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EP 0 778 910 B1 |
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EUROPEAN PATENT SPECIFICATION |
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Mention of the grant of the patent: |
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18.11.1998 Bulletin 1998/47 |
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Date of filing: 24.08.1995 |
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International Patent Classification (IPC)6: D21F 1/00 |
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International application number: |
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PCT/GB9502/007 |
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International publication number: |
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WO 9607/789 (14.03.1996 Gazette 1996/12) |
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PAPERMAKERS FABRIC
PAPIERMASCHINENBESPANNUNG
TOILE DESTINEE A LA FABRICATION DE PAPIER
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Designated Contracting States: |
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AT BE CH DE DK ES FR GB GR IE IT LI LU MC NL PT SE |
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Priority: |
03.09.1994 GB 9417720
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Date of publication of application: |
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18.06.1997 Bulletin 1997/25 |
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Proprietor: SCAPA GROUP PLC |
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Blackburn,
Lancashire BB2 6AY (GB) |
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Inventor: |
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- HODSON, Mark
Mellor
Lancashire BB2 7JU (GB)
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Representative: Goodwin, Mark et al |
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Wilson, Gunn, M'Caw,
41-51 Royal Exchange,
Cross Street Manchester M2 7BD Manchester M2 7BD (GB) |
(56) |
References cited: :
EP-A- 0 085 363
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EP-A- 0 259 294
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Note: Within nine months from the publication of the mention of the grant of the European
patent, any person may give notice to the European Patent Office of opposition to
the European patent
granted. Notice of opposition shall be filed in a written reasoned statement. It shall
not be deemed to
have been filed until the opposition fee has been paid. (Art. 99(1) European Patent
Convention).
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[0001] The present invention relates to papermakers fabrics and particularly, but not exclusively,
to a fabric for use in the dryer section of a papermaking machine.
[0002] Generally speaking papermaking machines are made up of three sections, namely the
forming, pressing and drying sections. In each section a fabric belt is used to transport
a continuous paper sheet through the papermaking equipment as the paper is being manufactured.
The structure of the fabrics for each section differs, as the requirements of each
section of the papermachine are different. For example, a forming fabric must have
both a precise permeability which provides the required water drainage and a surface
matched to the fibre type being processed, whereas a press fabric must be capable
of rapidly absorbing and expelling water while protecting the newly formed paper sheet.
Dryer fabrics are designed for heat resistance, high durability in adverse chemical
and physical conditions and permeability.
[0003] Patent application wo 91/19044 describes a papermakers dryer fabric incorporating
flat monofilament machine direction yarns interwoven with the cross machine direction
yarns in a manner such that floats are provided on the upper and lower surfaces of
the fabric. The floats provide a smooth fabric surface. The system of machine direction
yarns comprises upper and lower yarns which are vertically stacked in order to control
the permeability of the fabric. The machine direction yarns are woven contiguous with
each other to reduce the permeability of the fabric and to lock in the machine direction
alignment of the stacking pairs of machine direction yarns.
[0004] In the papermachine dryer fabrics pass over dryer cylinders. Here the fabric is subjected
to intense heat on the cylinder side, to steam degradation throughout, (but more predominantly
on the paper carrying side) and to wear on either side due to the nature of the paper
being formed and/or due to rusty or corroded felt rolls, degradation being a particular
problem at the edges of the belt which are always in contact with hot dryer cylinders.
[0005] It is an object of the invention to provide a papermakers fabric having superior
resistance to degradation due to heat, hydrolysis and wear.
[0006] According to the present invention there is provided a papermakers fabric woven from
machine direction yarns and one or more layers of cross-machine direction yarns, the
cross-machine direction yarns in at least one of the layers comprising relatively
large and small yarns and the machine and cross machine direction yarns being arranged
such that the machine direction yarns define outer floats or knuckles on one of the
faces of the fabric and inner floats or knuckles below said one face around small
cross machine direction yarns in one of the cross machine direction yarn layers, wherein
the parts of the machine direction yarns defining the inner floats or knuckles below
said one face do not extend to the plane of the obverse face of the fabric, characterized
in that the parts of the machine direction yarns defining the inner floats or knuckles
below said one face are spaced from the observe face of the fabric by air.
[0007] Ideally all of the layers of cross machine direction yarns comprise relatively large
and small yarns. Preferably floats are provided by machine direction yarns on both
the said one and obverse surfaces of the fabric with all of the inner machine direction
floats or knuckles being located within the body of the fabric between the said one
and obverse face of the fabric.
[0008] The fabric of the invention has particular, but not exclusive, application as a dryer
fabric.
