CA2030043A1 - Spinning nozzle or spinneret for producing filaments from a flowable material - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

In a spinneret, the spinning plate formed With the spinning capillaries and orifices constituted as a multiplicity of small plates pressed into stepped bores of a highly rigid support plate which can have a thickness independent of that of the capillary plates and can be composed of an appropriately hard material without limiting the density (number of capillaries per unit area) of the capillaries. For that purpose the small plates may be composed of softer material.

Description

77~s-MR

SP~NNING N0ZZLE OR SPINNERET FOR PRODUCI~G
F~LAME~TS FROM A FLOw~B~E M~TE~IA~

SpEcIFIc!ATIoN

Our present inventlon relate~ to a sp~nnlns nozzle or ~o-call~d spinneret having a nozzlo h~ad whioh oan pre~erably be provided w~th a h~atlnq pa~age ~receivlng a heat~d ~luld) ~or control o~ th- temperature o~ a ~lowablQ
mater~al to ~e extrudod ~rom the ori~l~es o~ th~ splnn~r-t ~n the production of filament~. Moro particularly, the -~ invention relat-s to a ~pinnerQt which, ln addttion to the nozzl~ head with ite hoating pas~ag- or pa~ag~s, comprl~e~
a ~plnninq plate whlch, ~ turn, i~ ~orm-d wi~h ~he : capillari~ dePining the orl~lcos.
,~

~ ro~: o- r~ v~
spinnlng nozzl~s or spinnor~t~ are reqylr-d ~or the production o~ ~bexs or ~ilament~ compo~ed o~ an organ~o or lnorganic ~at-rial. The ~tarting mat-rlal in ~ ~lowable ~orm can be ~oroed through the caplllario~ ~nd out o~ tho orl~lce~ ln ~xtremely ~ln- ~tr-am~ whlch can et to ~orm tho ~ilAments or filters.
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77~8-MR

The ~lowable or pumpable mater~al can have a very ; high viscoslty and i~ pressed from the nozzle capillaries which m~y be o various confi~urations at ~n appropriat~
pressure and, dependin~ upon the particular proce~s involved, can be collected a~ fiber~ or Pilam~nt~ ~or su~sequent treatment For example, continuou~ rllaments may be collected into fleece or mat~ ln the production o~
spun bond The continuous ~trand may be broken up lnto individual flbers whlch can be collected as melt-epun mats and ~ilament~ or flbers can be collectod into tow, rovlng or sli~er for a variety of purpose~
A good 6pinning nozzle or spinneret re~uires concern with respect to a number o~ charact~r~-tlcs or propertle~
thereo~ wh~ch affect tho ~uallty For example, ths guality o~ the bores, capillariQs or orlflceo in terms o~
dimen~ional pr~ciBlon ~B a concern AS i~ ths smoothne~ o~
the bore and orl~ioe walls, tbe ~harp--dg-d charaoter o~
the outlot ori~ice o~ th~ capillary, tho ~moothne~s o~ th~
noz~la botto~, corro~on reYiB~AnCe 0~ th- parto o~ the nozzle and tho ~pecial con~lguration8 o~ the ~plnning pas-ages which mAy b~ proVidQd One Or the most important ~actor~ with rRsp-ct to the opinning iB that o~ ~tabillty o~ th~ ~pinnlng nozzle or ~pinneret ~nc~ the ~pinnQret i~ ~norally under enormou-~e~sure str~ hi~ sp~cially the case ror the Rpinning o~ h~gh ~¢o~it~ o-llulo80 au~pen~lon8 whe~
6pinning pressure- o~ up to 200 bar must b- appll~d and the splnneret mat-rials mu~t with~tand the~- pr~-sur-s, speci~ioally so that de~ormatlon o~ the spinner~t in the reglons of the ~ap~llaries or orlflces must ~o minimized 7~98-MR
~J03~0~3 Thesa pro~lem~ arise in th~ spinnlng of cellulo~e solutions in aacordanc~ with th~ NMMO proce~. Thi~
proces~ i~ described in the examples o~ German Patent Document DE-OS 29 13 589 ~or inQtance. The NM~O stand~ ~or N-methyl ~orpholi~e-N-oxld- utili2ed as a solven~ ~or cellulose. ~ecau~e o~ the ~igh ~pinn~ng vi~cosit~e ln such systems, rein~orced spinning pla~es hava been required in the pa~t.
In addition, lncxeasing densities of capillarie~ and or$~ices of the Bpinning nozzles are do~lrable (l-e. there ~g a de~ire ~or hi~h~r numbe~s o~ ori~ceo per unlt area o~
the ~pinneret), thereby maximlzlng the output per unit area o~ the ~pinneret. Of course, an excess~vely clo6e po~ltionlng o~ the orificeo wlll o~u~e th~ ~ilam~nts or ~iber~ to tick together.
~o prov~d~ a high ~u~ace d-n~lty o~ the cAplllarles, thor~or~, tho otlokine~ o~ the ~llam~nt~ 1 reduc~d by ~ntroducing app~opr~at~ additive- into th-compo~ition whlch ls xtruded through the ori~aRo. For examplQ, a r~duc~ion ln the tac~ln-c- o~ tho ~lamento can be ensu~d by apply~ng a nonsoluble llquid a~ a ~heath on the Qxtrud~d ~ilam~nt to reduce the eP~eot o~ the solvent ~soo German Patent Dooum~nt D~-A9 28 44 163). A ~uitAbl-add~tive to th- t-rtlary amine oxld~ ~ 8 a polyalkylene ether, e~peclally polyethylen- ~lycol (~ee ~erman Pat~nt Document DD-PS 21 81 121).

