CA2126160C

CA2126160C - Multiple width fiber strip and method and apparatus for its production

Info

Publication number: CA2126160C
Application number: CA002126160A
Authority: CA
Inventors: Rudiger Dollhopf; Klaus P. Raufer (Deceased)
Original assignee: Rhone Poulenc Rhodia AG
Current assignee: Cerdia Produktions GmbH
Priority date: 1993-06-18
Filing date: 1994-06-17
Publication date: 1997-09-23
Anticipated expiration: 2014-06-17
Also published as: JP2652844B2; RU94022278A; CN1101688A; ID997B; EP0629722A1; DE59404387D1; UA27816C2; DE4320303C1; LT3481B; KR950000957A; EP0629722B1; CN1036669C; EE03181B1; RU2095499C1; CA2126160A1; JPH0748771A; KR970007691B1; LTIP1974A

Abstract

The invention relates to a multiple width fiber strip consisting of curled, interlaced filaments and having several zones extending in longitudinal direction of the fiber strip as well as at least one tear line (4) extending in longitudinal direction of the fiber strip, wherein the tear strength (daN) of the fiber strip, referred to the total titer (dtex) is at least about 1.7 x 10-4 daN/dtex (determined in analogy to DIN 53 834 Tl, February 1976, under a tension of 2.5 N).
Further it relates to a method for producing one or several such fiber strips, with several separate bands (1, 2) being formed of substantially parallelly extending filaments and the formed bands being curled jointly to produce one or several curled fiber strips. The apparatus for carrying out this method is characterized by a transport roll pair (8, 9) for jointly transporting the supplied bands (1, 2) and a curling unit (10.1, 10.2, 11, 12) which is arranged after the transport roll pair (8, 9), for curling the bands (1, 2) leaving the transport roll pair. The invention makes possible, in the case of the production of a multiple width fiber strip with the tear line referred to, processing on a double skein filter rod machine with a single (individual) treatment section.

Description

r 2 ~ L ~S ~

(Lett~rh~d of Hag~ - ~ & Kehl, Patent Attorneys) ,. . .
Rhone-Poulenc Rhodia ~ktiengesellschaft Munich Our Re~.: Pat 1237/5-93Ch JunQ 16, 1993 Multiple Width ~iber StriP and Method and APparatus for Its Production The ~esel~ invention relates to fiber strips, namely inparticular C filter tow strips consisting of interlaced filaments, a method for pro~u~n~ these fiber strips, and ana~a~t~s for carrying out this method.

By a ~ilter tow strip is to be unde.~ood a fiber strip which is composed o~ interlaced filaments or fibers. The fll. - g of the filter tow strip consist for example o~ cellulose acetate. The filter tow strip is curled by a so-called curling machine and is then - essed to a ~ale, to be ready for fur~her proces-ing to cigarette filter3 for rod-shaped ~ n~ articles. The entire manufacture from the starting U~ cellulose to the ~ilter tow strlp packed in the bale is known e.g. ~rom "Die Herstellung von Rhodia Filter Tow" Technische ~ In~ormatlon 1-01, Rhone-Poulen¢ iKhodia AG, Freiburg, January 1993. The known ~llter tow strips show uniform interlacing of the filaments over the entlre width oP the strip and have a substantially constant weight over thoir length.

The ob~ect o~ the present inven~ion is to propose a fiber strip,,in parttcul~ a filter tow strlp, which offers productivity adv~ages in it~ procea~ g to filter skeins. In addition, an advan~A~eo~-~ method ~or produoing this fiber strip, including apparatus for its execution, i8 to be pro~ooed.

Thls problem is ~olved by a multiple width fiber strip, in particular multlple width ~ilter tow strip, which consists of curled, interlaced i~11aments and which has several zones extending in longitudinal . ~ . ' directlon of the fiber strip as well as at least one tear line extend-ing ln longitudlnal direction of the fiber strip, the tear ~ yLh (daN~ o~ the fikfer strlp, referred to the total titer (dtex), being at least about 1.7 x 10-4 daN/dtex (determined in analogy to DIN 53 634 Tl, February 1976, under a tension of 2.5 N).

A solution c --t of this problem is also the method according to claims 4 to 12 and an apparatus according to claims 13 to 16.

