Note: Descriptions are shown in the official language in which they were submitted.
5~i
BACKGROUND OF THE INVENTION
The presen~ invention relates to a novel resin-pre-
impregnated, textile material ~hich can in particular be
used in the production of laminated articles or various
coatings.
Laminated articles based on thermosetting or thermo
plastic resin reinforced by a textile insert have long
been known and are used ~or many differen~ purpose~ in
Yarious fields.
109 In general, such articles are made by impregnating a
textil2 reinforcing material~ such as a abric9 felt,
sheet of threads or ~he like. Optionally7 the textile
reinforcer~ent can be ob~ained by superimposing several
layers o~ the same or different types which may or may
not be crossed, as a ~unction of the mechanical ~harac-
terlstics ~ich it is intended to give to the materi21.
Impregnation is prefe~ably carried out by means of a
thermose~ting resin such as a phenol resin, epoxy resin
or polyester resin, which is polymerised under the action
o heat and/or pressure.
Moreover, for cer~ain applications in which it is desired
to obtain m~terials with a parti~ularly high strength
in all directions7 and particularly a resistance to
splitting o~f, it has been proposed to use as the tex~ile
reinforcing element three-dimensional articles, i.e~ having
6S96
threads in all three directions. Thus, it has been
proposed ~o superimpose layers of longitudinal and
transverse threads and to interconnect said layers by
seams permitting the introduction o threads in the
thickness direction of the article.
Other equivalent methods make it possible to ob~ain
similar articles.
In general, threads which are not resin-impregnated and
often called "d~y threads" are used in the production o
this ~ype of textile reinforcing articles, impregnation
taking place once the textile article is finished.
However, during the production o~ laminated articles,
with a dènse textile insert and/or a large thickness it
is virtually impossible to obtain ~ homoge~eous distri-
lS bution of the resin up to the core of the material. Thisstructural heterogeneity of the material leads to
numerous problems such as irregular mechanicalFropert
ies and the danger of splitting off when the material
i~ in the form of several layers.
ZO To solve this problem~ and obtain a good impregnation
by the resin, it has been proposed to use resin~preim~
pregnated textile sheets or threads. This preimpregna~ion
can either be carried out beforehand o~ the-thread which
is to be used in the formation of the textile sheet, or
by impregnating ~he sheet after its formatio~ ~rom the
dry threadsr
. . ... ,,, : .. . :
:. . ,
: :. . - , . . .
: .
-4-
When it is desired to produce resin-impregnated threads
comprising a plurali~y of substantially parallel fila-
ments, impregnation is generally obtained by passing
these threads througha resin bath and calibrating by
means of a spinneret. These preimpregnated threads are -
used to make laminated materials in which layers o~
parallel threads are formed. The layers are optionally
crossed relative to one another and the resin is poly- -
merised after forming the layers.
This procedure makes it possible to produce articles in
which the resin distribution is homogeneous, but it has
been found that for certain applicat-ions, in whi~h the
laminaked materials are subject to high stresses and
loads, there is s~ill a risk of splitting of~ between
the various layers.
Moveover, it is relatively difficult to store such
resin-preimpregnated threads and it is generally necess-
ary when they are stored in the form of a coil to provide
a separating element be~ween each layer of turns, for
example a shee~ of siliconed paper which prevents
sticking between the individual layers. Moreov~r~ in
this case, the coil cannot be formed from contiguous
turns, which limits the quan~ity o~ material which can be
stored on each coil.
~urthermore, due to their adhesive properties, it is not
possible to partly or wholly used such preimpreO~nated
threads Lor the production o~ corventionRl warp and wet
-s~
fabrics and ~or the production o~ three-dimensional
text-i~ articles.
Finally, the thus preimpregnated threads are either
in the ~orm of a flat wick of limited thickness in which
S the filaments are parallel to one another or in the form
of a substantially elliptical member, but it has been
found thak it is virtually impossible to obtain a
thread with a strictly circular cross-sec~ion, which
is particularly adva~tageous when m~king high density
materials.
In addition, the cross-sectional shape of the threads
produced in th~s way can be deformed of modi~ied durin~
subsequent manipulations, making numerous precautions
necessary during the latter.
