LINING FOR USE IN THE FOOTWEAR INDUSTRY

DOUBLURE INTERIEURE POUR L'INDUSTRIE DE LA CHAUSSURE

English Abstract

The invention relates to a lining for use in the footwear industry, consisting
of a non-woven fabric with surface weights of between 80 and 170 g/m2 and a
resistance to crack propagation both in the longitudinal and in the transverse
direction > 7 N. The non-woven fabric consists of multi-component continuous
filaments which are extruded, aerodynamically drawn and immediately arranged
in a web and which have a filament grade of between 1.5 and 5 dtex. At least
80 % of the multi-component continuous filaments after being pre-bonded, are
optionally split and bonded into micro continuous filaments with a filament
grade of between 0.1 and 0.8 dtex.

French Abstract

L'invention concerne une doublure intérieure pour l'industrie de la chaussure, constituée d'un non-tissé présentant un grammage compris entre 80 et 170 g/m?2¿ et une résistance à la déchirure amorcée, aussi bien dans le sens longitudinal que transversal, > 7 N. Ce non- tissé est constitué de filaments continus à plusieurs composants, qui sont filés par fusion, étirés par voie aérodynamique et déposés directement pour former un voile, et dont le titre est compris entre 1,5 et 5 dtex. Au moins 80 % de ces filaments continus sont, éventuellement après une consolidation préalable, scindés et consolidés pour former des microfilaments continus dont le titre est compris entre 0,1 et 0,8 dtex.

Claims

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CLAIMS:
1. Inner lining for the footwear industry consisting of nonwoven web surface
weight of
80 to 170 g/m2 and tear propagation resistance in longitudinal as well as
transverse
direction > 7N, whereby the nonwoven consists of meltspun, aerodynamically
stretched
multi-component endless filaments immediately laid down into a nap and with a
titre of
1.5 to 5 dtex, the multi-component and the filaments after a pre-consolidation
being split
to at least 80% into micro-endless filaments with a titre of 0.1 to 0.8 dtex,
and
consolidated.
2. Inner lining according to claim 1, characterized in that the nonwoven
consists of
meltspun, aerodynamically stretched multi-component endless filaments
immediately laid
down into a nap and having a titre of 2 to 3 dtex, the multi-component endless
filaments,
possibly after pre-consolidation, being split to at least 80% into micro-
endless filaments
with a titre of 0.1 to 0.5 dtex, and consolidated.
3. Inner lining according to claim 1 or 2, characterized in that the mufti-
component
endless filament is a bi-component endless filament of two incompatible
polymers,
especially a polyester and a polyamide.
4. Inner lining according to one of claims 1 to 3, characterized in that the
multi-
component endless filaments have a cross section with an orange type mufti-
segment
structure, whereby the segments alternately respectively include one of the
two

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incompatible polymers, and/or have side-by-side structure.
5. Inner lining according to one of claims 1 to 4, characterized in that the
nonwoven
made of the multi-component endless filaments is pre-calendered for pre-
consolidation.
6. Inner lining according to one of claims 1 to 5, characterized in that it
has a textile
appearance.
7. Inner lining according to one of claims 1 to 6, characterized in that at
least of one of
the incompatible polymers forming the multi-component endless filaments
includes an
additive, such as colour pigments, permanently acting antistatics and/or
additives
influencing the hydrophilic character, in amounts of up to 15% per weight.
8. Inner lining according to one of claims 1 to 7, characterized in that the
multi-
component endless filament is uncrimped.
9. Inner lining according to one of claims 1 to 8, characterized in that one
of the sides
is provided with a hot melt adhesive coating.
10. Process for the manufacture of an inner lining according to one of claims
1 to 9,
characterized in that the multi-component endless filaments are spun from the
melt,
aerodynamically stretched and immediately thereafter laid down as a nap, a
preconsolidation by pre-calendering or needling is possibly carried out, and
the nonwoven

