CA1136366A - Spinning process - Google Patents
Spinning processInfo
- Publication number
- CA1136366A CA1136366A CA000351780A CA351780A CA1136366A CA 1136366 A CA1136366 A CA 1136366A CA 000351780 A CA000351780 A CA 000351780A CA 351780 A CA351780 A CA 351780A CA 1136366 A CA1136366 A CA 1136366A
- Authority
- CA
- Canada
- Prior art keywords
- air
- stream
- fibres
- cup
- humid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/04—Dry spinning methods
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/12—Stretch-spinning methods
- D01D5/14—Stretch-spinning methods with flowing liquid or gaseous stretching media, e.g. solution-blowing
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01D—MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS
- D01D5/00—Formation of filaments, threads, or the like
- D01D5/18—Formation of filaments, threads, or the like by means of rotating spinnerets
-
- D—TEXTILES; PAPER
- D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
- D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- D01F6/00—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof
- D01F6/58—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products
- D01F6/76—Monocomponent artificial filaments or the like of synthetic polymers; Manufacture thereof from homopolycondensation products from other polycondensation products
Landscapes
- Engineering & Computer Science (AREA)
- Textile Engineering (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Artificial Filaments (AREA)
- Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
Abstract
Abstract Spinning process Fibres are produced by centrifugal spinning a solution of thermosetting aldehyde resin, e.g. an aqueous UF resin solution, and drying the fibres by contact with a stream of hot, dry, air flowing downwardly from above the spinning cup.
To avoid premature drying of the resin solution and fibres, a stream of cold, humid, air is fed to the spinning cup, from whence it is thrown, by rotation of the cup, as an outwardly directed stream having the fibres entrained therein. This out-wardly directed stream of cold, humid, air is deflected downwards, e.g. by the hot, air stream or by a subsidiary cold air stream, to avoid the formation of a vortex into which the fibres might become entangled.
To avoid premature drying of the resin solution and fibres, a stream of cold, humid, air is fed to the spinning cup, from whence it is thrown, by rotation of the cup, as an outwardly directed stream having the fibres entrained therein. This out-wardly directed stream of cold, humid, air is deflected downwards, e.g. by the hot, air stream or by a subsidiary cold air stream, to avoid the formation of a vortex into which the fibres might become entangled.
Description
~IL36~
Thi8 invention relates -to a spinning process and in particular to a process of produoing fibres by centrifugal spin-ing from a solution containing a thermosetting aldehyde resin such as an amino- and/or phenol- aldehyde resin, particl~arly a urea~ formwldehyde resin.
In our United States Patent Serial No. 4178336 issued December 11, 1979 , we describe a proce3s wherein the resin solution, containing a suitable cur ing catalyst, is centrifugally spun from a spinning cup rotating about a substantially vertical axis. ~ stream of cold, humid, air is directed do~nwardl~ into and around the cup to retard evaporation of the solvent and curing of the resin while'a stream of hot dry air is blown outwardly from beneat'h the cup so as to heat, and hence d~y, the fibres spun from the cup and to transport thsm to a collscting zone.
In addition to retarding evaporation of the solvent'and curing of the resin in the cup~ the downward stream of cold humid air into and around the cup provides an environment around the cup of cold humid condition~ within which the fibres spun from the cup are attenuated prior to contact with the hot d~y air.
In a preferred embodiment, the resin i9 spun through a series of perforations in the wall o the cup or from the rim '~
thereof, entrained in a stream of -the cold humid air thrown out of the c~p b~ the rotation thereof. Where a perforated cup is used the resi~ flow rate is such that the perforations are not comp-letsly filled with the resi~ 80 that some of the cold humid air -.: .,: ~ : . ,~
~363~i6 flows through the perforation~ with ths re~in.
We have found that this stream oE cold humid air thrownout of the cup may provide the cold, humid, environment for atten-uation of the fibres, thu~ obviating the nsed for a downwardly directed oold humid air stream around the out~ide of the cup. 'rhe spu~ fibres are th~s attenuated whiLe entrained in the cold humid air stream emanating from the perfora-tions of ths oup. The atten-uation i9 partly effected by the entraining air stream and partly by inertia effects, prior to oontact with the hot dry air ~tream.
However, in the absenoe of the downwardly directed ~tream of oold, humid, air around th0 CUp7 the outwardly dire¢ted air stream having the fibres entrained therein emanating from the cup often gives rise to a torroidal vortex of cold humid air of somewhat greater diameter than the spinnin~ cup and located in a plane just above the spinning plane ie the plane of the fibre~ a~
they are spun from the cup. In some cases the fibres may be oaught up by this vortex and beoome entangled and/or thrown up on to the underside of the top of the enclosure in whioh the spinning operation is conduoted where, beoause the fibres are ~till only partially dried and hence are of a somewhat a &qsi~e nature, they adhere and 80 are not transported to the colls¢tion zons. Evsnt-ually suoh adhering fibres interfsre with the sati~factory spin-ning of the rest of the rssin.
We have found that the~e problems may be overcome by spinning the fibres entrained in the outwardly direoted stream of oold, ~umid, air into an enolo~ure in which a ~tream of hot, dry, air is flowing downward~ and deflecting the outwardly directed stream of oold, humid, air downwards. ~he down~ardly direoted stream of hot dry air is u-tili~ed in addition to, or instead of, the upwardly and outwardly direoted ~tream of hot dry air from beneath the ~pinning oup.
Therefore acGording to the present invention we provide a process for the ~anufaoture of fibre~ from a solution containing a thermosetti~g aldehyde resin and a curing cataly3t therefor-oomprising . . .
~3~3~
(i) feedin~ said solution to the interior of a spinning cup mounted within an enclosure and rotating about a subatantially vertical axis, (ii) feeding cold, humid, air into the cup from whence it ia pumped, by rotation of the cup, as an outwardly directed stream whereby said resin solution i8 Bpun from the cup into said encloa-ure as fibres entrained in said outwardly direoted stream of air wherein ~aid fibres are attenuated, (iii) providine in the enclo~ure a stream of hot, dry, air at a temperature sufficient to dry the attenuated fibres, aaid stream bein~ downwardly directed from above the the apinning c~p, (iv) defle¢ting downwards the outwardly directed stream of cold, humid, air having the fibres entrained therein, (v) conta~ting said outwardly directed stream of air having attenuated fibres entrained therein with the atream of hot, dry, air whereby said attenuated fibres are dried, and (vi) transporting the attenuated fibres by said stream of hot, dry, air to a collection zone.
