Note: Descriptions are shown in the official language in which they were submitted.
1 This inven~ion relates to an improvement in a
2 proce~s for the product~on of a nonwoven fabric comprl~in~
3 spinning continuou~ly a fused thermoplastic material from
4 spinning holes, simultancou~ly exhausting a gas at a high
speed from a ga~ exhaust hole provided ad~acen~ to the
6 spinning holes to stretch fibers of the spun thermoplastic
7 material and to form a fiber ~tream consisting of the fibers
8 and gas and then collecting the fiber ~tream9 and more par-
9 ticularly, lt i8 concerned with a proce~ for producing
pinhole-free nonwoven fabric having a good hand or a non-
11 woven fabric consisting of a resln which has a long harden-
12 ing time ~uch as polyamides (e.g" nylon 12) or ~hermoplastlc
13 polyurethane~ by contacti~g the fiber stream with fine liquid
14 drops and then collect~ng lt.
Processes for the productlon OIC a nonwoven fabric
16 comprising spinning a melted thermoplastic resin and blowing
17 it as fine fibers against a moving collecting plate by ~
lB high speed gas, thereby collecting the nonwoven fabric have
19 been known as the oo oalled "melt~blQwing process" (3apanese
Patent Public Dlsolo~ure Nos. 10,258/lg74, 48,g21/1974,
21 121,570~1~75 and 46,972/1975) or "jet-~plnning process"
22 (Japanese Patent Publication Nos. 253871/196g and 26,977tl9693.
23 The nonwoven fabrics obtained by these processes
24 are porous nonwoven fabrics havi~g a pore diame~er of 0.5
to 20 microns which can be varied widely with the ob~ec~ of
~6 use, and are u~ed as diaphragms for electrodes of lead ~or~
27 age battery~ filters, m~sks or medical treatment , artif~-
28 cial leathers~ adhe~ives and the like. The processes of
29 the prior art have the disad~antage that ~hen a thin no~woven
fabric is produced, pinhole~ occur often to lower the wor~h
31 as a commercial artlcle and ~o ~or~ a part that is of no use,
32 and i~ is difficul~ to ob~ain a long article. In addition,
1 since resins having a long hardening time or high adhesive-
2 ness (blocking property) ~uch as polyamides ~particularly~
3 nylon 123 or thermopl~stic polyure~hanes tend to fu~ and
4 ~dhere when their fibers are blown against a collecting
plate, lt i3 very difficult to produce a nonwoven fabric by
6 the prior art process,
7 In accordance with the in~ention the forma~ion of
8 pinholes is prevented by contacting the fiber ~tream wi~h
9 fine liquid drops and then recovering it~ Furthermore, it
is found that according to the process of the present lnven-
11 tion, nonwoven fabrics can be produced from resins havi~g a
12 long hardening time and high adhesiveness (blocking proper-
13 ty), whieh production is very difficult by the process of the
14 prior art.
That is to say, the gist of the present invention
16 consists in a process for the product~on of a nonwoven fabric
17 comprising spinning con~inuously a fused ~hermoplastic mate-
18 rial rom a plurality of spinning holes provided in a ~pin-
19 ning apparatus, simultaneously blowing a gas at high speed
from a gas exhaust hole provided adjacent to the spinning
21 holes to stretch fibers of the thermoplastic material an~ ~o
2~ form a fiber stream consisting o the fiber~ and gas and then
23 blowing the fiber stream against a collecting plate, charac
24 terized by contactin~ the flber stream wlth fine llquld
25 drops, followed by blowing the fiber stream against the eollec-
26 tin8 plate arld cc~llecting it,
27 The inventlon wil~ be better under~tood from the
2~ following descrip~ion taken wi~h the accompany~ng drawi~gs
29 wherein:
Fig. 1 is a schematic view of one em~odiment ac~ord~
31 lng to the present invention;
32 Fig., ~ is a partial plan view of l:he surface of
33 drum 31 o Fig. 1~ Fig~ 5 (a) and Fig. 6 and drum 41 of Figo 69
~7~2
" ~ ~
~ 3 -
1 Fig~ 3 is a cro~s Bectional view of Flg. 2;
2 Fig. 4 (a) i8 a schem~tlc view of another embodl-
3 ment according to the present invention, (b~ i~ an enlarged
4 pl~n view of liquid drop feeding means 10, (c) i8 a cro~s
sectional view of (b~ along l~ne W~W';
6 Fig. 5 (a) i5 a schematic view of further embodi-
7 ment according to the present invention, ~b) i8 a plan view
8 of slit 200;
9 Fig. 6 is a &chematic view of ~tlll further embodi-
ment ~ccording to the present ~nvention; and
11 Flg. 7 comprises CrO~8 sectional views of non-
12 woven fabrics produced by the process of the preAent inven-
13 tion, in particular, a~ shown in Fig. 6.