15 It has also be n proposed to make pa~tly polymerised
resin~preimpregnated textile materials in order to
eliminate the adhesive properties. These materials are
either in the ~orm of filiform elements or in the form
o~ sheets of limited ~hickness. ~hey have a certain
rigiai~y, ~hich facilitates their storage and optionally
their use for certain special applications~ for example
when it is desired to p~oduce articles having a complex
shape in which it is necessary to cut the material
either to a precise shape in the case of a sheet, or
to a given length in the case of a filifonm element.
In both cas~s7 the thus produced resin-preimpre~nated
~Q ~
-6-
textile material has a substantially smooth ou~er
. .
surface and the resistance to splitting off between
the different layers formed is limited then due to
this sur~ace state.
BRIEF SUMMARY OF THE INVENTION
... . , ~
The present inven~ion provides a novel resin-preimpreg-
nated fili~onm tex~ile material which can be used in
the productlon of lamina~ed articles which overcomes
the disadvantages of the prior art products and in
particular makes it possible to easily store the pre-
impregnated materials and in particular to obtain a
very good bond between the textile reinforcing material
and the resin in the ~nished laminated article.
Moreover,- the resin-preimpregnated iliform textile
material according to ~he invention can be used ~or
producing the two or three-dimensional textile reinforc-
ing structure or can optionally be converted into a
conventional warp and weft ~abric, said material forming
all or part of the thus obtained textile structure.
~ptionally, the material according ~o the in~en-~ion
can undergo a partial prepolymerisation treatment in
order to give it a cPrtain stiffness acilitating
storage, handling and use in certain special applications.
In a gen~ral manner, the iliform textile material
25 according to the invention,for producing textile inserts
used in the manufacture of laminated articles comprises
S~
a plurality sf resin-preîmpregnated continuous
chemical ilaments, wherein the individual resin-
preimpre~nated ilaments are covered by at least one
wrapping textile materîal layer~ In the present Applica-
tion "wrapping textile material layer" is understoodto mean a thread which is not impregnated with resin
~f a similar or different nature to those of the resin-
preimpregnated filamen~s and which is wound round the
preimpregna~ed filamen~s in the form o a helix with
contiguous or non-contiguous tu~ns.
According to the invention, this wrapping textile
material layer maintains the resin-preimpregnated
threads in such a way that they have a strictly
- circular cross-section9 whilst said ~rapping layer
also orms an outer surface with relief portions. The
resin-preimpregnated multifilam~nt chemical threads
can be any threads conventionally used in the product-
ion o~ laminated articles, for example glass fibres,
carbon fibres~ etc 7 whilst said threads are impregnated
- 20 with a conventional resin.
Furthermore, the wrapping thread which retains the
thus resin-preimpregnated filaments is chosen from
among the materials which are compatable with the resin
and which ca~ be of the same or a different nature to
: 25 the preimpre~nated ilaments. Advantageously~ the
wrapping thread has a titre which is well below that
o~ the system of filaments which it covers~ said ~i~re
~ Q ~
being adv~ntageously half as great.
Such a prei~preO~nated filiform textile material can
be used as it is, alone or combined with other non-
impregnated textile materials, for example to produce
two or three-dimensional sheets of ~abrics. According
to the invention and as a function of the articles
which it is desired to produce, it is optionally
psssible to assemble several preimpregnated ~îliform - -
textile materials~ for example by wrapping. This
assembly can either be obtained by twisting together
the individu~l elements, or optionally by maintaining
; them parallel to one another and covering them with
an external holding la~er~ also provided by wrapping.
In the latter case and as a function of the number
of the thus assembled threads, it is possible to vary
the cross-sectional shape o~ the assembly and obtain
- for example elements of substantially rectan~ular,
square or even triangular cross section, or to vary
the appearance and conse~uentl~ the surface s~a~e of
such a material by giving i~ the form of a chain~ cord7
spring, etc~
.
According to a variant o~ the in~ention, the resin-
impregn~ed filiorm textile material according to
the invention may optionally u~dergo a partial poly-
merisation treatment, which makes it possible toobtain an article having a certain stiffness.
The invention also relates to a pro~ess for obtai~ing
l-9
such a resin~preimpregna~ed filamentary ~2xtile
material.