The thermosetting resin is preferably a condensate of an amino compound with an aldehyde such aa formaldehyde. Some or all of the fo~maldehyde may be replaced by a higher aldehyde such as acetaldehyde~ The amino compound is preferably a polyamine, partic-ularly urea and/or melamine. In order that the resin is water aoluble, ao that water can be used as the solvent, the amino oom-pound ia preferably urea, alone or in admlxture with up to 5% by - weight of melamine. Some or all of the ami~o compound may be re-placed by a phenol auch as pbenol, cresol or reaorcinol.
It ia preferred that the molar ratio of aldehyde to phenol and/or amino group~ is between 0.6:1 and 1.5:1j preferably between 0.7.1 and 1.3:1.
The curing catalyst, which i9 preferably added to the resin aoluti~ just before the latter ia fed to the spinning oup, ::
~3~3~ii6 may ba n weak ¢atalys-t such as di(a~onium) hydro~en pho~phate or ammoniu~ formate, a moderate oatalys-t such ~ formic acid, ammoniu~
sulphate, ammonium chloride or ammonium dihydrogen phosphate, or a strong catalyst such aB phosphoric, sulphuric, sulphamic or hydro-chloric acid. ~e amount of ca-talyst will generally be within the range 0.05 to 1~ by weight of the resin solids.
In some cases, parti¢ularly where -the fibres are to be used in the manufacture of paper, it may be desirable to incorpor-ate an adhesion modifier into the resin. Such modifiers in¢lude cer-tain inor~anic oxyacid radicals which react with aldehydes.
Examples of suitable radicals inolude sulphite, phosphite, and borate radicals. When used as adhesion modifiers, such radi¢als are incorporated into the resin during the condensation of-the amino or phenol compound with the aldehyde.
~lternatively adhesion modifiers, such as carbohydrates, particularly formose, may be incorporated into -the resin solution before, during, or after condensation of the amino or phenol com-pou~d with the aldehyde. The incorporation of modifiers is further described in ourCanadian Patent Applications Nos, 321507 and 321610, ~iled July 29, 1977, The solvent used to ma~e the solution is preferably water, but alter~a-tively may be any solvent which is relatively - volatile at the temperatures to which the spun fibres are heated by the hot dry air stream.
In order -to improve the spinning properties of the resin solution, it is preferred to incorporate into the solu-tion a small amount of a thermoplastic polymer that is soluble in -the solvent employed. Examples of suitable wa-ter ~oluble polymers include polyvinyl alcohol and poly ethylene oxide. The amount of thermo-30 plastic pol;ymer used is preferably 0.01 to 5% by weight of the thermosetting resin solids. While -the -thermoplastic polymer may be incorporated before or during condensation of the amino and/or phenol compound with the aldehyde, it is conve~iently added with the curing catalyst.
q~he resin solution, to which the curing catalyst has been ~ ' ' .
,:,, - : ,.
, ~, ~3~36~
added, i3 fed to a spinnine cup. ~'he ¢up, whioh iH mounted for rotation about a substantially vertioal axi~, iY a hollow vessel havin~ one or more spinning surfaoes. For example the oup ma~
be open-ended and the spinning surface oomprises the end of the open wall thereof. Alternatively the cup ~all m~y be provided with a plurality of spinning surface~ in the Eorm of perforations.
~he ~ize and nu~ber of perforations will be detérmined by the oup diameter and rotational speed: however typioally for a 12 om diameter oup rotating at 5000 to 10,000 rpm, 24 perforations of 3 mm width are suitable. ~he perforations are preferably re¢t~
an~ular in oonfig~ration and the re~in solution feed rate and oup rotational speed are preferably adjusted ~o that the resin solutinn is spun from paFt of the perimeter of the perforations.
~h~ spinning solution preferably ha~ a visoosity between 5 and 100 poi~e at room temperature a~ measured by ~ritish Standard 1733 u~ing oup B6. The vi~cosity may be adjusted by conoentration or dilution of the solution as necessa~y.
In order to prevent premature ouring of the resin and evaporation of the solvent, oold, hu~id, air is supplied to the interior of the cup from whenoe it is pumped, by rotation of the cup, alon~ with the resin solution. ~ormally air from the external surroundings of the spinnin~ apparatus may be employed, eg ambient air having a temperature below 30C and a relative humidity in excess of 50~ is suitable. The temperature and humidity of the cold, humid air may be modified as neoessary to provide satisfac-to~ spinning but generally the air temperature should be below 40C and the air should have a relative humidity above 40~. It will be appreoiated that ac the air temperature i~ reduced, the relative humidity need not be 80 high in order to retard drying 3~ of the spun fibres.
The fibres are entrained in the stream of cold humid air a~ they are spun from the 3pinning cup. While so entrained in the oold humld en~ironment the fibre3 are attenuated, partly by inertia and partly by the effeot of the oold humid air stream. The fibres ~5 are preferably drawn out to a mean dia~eter of the order of 1 to , ~ : ~:: .: .
11:3 63~6 50 ~, particularly below 30 ~. To permit ~uoh attenuation it i~
neoessary for the fibrea to remain entrained in the cold, humid, air stream for some distLnce Yrom the spinrLing cup. Generally they should be 80 entrained until they have reached a di~tance of at least the diameter of the ~pinning cup from the axis of the cup .
The extent to which the fibres are attenuated depends on a number of factora, including the extent to whioh they remain erLtra~Led ~L a cold humid environme~Lt, as indicated above. ~he strea~L of hot, dry, air will eventually mix with the ¢old humid air and dry the fibres thereby preventine further a-ttenuation.
I~Le e~terLt of attenuation will therefore also depend on the relative velooities, positioning, temperature and humidity of the air streams.
In the process of the irLvention, the ~tream of cold, humid air emanating from the spinning cup is deflected dowrLwards:
it should be deflected downwards to ~uch a~ extent that any tor-roidal vortex betweerL the streams of hot dry air a~Ld cold,humid air is eliminated to such an exterLt that the fibres entrained in the cold,h~Lmid air stre~m are not caught up in ~uch a vortex.
The cold, humid, air ~tream may be deflected downwards by the downwardly directed hot air stresm. Increasing the flow rate of the hot,dry, air stream will reduoe or elim~nate completely ~uoh a vortex but at the ~ame time will re~uce the extent of attenuation of the fibres. ~owever simple experime~tatio~ pArticularly aided ; by an inspe¢tion window in the casing of the ~pinning apparatus and suitable illu~inatio~, will reveal whe-ther the fibres are be-ing oaught up in any vortex, while examination of the produot will reveal whether the desired atte~uation has been achieved. However where the deslgn of the ~y~tem is s~oh that the downwardly directed hot air stre~m would deflect and mix with the outwardly directed cold air stream too early; ie before the fibres have attenuated sufficiently, the hot air stream may be defle¢ted outwardly by a subsidiary stream of oold,humid, air above the spinning cup.