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is consolidated by high pressure fluid jets as well as simultaneously split
into
microfilaments with a titre of 0.1 to 0.8 dtex, as well as subsequently
impregnated with a
polymer.
11. Process according to claim 10, characterized in that the pre-consolidation
and the
splitting of the multi-component endless filaments is carried out in that the
possibly pre-
consolidated nonwoven is subjected to high pressure water jets at least once
from each
side.
12. Process according to claim 10 or 11, characterized in that the last high
pressure
water jet treatment is carried out on sieve support with mesh sizes of 5 to 50
mesh.
13. Process according to one of claims 10 to 12, characterized in that after
treatments
such as dyeing, tumbling, grinding and/or sanforizing are carried.

Description

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INNER LINING FOR THE FOOTWEAR INDUSTRY
DESCRIPTION
The invention relates to an inner lining for the footwear industry and a
process for its
manufacture.
Wear resistant materials are used in the footwear industry for the lining of
the inner
part of the shoe, the so-called inner lining. Those materials are intended to
support on the
one hand the outward humidity transport by sweat generation at the foot, in
order to
guarantee a dry foot, and on the other hand distribute the forces generated
during the
rolling of movement onto large regions of the shoe leather, in order to
thereby prevent the
generation of folds and the faster wear associated therewith.
Thermally bonded and embossed calendared polyamide nonwovens were so far used
for this purpose, napped or brushed nonwovens with textile appearance and soft
hand,
napped wovens, synthetic leathers on the basis of polyurethane coagulates or
split leather
of natural raw materials.
It is an object of the invention to provide an inner lining for the footwear
industry,
which at surface weights of 80 to 170 g/mz has initial tear strength and tear
propagation
strength in longitudinal and transverse direction > 7 N.
It is a further object of the invention to provide a process especially suited
for the
manufacture of such an inner lining.
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This object is achieved in accordance with the invention with an inner lining
which
has surface weights of 80 to 170 g/m2 and a tear propagation strength in
longitudinal and
transverse direction > 7 N, whereby the inner lining is made of meltspun
aerodynamically
stretched mufti-component endless filaments immediately laid down into a nap
with a titre
of 1.5 to 5.0 dtex, the mufti-component endless filaments after a pre-
consolidation being
split to at least 80% into micro-endless filaments with a titre of 0.5 to 0.8
dtex, and then
consolidated. These inner linings have high tension strength and wear
resistance at low
surface weights. Furthermore, because of the endless filaments, no edging is
required with
the inner lining in accordance with the invention and no fraying occurs and
bulges in the
seam region, and thereby possible pressure points, are avoided.
The inner lining is preferably one wherein the nonwoven consists of meltspun
aerodynamically stretched mufti-component endless filaments immediately laid
down into
a nap and having a titre of 2 to 3 dtex, the mufti-component endless filaments
possibly
after a pre-consolidation being split to at least 80% into micro-endless
filaments with a
titre of 0.1 to 0.5 dtex and consolidated. The inner lining has an isotropic
filament
distribution in the nonwoven. It is therefore not necessary to take the
machine direction
into consideration during the cutting of the inner lining.
The inner lining is preferably one wherein the mufti-component endless
filament is a
bi-component endless filament of two incompatible polymers, especially a
polyester (PES)
and a polyamide (PA). The mufti-component endless filament has thereby a good
splittability and a very advantageous ratio of strength to surface weight.
The inner lining is preferably one wherein the mufti-component endless
filaments
have a cross section with an orange type or "pie" mufti-segment structure,
whereby the
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segments alternately include respectively one of the two incompatible
polymers. Apart
from this orange type mufti-segment structure of the mufti-component endless
filaments, a
"side-by-side" (s/s) segment arrangement of the incompatible polymers in the
multi-
component endless filament is also possible, which is preferably used for the
generation of
crimped filaments. Such segment arrangements of the incompatible polymers in
the multi-
component endless filament have proven to be very well splittable. The inner
lining has a
very advantageous ratio of surface weight to insulation capacity, so that a