14 The thermopla~tlc materials used in ~he process
of the present in~ent~on are thenmoplastlc re~ins, fsr exam-
16 ple, homopolymers or copolymer~ of ~X-olefins such as ethyl-
17 ene, propylene, butene~ methylpentene-l and the like,
18 or mixtures of these polymers; modifled polyolefins ob~ained
19 by grafting various unsaturated monomers, ~or e~ample, male~c
anhydride, HIMIC ~nhydride (trade name of endo~bicyclol2~2,1
21 5-heptene-2,3-dicarboxylic acid anhydride), acrylic acid or
22 it& e~ers ~o homopolymers or copolymers of C~-olefins or
23 mixtures o~ these polymers; mixtures of the above descrlbQd
24 homopolymers or cop~lymers of C~-oleins or mixtures of the~e
polym~r~ with the modified polyole~ins; polyamides such as
26 nylon 6, ~ylon 66, ~ylon 6, 12, nylon 12, ~ylon 11 and nylon
27 610 (commercial name or general name) or mixtures thereof;
28 polyesters such as polyethylene glycol terephthalate, poly~ ~
29 butylene glycol terephthalate ~r mixtures thereo~; thenno~
plastic polyurethanes; polys~yrene; and me~h~l polyacryla~e,
31 asphal~, pitch and ~he like. In par~icular, poly~lefin~,
32 polyamides, polyestar~g ~hermoplastic polyure~hanes an~ pitch
7~
-- 4
1 are preferably used, In addition, resins with a slow har-
2 dening speed and high adhesiveness (hlocking property)
3 such as nylon 12, nylon 6, 12 and thermoplastlc poly-
4 urethanes can also be used in the present invention.
The spinning die used in the present invention
6 is a die in which spinning holes are provided annularly
7 or linearly and any dies provided with spinning holes
8 linearly or annularly can be used which have the struc-
9 tures as disclosed in, for example, Japanese Patent Public
Disclosure Nos. 10258/1974, 48921/1974, 121570/1975,
11 46972/1975 and 67411/1976 and Japanese Patent Publica-
12 tion Nos. 25871/1969 and 26977/lq69. In particular, the
13 dies having the structures described in Japanese Patent
14 Publication No. 25871/1969 and Japanese Patent Public
Disclosure Nos. 48921/1974 and 67411/1976 are preferable.
16 As the collecting plate of the present invention
17 there can be used sheets, films, thin plates, woven fa-
18 brics, nonwoven fabrics, nets or porous plates made by
19 knitting, punching or other methods, which are of metals
or synthetic resins. In particular, the shape o~ the
21 collectino plate is preferably hollow-cylindrical, annular
22 or belt-like and there are thus used nets or porous plates
23 wound round cylindrical drums or rolls, or woven fabrics
24 or nonwoven fabrics wound fu.rther about these surfaces.