This sub~idi~ry stream may have a downward oomponent which oauses - ~ . . . . ............... . . .
. : , ,. -, .
:; ~ ,. ,: . , :
~3~3~6 some or all of the downward deflection of the stream of cold, humid, air having the fibres entrained therein. ~he prooe~
i~ conveniently se-t up by fixing -the temperature, humidity and flow rate of the cold, humid air stream~s), the resin feed rate, and the rotational 3pead of the cup, and then adjusting the flow rate and te~perature of the hot dry air to eliminate vortex form-ation a~d to give fibre~ having the desired degree of atte~uation.
The temperature and rate of flow of the hot, drg,air stream must be sufficient to dry the attenuated fibres to render them non-fltioky. The temperature of the hot, d~y, air i~ prefer-ably in the range 80 to 270C, partioularly 100 to 220C. ~he relative humidity of the hot air is preferably below 50%. Co~-veniently the hot, dry, air may simply be ambie~t air heated to the desired te~perature without asy drying step.
In some cases it may be found that a vorte~ i~ formed below the spinning cup. While it is not neoessary to eliminate such a vorte~, it~ removal may be da~irable in somo oases. It may be eliminated by the provision of an outwardly directed stresm of air from below the cup and/or by the provision of a suitably ~haped housing below the spinning cup to give stream-lined flow of the air streams thereover.
The stream of hot, dry, air serves to dry the fibres and to transport them to the collectio~ zone. The hot, dry, air ~ay also serve to at least partiall~ cure the resin. Further curing of the re3in fibres may be effe¢ted9 if desired9 by heating, for example Ln an oven, at 80 to 250C, preferably lOO to 200C for a suitable period of time. ~he nature and amo~nt of the catalyst, together with the spiDning and post spin~ing heat treatment con-ditians will determins the d~grae o~ o~re for a~y given resin.
For some applications it may be desixable to only partially cure the resin. ~he degree of cure may canv~niently be as~essed by determaning the proportion of fibre dis~olved in water under specified condition~. A ~uitable procedure i~ as follows:
~ sample (approx 5g) of the dry fibre i~ accuratel~
~eighed and then dige~ted with 200 ml of water for 2 hour~ at ., ~3~3~6 50C. The undissolved fibre remaining i8 reoovered by filtration and dried at 100 C in air for 2 hours ~nd the~ reweighed. ~he (%) degree of cure i8 defined as YC~SbL~ v~r~ Iibre x 100 original weight of fibre ~he use of cer-taLn partially cured resin fibrei in paper manufacture i8 described in our Europea~ paten-t application 80.300016.
~ibres produced by the process of the invention are of particular utility in paper manufacture either as the sole fibrous constituent or in admixture with cellulosic fibres9 eg conventional mech~nical or ohemioal pulp, or other synthetio fibrous ~aterials, eg polyolefin fibres.
Two embodimenta of the invention axe illu~trated by refer-ence to the drawings in which ~igure 1 ia a vertical section through the apparatus of a first embodiment and ~igure 2 ia a vertical sec-tion through pa~t of the apparstus of a second embodiment. In ~i~ure 1 the spinning apparatus has an outer casing 1 on the top 2 of which i8 mounted a motor 3 driving a shaft 4 carr~ing a spinning cup 5. The cup 5 has a vertical ~ide wall 6 in which there i~
provided a plurality of rectsngular perforations 7. ~esin solutio~, Ln admi~ture with a solution of a curin~ catalyst, and optionally a soluble thermplastic polymer, i8 fed to the cup 5 via a feed pipe 8. Cold~ humid, air is fed to the cup via an air faed pipe 9. On rotation of the cupl eg at 5000 - 10,000 rpm, the resin solution is spun from the lower edge of the perforations 7 as ribres 10 e~trained in 2n outwardly directed stream 11 of cold, humid, air pumped from the supply 9 through the perforationa 7 by rotation of the cup 5. ~etween the top of cup 5 and casin~ 1 i8 a shroud 12 ~urrounding the driYe shaft 4 and feed pipes 8, 9.
A small gap 13, for example about 1 mm, iæ left between the bottom of shroud 12 and the top of cup 5. Rotation o~ cup 5 also causes an outwardl~ directed ~tream 14 of the cold, humid, air to iasue from gap 13. ~ot, dl~, air is pumped to a plenum chamber 15 on the top 2 of the apparatu~ from whenoe it flows as a downwardly directed stream 16 through an aNnular orifice 17. ~his ~tream 16 `''' :`
1~363~i~
of hott dry, air is deflected outwa~dly by the stream 14 of cold, humid, air issuing from gap 13 and impinge~ o~ the stream 11 of cold, humid, air issuin~ from the perforation 7 of the cup, de~
flecting the stream 11 downwards thereby eliminating the tor-roidal vortex 18 (shown dotted) which would form in the absenoeof the do~wa~dly directed stream 16 of air. ~he ~hroud 12 may, if desired, be provided with vanes (not shown) to deflect the hot, dry, air stream outwardly thus auementing the radial de-flection given by stream 14.
While the fibres 10 are entrained in the cold, humid, air stream 11 dryin~ is retarded so that they are attenuated, partly by the effect of the cold, humid, air stream 11.
~ he stream of hot, dry, air lS eventually mixes with the atream of oold,humid, air 11, dries the fibres 10, and trans-ports them to a conveyor (not shown) at the bottom of the ~pinning appAratus.
~ eneath cup 5 there is provided a housing 19 which servesto streamline the air flow. ~ hole 20 is provided in housing 19 beneath cup 5. The rotatin~ cup 5 acts as an air pump drawing air in throu~h hole 20 and expelling it radiall~ as a stream 21. ~hi8 air stream preve~ts the formation of a vortex below the spinning cup 5-In Fi~ure 2 the spinning cup ?2 comprisea a hollow ves-sel divided into upper and lower portions by an integral plate 23 having a plurality of perforations 24 therein. Ihe cup i9 driven by a shaft 25. ~ resin feed supply tube 26 e~tend~ throu~h the ope~ upper end of cup 22 and ~upplie~ the resin on to plate 23 from whenoe it pasæes, through perforations 2~ on to the interior wall 27 of the lower portion of cup 22. The re~in flows down wall 27 and i~ spun as ~ibres 28, by centrifu~al force, from the lower edge of wall 27.
Cup 22 is mounted for rotation within an enclosure, not shown, carx~ing a stationary shroud 29 surrounding the drive shaft 25 and ths reein supply tube 26. Cold, h~mid, air iB pumped down the interior of ~hroud 290 Some of the cold, humid, air flows ,.. . . . . .