According to a preferred form of the multiple width fiber strip according to the invention, said tear YL~el.ff~ffLh referred to the total tlter is at least about 2.5 x 10-4, in part~f~ll~r at least about 3.5 x 10-4 daN/dtex. These values are det- tnff-ffd in analogy to DIN
Specification 53 834 Tl of FeLff~fla~y 1976. This specification is actually ~ntPnded for the determination of cffff~efs~fonffftnf3 values for yarns and twists and refers to the t¢n~lle slLLff~yffh referred to ~lnfPfnPff~s. Under the definition of the multiple width fiber strip according to the invention, here nf_~ff_vu~ the term "tear shff~fllyf'illl is used. The measuring is done with application of a ~f~ffn~fifofn of 2.5 N. The multiple width ~iber strip according to the invention must therefore have the tear efffftrength referred to so that it can be treated in the convfsntlonal treatment seations of a filter rod -chtnff8f with a normal ~ilament denEffffity distribution.

~he filaments forming the multiple width fiber strip according to the invention are curled and interlaced. By "interlacing" is to be under~
fffrffftocd that ~for example!in the,filter tow efffftrip the filaments cross asln netting, to form a cohesive filter tow strip. mis net-like structure can be seen of~pec-iAlly well when the filter tf~W strip is spread out. The interlacing, however, means also that the filter tow fffffffffffffftrip can not be readily divided, as the hooking of the crosiswise~ilaments must rirst be undone, which may be of importance for instance 1 thfe fllter tow strip is to be subdivided for further prff~fcessing. If many filaments in the fiber strip are hooked together, there is strong interlacing of the filaments. This is referred to as a high degree of ''."';''''~''.' ' ~ ,. .. .
f~', ... " ", " "~

~ L2v ~ ~

interlacing. Conversely, if few f~ nts are hooked together, the interlacing is relatively slight. One speaks of a "low degree of interlacing." The known filter tow strips have over the entire filter tow strip an essentially constant degree of interlacing, which can be rated as normal or maximal. In conL~ a~L to the known fiber strip, the ~iber strip according to the present invention can h~ve zones whose degree of interlacing i8 below the normal degree of interlacing. In the context o~ the present invention, thls zone involves the "tear line."
Under the action of a ~-e~ling force in longituA~nAl direction, the multiple width fiber strip according to the invention can, if desired, bs divided lnto two or more parts. This stretching force must be below ths tear sLL~yLh of the fiber strip. In the -~olal filter tow strips these maximum tear ~LLen~Lh values, referred to the total titer, dete ~nP~ in analogy to the above DIN spec~flcation (tension 2.5 N), lle bet~-~en about 2.5 x 10-4 and 4.5 x 10-4 daN/dtex. This d~pen~ on the ~esye~Live spec~t"~cAtion. To divide the multiple width fiber strip according to the invention into the desired parts based on the forma-tion o~ the tear line, the mentioned stretching ~orce to be applied muet be lower than the tear s~ènyLh of the fiber strip. This is generally achieved when the tear ~L-anyLh i8 fallen short of by about 10%, pre~srAhly by about 25% and more partl~llArly by more than 50%.
:, In the ~bove-cited DIN specification, a modification has been made, as ha~ been stated before, in the sense that for the determination of the tear eL.~,yLh a tenaion of 2.5 N is applied. At a degree of interlacing outside the scope of the invention (tending toward 0), already the ten~lon o~ 2.5 N brlngslabqut alcomplete se~alation of the zones of the ~iber strip. In other words this means that the minimum degree of interlacing is fixed in the above sense by the tension of 2.5 N, ~ e~ ntly of the speciflcation. The maximum degree of interlacing o~ the tear line, and hence the stretching force nPcessAry L'or the separatlon of the zones o~ the fiber strip, are guided by the speci~ication-~PpPn~Pnt tear s~enyLh The filter tow strips of the invention are formed from several uncurled ~12~
.

bands, arranged side by side, which are sub~ected to a simul~ .e~usly occurring ~oint curling, in which connection the process measures described below for the formation of the tear line musit be observed.

