US3280241A

US3280241A - Drawn branched filament

Info

Publication number: US3280241A
Application number: US222993A
Authority: US
Inventors: Scragg Frederick; Chubb Alexander Albert
Original assignee: Ernest Scragg and Sons Ltd
Current assignee: Ernest Scragg and Sons Ltd
Priority date: 1960-12-06
Publication date: 1966-10-18
Anticipated expiration: 1983-10-18

Description

Get. 18, 1965' sc c; ETAL 3,280,241

DRAWN BRANCHED FILAMENT Filed Sept. 6, 1962 FIG. 2.-

-FIG. 3.-

INVENTOR:

United States Patent Ofifice 3,Z8fi',24l Patented Oct. 18, 1956 3,280,241 DRAWN BRANCHED FILAMENT Frederick Scragg and Alexander Albert Chnbb, Macclesfield, England, assignors to Ernest Scragg & Sons Limited, Macclesfield, England Filed Sept. 6, 1962, Ser. No. 222,993 Claims priority, application Great Britain, Dec. 6, 1960, 41,955/60; Sept. 6, 1961, 32,008/61 6 Claims. (Cl. 264-290) This application is a continuation-in-part of co-pending application Serial No. 157,080, filed December 5, 1961, now US. Pat. No. 3,243,339, and entitled Yarn and Process and Apparatus for Manufacturing the Same.

The present invention relates to branched textile filaments and a process used during the manufacture of such filaments.

As is disclosed in the above application it is possible to manufacture thermoplastic yarns which have branches from the filamentary portions of the yarns. The filament is produced from synthetic thermoplastic material having a highly polymerized molecular structure, and the filament is distinguished by having a series of side projections or branches which are produced in a manner described in the above application. It is known that in order to provide a filament with a structure enabling it to be used as a textile yarn it must be drawn so as to orient its molecular structure and increase its strength.

It is accordingly a primary object of the present invention to provide a branched filament of the above type which has both the filamentary portion thereof as well as the branches which project .therefrom oriented with respect to their molecular structure and of an increased strength as compared to the untreated yarn, and the objects of the present invention also include the process for manufacturing this yarn.

It is in particular an object of the present invention to provide a process during which the branched filament will be drawn not only at its elongated filamentary portion from which the branches project but also at the branches themselves, so that in this way as a result of the drawing, the drawn yarn has at its filamentary portion a lesser diameter than the diameter of the untreated yarn and also the branches are of a smaller diameter than the branches of the undrawn yarn, and in this way the rigidity of both the filamentary portion of the yarn as well as the branches thereof is increased.

Also, the objects of the present invention include a process wherein the filament is initially placed in a condition which will promote the proper drawing thereof both at its branches and at its filamentary portion, as well as a process which after the drawing of the yarn will restore it to the condition where the branches project from the filamentary portion of the yarn. With these objects in view the invention includes, in a process for manufacturing a branched thermoplastic filament, the steps of bending the branches of the thermoplastic filament inwardly toward the filamentary port-ion thereof on which the branches project, and then drawing the filament both at its filamentary portion as well as at its branches, preferably with the simultaneous application of heat to the filament, so that in this way the filament is drawn both at its filamentary portion and at its branches to improve its molecular structure as well as to increase its strength.

After drawing of the filamentary portion and the branches, the latter are preferably brushed up from the filamentary portion. Also, the yarn can be treated in accordance with the invention either separately or preferably in relatively large numbers of filaments which are treated simultaneously, the filaments being combined as,

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 is a schematic side elevation of one embodiment of an apparatus which may be used to practice the process of the invention in order to manufacture the yarn of the invention;

FIG. 2 is a side elevation of an embodiment similar to FIG. 1 but including more detail with respect to the particular components;

FIG. 3 is a schematic illustration of an untreated filament before it has been drawn according to the invention;

FIG. 4 is a schematic illustration of the filament of FIG. 3 after it has been drawn; and

FIG. 5 shows a schematic plan view of the manner in which the drawing rolls act on the filament, the line along which the drawing rolls engage the filament being shown in a dot-dash line in FIG. 5

Referring now to FIG. 1, there is shown therein a roll 11 of untreated filament 12, this filament passing through a known condenser 26 so as to have the branches bent inwardly toward the axis of the filament along which the filamentary portion thereof extends, the branches projecting from the filamentary portion. Thus, with the filament 12 moving to the right, as viewed in FIG. 1, the free ends of the branches will be directed toward the left, as viewed in FlG. 1, and a first pair of

drawing rolls

13 and 14 receive the filament 12 from the condenser, one or both of the

rolls

13 and 14 being heated so that the filament will be heated.

The filament is received from the first pair of

drawing rolls

13, 14 by a second pair of

drawing rolls

15, 16 which rotate at a speed faster than the rolls 13, 1 4 so that the filament is drawn as it passes along the path extending between the pairs of drawing rolls.

