Note: Descriptions are shown in the official language in which they were submitted.
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This invention relates to a process and apparatus
for the production of a multi--component filament, more parti-
cularly, it relates to a process for the production of a
multi-component filament comprising at least two synthetic
polymer components, comprising a matrix of one of said poly-
mer components and a plurality of segments of at least one
other polymer component separated from each other by the
matrix, there are at least two, preferably at least three,
segments, the segments retain their shape and position in
the cross-section along the filament, and to an apparatus
for carrying out this process.
There-are numerous processes for producing from
two or more synthetic polymer components filaments in the
cross-section of which one of the components separates at
least two segments of the other component from one another,
these segments retaining the shape and position thereof in
the cross-section along the filament.
For example, British Patent ~o. 1,171,843
describes a process for the production of a matrix microfil
filament in which a number of very fine microfilaments
(segments) of component A are surrounded and separated from
one another by a matrix component B. Such filaments are
said to be produced by initially pre-forming two-component
structures having a core-sheath or side-by-side structure,
collecting a plurality of the thus-pre-formed structures in
a chamber tapering like a funnel and opening into a spinning
~F
orifice and estruding them through the spinning orifice. The
arrangement of the segments relative to one another in the
cross-section of the final filament and also the separation
of the segments by the matrix component are random in characte~r.
Particular cross-sectional geometries canno-t be reproducibly
obtained.
Gcrman O-tfell]egungsschrift No. 2,ll7,076 describes
a process lor the production of filaments consisting of
SCVCl'al. sc~mcnt;s, in wllich the segment component is axially
delivered and assembled by laterally delivered thin layers
of a matrix component. Although Figures 1 to 6 of this
Offenlegungsschrift show cross-sections having from three
to six segments, it is pointed out on page 11~, paragraph
1, that filaments having three, five or more (except six)
segments are difficult to produce. The spinning heads
known from this Offenlegungsschrift are also difficult to
produce. It la virtually impossible to change the spinning
heat~s from one filament cross-section to another, for example
from a filament cross-section having four segments to one
having six segments.
0 Gcrman Offenlegungsschrift No. 2,040,802 also
shows filament cross-sections in which several segments are
separated by a matrix component. The production of such
filaments is not discussed in detail.
Also, Dutch Offenlegungsschrift No. 6,712,909
shows filament oross-sections containing more than two
segments. The segments all consis-t of different polymer
coml)ollcllls wllicll arc not se~)aratecl Lrom one ano-thcr by a
matrix component. In addition, most of the filament
cross-sections are surrounded by the matrix component.
Filaments of this type cannot be divided up into a bundle
of extremely fine filaments and/or fibres by mechanical
and/or chemical after-treatment, although this is a
principal object of many recent developments in the field
of mul-ti-component filaments.
~n object of the present invention is to provide
a filament cross-section which comprises at least two,
preferably at least three, segments embedcled in a matrix
component which separa-tes them, in the filament cross-section,
the segments not all being surrounded by a peripheral matrix
l~lycr, 11lll; ills-tca(l arc thomsclves intcnde(l to occupy
1~ considerable areas of the surface of the filament to enable
the segments to be readily separated into microfilaments.
In addition, the matrix layers between the segments are
intended to be able to be kept as thin as possible in order
to obtain a bundle consisting of very fine capillary
filaments of predominantly one polymer after the segments
have been separated from one another. To this end, it is
of course essential for the segments substantially to
retain the shape and position thereof in the cross-section.
Another object of the present invention is to ensure by
constructive mcasures that, using one and the same spinning
head, it is possible either successively to produce completely
-- 5 --
different filament bundles or to spin different filament
cross-sections at the same time from different spinning
orifices.
According to the present invention, these
objects are achieved in a process of the type referred to
above in that the matrix component is coaxially delivered
to the spinning orifice of a spinning jet in an initially
uninterrupted core stream and in that the segment component
or segment components is/are radically introduced under
pressure into the matrix component in spatially separated
partial streams before the matrix component emerges from
the spinning orifice.