,, . , , 1~L3~3~6 into the upper poFtiO~ of oup 22, through perforatlon~ 24 a~d out of the bottom of the cup aa an outwardly directad air ~trea~ 30 having the fibres 28 e~tra1ned therein. A deflector ring 31 mounted under and rotatable with plate 23 is provided to limit the flow of oold, humid, air OEnd to direot it outwardlg to entrain fibres 28.
The remainder of the oold, humid, air flows outwardly as a strea~ 32 from between the bottom ~urfaoe 33 of shroud 29 and the top ~urface 34 o o~p 22. These bevelled ~urfaces 33, 34 impart a downward oomponent to the air stream 32 flowing from therebetween.
0utside cup 22, but within the enolo~ure, i~ a down~
wardly directed ~tream ~5 of hot, dry, air. qhi~ stream 35 i~
deflected outwardly b~ the air stream 32 80 that it does not meet the cold alr stream 30 flowing out of the bottom of cup 22 with the fibre~ 28 entrained therein until the fibres have been attenuated to the desired degree. As oold air Ytream 32 has a downw æd, ae ~ell as outward, component it also serves to defleot the cold air stream 30 flowing out of the bottom of cup 2~ down-ward8 tIlu~ eliminating vorte~ formationO
As in the embodiment of Figure 1 a housing 36 is providedto smooth the air flows belo~ the ~up 2?. ~hls housing 36 is pro-vided with an aperture 37 from whioh air ia drawn, and thrown out-wardly by the pumping aotion of the rotation of cup 22, as an air stream 38.
The invention ia ~rther illu~tratad by the following example.
A~ aqueo~ ~ol~tio~ of a urea/formaldehgde resin havine a urea:formaldehyde ratio of 1:2 and a solids content of 65% by ~eight was m1yed with 16 ~19 per 100g of the resin solution, of an aqueous solution oontain;ng 2.5% by wei~ht of a polyetbylene oxide of mean molecular wei~ht 600,000 and 0.44% by weight of am~onium sulphate ae c~ring cat~lyst. ~he resultant ~olution, which had a ~isco~ity of a~out 20 poise at room temperature, was ~pun into fi~res usine apparatus of the type ~hown in ~igure 1 , , . . ! ~
'; '' `, :1~3~36~
but in whi¢h housing 19 W8~ omitted.
The solution was fed at 20C at a rate of 80 ml/~in (approx 75g of re~in per mi~uta) to the ~pinninæ ¢up whi¢h had a diameter of 12 cm and 24 rectangular perforation~ of 3 mm width and 5 mm height in its ~idewall~ The rotational speed of the cup was 7000 rpm~
~ ir at 30C and 70~ rela-tive humidity wa~ fed to the cup at a rate of approximately 63 m3~ our. Dry air at 170C
(obtained by heating ambient air to 170C without any d~ying step) was fed to tha pler~um cham~er at 185 m3thr from whenoe it flowed Vi8 an annular gap of 20 ¢m outside diameter and 4 ¢m width, into the spraying chamber whioh had a diameter of 1.2 m.
The resultant etrea~ of hot, dry, air deflec-ted the ~tream of ¢old, humid, air emanat~ng from the ~pinnin~ cup perforations and from the g88 between the shroud snd the top of the cup, downwaras and carried the fibres, while drying them, to the collectio~ ~one. ~he resultant fibre~ had an average diameter o~ abo~t 8 ~.
~he proce~s ~a~ repeated v8rying the ~pinnlng con-ditions a~ set o~t~in the ~ollowing table.
: . . , . :- ~ . , - :, . .
- ': : ;; - :
. ~ ' ', , -~L363~
_ ~
~ot Ai~
~ _ ~esin Feed Cup Speed Flow ~emp 5 _ Rate g/min rp~ ~3 ~ C Remark~
1 75 70V0 185 170 Good fibrss
Thi8 invention relates -to a spinning process and in particular to a process of produoing fibres by centrifugal spin-ing from a solution containing a thermosetting aldehyde resin such as an amino- and/or phenol- aldehyde resin, particl~arly a urea~ formwldehyde resin.
In our United States Patent Serial No. 4178336 issued December 11, 1979 , we describe a proce3s wherein the resin solution, containing a suitable cur ing catalyst, is centrifugally spun from a spinning cup rotating about a substantially vertical axis. ~ stream of cold, humid, air is directed do~nwardl~ into and around the cup to retard evaporation of the solvent and curing of the resin while'a stream of hot dry air is blown outwardly from beneat'h the cup so as to heat, and hence d~y, the fibres spun from the cup and to transport thsm to a collscting zone.
In addition to retarding evaporation of the solvent'and curing of the resin in the cup~ the downward stream of cold humid air into and around the cup provides an environment around the cup of cold humid condition~ within which the fibres spun from the cup are attenuated prior to contact with the hot d~y air.
In a preferred embodiment, the resin i9 spun through a series of perforations in the wall o the cup or from the rim '~
thereof, entrained in a stream of -the cold humid air thrown out of the c~p b~ the rotation thereof. Where a perforated cup is used the resi~ flow rate is such that the perforations are not comp-letsly filled with the resi~ 80 that some of the cold humid air -.: .,: ~ : . ,~
~363~i6 flows through the perforation~ with ths re~in.
We have found that this stream oE cold humid air thrownout of the cup may provide the cold, humid, environment for atten-uation of the fibres, thu~ obviating the nsed for a downwardly directed oold humid air stream around the out~ide of the cup. 'rhe spu~ fibres are th~s attenuated whiLe entrained in the cold humid air stream emanating from the perfora-tions of ths oup. The atten-uation i9 partly effected by the entraining air stream and partly by inertia effects, prior to oontact with the hot dry air ~tream.
However, in the absenoe of the downwardly directed ~tream of oold, humid, air around th0 CUp7 the outwardly dire¢ted air stream having the fibres entrained therein emanating from the cup often gives rise to a torroidal vortex of cold humid air of somewhat greater diameter than the spinnin~ cup and located in a plane just above the spinning plane ie the plane of the fibre~ a~
they are spun from the cup. In some cases the fibres may be oaught up by this vortex and beoome entangled and/or thrown up on to the underside of the top of the enclosure in whioh the spinning operation is conduoted where, beoause the fibres are ~till only partially dried and hence are of a somewhat a &qsi~e nature, they adhere and 80 are not transported to the colls¢tion zons. Evsnt-ually suoh adhering fibres interfsre with the sati~factory spin-ning of the rest of the rssin.
We have found that the~e problems may be overcome by spinning the fibres entrained in the outwardly direoted stream of oold, ~umid, air into an enolo~ure in which a ~tream of hot, dry, air is flowing downward~ and deflecting the outwardly directed stream of oold, humid, air downwards. ~he down~ardly direoted stream of hot dry air is u-tili~ed in addition to, or instead of, the upwardly and outwardly direoted ~tream of hot dry air from beneath the ~pinning oup.
