBON WITHOUT PULLING OUT OF THE BALE ADJACENT TOW RIBBON.