The shape of a portion of the collecting plate may simply
26 be flat, butt in order to obtain a uniform nonwoven fabric
27 without scattering fibers, it is particularly desirable
28 to provide a collecting plate having a number of holes
29 and a press~plate having a number o~ holes in such a
manner that they are movable and contacted with each
-- 5
1 other through fibers and a fiber collecting section is
2 formed wherein the interval between the surfaces of the
3 collecting plate and press plate in the opposite direction
4 to the movement of the collecting plate is increased with
the increase of the distance from the contact portion
6 and the distance from the contact portion is adjusted
7 to at most five times as much as ~he width of a fiber
8 stream on the collecting plate. Examples of the collect-
9 ing pla~e and press plate in the fiber collecting section,
capable of satisfying such conditions, are as follows:
11 (1) Either or both of the collecting plate and
12 press plate are hollow-cylindrical and in the fiber col-
13 lecting section, at least one of them is a part of
14 hollow-cylindrical form.
(2) Either or both of the collecting plate and
16 press plate are annular and in the fiber collecting sec-
17 tion, at least one of them is a part of hollow-cylindrical
18 form.
19 ~3) The collecting plate and press plate are
belt like and provided on a drum or roll and in the fiber
21 collecting section, at least one of them is a part of
22 hollow-cylindrical form.
23 Preferably examples of the collectirlg plate and
24 press plate are nets of metals or synthetic resins with
5 to 100 meshes or porous plates corresponding to these
2~ meshes, which are supported by hollow-cylindrical drums
27 or rolls, the hollow-cylindrical drum in the iber collect-
28 ing section having holes with a diameter of 1 to 50 mm all
29 over the side wall.
A thermoplastic resin is spun from spinning holes,
31 stretched by a high speed gas to be fine ~ibers and blown
1 against a collect.ing plate in the form of a fiber stream
2 with the gas, as described above. During the same time,
3 the fiber stream i5 contacted with fine liquid drops and
4 then blown against the collecting plate according to the
present invention. The liquid used for the liquid drops
6 is ordinarily water, aqueous solutions or aqueous suspen- `
7 sions, and depending upon the object, organic solvents
8 such as alcohols, hydrocarbons and chlorinated hydrocar-
9 bons or their solutions can also be used. ~s the aqueous
solution, there can be used aqueous solutions of inorganic
11 ~alts, surface active agents, water-soluble resins and
12 dyes or mixtures with organic solvents, and as the sus-
13 pension, there can be used suspensions containing inor-
14 ganic substances such as silica, silica gel, calcium car-
`5 bonate, alumina, alumina gel, talc, clay, pigments and
16 flame proofing agents with or without water-soluble
17 resins or surface active agents, and suspensions or
1~ emulsions of oryanic substances such as fats and oils,
19 mineral oils, perfumes, flame proofing agents, synthetic
resins and natural resins.
21 ~ir is ordinarily used as the high speed gas of
22 the present invention, but, depending on the variety of
23 thermoplastic resin used, a gas inert to the thermoplastic
24 resin such as nitrogen or carbon dioxide can be used.
The liquid drops are preferably finel but this
26 is not always essential. The liquid drops have generally
27 a diameter of 0.1 to 1000 microns, preferably 0.1 to 20
~8 microns, which are obtained by spraying, rotary atomiza-
29 tion or ultrasonic wave atomization. In particular, the
ultra~onic wave atomization method is suitable for obtain-
31 ing ine liquid drops.
1 Contacting of a fiber stream with liquid drops
2 is carried out by feeding or spraying the liquid drops to
3 near a collecting plate or directly to the fiber stream.
4 The quantity of liquid drops to be sprayed varies with
various conditions and in the case of producing a nonwoven
6 fabric of polypropylene, polyamide or polyurethane, it is
7 preferably 0.1 to 10 parts by weight per 1 part by weight
8 of the resin. Since through the contact of a fiber stream
9 and fibers contained in the fiber stream with liquid drops
as described above, not only the temperature is rapidly
11 lowered partly by the liquid drops and partly by the
12 evaporation latent heat of the liquid dro~s, but also
13 the surfaces of the fibers are covered with the li~uid
14 molecules, the bulb-like materials are cooled to prevent
formation of pinholes. Even in the case of using a resin
16 with a slow hardening speed such as nylon 12, fusion and
17 adhesion of the fibers to each other can be prevented
18 to give a nonwoven fabric consisting of the fine fibers
19 of such a resin.