Accordingly, the present invention provides
a process for the production of a multi-component filament
comprising at least two synthetic polymer components
comprising a matrix of one of said polymer components and
a plurality of segments of at least one other polymer com-
ponent separated from each other by said matrix, the seg-
ments retaining their shape and position in the cross-
section along the filament, which process comprises coaxially
delivering the matrix component to a spinning orifice of a
spinning jet in an initially uninterrupted core stream and
radially introducing the segment component or segment
components under pressure into the matrix component in
spatially separated partial streams before the matrix
components emerges from the spinning orifice.
3.~L18~79~
-- 6
In this way, it is possible to produce multi-
component filaments in which the segments are situated either
only at the periphery of the filaments of even in the
interior thereof. Geometrically, they are strictly fixed,
i.e., have a certain shape and position in the cross-section
of the filaments. In this way, it is possible without
difficulty to produce more than six peripheral segments and,
in addition, a plurality of segments situated within the
filament. In this way, the proportion of matrix component
may be kept very small. As a result, the mechanical and/or
chemical disintegration of a filament produced in accordance
with the present invention to form a bundle of filaments of
fine microfilaments is no longer a problem.
The present invention also relates to an apparatus
for carrying outthe present process which comprises a rear
die body having bores for the passage of delivery elements
for one polymer component, a front die body having bores for
the insertion of the delivery elements, the bores of said
front die body aligning with the bores of said rear die
body and opening into the spinning orifices and further
comprises at least one delivery passage and at least one
distributing compartment for at least one other polymer
component, each at least one distributing compartment being
traversed by the axes of the bores of said front and rear
die bodies and, in the region of the die bores and/or in the
region of the at least one distributing compartment, have
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at least one throughflow opening for one of the polymer
components.
Accordingly, the present invention also provides
an apparatus for the production of a multi-component fila-
ment which comprises a rear die body having bores for the
passage of delivery elements for a first polymer component,
a front die body having bores for insertion of the delivery
elements, the bores of said front die body aligning with the
bores of said rear die body and opening into spinning ori-
fices, and which further comprises at least one delivery
passage and at least one distributing compartment for a
second polymer component, each at least one distributing
compartment being traversed by the axes of the bores of said
front and rear die bodies and in at least one of the region
of the die bores and the region of the at least one dis-
tributing compartment, have at least one throughflow open-
ing for the second polymer component, the delivery elements
having outlet ends for the first polymer component of an
external diameter which corresponds to that of the bores
of the front die body and, towards the spinning orifices
being fitted in form-locking manner into the bores and
having in the region of the at least one distributing
component, at least two radial throughflow openings for the
second polymer component.
In one aspect the delivery elements have in one
region at least partly smaller dimensions relative to the
bore diameter.
-- 8 --
Apparatus of this general type is known from
Dutch Offenlegungsschrift ~o. 6,712,909. However, the
- apparatus described in this Offenlegungsschrift is all
intended for the production of filaments in which the
segments of the filament are peripherally surrounded by the
matrix component. Such filaments cannot be converted into
a bundle of microfilaments. In the known apparatus, the
polymer components are always guided in such a way that
one component initially issues outwards through a through-
flow opening from the axial bore of a delivery element and
subsequently flows past the cutlet end of the delivery
element towards the spinning orifice. On emerging from
the spinning orifice, this component is always situated
at the periphery of the filament so that the various
objects of the present invention cannot be achieved in
this way.
In order to obviate the disadvantages of this
known apparatus, the present invention provides an apparatus
which is characterised in that, at the outlet end thereof,
the delivery elements for the matrix component have an
external diameter which corresponds to that of the bore for
- insertion of the delivery elements and, towards the spinning
orifices, are fitted into the bores in form-locking manner,
and in that, in this region, they have at least partly
_9_
smaller dimensions rela-tive to the bore diameter and/or in
the regioll of the dis-tribu-ting compar-tmcnt or distributing
compartments comprise at least two, preferably at least
three, radial throllghflow openings for the segment
componellt or scgment comIonents.
l~efcrring to the accompanying drawings:
Figure 1 shows a filament produced in accordance
with the prcsent invention having three separate segments.
