Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
1319234
FIELD OF ~HE INVENTION
The present invention relates to a method
for producing fire-proof lining parts and
designed for amenity items, such as seats for
public transport vehicles and more particularly
for planes, armrests, head rests, seating units,
damping terminals or analogous devices and items
equipped with the lining parts thus obtained.
o
BACKGROUND OF THE INVENTION
It is already known how to provide the
frame of vehicle seats with a shock absorber
lining part whose shape is adapted to that of the
seat and which is made of foams comprising a
grille cloth external coating.
Moreover, it is now customary for this
purpose to use polyurethane foams which, from
amongst the shock absorber polymers currently
used in industry, are probably the most suitable
materials as regards their mechanical properties
and the cost price.
However, given the fact that unfortunately
2s polyurethane foams are very sensitive to
temperature (because their urethane groups easily
suffer pyrolysis and their aliphatic bonds are
thermally oxidizable, the decomposition of these
foams already occurs at about 250 C), it is
common practice to protect against fire by
providing a polyurethane lining part by means of
a fireproof barrier constituted by a flame-
retardant, and thus fireproof, lining or cover,
inserted between the lining part and the grille
2 13~9234
cloth.
Up until now, two types of the following
linkages are known to be used between the
fireproof layer and the grille cloth :
s 1. - loose or flaccid linkage, without any
mutual adherence, which firstly requires an
additional construction for the seat
coverer who needs to separately secure the
fire-proof lining or cover to the lininq
0 part and frame and then to fix the covering
and ,secondly, the relative displacement or
movement between the lining and the coating
with the formation of unaesthetic folds ;
in addition, the presence of seams in the
fireproof lining is another negative aspect
of this solution. ;
2. - intimate bonding by means of bonding
agents (glues), which, apart from reducing
the flexibility of the entire unit, exhibit
fire-resistance properties which are
unsatisfactory and which seriously
compromise the protective function of the
fire-proof lining.
However, even if solution 2 is preferable to
25 the first in that it ellminates the aforesaid
drawbacks due to loose bonding of the lining with
regard to the qrille cloth, the second sol~tion
presents drawbacks identical to those of the first
solution as regards the lining.
The present invention is therefore seeking to
provide a method enabling an intimate bonding to
be obtained between the fire-proof lining and the
lining part, so that the latter and its fire-proof
protection are like a monolithic structure,
1319~3~
obtained without any glue or seam.
SUMMARY OF THE INVENTION
The aim of the present invention is to
provide a production method relating to a lining
part integrally with a fire-proof barrier surrounding
it, the said lining part being made of an inflammable
polymer foam and is obtained by moulding and is
intended for any amenity item, such as a seat,
armrest, headrest, seating unit, shock absorber
terminal or an analogous device, the said method
being characterized in that it comprises the
following stages :
i) embodiment of thin ductile impervious sheets
by coating the internal side with a shirred
fabric exhibiting a high degree of resistance
to flames means of an elastic polymer
material, especially elastomer, which includes
a filler designed to render it fire-retardant
and is compatible with the material
constituted by the lining part,
ii) covering of the walls of the mould used for
moulding the lining part by means of the
ductile impervlous sheets thus coated,
iii) cladding these lmpervious coating sheets
against the corresponding walls of the mould,
by means of suction,
lv) injection of the polymer material constituted
by the lining part inside the mould.
As regards the garnishing material used
within the scope of the present invention, this
preferably consists of polyurethane foam whose
expansion occurs inside the mould following the
4 ~3~3~
aforesaid injection operation at iv).
The fact that the fire-proof barrier
(namely, the aforesaid shirred fabric) is
integrally embodied with the lining part offers
the advantage of eliminating wear and tear of the
barrier, this being due to the relative
displacement occurring in embodiments of the
previous Art, and which does not occur with the
articles embodied as claimed in the invention
0 because the intimate bonding between the fire-
proof barrier and the polyurethane foam results
in the coated fire-proof fabric undergoing the
same deformations as those of the lining part.
According to one mode of embodiment
favorable to the invention, the said shirred
fabric consists of polyaramid fibers and
preoxidized fibers which are woven together,
specially by knitting, so that they provide the
fabric with a multidirectional elasticity.
According to another mode of embodiment
favorable to the method as claimed in the
invention, the fire-protected lining part thus
obtained comprlses a grille cloth which is
preferably made of the said multidirectional
elastic protectlve fabrlc.
Apart from the preceding dispositions,
the invention still includes other dispositions~
which will be specified in the following
description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be more readily
understood by referring to the following
131923~
additlonal description, which relates to the
annexed drawings in which :
figure 1 is a diagrammatic view
illustrating the working principle of the mould
used for implementing the method as claimed in
the invention ;
figures 2, 3 and 4 are also diagrammatic
views of the various stages of this method ; and
figure 5 is again another diagrammatic
0 view of an amenity article (cushion) obtained by
means of the method as claimed in the invention.
However, it should be properly
understood that these drawings and the
corresponding descriptive parts are given solely
as an example illustrating the aim of the
invention and consequently in no way limit the
possibilities of this invention.
DETAILED DE~CRIPTION OF THE PREFERRED EM~ODIMENT~
The working principle of a mould likely
to be used within the context of the present
invention can be more readily understood by
referring to figure 1 where a mould 1 is shown in
two parts defined by the numerical references 2
and 3. In each part of the mould, a large number
of suction pipes are provided, uniformly
distributed such as 4'a to 4'_ and 4"a 4"S,
connected to a main pipe S and 6 respectively,
which are connected to a suction pump 7 and 8
respectively.