The process according to the invention comprises in
per se known manner su~ying a conventional wrapping
spindle, said spindle being hollow, with a multi-
filament chemical thread or~ing the core and a wrapping
thread~ wherein the multifilament thread forming the
core is preimpregnated with resin prior to it bein~
covered by the wrapping thread and the assembly formed
optionally u~dergoes a drying heat treatment prior to
~inding.
According to the inven~ion~ the preimpregnation of the
core thread wi~h resin is perfo~med either upstream or
downstream of the wrapping spindle, but at a point
located bet~een the top of the spindle and the point
at which the wrapping thread is joined to the core
thread.
Moreover, wrapping can either be efected with contiguous
turns or optionally with spaced turns. It is also poss-
2~ ible to surround the resin~preimpregna~ed core threadwith two layers of superimposed wrapping threads,
coiled ~ opposite directions.
Finally, the multifilament threads used for forming
- the resin preimpregna~ed core are preferably untwisted
~5 ~hreads with parallel s~rands~
BRIEF DESCRIPTION OF l~IE DRAWINGS
. .
-~o- ~
The invention will be described in greater detail
hereinaftex relati~e to non-limitative embodiments
and with reference to the attached drawings, ~erein
show:
Fig 1 a resin-preimpregnated filamentary tex~ile
material according to the invention.
Fig 2 a resin-preimpregnated textile material compris-
ing several preimpregnated filamentary materials
according to the inven~ion which have been twisted
together.
. Figs 3 and 4 variants in whîch several resin-p~eimpreg-
nated filamentary textile materials according
to the invention are assembled and kept parallel
to one another by means of a bondlng layer fo~med
by wrapp;ng.
Fig 5 a variant of ~he use o~ the material according
to Fig 1 in the form of a spring.
Fig 6 an insta~ation permitting the production o~ a
: resin-preimpregnated ilamentary textile material
according to the inven~ion.
.
~ETAILED DESCRIPTIO~ OF I~E PREFERRED EMBODIMENTS
hccording to the installa~ion described in Fig 6,
a preimpregnat~d fili~orm tex~ile material according
to the invention is. produc~d in the manner shown in
Fig 1. This material is essentially produced on an
installation comprising a hollow spindle lO equlpped
with wrapping means llo This con~entional ins~allation
makes it possible to wind a wrapping thread 2 coming
'
5~6
from a support which is ixed directly to the hollow
spindle 10 around a core thread 1 coming from a fixed
feed source 3 and maintained under tension by a stret- -
ching device 18 and which passes through the spindle 10.
During the passage of the core thread through the
- spindle the wrapping thread is wound in the foxm of a
helix arou~d said core thread and the assembly is wound
in the orm o~ reels 12. The core t.hread is impregnated
with resin pxior ~o covering it with the wrapping thread. -
This impregna~ion process is advantageously performed
by passing the thread ~hrough a tank 13 containing
resin and then ~he thread is passed in~o a spinneret
14 which removes surplus resin.
Moreover~ after wrappinv, the wrapped assembly is
optionally passed into an oven 15 for ~he drying or
prepolymerisation of the resin.
Example
Using an installation as described. hereinbefore, a
multifilament glass thread 1 ha~ing 1600 parallel strands
and of 6000 deci~ex is charged. Preferablyg harging
takés place by p~ssin~ ~he thread from bottom to top,
After removal from its support 3, the thread 1 passes
into a tank 13 containing an impregnatlng resin and
then through the hollow shaft of spindle 10,
The impregnating tank 13 is supplied with resin a~d
has in its upper part a spinneret 14, which ensures
-12-
that only the desired quan~ity of substance is deposited
on the filaments o thread l. Advantageously, spinneret
14 has inwardly inclined ledges 16, 17 which help the
ex~ess resin to flow back into tank 13.
After passing through hollow spindle lO, the resin-
preimpregnated thread 1 is wrapped with a glass filament-
based thread-2, whose titre is 1360 decitex and which
has 816 filaments. The passage speed of ~hreads 1 and
the rotation speed o~ spindle lO are regula~ed i~ such
a way that thread 2 encircles preimpregnated thread 1
in the form of substantially contiguous turns.
Advantageously, ~he as~embly formed by the resin pre
impregna~ed hread l wrapped with enveloping thread 2
passes, a~ter windin~ on at 12, in~o an oven lS ~or
drying or prepolymerising the resin.