Since these expedi~nts allow a relatively close spacing o~ tbe capillaries an~ orl~lce-, there ha~ been a requirement for a spinnlng nozzlQ or spinneret o~
relatively large diameter and hlgh capillary dQnslty (larga number o~ capillarie~ per unlt ar-a) and thu~ a ubotantial number of capillaries For eoonomical 6pinning of cellulose solutions, such opinning nozzlQs must withstand high pre8sure~ of, ~or exa~ple, up to 130 bar Some con~entional sp~nnlng nozzle~ or ~pinnerets do have r-lativ-ly high caplllary den~ty in part, but th-oe cannot with~tana h~gh splnning pr-ssure- The 6pinning plate~ bulge or ruptur- Thl~ problem is recognized in th~
v~ccose proce~s Conv-rsely, th~re ar- ~pinnlng nozzles or ~plnnex~t~ whlch are co~posed o~ ~p~c~al typ-s of ~teel which can wlth~tand high pre~uro ~tr-o~es Such ~p~nnlng nozzl~o are used ln dry plnn~ng proc-o~e~ ~or '~ ther~opla-tic malte ~hes~ ~pinn-r-t ¢on~truction~ hav-, how~er, the dr~wbacX that, ~or the complicat-d ~ormation o~ the nozzle hole~ ln the nozzl- plat-o, a prcllmlnary boring ~or each ~plnnlng caplllary io nec--~ary ln rel~tlv~ly hard material to prov~de th- caplllarle~ wlth ~uf~icl-ntly omall diamet~r~ Utillz~ng th- l~rg-r pr~liminary boro~, however, ~eano that only a reduced nu~ber of ~plnning caplllarleo can b- provided ln the ZS nozzle plate, th~r-by limitlng the caplllary den-ity 77~8-MR
.

2 ~ 3 ~ s r3 ~b~eçt~ o~ th~ ~nvent~o~
It iB, there~ore, th- prlnaipal ob~ect o~ th-present invention to provid~ an ~mproved ~pinnlng nozzle which, on the one hand, can wi~h~tand high spinnlng pressures w~thout bulging or ruptura And, on the oth~r hand has a hi~h capillary den~lty, i.e. ~ l~rgo numb~r o~
¢apillaries per mm2.
It ~B another ob~ct of th~ inv-ntlon to provide a ~pinn$ng nozsle or ~pinneret which 1- ~roo ~rom th-dra~back- enumerat~d ~bov- and can provld~ h~gh output in th~ production o~ ~bers and ~ m-nto.
Still anothQr ob~ect Or the lnv-ntion 19 to provlde an i~provQd ~pinning no~zl~ or ~plnneret whloh avoid~
drawba¢ks of prior art ~y~tems.

summarv o~ the Inventlon The~e ob~-ct~ And other~ wlll becomo ~ore readily appArent herelna~t-r in a ~plnnlng nozzl- ln which the Bp~nnlng plate lo compri-ad o~ a stable ~uppor~ plato in whiah hol-~ are provided ànd into which s~all plAtes can be ln~erted or pre~ed, th- 8~all plate~ b-~ng ~orm~d with the c~pillarl~.
It has been ~ound to be advantAgeouB to con~truct the ~upport plAt- o~ sta~nle~ oteel And the ~11 pl~t~-~ro~ a ~terlal which ha~ a roduced hardneB~, l.e. a 2~ h~rdness le~ than that o~ st--l but compo-ed o~ A no~l-~etAl, pre~er~bly gold, ~lver, t~ntalum and ~lloy~
thereo~.