The tear lines may be Aq~t~ to zones of equal width of the filter tow strip with normal degree of interlacing. This constitutes a 80-called multiple width divisible filter two strip, which in the further proc~ssing is divided at the tear lines into single strips of equal width and egual total titer. Preferably the division is ~~-rc- - with a titer accuracy of + 5%, more p-r~ Arly + 3%, referred to the total titer.

Ths filter tow strip of the invention can be packed in a bale and can then bs used in the pL~u~ion of filter skeins for making cigarette ~llters and c1i ~l Ar articles, in that the multiple width filter tow strip is surpl~e~ to a filter skein --h~ns which divides the multiple width filter tow strip at the tear lines into individual single-width ~ilter tbW ~t~$psi ~h~ch are 8~mult~n~0uqly yL~C~Sed in the fiiter skein machine to the ~~~e~tive number of filter skeins. F~peciAlly by u~ing a double filter skein machine with individual processing section, an advantage is achieved here. Considerable 6avings with regard to cost o~ ~s~_o.~,el and time, ln part~ a~r when rhAn~ the fllter tow bale~i, c~n thereby be obtained, thus increasing the ~Lv~iU~iVity. In addition, these slngle ~ilter tow strips produced by division of the multlple width ~ilter tow strip have, as has been mentioned above, Qe~nt~lAlly the same total titer and also identical curl indez, thus re~tci~ w rap in the ~ u~ Lion o~ilter ~keins. Such a double ~ilter ~keln machine ie described in the application "Method and Apparatus for Producing Fiber Skeins" ~iled simultaneously with the present applica-tlon, origlnating ~rom the same applicant as that of the present appllcatlon. Re~erence is here expressly made to the content of that appllcation.

The new method for the production of the multiple width fiber strip accordlng to the invention is characterized in that several separate ' '"' "';''"''.' ,",""~

212'~

bands of f~ ts essentlally extending parallel to each other are ~ormed and the resulting bands are lastly curled ~ointly, to produce one or more curled fi~er strips, in particular a filter tow strip.

~referably, in carrylng out the method according to the invention, the uncurled bands are - shortly before ~ ing curled ~ointly - no longer guided separately. This means, in other words, that the ad~acent uncurled bands finally touch, whe~u~vn, after curling, a tear line with the desired degree of interlacing is pL ~UCed . In speclfic cases C it may be of adv~l~agQ that uncurled bands of different width are ~ormed, which are curled ~ointly. It may also be ad~ n~J~o1~c that se~eral, Opecific~ y two, uncurled bands Or equal width are formed, which are curled ~ointly. It is preferred in this colu.ec~ion that the two uncurled bands are guided se~ra~ely to ~ust before the ~oint curllng, -~he~y there resultO after the curling of the two bands a curled fiber Otrip which has a tear line ext~n~7~7ng centrally.

A further development of the me~hod acaerding to tha im ention conziztz in that sl~h~e~lQntly a~lop-late pac~1ng measures are taken. In this cv~ e~ion it is preferred that the tear line(s) has/have so low a degree of interlacing that, after leaving the curling ~~~7~ne~ several lndlvldual Piber strlps are formed, in that the distance of the ~op~ratlng wall Prom the nip region bet/ -- the transport rolls is r duced and/or the thicknesO of the separating wall is increased, that the ~L~ced fiber strip(s) are deposited, pressed, and packed to a balo, that the at least two individual fiber strips are deposited in a common re¢eptacle compartmented by a separating wall, and after removal o~ the se~Atatihg wall arel~ointly pressed and packed to form a uniform bale, and that the individual fiber strips are deposited in two ~eparate receptacles, are pressed Oeparately and packed to form two lndividual bales. The above apparatus parts will be explained below.

The new apparatus ~or carrying out the method according to the inventlon 19 characterlzed by the following features: A transport roll palr ~or ~oint conveyance of the supplied bands and a curling unit ,~".~

6 ~ ;
dlsposed after the transport roll pair, for curling the bands leaving ~-the transport roll pair.