The process of the present invention has an ad-
21 vantage that a surface-treated nonwoven fabric can directly
22 be obtained by the use of liquid drops consisting of an
23 aqueous solution or suspens.ion.
24 In addition, the process of the present invention
25 has another advantage that since the position can option- :
26 ally be dete.rmined where a fiber stream i5 brought into
27 contact with iiquid drops, not only the heat history of
28 the fiber can be provided optio.nally depending on the
29 property of a nonwoven fabric to be pxoduced, but also a
stable fiber stream can continuously be obtained for a long
31 time without af~ecting unfavorably the gaseous flow near
7~2
-- 8 --
1 spinning holes.
2 In the present invention, the fiber stream is
3 brought into contact with liquid drops at a position where
4 fibers consisting of a fused xesin exhausted from spinning
holes are sufficiently stretched and are not completely
6 solidified and this position can optionally be determined
7 depenaing upon the spinning conditions and variety of
8 resin employed. If the fiber stream is contacted with
9 liquid drops near th~ outlet of a spinning hole, the fibers
are quenched, and, consequently, stretching of the fibers
11 is insufficient. There~ore, this position is not desirable,
12 in general. For the contact of the fiber stream with li-
13 quid drops, it is possible to employ not only a method
14 comprising spraying liquid drops to the fiber stream, but
also a method comprising providing an atmosphere contain-
16 ing liquid drops between the die and collecting plate,
17 blowing a fiber stream aoainst the atmosphere to thus
18 draw the liquid drops into the fiber stream thereby con-
19 tacting them.
As apparent from the foregoing illustration,
21 the process of the present invention has an effect funda-
22 mentally different from that of the known method which
23 comprises exhausting water from a water exhaust hole pro-
24 vided adjacen~ly to a gas exhaust hole~ thus adding water
drops to a high speed gas from the gas exhaust hole and
26 removing a resin precipltated on near spinning holes
27 (Japanese Patent Publication No. 20248/1968). That is,
28 this process aims at removing a resin precipitated on
29 spinning holes or preventing the precipitation thereof
by spraying water to near the spinning holes, so the struc-
31 ture near the spinning holes is so complicated that the
~7~
,
g
l production thereof costs a great deal and control of the
2 spinning holes~ gas exhaust holes and water exhaust holes
3 is very complicated and, in addition, these holes are
4 always contacted with water resulting in a violent corxo-
sion thereof, which requires a special material for the
6 purpose of preventing this rorrosion. This is difficult
7 from a technical or economical point of view. Moreover,
8 the fibers spun from spinning holes are immediately
9 quenched, so that stretching thereof cannot sufficiently
be carried out and it is difficult to produce a nonwoven
ll fabric consisting of fine fibers. ~ccording to the pro-
12 cess of the present invention, on the other hand, fibers
13 can be cooled after stretched sufficiently as described
14 above and therefore there is obtained a nonwoven fabric
consisting of fine fibers by means of a simple apparatus.
16 Fig. l to Fig. 6 show embodiments of the present
17 invention without limiting the same. Referring to Fig.
18 l, a thermoplastic material is fed to hopper ll of extru-
l9 der l, where it is heated and fused, it is then fed to
die 2 provided to extruder l and continuously spun fxom
21 spinning hole 21 of die 2. Die 2 is provided with gas
22 exhaust hole 22 and gas feed pipe 23 for feeding a gas
23 to gas exhaust hole 22, positioned adjacently to the
24 both sides of spinning hole 21. A high pressure gas
fed to gas feed pipe 23 of die 2 is exhausted at a tran-
26 sonic speed from gas exhaust hole 22. The thermoplastic
27 matexial spun from spinning hole 21 lS converted into
28 ~ine fibers by the high speed gas flow exhausted from gas
29 exhaust hole 22 and forms fiber stream 7 with the gas.