2 û ~

MorQ particularly, a splnneret for producin~
~ilament from a flowable material compri~s~
a nozzle h~ad ~or receivlng the flowable materlal:
a mea~anically stable rl~ld support pla~ rocelved ln the nozzle head and provided wlth a multipllcity o~
throughgo~ng hol~s; and a reopectlve orifice plat~ rec-lved ln each o~ th~
hole~ and formed w~th a plurality of caplllarie~ forming rQope~iv~ ~llament emittlng orifiae~.
Accordln~ to the inv~ntion, th~ro~ore, a support plate io used whose thic~n-s~ càn be ~uffloiently large that it can withstand high ~plnnln~ pr-~sures, ~or example, preo-ura~ o~ 130 - 200 bar wlthout ~ubstantlal bending or bulgln~. Into the st~ppad bor~- o~ the oupport plat-, ~all pl~te~, ~op~clally noble m-t~l plato~ aro lnsertoa ~n~ ~reo~ and ln which, bacau~ o~ the r~lAtivo 50~tneo~
o~ th~ ~ateri~l, the r~ui~lte numbor o~ o~nnlng cap~ rie~ aan b~ ~orm-d wl~hout ~ pr~limlnary drlll$ng o~
the small plat~.
Th~ otapped bora~ of th~ ~upport plat- can h_v-th~lr ~top~ proxlmal to th~ out-r ur~ac~ o~ ~he ou~ort plato and th~ ~mall diamet~r out~-t openlng at the out~r ~ur~aco. ~his on~ures that the omall plat-- wll? ba held by tho ~hould~ro between the lArg~ and ~mAll Bt~p~ 0~ eaoh boro and can re~l~t very high ~pinnlng pre8~ur-s.

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'~ ~ 9 ~

2~
It ha~ been ~ound to ~o advant~geous, moreover, to provide on the inner ~ur~ce or sido o~ th~ support plate, a pe~orated plate and to di6pose between the 6upport plate and the perforated plate a ~ilter.
Th~ holes o~ the per~orated plate preferably regi6ter with the bore~ and the perforated plate ~exve~ to uni~ormly distr~bute the c-llulo~e ~olution or polymer melt to the bores o~ the support plate. ~he ~ilter re~oveQ dirt pa~ticles or undi~solved piece-~.

~------Th- above and oth-r ob~eats, ~-ature~ and advantages o~ our lnvQntion will ~com- more rQad~ly apparent ~rom th-~ollowlng desoriptlon, referonc- being mad~ to the accompanylng highly dla~rammatic dr~wlng in w~ich:
PIa. l is an axial ~eatlonal vlew o~ a 6plnning nozzle o~ pinneret w cording to th- invention.
PI~. 2 18 an lovatlon~l v~ew o~ th- ~upport plate u0~d ~n th~ ~pinn~r~t o~ FIG. 1, drawn to a largor scal~
and ~own in C~o~- ~eation;
FIC. 3 ~ a d-t~il vi~w o~ ~ ~mall plAte utlli~ed ln the ~upport plat-, o~ PlG. 2 but dr~wn to a larg~r cal~
than that o~ Fla. 2:
FI~. 4 1B a plan vlew o~ th~ Asse~bly con~tltut~d by the ~upport plate ~nd the ~mall plates; and ~3~
FIG~ 5 is a top plan view o~ the aesembly covered by the p0rforated plate and the filter.