Figure 2 shows a filament prodllced ln accordance
with the present invention having six separate segments.
Figllre 3 sho~s a filament produced in accordance
with the present invention having six peripherally arranged
segments and one core segment.
Figure 4 shows a filament produced in accordance
with the present invention having six peripherally arranged
sc~ments and three core segments.
Fignre 5 shows a filament produced in accordance
with the present invention having eight peripherally arranged
segments and thirteen segments completely surrounded by the
matrix component.
Figure 6 shows a ~ilament produced in accordance
with the present invention having six separate segments
extending into the core region of the cross-section.
Figure 7 shows a feature, specifically the
spinning part, of a spinning apparatus in accordance wi-th
"5 I;llc Imcscllt illvcnl,iorl.
Figure 8 shows an arrangement adopted in accordance
L7~L
--10--
with the presen-t invention for the deli~!ery elcments.
Figure 9 shows the delivery element o~ Figure 8
on a larger scale.
Figure 10 is a section through the delivery
element of Figure 9 on the line X-X.
Figure 1I shows another delivery element in which
the throughflow openings for the segment component are
arranged in two planes.
Figure 12 is a plan view of the delivery element
shown in Figure 11.
Figure 13 shows another delivery element having
throughflow openings arranged in two planes.
F'igure 14 is a section on the line XIV-XIV through
the delivery element of Figure 13 and through the delivery
element of Figure 16.
Figure 15 is a section on the line XV-~V -through
the delivery element of Figures 13 and 16.
Figllrc 16 S]IOWs a delivery element having
throughflo~ openings arranged in three planes.
Figure 17 is a section through the delivery
element of Figure 16 on the line XVII-XVII.
Figure 18 shows part of a delivery element having
a coaxially arranged pin.
The filament cross-section illustrated in Figure 1
consists of three peripherally arranged segments 2 whicll
are se~arated from one another by a relatively thin layer
of the matrix component 1. By contrast, the filament shown
in Figure 2 has a more pronounced matrix 3 which forms the
core of thc filament and Yhich, in this case, is surrounded
by six peripherally arranged segments. IIo~ever, it could
even be surrounded by seven or more peripheral components.
In the filament shown in Figure 3, the matr-ix 5 is interrupted
at its centre by a core segment 7, while si~ segments 6 are
arranged a-t the periphery of the filament. One preferred
cross-section comprises eight such peripheral segments. The
cross-section shown in Figure 4 has~six peripheral segments
9 and three core segments 10 separated from one another by
the matrix component 8. Other combinations, for example
four core segments and eight peripheral segments, are
possible. The filament cross-section sho~in in Figure 5
consists of eight peripheral segments 12, five core segments
1~ and another eight externally arranged segments 13 which
are also completely surrounded by the matrix component ll.
Also, Figure 6 shol~s a filament cross-section which i5
similar to that shown in Figure 2, except that the segments
~- separated by the matrix 3' extend from the periphery into
the core region of the cross-section. The numher of segments
may be greater -than six, in particular twelve or more.
Figure 7 diagrammatically illustrates the spinning
part of a spinning jet consisting of a rear die body 15 and
a front die body 16. Between the two die bodies is situated
the distributing compartment 18 for the segment component A
delivcred thIo-lgll the delivery passage 17. The rear die
body 15 compr:ises bores 20 for -the passage Or delivery
.,3.. 1! ~
- 12 -
elements 19, one of which is shown, for the matrix component
B whilst the front die body 16 comprises bores 21 aligning
with the bores 20 for the insertion of the delivery elements
19, the bores 21 opening at the outlet ends thereof into
the spinning orifices 22.