soft and
warming inner lining can be manufactured, especially with downstream treatment
steps
such as napping.
The inner lining is definitely one wherein the nonwoven made of the multi-
component endless filaments is pre-calendered for pre-consolidation. The
material thereby
has a very good thickness consistency.
A material with a textile appearance and a wear proof surface is further
preferred as
inner lining, which was obtained by treatment with high pressure water jets on
a structured
and/or open meshed sieve base.
Furthermore, an inner lining is especially preferred wherein at least one of
the
incompatible polymers forming the mufti-component endless filament includes an
additive, such as colour pigments, permanently acting antistatics and/or
additives which
influence the hydrophilic or hydrophobic properties, in amounts of up to 15%
per weight.
The inner lining can thereby be positively influenced with respect to its
light permanence,
the propensity for static charging, the sweat transport or the humidity
damming action.
The addition of the colour pigments into the extrusion mass furthermore
enables the
manufacture of deeper and wear resistant colours.
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Furthermore, an inner lining is especially preferred wherein the mufti-
component
endless filament is uncrimped, since thereby the textile hand resulting from
the good
splittability into micro-endless filaments is guaranteed.
The inner lining is preferably one wherein one of the sides is coated with a
hot melt
adhesive coating. Such a material is especially suited for the further
processing on
automated machinery.
The process in accordance with the invention for the manufacture of the inner
lining
consists in that the mufti-component endless filaments are spun from the melt,
aerodynamically stretched and immediately laid down into a nonwoven, an
optional pre-
consolidation by pre-calendering or needle punching is carried out and the
nonwoven is
consolidated by high pressure fluid jets and simultaneously split into micro-
endless
filaments with a titre of 0.1 to 0.8 dtex, preferably 0.1 to 0.5 dtex. The
parts so obtained
are very even with respect to their stability loading capacity, since a
largely isotropic
thread distribution is present in the product. The products show no tendency
to de-
lamination and have high module values and tear strength or tear propagation
strength.
Furthermore, the inner linings in accordance with the invention have very good
humidity
transport properties which positively influence the comfort of the shoe
provided therewith,
with respect to the water vapour transport and the drying of wet shoes.
A further advantageous embodiment of the process consists in that the pre-
consolidation and splitting of the mufti-component endless filaments is
carried in that the
possibly pre-consolidated nonwoven is subjected at least once from each side
with high
pressure water jets. This type of consolidation and spreading of the mufti-
component
endless filaments leads to very dense nonwovens with smooth surfaces.
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The last high pressure water jet treatment is preferably carned out on a sieve
base
with mesh sizes of 5 to 50 mesh. The inner lining fabric is thereby
additionally
consolidated, becomes more wear resistant and is given a textile appearance.
Preferably, the impregnated material is subjected to downstream treatments
such as
dyeing, tumbling, grinding and/or sanforizing. The surface structure and hand
of the
material obtained can be further improved with these measues.
EXAMPLE
A filament nap with a surface weight of 110 g/mz is produced from a PES-PA-bi-
component endless filament and is subjected alternately from both sides to a
water jet
needling at pressures of 280 bar. The water jet needling is thereby carned out
in a total of
four treatment passes, whereby the fourth passage is carried out on a 20 mesh
sieve base.
A structured and/or perforated surface is thereby produced and the inner
lining obtains a
textile appearance and a soft hand. The water jet needling simultaneously
achieves the
splitting of the starting filaments to a titre < 0.2 dtex. The inner lining so
produced is
subjected to a jet dyeing and can be used without consideration to the machine
direction.
The inner lining obtained has the stability perimeters listed in the following
table and is
well-suited for the indicated use.
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Properties Unit Value
Weight g/mz 110
Module 10% longitudinalN/5 cm 60
Module 10% transverseN/5 cm 40
Tear propagation N 8
strength
longitudinal
Tear propagation N 8
strength
transverse
Martindale (abrasionNote dry after 51,200good
at rounds good
12 kPa) Note wet after 12,800
rounds
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