Each of these pumps 7 and 8 is intended
to clad, against the internal side of the
corresponding mould portion 2 and 3,a shee~ 11
6 13~923~
and 12 ~visible on figure 2) by means of the
suction produced by the aforesaid pumps (cf. also
figure 3).
The sheets 11 and 12 are thin compound
impervious ductile sheets, each of which is
obtained from a thin fire-proof shirred fabric 13
and 14, respectively, which is coated on one side
- namely the internal side intended to come into
intimate contact with the lining part, by
becoming integral with the latter - by means of
an elastic polymer compound, preferably an
elastomer, which is firstly rendered fireproof by
incorporating a suitable filler (recognised by
technicians) and which is stretched over each thin
sheet of fabric 13 and 14, in the form also of a
thin layer 15.
Once this preliminary stage for
preparing the thin ductile impervious sheets 11
and 12 is ended, this involves :
- positioning them in each of the portions 2 and
3 of the mould 1, as shown on fiqure 2,
- cladding them against the internal face 9 and
10 of the corresponding mould portion 2 and 3,
respectively ,by activating the suction pumps 7
and 8 ~cf. figure 3),
- closlng the mould 1 by superimposing the
portion 2 onto the portion 3 of the mould
whilst maintaining the suction produced by the
pumps so that the composite sheets 11 and 12
are always intimately cladded against the
aforesaid internal faces 9 and 10 ~cf. figure
4),
- injecting a suitable polymer material inside
7 13~3l~
the previously prepared rnould 1 in order to
receive this material with the aid of an
injection device (shown diagrammatically on
figure l):the chosen lining polymer material may
consist of polyurethane (PU) which is sucked
in its liquid state from a vessel 17 by a pump
18 cooperating with a blending device 19
disposed downstream of the pump 18 immediately
before the injection nozzle 20 (cf. also figure
0 4) : the blending device 19 has two inputs 21
and 22, the first being for the polyurethane
and the second for additives, especially
consisting of accelerators, intended to favor
cross-linkage of the polyurethane derived from
lS the vessel 17;
- extracting the moulded product - after
expansion of the polyurethane (cf. the
numerical reference on figure 4), which is
naturally linked to the composite sheets 11 and
12 by virtue of the compatlbility between the
polyurethane and the flame-retarded elastomer
coated on each thin shirred fabric sheet 13 and
14 - such as the cushion 23 shown
diagrammatically on figure 5, in order to carry
out the required finishlng operations, such as
the cutting of the portions of the composite
sheets exceeding the spatial requirement limits
of the moulded product and welding of this
sheets along the circumference of the cut.
By means of the method as claimed in the
invention, it is thus possible to obtain amenity
items, such as seats, headrests, armrests, seating
units, damping terminals or other items, the
lining of these items being embodied integrally
8 ~ 3~ ~23~
~intimately llnked) with the fireproof barrler
constltuted by the aforesald composlte sheet whose
supporting shirred fabrlc of the coated elastomer
can preferably also play the role of an appearance
cover, itself also thus belnq lntegrated w}th the
llnlng.
Of course, it is possible to provide the
product obtained by means of the method as claimed
in the invention with a separate appearance cover
o without, however, departing from the context of
the lnvention.
By way of example in no way restrictive,
here are some of the materlals which can be used
I to implement the method as claimed in the
inventlon :
- as regards the ductlle shlrred fabric, it would
be an advantage for this to be made of a
"PANOTEX"* jersey fabric comprised of "PANOX P
505"*fibers and aramid,
- as regards the impervious linking coating
lntended to be coated on one face of the sald
ductile fabric, it would be an advantage for
thls to be a flame-retarding polyurethane based
mixture (flame-retardlng agents possibly
2s includlng, amongst other elements, a halogen
compound) ; the thickness of the impervious
film is preferably between l and 8/lOO mm, half
of which ls retrleved - after absorptlon - on
the coated slde of the fabric ;
- as regards the cellular polyurethane, this ls a
bi-constituent llquid, the polyalcohol of which
is formularized ln partlcular with an agent
swelllng at low temperatures and organo-
metallic flame-retarding agents.
* trademark
9 131923~
The working temperature ls between 30
and 40 C ~preferably, the mould is also slightly
heated).
Finlshing of the product obtalned via
the method described earller concerns the cuttlng
of burrs and especially the weld seam of the two
coated fabrlcs 13 and 14 by means of meltlng the
coating polyurethane.
In one variant, the fireproof barrier is
0 embodied as claimed in the invention with the aid
of a fabric having a high degree of resistance to
fire with at least one of its faces being coated
impervlously wlth a dissolution of a flame-
I retarded silicon/elastomer mixture. Preferably,
s this fahric consists of a glass fabric, especially
of the "STEVENS-GENIN T 235"*type whose weight is
about 90 grams per square metre. The fabric thus
coated and the polyurethane foam cushion conform
to the standard ATS 1000.
Even if, such a coated fabric may also be glued
onto a polyurethane foam lining by means of a glue
consisting of a cold cross-linkable silicon diluted inside
a solvent (of course, the viscosity needs to be adjusted
in order to facilitate the coating which, preferably, is
carried out on the two sides to be glued), the method
according to the present invention gives better results
as it allows to obtain the fire~proof barrier integrally
with the lining.
The fabric is in the form of a linen
cloth or, preferably, a jersey cloth.
Thus, the present inventlon makes it
possible to embody extremely light fireproof
barriers, whilst being highly fire-resistant in an
exceptional fire.
* trademark
lo 131~234
It is also possible to use other fabrics having
a high degree of resistance to fire and, in particular,
a fabric with preoxidized fibers, especially the fabric
known under the trade ~ark "FIROTEX".