The structure is shown in FIG. 2 where the filament moves to the right, the supply roll 11 being shown at the left, and as is indicated in FIG. 2 before the filament reaches the

drawing rolls

13, 14 it passes between a pair of

rolls

17, 18 which absorb any tension differences experienced during unwinding of the untreated filament 12 from the roll 11 and which provide a uniform rate of feed of the filament to the first pair of

drawing rolls

13, 14. The

rolls

14 and 18 are driven from a common motor 19 through an endless belt 20 which engages pulleys driven by the motor as well as coaxial with the

rolls

14 and 18 connected thereto, and a heating means is shown diagrammatically in FIG. 2 connected operatively with the lower roller 14 of the first pair of

drafting rolls

13, 14. For example, the roll 14 may be hollow and may have in its interior an electrical heating element 25 connected electrically with slip rings located at an end wall, or at both end walls, of the roll 14 and engaging brushes which are connected electrically to a source of current which places the heating elements in the interior of the roll in an electrical circuit which will cause them to become heated and to heat the roll :14 so that in this way the yarn itself will be heated as it passes between the

rolls

13, 14.

In order to insure that the filament is securely gripped between the second pair of rolls 15, 16 a circumferentially grooved idler roll 21 permits the filament to be wrapped twice around the roll 15, the filament passing around the idler 21, before passing around a guide member 22 so as to be finally collected on the package 23 which takes up the filament in a known manner by frictionally engaging, through its own weight, the peripheral surface of a driving roll 24, as indicated in FIG. 2.

The filament 12 is indicated in FIG. 3 before it is treated according to the invention and as may be seen the branches of the filament extend in such a direction that when the filament is between the

rolls

13, 14 and 15, 16, the free ends of the branches of the filament are directed toward the

rolls

13, 14. As may be seen from FIG. 5, the

rolls

13, 14 grip the filament as it moves to the right, as viewed in FIG. 5, along the dot-dash line indicated in FIG. 5 with the diameter of the filamentary portion as Well as the branch becoming smaller as shown on an exaggerated scale in FIG. 5, as the yarn advances to the right, as viewed in FIG. 5, beyond the line where the yarn is gripped between the

rolls

13, 14. Of course, it is the faster speed of the

rolls

15, 16 which draws the yarn so that it will become elongated at the line along which it is gripped by the first pair of drawing rolls, as indicated in FIG. 5.

The resulting filament according to the invention is illustrated in FIG. 4 which, as compared with FIG. 3 clearly indicates how the filament has had its diameter reduced both along its filamentary portion as well as along the branches extending from the filamentary portions, and it will be noted from a comparison of FIGS. 3 and 4, how much longer the branches are in FIG. 4 than in FIG. 3. Any suitable rotary brushes or the like may be applied to the filament in order to brush up the branches thereof subsequent to the drawing operation.

The bending of the branches by the condenser bends inwardly toward the filamentary portion of the filament so that the branches shown in FIG. 3 will turn in a substantially counterclockwise direction with respect to the junctions between these branches and the filamentary portion of the filament during the inward bending of the branches by the condenser. As is apparent from the above description, the yarn of the invention manufactured according to the process of the invention can be continuously treated so as to produce a branched filamentary structure to be used in connection with textile materials wherein the filaments are fully drawn so that the maximum strength of the material is achieved both.

in the filamentary portion thereof as well as in its branches, and the material may be dyed either before or after the drawing operations, or the dye may be incorporated in the melt from which the filaments are formed.

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 textiles differing from the types described above.

While the invention has been illustrated and described as embodied in thermoplastic filaments, 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 within the meaning and range of equivalence of the following claims.

Thus, it is not necessary to use a condenser if the filament is made in a particular manner. If the branches are produced in such a manner as to project substantially at right angles to the line of the filament, then some bending device is of course necessary. However, it is just as easy to cast or extrude a shape in which the branches lie substantially parallel with the main filament at an angle substantially as shown in FIGS. 4 and 5, in which case the condenser is unnecessary.

What is claimed and desired to be secured by Letters Patent is:

1. In a process for manufacturing from thermoplastic material a branched textile filament comprising a trunk and a plurality of branches each of which extends substantially lengthwise of the trunk and is connected to said trunk at an end thereof, the step of engaging and pulling the trunk and free ends of the branches of said filaments so that portions of said branches spaced from said connected ends as well as said trunk are stretched, whereby the molecular orientation of the trunk as well as of said branches will be improved.

2. A process as defined in claim 1, and further comprising the initial step of bending said branches inwardly toward said trunk from which they project.

3. A process as defined in claim 1, and further comprising the step of heating the filament simultaneously with the pulling of said trunk and branches.

4. A process as defined in claim 1, and further comprising the step of brushing up the branches from said trunk of the filament subsequent to pulling of said trunk and branches.

5. A process as defined in claim 2, wherein the step of bending said branches inwardly includes directing the filament through a condenser.

6. A process as defined in claim 1, wherein the step of stretching said trunk and said branches includes directing the filament along a path extending between two pairs of drawing rolls, one pair of which rotates at a speed which is faster than the speed of the other.

References Cited by the Examiner UNITED STATES PATENTS l,881,337 10/1932 Willis 264l62 2,012,984 9/1935 Bradshaw 18-8 2,347,036 4/ 1944 Durnont 264-290 2,394,540 2/1946 Finzel 264290 2,423,182 7/1947 Fields 264290 2,778,058 1/ 1957 Gabler 18-8 3,127,915 4/ 1964 Bottomley.

ALEXANDER I-I. BRODMERKEL, Primary Examiner.

A. L. LEAVITT, F. S. WHISENHUNT,

Assistant Examiners.