Figures 8, 9 and 10 show the main part of the spin-
ning section of a spinning jet. The distributing compart-
ment 18 for the segment component A is situated between the
rear die body 15 and the front die body 16. A delivery ele-
ment 19 for the matrix component B is passed through the rear
die body 15 and inserted into the front die body 16, the
matrix component B flowing through the axial passage 23
towards the spinning orifice 22 in the form of an initially
uninterrupted core stream. At its outlet end 19', i.e.
towards the spinning orifice 22, the delivery element 19 is
fitted in form-locking manner into the bore 21 (Figure 7)
of the front die body 16. In it~ most simple form, the
delivery element 19 may be a cylindrical capillary which
is fitted both into the bore 20 and into the bore 21
and which, in the region of the distributing compartment
18, has at least two, for example, diametrically
arranged, throughflow openings for the segment component A
(not shown). However, at its centre, i.e. in the region
of the distributing compartment 18 and also in the region
of the bore 21 (and/or in the region of the bore 20 in the
rear die body 15, not shown), the delivery element 19 may
~, ~
7 ~
- 13 -
also have a zone 19" of at least partly smaller dimensions
relative to the diameter of bores 20 and 21, zone 19" in
this case, being formed by a recess 25. Radial throughflow
openings 24 (in this case four) are provided in this zone
for the segment component A. Instead of an annular
recess 25, as provided in the embodiment shown in Figures
9 and 10, it would also be possible to provide two or more
grooves in order to obtain the reduction in dimensions (not
shown). Also, the delivery element may also have a recess
extending to a point situated relatively close to its outlet
end and (instead of the throughflow openings) two or more
axially extending grooves at its outlet end through which
the segment component A is introduced under pressure into
the matrix component B just before the spinning orifice (not
shown).
From the distributing compartment 18, the segment
component A is introduced under pressure via the recess 25
through the radial throughflow openings 24 into the matrix
component B in four spatially separated partial streams
before the matrix component B emerges from the spinning
orifice 22, cf. Figure 10. A filament cross-section having
four peripheral segments is formed. The size of the seg-
ments and the thickness of the matrix layers separating
them (i.e. the distribution of the components) may be adjust-
ed by the input and/or pressure of the components A and B.
The delivery element 26 shown in Figures 11 and 12
differs from the above-mentioned delivery element 19 in that in
1 p
the region of reduced dimensions 26", it has six
throughflow openings 27 for the segment component ~ and,
in addition, another throughflow opening 28 which lies in
a plane situated further away from its outle-t end 26~.
This throughflow opening 28 is formed by a capillary 34
which opens in the immediate vicinity of the axis of the
delivery element 26.
With this version of the delivery element 26,
it is possible to procluce a filament cross-section of the
type shown in Figure 3. The segment component A flowing
into the matrix component B through the capillary 34
pre-for~s an axially extending core segment, whilst the
six partial s-treams introduced ~Inder pressure through the
throughflow openings 27 form six peripherally arranged
segments.
Another version of a delivery element 29 is shown
in Figures 13,.-14 and 15. In the zone of reduced dime.nsions
29", throughflow openings 30, 31 are arranged in two planes,
the throughflow openings 31 in the plane situated further
away from the outlet end 29~ being in the form of capillaries
35 which project equally into the passage 23.
With this version, it is possible to produce a
filament cross-se~tion of the type shown in Figure 4. It
has three core segments and six peripheral segments.
Figures 16, 14, 15 and 17 show a delivery element
25 32 in which the throughflow openings 30, 31, 33 are
~ arranged in three planes. In the plane si-tuated nearest
~15-
the outlet encl 32~, there are six -throughrlow openings 30
and, -in thc ccntral plane, threc capillaries 35 projecting
into the passage 23. In the plane situa-ted fllrthest a~iay
frolll the outlet end 32~, a capillary 36 projects almost
up to the axis of the delivery e~ement 32.