Fiber stream 7 is contacted with liquid drops lOl pro-
31 duced by a liquid drop producing apparatus (e.g., ultra-
,7~
-- 10 --
1 sonic spray) and fed from liquid drop feeding means 10
2 according to the present invention and then blown against
3 fiber blow portion P on collecting plate 3. Collecting
4 plate 3 is a net or porous or perforated plate made of
a metal or synthetic resin having a mesh size of 5 to
6 200 meshes, preferably 5 to 100 meshes, more preferably
7 10 to 40 meshes and being provided on hollow-cylindrical
8 drum 31 having a number of holes on the side wall. These
9 holes have preferably a tapered form in cross section as
shown in Fig. 2 and Fig. 3. The fibers blown against on
11 the surface of collecting plates 3 as fiber stream 7 are
12 separated from fiber stream 7 to form nonwoven fabric 5
13 which is then pressed to a predetermined thickness by
14 press plate 4 and taken up by winder 8 via rolls 71 and
71'. Press plate 4 is a net or perforated plate similar
16 to collecting plate 3 and wound about drum 41 similar
17 to drum 31 and drum 41'. In the case of Fig. 1, fiber
18 stream 7 is hlown against fiber collecting section 6 con-
19 sisting of collecting plate 3 and press plate 4 to thus
give a uniform nonwoven fabric with less scattering of
21 fibers as compared with the case of blowing fibers
22 against a flat collecting plate as shown in Fig. 4ta)~
23 In the present invention, fiber stream 7 is
24 blown against a collecting plate to separate fibers
after being contacted with fine liquid drops 101, which
26 is accomplished by spraying liquid drops 101 from liquid
27 drop feeding means 10 with a gas to fiber stream 7 as
28 shown in Fig. 1. Liquid drops 101 are usually of water~
29 but as occasion demand~, may be of solutions, disper-
sions or suspensions~ which can be fed in a dispersed
31 state in a gas such as air. In the case o using water
7~2
1 drops as the liquid drops, the quantity thereof is pref~r
2 ably 0.1 to 10 parts by weight per 1 paxt by weight of a
3 thermoplastic material. In the case of Fig. 1, liquid
4 drop feeding means 10 is an ultrasonic wave spray, but
it may be a simple spray, rotary atomizer, ultrasonic
6 wave moistener, etc. 9 is a spray for cooling collecting
7 plate 3 and, depending on the quantity of liquid drops
8 used, it can be omitted.
9 Fig. 4(a) shows a position P on the flat sur-
face of annular collecting plate 3 supported by dxum 31
11 and drum 31' where fiber stream 7 is blown against. In
12 this case, water dxops dispersed by ultrasonic wave of a
13 liquid drop producing apparatus (not shown) are fed via
14 feed pipe 104 to liquid drop feeding means 10 and 10'
having slit openings 102 and 102' at the both sides of
16 fiber stréam 7. The liquid drops fed to liquid drop
17 feeding means 10 and 10l are applied to the both sides
18 of fiber stream 7 from openings 102 and 102l (Fig. 4(b)
19 is the plan ~iew of liquid drop feeding means 10 and 10'
and Fig. 4(c) is a cross sectional view of (b) along W-W
21 surface.)
22 Fig. 5(a) shows a case of producing a nonwoven
23 fabric of dual layer, in which thick fibers are produced
24 from extruder 1 and thin fibers are produced from extruder
25 1'. In this case, fiber stream 7' from extruder 17 iS ~ -
26 passed through gap 201 o slit 20Q and then blown against
27 a collecting plate, while liquid drops are sprayed simul-
28 taneously between die 2' and slit 200. When fiber stream ~ ;
29 7' is blown against a first nonwoven fabric 5 formed on
collecting plate 3 through slit 200 while, at the same
31 time, liquid drops are fed between die 2' and slit 200,
7~
- 12 -
1 the liquid drops are contacted very readily with fib~r
2 stream 7' and fibers. This embodiment is desirable.