Therefore acGording to the present invention we provide a process for the ~anufaoture of fibre~ from a solution containing a thermosetti~g aldehyde resin and a curing cataly3t therefor-oomprising . . .
~3~3~
(i) feedin~ said solution to the interior of a spinning cup mounted within an enclosure and rotating about a subatantially vertical axis, (ii) feeding cold, humid, air into the cup from whence it ia pumped, by rotation of the cup, as an outwardly directed stream whereby said resin solution i8 Bpun from the cup into said encloa-ure as fibres entrained in said outwardly direoted stream of air wherein ~aid fibres are attenuated, (iii) providine in the enclo~ure a stream of hot, dry, air at a temperature sufficient to dry the attenuated fibres, aaid stream bein~ downwardly directed from above the the apinning c~p, (iv) defle¢ting downwards the outwardly directed stream of cold, humid, air having the fibres entrained therein, (v) conta~ting said outwardly directed stream of air having attenuated fibres entrained therein with the atream of hot, dry, air whereby said attenuated fibres are dried, and (vi) transporting the attenuated fibres by said stream of hot, dry, air to a collection zone.
The thermosetting resin is preferably a condensate of an amino compound with an aldehyde such aa formaldehyde. Some or all of the fo~maldehyde may be replaced by a higher aldehyde such as acetaldehyde~ The amino compound is preferably a polyamine, partic-ularly urea and/or melamine. In order that the resin is water aoluble, ao that water can be used as the solvent, the amino oom-pound ia preferably urea, alone or in admlxture with up to 5% by - weight of melamine. Some or all of the ami~o compound may be re-placed by a phenol auch as pbenol, cresol or reaorcinol.
It ia preferred that the molar ratio of aldehyde to phenol and/or amino group~ is between 0.6:1 and 1.5:1j preferably between 0.7.1 and 1.3:1.
The curing catalyst, which i9 preferably added to the resin aoluti~ just before the latter ia fed to the spinning oup, ::
~3~3~ii6 may ba n weak ¢atalys-t such as di(a~onium) hydro~en pho~phate or ammoniu~ formate, a moderate oatalys-t such ~ formic acid, ammoniu~
sulphate, ammonium chloride or ammonium dihydrogen phosphate, or a strong catalyst such aB phosphoric, sulphuric, sulphamic or hydro-chloric acid. ~e amount of ca-talyst will generally be within the range 0.05 to 1~ by weight of the resin solids.
In some cases, parti¢ularly where -the fibres are to be used in the manufacture of paper, it may be desirable to incorpor-ate an adhesion modifier into the resin. Such modifiers in¢lude cer-tain inor~anic oxyacid radicals which react with aldehydes.
Examples of suitable radicals inolude sulphite, phosphite, and borate radicals. When used as adhesion modifiers, such radi¢als are incorporated into the resin during the condensation of-the amino or phenol compound with the aldehyde.
~lternatively adhesion modifiers, such as carbohydrates, particularly formose, may be incorporated into -the resin solution before, during, or after condensation of the amino or phenol com-pou~d with the aldehyde. The incorporation of modifiers is further described in ourCanadian Patent Applications Nos, 321507 and 321610, ~iled July 29, 1977, The solvent used to ma~e the solution is preferably water, but alter~a-tively may be any solvent which is relatively - volatile at the temperatures to which the spun fibres are heated by the hot dry air stream.
In order -to improve the spinning properties of the resin solution, it is preferred to incorporate into the solu-tion a small amount of a thermoplastic polymer that is soluble in -the solvent employed. Examples of suitable wa-ter ~oluble polymers include polyvinyl alcohol and poly ethylene oxide. The amount of thermo-30 plastic pol;ymer used is preferably 0.01 to 5% by weight of the thermosetting resin solids. While -the -thermoplastic polymer may be incorporated before or during condensation of the amino and/or phenol compound with the aldehyde, it is conve~iently added with the curing catalyst.
q~he resin solution, to which the curing catalyst has been ~ ' ' .
,:,, - : ,.
, ~, ~3~36~
added, i3 fed to a spinnine cup. ~'he ¢up, whioh iH mounted for rotation about a substantially vertioal axi~, iY a hollow vessel havin~ one or more spinning surfaoes. For example the oup ma~
be open-ended and the spinning surface oomprises the end of the open wall thereof. Alternatively the cup ~all m~y be provided with a plurality of spinning surface~ in the Eorm of perforations.
~he ~ize and nu~ber of perforations will be detérmined by the oup diameter and rotational speed: however typioally for a 12 om diameter oup rotating at 5000 to 10,000 rpm, 24 perforations of 3 mm width are suitable. ~he perforations are preferably re¢t~
an~ular in oonfig~ration and the re~in solution feed rate and oup rotational speed are preferably adjusted ~o that the resin solutinn is spun from paFt of the perimeter of the perforations.
~h~ spinning solution preferably ha~ a visoosity between 5 and 100 poi~e at room temperature a~ measured by ~ritish Standard 1733 u~ing oup B6. The vi~cosity may be adjusted by conoentration or dilution of the solution as necessa~y.
In order to prevent premature ouring of the resin and evaporation of the solvent, oold, hu~id, air is supplied to the interior of the cup from whenoe it is pumped, by rotation of the cup, alon~ with the resin solution. ~ormally air from the external surroundings of the spinnin~ apparatus may be employed, eg ambient air having a temperature below 30C and a relative humidity in excess of 50~ is suitable. The temperature and humidity of the cold, humid air may be modified as neoessary to provide satisfac-to~ spinning but generally the air temperature should be below 40C and the air should have a relative humidity above 40~. It will be appreoiated that ac the air temperature i~ reduced, the relative humidity need not be 80 high in order to retard drying 3~ of the spun fibres.
The fibres are entrained in the stream of cold humid air a~ they are spun from the 3pinning cup. While so entrained in the oold humld en~ironment the fibre3 are attenuated, partly by inertia and partly by the effeot of the oold humid air stream. The fibres ~5 are preferably drawn out to a mean dia~eter of the order of 1 to , ~ : ~:: .: .
11:3 63~6 50 ~, particularly below 30 ~. To permit ~uoh attenuation it i~
neoessary for the fibrea to remain entrained in the cold, humid, air stream for some distLnce Yrom the spinrLing cup. Generally they should be 80 entrained until they have reached a di~tance of at least the diameter of the ~pinning cup from the axis of the cup .