The th~s obtained resin-preimpregnated filiform textile
material has a surace wi~h protuberances and hollows
formed by the wrapping thread around the preimpregnated
- cor~ thread 1.
This thread ~an rapidly be wound in ~he form of reels
lZ and there is no n~ed to provide separating materi~l
layers to prevent sticking between the individual turns.
In addition, this thread has a substantially circular
cross~section and has a relatively low resin level of
~he order o 20% by weight compared with the total
weight7 ma~in~ it possible to obtain a preimpregnated
thread whose ~o~ume is not greatly increased compared
-13-
with a dry thread. - -
This thread can be used as it is, alone or combined
with other threads o~ the same or a differen~ nature
to produce, for example, fabrics which are then used
in the formation of lamLnated art;cles.
I~ may optionally be used in the production o~ coated
fabrics. In this case, the thread is used in the warp
and/or we~ combined wit~ other non-impregnated threads,
for example using one preimpregnated thread ~or two
; 1~ non-impregnated threads. This procedure gives rigidity
to the fabric formed~ facilitates subsequen~ coating
and increases the performance of ~he article.
- Finally~ fox certain applications it ;s advantageous
to polymerise to a greater or lesser extent the
material obtained in order to give it a more or less
grea~ rigidity. In this case? it may optionally ~e
cut into sections of prede~ermined length which can
be used or providing mul~idirectional inserts.
It should be noted tha~ for si~ilar applications,
laminated articles produced from the preimpregnated
thread according to the inventiQn ei~her have a be~er
resistance to splitting off than articles produced from
preimpregna~ed ~hreads wi~h parall~ strands, or give
stiffness to the resulting products, for example in
the case of coated fabrics.
In addition, and in a surprising manner, when the
,, '
, ~ .
,
.
-14-
preimpregnated ~hread is not pol~merised and stored
in the form of a coil it is found that the diferent
layers do not tend to agglomerate together as is the
case with preimpregnated threads with parallel strands.
S As has been stated hereinbefore, suc~ a thread ca~
be used as it is. However, for certain applications
it is possi~le to assemble several preimpregnated
threads produced in this way. - -
Thus, Fig 2 shows an embodiment in which four preimpre-
gnated threads are assembled by twisting. This makes
it possible to obtain a larger diame~er preimpregnated
assembly~ whose periphery has protuberances and valleys
49 5? which ~reatly improve the bond with the impregnat-
ing resin or the coating material.
Figs 3 and 4 show embodiments in which several preim
pre~na~ed threads produced according to t~e inventio~
are join~d by means o a complimen~ary wrapping thread
6. As is apparent fr~m Fig 3, this procedure makes
it possible to produce assemblies9 whose cross-sectional
coniguration, appearance and exte~nal surace state
can vary.
In Fig 3, this shape is substantially square, whilst -
in Fig 4 it is substa~tially trian~ular. This is made
possible by the fact that the preimpregnated ~iliorm
tex.tile e~ements ha~e a substantial~y circular cross-
section~
~5-
Finally, and as is shown in Fig 5 it is possible,
prior to the use of the preimpregnated textile thread,
to give it an overtwist ln the ~rapping direction,
making it possible to pass the wrapping thread to the
inside by giving it a substantially rectilinear
orienta~ion, the previously covered filaments ~ passing
into the outside and orming convolutions around the
thre-ad encircling the ~rapplng thread.
Compared with prior art resin-preimpregnated tex~ile
materials, the material according to the invention is
easy to handle and store and can be used in the product-
ion o~ any type of two or ~hree~dimensional reinforcing
textile mate~ials~ Moreover, it leads to a significan~
improvement in the properties of the laminated articles
produced and in particular in their resis~ance to
splitting of~
In addition, and as s~ated hereinbefore, i~ can be used
to give sti~fness to coated fabrics. I~ thiscase during
the p~oduction of the fabric certain warp and/or weft
threads are constituted by filiform textile elements
according to the i~vention, whilst the other threads
are of the same or a different type, but are not resin-
impregnated.
The in~ention is not limited to the e~bodlments described
and represented hereinbefore and various modifications
can be made ~hereto without passing beyond the scope
of the invPntion.