Preferably the apparatus according to the invention has a parting devlce, in particular a separating wall, in front of the transport roll pair. By means of this parting device, the zones of low degree of interlacing can be ~ uced in the formed fiber strip, i.e. the tear line. Preferably the separating wall is variable as to its distance from the nip zone of the ~n~o~L roll pair and as to its ~h~r~n~ss.
With decreasing distance of the separating wall ~rom the nip zone of the ~L~IsyvLL roll pair, the degree of interlacing within the tear line decreases. m e same i6 true for an increase in thickness of the separating wall. When the separating wall extends almost up to the nip zone, the bands can no longer touch from the nip zone on, owing to which fiber strips separated from each other are p~uced after the curling. In other words, the degree of interlacing i8 zero.

I~ the distance o~ the eep-ratir.g wall fro~ the n~p zona of tha LL~8~V~ roll pair is relatively short, there results for the tear llne of the produced fiber strip a relatively low degree of lnterlaclng, 80 that it i~ relatively easy to divide the multiple width Xlber strip into e.g. single-wldth fiber strips, yet sufficient c~h~-~or~ exl~ts. 7hls co~siQn is n~C~cs~ry untll the fiber strip enter~ for instance the double filter skein machine. Via the mentioned dl~tance o~ the varlable se~aLating wall from the nip zone of the LL~U~L roll pair, therefore, different fiber strips with different ~ i ~eL~lee can be ~r~uced, l.e. wlth more or less pronounced tear llnes. A similar control 18 possible also, as has been mentloned, by ' varying the ~h~k~e~s of the ~eparating wall.

Alternatlvely, more than one separating wall may be provided in the apparatus accordlng to the invention, the number of separating walls ~ -;
determlning the number of fiber strip zones that can be ~eparated from one ~nother. .

"'' , ~,' ''~.' ~ 1 ~7j?IjO

. ::. ..

The present invention is not limited to a certain material of the fiberstrips. In its practical realization it has been found that the ~llaments consist preferably of cellulose acetate, polyethylene terephthalate, polyolefins, such as polypropylene, or also pol-yhyd butyric acid esters, polyamides (e.g. nylon) and viscose.

Further advantages and poss~hil1ties of use of the pleserlt invention w~fll be evident from the following description of an ~ '-o~ nt of the ~nvention in col~wfl~ion with Figure 1.

Figure 1 Efhows a form o~ realization o~ an apparatus for produf~-in~ adouble-width divisible fiber strip 3 from two separate bands 1 and 2 of efqual width in which fll ~ g of cellulose acetate are all~f.yed substAnt~fAlly side by side, these bands being designated in the follt~ lng as -wf~uLed bands 1 and 2. The apparatus according to Figure 1 is also re~erred to as a curling machine.

Ths curling f~h;ne has two transport rolls 8 and g arranged and mounted one above the other" rotating toward each other about their roll axes in the direction of the entered arrows. In front of the two driven rolls 8 and 9, two parallel guide plates 5 and 7 are arranged, whlch laterally guide the uncurled bands 1 and 2. Between the uncurled ~ands 1 and a, in a refgion be~ore the roll pair with the rolle 8 and 9, there le provided a wall-type se~alaLing sheetmetal plate 6 as sfeparating device or divider, whiah reliably fseparates the two uncurled band3 1 and 2 ~rf~m each other before they get into the pull-in zone of the roll~ 8 and 9. The,guide ,plates 5 and 7 and also the seplarating plate 6 taper in wedge form in the direction toward the rolls, i.e. in the running direction o~ thé two uncurled bands 2 and 1, 80 that they can be gulded to alose to a nip zone B.

The curling machine further has two f~h ar walls 10.1 and 10.2, ~sfpoiff~fd parallel to each other, to guide between them the bands 1 and 2 in runnlng dlrection. The two ~h; '-r walls 10.1 and 10.2 also receive a relatively elongated delivery part 12, on which rests the :~ ;, .,.-:
'~,~ ~ ,''',,,',, .