The extent to which the fibres are attenuated depends on a number of factora, including the extent to whioh they remain erLtra~Led ~L a cold humid environme~Lt, as indicated above. ~he strea~L of hot, dry, air will eventually mix with the ¢old humid air and dry the fibres thereby preventine further a-ttenuation.
I~Le e~terLt of attenuation will therefore also depend on the relative velooities, positioning, temperature and humidity of the air streams.
In the process of the irLvention, the ~tream of cold, humid air emanating from the spinning cup is deflected dowrLwards:
it should be deflected downwards to ~uch a~ extent that any tor-roidal vortex betweerL the streams of hot dry air a~Ld cold,humid air is eliminated to such an exterLt that the fibres entrained in the cold,h~Lmid air stre~m are not caught up in ~uch a vortex.
The cold, humid, air ~tream may be deflected downwards by the downwardly directed hot air stresm. Increasing the flow rate of the hot,dry, air stream will reduoe or elim~nate completely ~uoh a vortex but at the ~ame time will re~uce the extent of attenuation of the fibres. ~owever simple experime~tatio~ pArticularly aided ; by an inspe¢tion window in the casing of the ~pinning apparatus and suitable illu~inatio~, will reveal whe-ther the fibres are be-ing oaught up in any vortex, while examination of the produot will reveal whether the desired atte~uation has been achieved. However where the deslgn of the ~y~tem is s~oh that the downwardly directed hot air stre~m would deflect and mix with the outwardly directed cold air stream too early; ie before the fibres have attenuated sufficiently, the hot air stream may be defle¢ted outwardly by a subsidiary stream of oold,humid, air above the spinning cup.
This sub~idi~ry stream may have a downward oomponent which oauses - ~ . . . . ............... . . .
. : , ,. -, .
:; ~ ,. ,: . , :
~3~3~6 some or all of the downward deflection of the stream of cold, humid, air having the fibres entrained therein. ~he prooe~
i~ conveniently se-t up by fixing -the temperature, humidity and flow rate of the cold, humid air stream~s), the resin feed rate, and the rotational 3pead of the cup, and then adjusting the flow rate and te~perature of the hot dry air to eliminate vortex form-ation a~d to give fibre~ having the desired degree of atte~uation.
The temperature and rate of flow of the hot, drg,air stream must be sufficient to dry the attenuated fibres to render them non-fltioky. The temperature of the hot, d~y, air i~ prefer-ably in the range 80 to 270C, partioularly 100 to 220C. ~he relative humidity of the hot air is preferably below 50%. Co~-veniently the hot, dry, air may simply be ambie~t air heated to the desired te~perature without asy drying step.
In some cases it may be found that a vorte~ i~ formed below the spinning cup. While it is not neoessary to eliminate such a vorte~, it~ removal may be da~irable in somo oases. It may be eliminated by the provision of an outwardly directed stresm of air from below the cup and/or by the provision of a suitably ~haped housing below the spinning cup to give stream-lined flow of the air streams thereover.
The stream of hot, dry, air serves to dry the fibres and to transport them to the collectio~ zone. The hot, dry, air ~ay also serve to at least partiall~ cure the resin. Further curing of the re3in fibres may be effe¢ted9 if desired9 by heating, for example Ln an oven, at 80 to 250C, preferably lOO to 200C for a suitable period of time. ~he nature and amo~nt of the catalyst, together with the spiDning and post spin~ing heat treatment con-ditians will determins the d~grae o~ o~re for a~y given resin.
For some applications it may be desixable to only partially cure the resin. ~he degree of cure may canv~niently be as~essed by determaning the proportion of fibre dis~olved in water under specified condition~. A ~uitable procedure i~ as follows:
~ sample (approx 5g) of the dry fibre i~ accuratel~
~eighed and then dige~ted with 200 ml of water for 2 hour~ at ., ~3~3~6 50C. The undissolved fibre remaining i8 reoovered by filtration and dried at 100 C in air for 2 hours ~nd the~ reweighed. ~he (%) degree of cure i8 defined as YC~SbL~ v~r~ Iibre x 100 original weight of fibre ~he use of cer-taLn partially cured resin fibrei in paper manufacture i8 described in our Europea~ paten-t application 80.300016.
~ibres produced by the process of the invention are of particular utility in paper manufacture either as the sole fibrous constituent or in admixture with cellulosic fibres9 eg conventional mech~nical or ohemioal pulp, or other synthetio fibrous ~aterials, eg polyolefin fibres.
Two embodimenta of the invention axe illu~trated by refer-ence to the drawings in which ~igure 1 ia a vertical section through the apparatus of a first embodiment and ~igure 2 ia a vertical sec-tion through pa~t of the apparstus of a second embodiment. In ~i~ure 1 the spinning apparatus has an outer casing 1 on the top 2 of which i8 mounted a motor 3 driving a shaft 4 carr~ing a spinning cup 5. The cup 5 has a vertical ~ide wall 6 in which there i~
provided a plurality of rectsngular perforations 7. ~esin solutio~, Ln admi~ture with a solution of a curin~ catalyst, and optionally a soluble thermplastic polymer, i8 fed to the cup 5 via a feed pipe 8. Cold~ humid, air is fed to the cup via an air faed pipe 9. On rotation of the cupl eg at 5000 - 10,000 rpm, the resin solution is spun from the lower edge of the perforations 7 as ribres 10 e~trained in 2n outwardly directed stream 11 of cold, humid, air pumped from the supply 9 through the perforationa 7 by rotation of the cup 5. ~etween the top of cup 5 and casin~ 1 i8 a shroud 12 ~urrounding the driYe shaft 4 and feed pipes 8, 9.
A small gap 13, for example about 1 mm, iæ left between the bottom of shroud 12 and the top of cup 5. Rotation o~ cup 5 also causes an outwardl~ directed ~tream 14 of the cold, humid, air to iasue from gap 13. ~ot, dl~, air is pumped to a plenum chamber 15 on the top 2 of the apparatu~ from whenoe it flows as a downwardly directed stream 16 through an aNnular orifice 17. ~his ~tream 16 `''' :`
1~363~i~
of hott dry, air is deflected outwa~dly by the stream 14 of cold, humid, air issuing from gap 13 and impinge~ o~ the stream 11 of cold, humid, air issuin~ from the perforation 7 of the cup, de~
flecting the stream 11 downwards thereby eliminating the tor-roidal vortex 18 (shown dotted) which would form in the absenoeof the do~wa~dly directed stream 16 of air. ~he ~hroud 12 may, if desired, be provided with vanes (not shown) to deflect the hot, dry, air stream outwardly thus auementing the radial de-flection given by stream 14.
While the fibres 10 are entrained in the cold, humid, air stream 11 dryin~ is retarded so that they are attenuated, partly by the effect of the cold, humid, air stream 11.