3 As shown in Fig. 5(b), distance 1 between slit 200 and
4 die 2' is generally 15 to 500 mm, preferably 50 to 200
S mm, width f of gap 201 of slit 200 is generally 20 to 200
Ç mm, preferably 50 to 100 mm, and length g of slit 200,
7 being longer than the width of the fiber stream, is gen-
8 erally 20 to 200 mm longer, preferably 50 to 100 mm
9 longer than the width of the fiber stream. The size of
slit 200 is not particularly limited, but, if too small,
11 the effect of slit 200 cannot well be obtained. ~or the
12 purpose of obtaining sufficiently the effect of slit
13 200, it is desirable that width h is two times or more,
14 particularly 3 to 5 times as much as f and length i is
so adjusted that i - g is two times or more, particularly
16 3 to 5 times as much as f.
17 In Fig. 6, collecting plate 3 and press plate
18 4 ~re respectively provided on hollow-cylindrical drums
19 31 and 41 each having a perforated side wall and a fiber
stream is blown against between intersection points A and
21 A' of the central axis of drum 31 and drum 41 with col-
22 lecting plate 3 and press plate 4. Fibers are separated
23 from the fiber stream blown against between A and A'
24 and thereafter pressed to a constant thickness by col-
lecting plate 3 and press plate 4~ In this casel liquid
26 drops are fed from liquid drop feeding means 10 and 10'
27 provided at the both sides of fiber stream 7 and the
28 whole assembly is held by vessel 400. rrhis apparatus
29 assembly is sui~able for the use of liquid drops, in
addition to water, such ~or example as aqueous solutions t
31 suspensions and dispersion. In this case, there is
7~2
-- 13 --
1 obtained a nonwoven fabric in which fibers 51 are vertical
2 to surface 50 ~a) and (b) and from which raised nonwoven
3 fabric (c~ is obtained by dividing into two, as shown
4 in Fi~. 7, and a laminated nonwoven fabric can be ob-
tained by winding a woven or nonwoven fa~ric round collect-
6 ing plate 3 and press plate 4 and blowing a fiber stream
7 against the surface thereof.
8 The process of the present invention will be
9 illustrated in detail by the following examples.
Example`1
11 Two kinds of nonwoven fabrics A and B differing
12 in basis weight were prepared by using polypropylene with
13 a melt flow rate of 15.0 and spraying to the fiber stream
14 liquid drops consisting of 80~ or more of water only with
a diameter of 10 microns in a proportion of 1 g to 1 g
16 of the polypropylene from spray nozzle 10, as shown in
17 ~i~. 1.
18 On the other hand, two kinds of nonwoven fabrics
19 A' and B' were prepared by the prior art method free from
spraying of liquid drops.
21 The properties of these nonwoven fabrics are
22 shown in Table 1, rom which it is apparent that the non-
23 woven fabrics A and B made of polypropylene according to
24 the process of the present invention are free from pin-
holes and more excellent in feeling and other properties.
26 Thus, the nonwoven fabric A is suitable for a separator
27 for an alkali cell and the nonwoven fabric B is suitable
28 fox a mask filter.
- 14 -
1 Table 1
2 Nonwoven Fabric
3 A A' B B'
Liquid Drops Liquid Drops
4 Property and Test Method Vsed No Used No
_
5 Basis Weight 100 100 30 30
6 Thickness (mm) JIS C2313 0.9 0~6 0.35 0.30
7 200 g/cm2 Stand Type
8 Gas Permeability ~cc/cm2/ 18 10 ~7 30
9 sec) ASTM D737 Frazier Method
10 Maximum Pore Diameter 1~) 51 36 58 42
11 ASTM F316 Bubble Point Method
12 Bacteria Shielding E~fi- - - 90 61
13 ciency MILIT Method
14 Pinholes (Nu~ber of 0.3 mm 0 15 0 6
15 or more/l cm )
16 Example 2
17 Nonwoven fabrics of polypropylene were prepared
18 in an analogous manner to Example 1 but using li~uid drops
19 consisting of 10~ by weight of silica sol, 1~ by weight
B 20 of a surface active agent (commercial name: Emalgen manu
21 factured by Toho Kagaku Co.) and the balance of water in-
22 stead of water drops.