With this versioIl, it is possible to produce
filament cross-sec-tions having four core segments and
six peripheral segments.
In the version o-f a delivery element 19 shown
in part in Figure 18 (cf.Figures 9 and 10), pin 37 is
coaxially arranged in the passage 23, terminating for
example in a point 37~ in the vicinity of the throughflow
openings 24, preferably just below them. With this version7
it is possible to produce filament cross-sections of the
type shown in Figure 6 in which the segments extend into
the core region of the cross-section.
A number of variations in regard to the
filaments whicll may be obtained and the products which may
be produced from them are possible according to the present
invention.
Thus, it is possible on the one hand, to use
several segment components A, A'........ instead of only
one segment component A. These segment components may
be delivered, for example, through distributing compartments
18, 18' .......... which are sealed off from one another and
which may be arranged in differe~nt planes.
In general, the matrix component A will be a
- 16 -
single component. However, it is also possible for two
matrix components B, B' to be delivered to the axial passage
23 of the delivery elements, for example in a side-by-side
arrangement or in the form of a polymer mixture.
Suitable components both for the matrix and also
for the segments are filament-forming polymers, such as
polyesters, polyamides, polyolefins and polycarbonates.
If only the filament properties are to be optimised
by the multi-component structure, i.e. if no fibrillation
(splitting up) of the components is to occur during the
after-treatment of the filaments, components having good
mutual adhesion (compatibility) are used, for example,
polyethylene terephthalate as the matrix component and a
polyethylene terephthalate containing a gas-former as the
segment component. In this case, the resulting filament
consists of foamed segments which are held together by the
solid matrix. Conversely, the segments may be solid and the
matrix foamed. In a particular embodiment the segment com-
ponents are of polyethylene terephthalates which differ in
their shrinkage capacities.
In cases where subsequent splitting up into very
fine filaments and fibres is required, it is preferred to
use components having only minimal compatibility. In this
case, polyethylene terephthalate is particularly suitable
for the segment component and polycaprolactam for the
matrix component. The filamnets may readily be split up
by an after-treatment, for example, a mechanical after-
treatment.
The ratio of matrix to segment component may
b~
-17-
vary within wide limits. Typical ratios, by weight, for
normal multi-component filaments are from 30:70 to 70:~0,
preferably about 50:50. ~here splitting up is desired, the
ratios, by weight, are preferably from 5:95 to 25:75.
Similar ratios, by weight, may also be used in cases where
it is intended subsequently to break up the segment
component (for example to obtain cleanly profiled filaments)
or the matrix component (for example to obtain a bundle of
very fine individual filaments from only one polymer) Such
microfilament capillary yarns have a very soft hand and an
outstanding appearance.
Thc denier of the multi-component filaments
should preferably be from 2.4 to 11.1 dtex after drawing,
the segments having an individual denier of, in particular,
from 0.2 to 0.5 dtex.
Instead of a round filament cross-section, it is
also possible ~o produce the conventional profiles, for
example polygonal (for example hexagonal) or multi-lobal
(for example tri-lobal) cross-sections.
To this end, the axial passages of the delivery
elements and/or the spinning orifices may be profiled.
By virtue of the apparatus according to the
present invention, it is possible by a number of possible
modifications to the delivery elements (e.g. number of
throughfiow openings, the arrangement thereof relative to
one another in different planes and the use of capillaries
~18-
projec-tirlg in-to the axial passages to different exten-ts)
to produce a nllmber of filament cross sections which, where
they arc knowll, may be prodllced more easily and with
greater precision. However, the apparatus according to
the presen-t invention also enables completely new cross-
sectional arrangements to be produced. In addition, itis possible to replace the delivery elemen-ts of a spinning
jet by another set of delivery elements and, in this way,
to change rapidly to another type of cross-section. In
addition, it is possible to insert different delivery
10 elements into one and the same spinning jet and in this
way to produce interesting blended yarns (for example
having individual capillaries of different denier).