~L~ .
As can be seen from FIG. 1, ~he nozzle head 1 comprises a ~outh 1~ in which a support plate 2 is held ~y a nut 5, the body 1~ of the nozzle head ~ing compo~ed of a ¢orrosion resis~ant sta~nless steel. A hoatlng passage 6 surroundR the duct 1~ th~ouqh whioh the materlal to ~e oxtruded flow~ and i~ connected to ~ ~ouroe of he~tlng fluid to control the temperature of the oellulo~e ~olutlon whlch is delivered via th~ duct 1~ and mu6t have lts temperature controlled during the entir~ ~plnnlng proce~.
In the nozzle head 1 o~ tha splnneret, abo~- the ~uppor~ plat- 2 is a ~llt~r 4 and, a~ov- that, a po~orated plate 3~ rhese three el~m~nt~ are pro~d lnto the nozzle head 1 by th~ threaded nut 5. For ~-aling purpo~ea A ~o~t ~ealln~ ~lng, ~or example, an O-rlng, not hown, can bo u~ed, ~h- ~upport plat- 2 ~see FIG. 4) ha- a multlpllalt~
O~ ~te ~ ~ boro~ 7. Th~s- boras are reAdlly vl~blo ln FIG. 4 although only ono has been shown in FIG~ 2. In the~e bore3, ~mall pla~88 8 (~e FIG. 3) o~ a ~aterlal wh~ch 1~ ~o~ter than that o~ the ~upport plate q can be pr~ d. In tho~e ~o~t ~mall plat~, becau~e of tho natur-~5 o~ the material, lt 1~ po~lblo to ~orm many capill~ 9 close to on~ ~noth~r. ~he multlpl- caplllarlo~ ar- ~hown ln FIG. 4 although only ~ ~ingle oaplllary 9 ha~ b~en lll w trated in FIG. 3.

~ ~ ~ o ~

7~3 Each o~ the holes 3' of the per~orated pl~te 3 register6 with a bore 7 of the support plata 2 and between the perforated plate~ 3 and the suppor~ plate 2, the ~ilter 4 can be provided.
~he ~llter 4 can, depending upon the cellulo~e solutlon or poly~er melt, have variou3 por~ width~ and may be composed of dif~erent materials. Pre~erred, however, ~ B
a corrosion resistant metal fleece.
The flowable mass of ma~erlal to be spun lnto ~ibers and filament~ is di~tributed by thQ perforated plate 3, ~lltered by the ~lter 4 and ~orc-d through th~ ~t~pped bore~ 7 and through the capillarle~ 9 o~ the ~mall plates 8.
In the aon~txuction o~ the invention the ~pinneret has a h~gh pres~ur- resi~tancQ and in 6pite o~ that a high capillary d~n~ity. For a spinn-rot o~ a dl~motor o~ 45 mill~met~r~, 1147 ca~ rl-~ can bQ provlded wh~ch c~n co~re~pond to 16.23 caplllaries/mm2 ln a ~pinneret aapa~lo o~ op~ratlon at 85 bar wh-reac a conventlonal Z~ 8plnneret wlth a maxlmum op-rating pressure OP Sg bar may h~ve only 1.19 cApillarleg/~m2~ The construation o~ the p~nn8r-t o~ th- ~nv~ntlon ~e~m$ts the u~- o~ st~lnl-~o ~teQl ~all plAte~ ln whlC~ capillarl~ o~ di~eront diam~t~r~ ngth~ and cro~ ~ootlon~ may be prov$ded.

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Claims (10)

1. A spinneret for producing filaments from a flowable material, comprising:
a nozzle head for receiving said flowable material;
a mechanically stable rigid support plate received in said nozzle head and provided with a multiplicity of throughgoing holes; and a respective orifice plate received in each of said holes and formed with a plurality of capillaries forming respective filament emitting orifices.

2. The spinneret defined in claim 1 wherein said orifice plates are set into said holes.

3. The spinneret defined in claim 1 wherein said orifice plate are pressed into said holes.

4. The spinneret defined in claim 1 wherein said support plate is composed of stainless steel.

5. The spinneret defined in claim 4 wherein said orifice plates are formed from a material of lesser hardness than steel.

6. The spinneret defined in claim 5 wherein said orifice plates are formed from a noble metal.

7. The spinneret defined in claim 6 wherein said orifice plates are formed from silver or gold.

8. The spinneret defined in claim 5 wherein said orifice plates are formed from tantalum.

9. The spinneret defined in claim 5 wherein said holes are stepped bores having inwardly extending shoulders close to an outer surface of said support plate and against which said orifice plates rest.

10. The spinneret defined in claim 9, further comprising a perforated plate disposed along an inner side of said support plate and having bores registering with said holes, and a filter between said perforated plate and said support plate.