~ he stream of hot, dry, air lS eventually mixes with the atream of oold,humid, air 11, dries the fibres 10, and trans-ports them to a conveyor (not shown) at the bottom of the ~pinning appAratus.
~ eneath cup 5 there is provided a housing 19 which servesto streamline the air flow. ~ hole 20 is provided in housing 19 beneath cup 5. The rotatin~ cup 5 acts as an air pump drawing air in throu~h hole 20 and expelling it radiall~ as a stream 21. ~hi8 air stream preve~ts the formation of a vortex below the spinning cup 5-In Fi~ure 2 the spinning cup ?2 comprisea a hollow ves-sel divided into upper and lower portions by an integral plate 23 having a plurality of perforations 24 therein. Ihe cup i9 driven by a shaft 25. ~ resin feed supply tube 26 e~tend~ throu~h the ope~ upper end of cup 22 and ~upplie~ the resin on to plate 23 from whenoe it pasæes, through perforations 2~ on to the interior wall 27 of the lower portion of cup 22. The re~in flows down wall 27 and i~ spun as ~ibres 28, by centrifu~al force, from the lower edge of wall 27.
Cup 22 is mounted for rotation within an enclosure, not shown, carx~ing a stationary shroud 29 surrounding the drive shaft 25 and ths reein supply tube 26. Cold, h~mid, air iB pumped down the interior of ~hroud 290 Some of the cold, humid, air flows ,.. . . . . .
,, . , , 1~L3~3~6 into the upper poFtiO~ of oup 22, through perforatlon~ 24 a~d out of the bottom of the cup aa an outwardly directad air ~trea~ 30 having the fibres 28 e~tra1ned therein. A deflector ring 31 mounted under and rotatable with plate 23 is provided to limit the flow of oold, humid, air OEnd to direot it outwardlg to entrain fibres 28.
The remainder of the oold, humid, air flows outwardly as a strea~ 32 from between the bottom ~urfaoe 33 of shroud 29 and the top ~urface 34 o o~p 22. These bevelled ~urfaces 33, 34 impart a downward oomponent to the air stream 32 flowing from therebetween.
0utside cup 22, but within the enolo~ure, i~ a down~
wardly directed ~tream ~5 of hot, dry, air. qhi~ stream 35 i~
deflected outwardly b~ the air stream 32 80 that it does not meet the cold alr stream 30 flowing out of the bottom of cup 22 with the fibre~ 28 entrained therein until the fibres have been attenuated to the desired degree. As oold air Ytream 32 has a downw æd, ae ~ell as outward, component it also serves to defleot the cold air stream 30 flowing out of the bottom of cup 2~ down-ward8 tIlu~ eliminating vorte~ formationO
As in the embodiment of Figure 1 a housing 36 is providedto smooth the air flows belo~ the ~up 2?. ~hls housing 36 is pro-vided with an aperture 37 from whioh air ia drawn, and thrown out-wardly by the pumping aotion of the rotation of cup 22, as an air stream 38.
The invention ia ~rther illu~tratad by the following example.
A~ aqueo~ ~ol~tio~ of a urea/formaldehgde resin havine a urea:formaldehyde ratio of 1:2 and a solids content of 65% by ~eight was m1yed with 16 ~19 per 100g of the resin solution, of an aqueous solution oontain;ng 2.5% by wei~ht of a polyetbylene oxide of mean molecular wei~ht 600,000 and 0.44% by weight of am~onium sulphate ae c~ring cat~lyst. ~he resultant ~olution, which had a ~isco~ity of a~out 20 poise at room temperature, was ~pun into fi~res usine apparatus of the type ~hown in ~igure 1 , , . . ! ~
'; '' `, :1~3~36~
but in whi¢h housing 19 W8~ omitted.
The solution was fed at 20C at a rate of 80 ml/~in (approx 75g of re~in per mi~uta) to the ~pinninæ ¢up whi¢h had a diameter of 12 cm and 24 rectangular perforation~ of 3 mm width and 5 mm height in its ~idewall~ The rotational speed of the cup was 7000 rpm~
~ ir at 30C and 70~ rela-tive humidity wa~ fed to the cup at a rate of approximately 63 m3~ our. Dry air at 170C
(obtained by heating ambient air to 170C without any d~ying step) was fed to tha pler~um cham~er at 185 m3thr from whenoe it flowed Vi8 an annular gap of 20 ¢m outside diameter and 4 ¢m width, into the spraying chamber whioh had a diameter of 1.2 m.
The resultant etrea~ of hot, dry, air deflec-ted the ~tream of ¢old, humid, air emanat~ng from the ~pinnin~ cup perforations and from the g88 between the shroud snd the top of the cup, downwaras and carried the fibres, while drying them, to the collectio~ ~one. ~he resultant fibre~ had an average diameter o~ abo~t 8 ~.
~he proce~s ~a~ repeated v8rying the ~pinnlng con-ditions a~ set o~t~in the ~ollowing table.
: . . , . :- ~ . , - :, . .
- ': : ;; - :
. ~ ' ', , -~L363~
_ ~
~ot Ai~
~ _ ~esin Feed Cup Speed Flow ~emp 5 _ Rate g/min rp~ ~3 ~ C Remark~
1 75 70V0 185 170 Good fibrss
2 110 7000 170 216 Good fibre~
125 7000 170 181 Good fibre~
4 100 7000 60 170 Fibres stuok to roof of vessel.
6000 180 165 Good fibres 6 250 7500 365 lgo Fibres insuffi¢ientl~
attenuated.
7 300 7500 190 250 ~ibres ver~ slightly damp 8 400 7500 200 250 Fibre~ damp and stiok~
9 23D 8000 190 190 ~i~res slightly d~mp and sticky tendin~ to stick on vessel wall.
190 12~00 200 216 ~ibres dry but some hang-ing o~ vessel wall.
~ __ _ . .
In ran 4 it is seen that the hot air flow rate wa~ insuffici~nt to . prevent the fibres from being flun~ o~to the ves~el roof. In run 6 the hot sir flow rate wa~ too great and did not permit the fibre~
to remain entrained Ln the cold, humld, air ~tream for a su~ficient time.
:~ PA/CG ~
19 March:l9~0 ' ,`~
125 7000 170 181 Good fibre~
4 100 7000 60 170 Fibres stuok to roof of vessel.
6000 180 165 Good fibres 6 250 7500 365 lgo Fibres insuffi¢ientl~
attenuated.
7 300 7500 190 250 ~ibres ver~ slightly damp 8 400 7500 200 250 Fibre~ damp and stiok~
9 23D 8000 190 190 ~i~res slightly d~mp and sticky tendin~ to stick on vessel wall.