fiber strip 3. Above the fiber strip 3, between the chamber walls 10.1 and 10.2 and under an angle of 9o~ to them, a movable flap ls provided.
Said parts 10.1, 10.2, 11 and 12 bring about the curling in the usual manner on the principle of an upsetting rh: -r~ By the tLona~VL~ rolls 8 and 9 the two uncurled bands 1 and 2 are transported into the upsetting ~.h~
:
By duplication of the separating plate 6 and scaled adaptation of the rolls 8 and 9 and of the other parts of the curling - '~ne, it is easy C to modify the curling machine used according to the invention to ~udua8 e.g. triple-width, quaeruple-wldth or quintuple-width filter tow strips with the coLle~ ng number of tear lines.
~ ':
According to another -~fl~tion of the form per Figure 1, e.g. the distance of the sepa.a~ing plate 6 from the guide plate 7 and guide plate 5 may be different, ~h~.~by uncurled bands of different width and dis~imilar with l~s~eoL to their total titer are supplied to the , ,,,~',,~,,~!;
curling sta~ion, to p,o~u~a a filtar tow etrip with tow halvee o~ ;;;~
dl~ferent width. ;~

According to another modification, the separating plate 6 may be adapted to be ad~u~table, so that the distance bet 3~l the end of the ~eparating plate 6 and the nip zone B of the two rolls 8 and 9, seen in the dlreatlon of the rolls 9 and 8, can be set or varied. The ~eparating plate 6 may also be pivotable.

~ '~C
', '-',~,'''.

Claims

1. Multiple width fiber strip, in particular multiple width filter tow strip (3) consisting of curled, interlaced filaments and having several zones extending in longitudinal direction of the fiber strip as well as at least one tear line (4) extending in longitudinal direction of the fiber strip, the tear strength (daN) of the fiber strip, referred to the total titer (dtex), being at least about 1.7 x 10-4 daN/dtex (determined in analogy to DIN 53 834 Tl, February 1976, under a tension of 2.5 N).

2. Fiber strip according to claim 1, characterized in that the tear strength is at least about 2.5 x 10-4 daN/dtex, in particular at least about 3.5 x 10 x -4 daN/dtex.

3. Fiber strip according to claim 1 or 2, characterized in that the zones of the fiber strip separated by the tear line(s) have an identical or different total titer.

4. Method for producing one or several fiber strips, in particular according to one of the preceding claims 1 to 3, wherein:
- several mutually separated bands (1, 2) are formed from filaments extending substantially parallel to each other and - the formed bands are lastly curled jointly, to produce one or several curled fiber strips, in particular a filter tow strip (3).

5. Method according to claim 4, characterized in that, shortly before they are curled jointly, the uncurled bands (1, 2) are no longer guided separately.

6. Method according to one of claims 4 or 5, characterized in that uncurled bands of different width are formed, which are curled jointly.

7. Method according to one of claims 4 to 6, characterized in that several, in particular two, uncurled bands (1, 2) of equal width are formed, which are curled jointly.

8. Method according to claim 5 or 7, characterized in that two uncurled bands (1, 2) of equal width are formed and that the two uncurled bands are guided separately to just before the joint curling, whereby after the curling of the two bands there results a curled fiber strip having a tear line (4) extending centrally.

9. Method according to at least one of claims 4 to 8, characterized in that the tear line(s) has/have so low a degree of interlacing that after leaving the curling machine, several individual fiber strips are formed in that the distance of the separating wall (6) from the nip zone (B) between the transport rolls (8, 9) is reduced and/or the thickness of the separating wall (6) is increased.

10. Method according to one of claims 4 to 8, characterized in that the produced fiber strip or strips are deposited, pressed, and packed to form a bale.

11. Method according to claim 9, characterized in that the at least two individual fiber strips are deposited in a common receptacle compartmented by a separating wall and after removal of the separating wall are pressed jointly and packed to form a uniform bale.

12. Method according to claim 9, characterized in that the individual fiber strips are deposited in two separate receptacles, pressed separately, and packed to form two individual bales.

13. Apparatus for carrying out the method according to at least one of claims 4 to 12, characterized by a transport roll pair (8, 9) for joint transporting of the supplied bands (1, 2), a curling unit (10.1, 10.2, 11, 12) arranged after the transport roll pair (8, 9), for curling the bands (1, 2) leaving the transport roll pair.

14. Apparatus according to claim 13, characterized in that a separating device (6) is arranged in front of the transport roll pair (8, 9) for separate guiding of the uncurled bands (1, 2).

15. Apparatus according to claim 14, characterized in that the separating device (6) is a separating wall.

16. Apparatus according to claim 15, characterized in that the separating wall (6) is variable in its distance from the nip line (B) of the transport roll pair (8, 9) as well as in its thickness.