23 On the other hand, nonwoven fabrics were simi~ .
larly prepared but not using the above described mixed
liqu.id drops.
26 The density of pinholes and the properties of
27 the nonwoven fabrics obtained by these methods are shown
28 in Table 2, from which it will clearly be understood that
29 the nonwoven fabrics obtained by the process of the pre
sent inven~ion are free from pinholes and have a much
31 higher nerve than those obtained by the prior art method
32 using no liquid drops.
T~ e ~Qkk
- 15 -
1Table 2
2Property
3Stiffness and Softness
4(MD) (mg) Pinholes (number 2
5JIS L1079 GarY tY~e of 0.33 mm or more/cm )
6Liquid Drops Liquid Drops
7 Basis Weight Used No Used No
-
8 50 40 20 0 6
9 100 35~ 180 0 10
10 150 500 340 ~ 16
11 200 800 ~3~ 0 18
12 Example 3
13 Nonwoven fabrics o~ Nylon 12 having the general
14 formula H-(NH-(CH2)11CO)nOH) were prepared in an analogous
manner to Example 1 except using Nylon 12 in place of the
16 polypropylene. The results are shown in Table 3, ~rom
17 which it is apparent that in the prior art method using
18 no liquid drops, the resin fibers extruded from a die are
19 fused and adhered each other and formation of a fibrous
layer i5 impossible, while in the case of using liquid
21 drops according to the process of the present i.nvention,
22 nonwoven fabrics of Nylon 12 can be produced with a good
23 workability and exhibit more excellent properties.
24 Table 3
Tensile
26 Basis Weight Worka- Strength Elongation
27 (g/m2`)bility (Kg/25 mm) (%)
28 Test MethodJIS L1085-JIS L1085- JIS L1085-
29 1969 1969 1969
Liquid Drops
31 Used 25 Good 1.0 300
32 85 Good 3.2 250
33 No 25 Bad No formation of fibrous
34 layer
Bad
7~Z
- 16 -
1 Example 4
2 Nonwoven fabrics of thermuplastic polyurethane
3 were prepared in an analogous manner to Example 1 except
4 using a thermoplastic polyurethane elastomer consisting
of polytetramethylene ether glycol and 4,4'-diphenylme-
6 thane diisocyanate in place of the polypropylene and using
7 liquid drops consisting of a mixed solution of 95% by
8 weight of water and 5% by weight of process oil in place
9 of the liquid drops consisting of water only.
The results are shown in Table 4. As evident
11 from the results of Table 4, there is no formation of a
12 fibrous layer in the case of not contacting with liquid
13 drops as in Example 3, while in the case of contacting
1~ with liquid drops, nonwoven fabrics of thermoplastic
polyurethane having more excellent properties can be
16 prepaxed with a better workability.
~ 7~
-- 17 --
O U~ ~ ,
~ _ ~ ~D o ~~ ::1
O U~ ~ ~ ~ I` ~
I L1 H
o
~ o
~ ~ ~ ,
~ S~ ~ ~D O U~ O O
E~ u~ K u~ ~I N ':1' ~
~ ' 8 g 8 ~ ~ ~
~ t~ ~ ~ Q
~0
a~ ~ u~
~o~
E~ 5: ,_ a~ ~D ~ O
3 ~ ~ o o o z ~ ~
E~
o
~ ~ o o o o o o
IYl ~3 _ ~ H ~1 ~ ~ ul o
O O
::1 D .~.3
- 18 -
1 Example 5
2 A nonwoven fabric of pitch was prepared in an
3 analogous manner to Example 1 except using a pitch hav-
4 ing a melting point of 250C. The nonwoven fabric of
pitch obtained in this way is useful as a raw material
6 for carbon fiber.
7 In the case of contacting with no liquid drops,
8 on the other hand, production of a nonwoven ~abric was
9 impossible.