190 12~00 200 216 ~ibres dry but some hang-ing o~ vessel wall.
~ __ _ . .
In ran 4 it is seen that the hot air flow rate wa~ insuffici~nt to . prevent the fibres from being flun~ o~to the ves~el roof. In run 6 the hot sir flow rate wa~ too great and did not permit the fibre~
to remain entrained Ln the cold, humld, air ~tream for a su~ficient time.
:~ PA/CG ~
19 March:l9~0 ' ,`~
Claims (10)
1. A process for the manufacture of fibres from a solution containing a thermosetting aldehyde resin and a curing catalyst therefor, comprising (i) feeding said solution to the interior of a spinning cup mounted within an enclosure and rotating about a substantially vertical axis, (ii) feeding cold, humid, air into the cup from whence it is pumped, by rotation of the cup, as an outwardly directed stream whereby said resin solution is spun from the cup into said enclosure as fibres entrained in said outwardly directed stream of air wherein said fibres are attenuated, (iii) providing in the enclosure a stream of hot, dry, air at a temperature sufficient to dry said attenuated fibres, (iv) contacting said outwardly directed stream of air having attenuated fibres entrained therein with the stream of hot, dry, air, whereby said attenuated fibres are dried, and (v) transporting the attenuated fibres by said stream of hot, dry, air to a collection zone, characterised in that the outwardly directed stream of cold, humid, air having the fibres entrained therein is deflected downwards and contacted with the stream of hot, dry, air which is directed downwards from above the spin-ing cup.
2. A process according to claim 1 characterised in that the stream of hot, dry, air is deflected outwards by a subsidiary out-wardly directed stream of cold, humid, air above the spinning cup.
3. A process according to claim 2 characterised in that the stream of cold, humid, air having the fibres entrained therein is deflected downwards by said subsidiary stream of cold, humid, air which subsidiary stream has a downward component in addition to its outwards component.
4. A process according to claim 1 or claim 2 characterised in that the outwardly directed stream of cold, humid, air having the fibres entrained therein is deflected downwards by the stream of hot, dry, air.
5. A process according to Claim 1 characterised in that the outwardly directed stream of cold humid, air having the fibres entrained therein is not contacted with the stream of hot, dry, air until the fibres have reached a distance from the axis of the spinning cup at least equal to the spinning cup diameter
6. A process according to Claim 1 characterised in that a further stream of hot, dry, air is provided outwardly directed from below the spinning cup.
7. A process according to Claim 1 characterised in that the resin solution is spun as fibres from perforations in the wall of the spinning cup.
8. A process according to Claim 7 characterised in that the resin solution is spun from part of the perimeter of each perforation with the outwardly directed stream of cold, humid, air flowing through the remainder of said perforation
9. A process according to Claim 1 characterised in that the fibres are spun from an aqueous solution of a resin formed from formaldehyde and an amino compound component comprising urea and 0 to 5% by weight, based on the weight of said amino compound component, of melamine.
10. A process according to Claim 1 characterised in that the fibres are spun from an aqueous solution of said thermosetting aldehyde resin, said solution containing 0 01 to 5% by weight, based on the weight of the resin solids, of a water soluble thermoplastic polymer.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7916863 | 1979-05-15 | ||
| GB7916863 | 1979-05-15 | ||
| GB8005838 | 1980-02-21 | ||
| GB8005838 | 1980-02-21 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1136366A true CA1136366A (en) | 1982-11-30 |
Family
ID=26271530
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000351780A Expired CA1136366A (en) | 1979-05-15 | 1980-05-09 | Spinning process |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0019383B1 (en) |
| AU (1) | AU528448B2 (en) |
| CA (1) | CA1136366A (en) |
| DE (1) | DE3060576D1 (en) |
| FI (1) | FI65094C (en) |
| NO (1) | NO149357C (en) |
| NZ (1) | NZ193641A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3161960D1 (en) * | 1980-07-29 | 1984-02-23 | Ici Plc | Method of making a laminated sheet material |
| NL187915C (en) * | 1981-02-16 | 1992-02-17 | Sten Halvor Harsem | METHOD FOR SPINNING FIBERS AND APPARATUS FOR CARRYING OUT THIS METHOD |
| FR2543169B1 (en) * | 1983-03-23 | 1986-03-28 | Saint Gobain Isover | PROCESS FOR PRODUCING PHENOPLAST FIBERS |
| DE3801080A1 (en) * | 1988-01-16 | 1989-07-27 | Bayer Ag | METHOD FOR PRODUCING FINE POLYMER FIBERS |
| DE4315609A1 (en) * | 1993-05-11 | 1994-11-17 | Basf Ag | Process and device for producing fibers by a centrifugal spinning process |
| DE102005048939A1 (en) * | 2005-07-01 | 2007-01-11 | Carl Freudenberg Kg | Centrifugal melt spinning, especially for producing nanofibers, uses an air stream to guide and treat fibers emerging from rotating melt container |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1357206A (en) * | 1920-02-10 | 1920-10-26 | Fuller Allen Reed | Method of making fibers |
| US2336743A (en) * | 1941-10-13 | 1943-12-14 | Fred W Manning | Method and apparatus for spinning unwoven fabrics |
| GB1573116A (en) * | 1977-03-11 | 1980-08-13 | Ici Ltd | Production of formaldehyde resin fibres by centrifugal spining |
| GB2001578B (en) * | 1977-07-29 | 1982-01-27 | Ici Ltd | Spinning fibres |
-
1980
- 1980-04-25 DE DE8080301366T patent/DE3060576D1/en not_active Expired
- 1980-04-25 EP EP80301366A patent/EP0019383B1/en not_active Expired
- 1980-05-07 NZ NZ193641A patent/NZ193641A/en unknown
- 1980-05-08 AU AU58225/80A patent/AU528448B2/en not_active Ceased
- 1980-05-09 CA CA000351780A patent/CA1136366A/en not_active Expired
- 1980-05-13 NO NO801417A patent/NO149357C/en unknown
- 1980-05-14 FI FI801565A patent/FI65094C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| NO149357C (en) | 1984-04-04 |
| FI65094B (en) | 1983-11-30 |
| NO801417L (en) | 1980-11-17 |
| DE3060576D1 (en) | 1982-08-12 |
| AU5822580A (en) | 1980-11-20 |
| FI801565A (en) | 1980-11-16 |
| NZ193641A (en) | 1983-03-15 |
| EP0019383B1 (en) | 1982-06-23 |
| AU528448B2 (en) | 1983-04-28 |
| FI65094C (en) | 1984-03-12 |
| EP0019383A1 (en) | 1980-11-26 |
| NO149357B (en) | 1983-12-27 |
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