[0009] As the floats or knuckles of the machine direction yarns do not extend to the fabric
surface, the opposite face of the yarn is insulated by air from heat from a dryer
cylinder. As air is a better thermal insulation medium than fabric the papermakers
fabric of the invention offers exceptional resistance to heat degradation, whilst
the increased remoteness of the yarns from the fabric surface increases the resistance
to degradation by wear and hydrolysis. This is of upmost importance in the dryer section
of a papermachine.
[0010] The machine direction yarns floating on one face and the machine direction yarns
floating on the obverse face of the fabric may be made from the same material or different
materials. The same or different materials may be used for the cross machine direction
yarns provided at said one face and the obverse face of the fabric and/or within the
individual cross machine direction layers. Suitable materials for the machine direction
yarns include polyesters, such as polyethylene terephthalate (PET) and polyethylene
naphthalate (PEN), polyamides, polyphenylene sulphide (PPS), polyetheretherketone
(PEEK) or PCTA (copolymers of cyclohexane dimethanol with terephthalic acid and isophthalic
acid). One suitable fabric is made entirely from polyester (e.g. PET), whilst another
has polyester machine direction yarns on the back surface of the fabric and high performance
machine direction yarns (e.g. PPS, PEN or PEEK) on the opposite surface.
[0011] As the machine direction yarns on one surface of the fabric do not come into contact
with the opposite surface of the fabric in the dryer machine section, machine direction
yarns at the paper side of the fabric will not come into contact with the dryer cylinders
and will therefore not be subjected to such extreme temperatures. Thus there is no
need for the yarn to exhibit exceptional resistance to degradation by heat or wear.
The yarns provided at the opposite surface of the fabric may be chosen to exhibit
improved resistance to abrasion and heat.
[0012] Thus by selecting the appropriate materials for the machine direction yarns at the
two surfaces of the fabric the working life of the fabric may be increased.
[0013] The cross machine direction weft yarns are typically made from polyester (e.g. PEN,
PCTA), PPS, PEEK or combinations thereof.
[0014] A further novel aspect of the invention is the use of different combination patterns
of cross machine direction yarn sizes in order to control permeability. Typical cross
machine direction yarn sizes are 0.3mm diameter alternating with 0.6mm, 0.4mm or 0.2mm.
WO 91/19044 achieves permeability control by altering the number of machine direction
yarns and cross machine direction yarns in the fabric. This is disadvantageous compared
with altering the difference between the cross machine direction yarn diameters since
it involves time consuming re-setting of the loom. Other alternative methods of permeability
control include the insertion of stuffer cross machine direction yarns, altering the
number of machine direction yarns, changing the cross machine direction yarn density
and utilising non-circular or multifilament cross machine direction and/or machine
direction yarns.
[0015] Examples of cross machine direction yarn diameter combinations are 0.5mm and 0.7mm;
0.5mm and 0.8mm; 0.5mm and 0.9mm; and 0.4mm and 0.9mm. The difference in diameter
of the cross machine direction yarns is preferably in the range from 0.1mm to 0.6mm.
[0016] In a preferred embodiment of the invention the fabric comprises at least two layers
of cross machine direction yarns. Preferably all of the layers of cross machine direction
yarns comprise relatively large and small yarns. The large and small yarns are preferably
provided in an alternating fashion both in any single cross machine direction yarn
layer and vertically in adjacent layers. In a preferred embodiment of the invention
"Stuffer" cross machine direction yarns are further included in order to control the
permeability. These are incorporated by weaving cross machine direction yarns having
a large surface area into the fabric. The incorporation of additional yarns would
decrease the permeability of the fabric. These additional yarns are preferably profiled
yarns.
[0017] The machine direction yarns of the invention are preferably flat monofilaments preferably
having an aspect ratio in the range from 2:1 to 4:1. However, other profiled (i.e.
non-circular cross section) yarns may be used such as triangular yarns. Alternatively
circular cross-section yarns may be used. Especially preferred is the use of "D" shaped
yarns. Such yarns would be arranged such that the curved surface faces into the body
of the fabric. The curved surface gives improved resistance to contamination and facilitates
easy cleaning of the yarns (using high pressure air/water jets). The fabric may contain
different cross sectional sizes and/or shapes of machine direction yarns, for example
as an alternative means of keeping certain yarns out of contact with the sheet and/or
dryer cylinders.
[0018] Preferably the machine direction yarns float over at least two relatively large cross
machine direction yarns and any small cross machine direction yarns therebetween thereby
forming a float. In a multilayer fabric the knuckle from the machine direction yarn
provided at the opposite surface of the fabric would be formed under a single cross
machine direction yarn in the fabric.
[0019] In order that the present invention may be more readily understood specific embodiments
thereof will now be described by way of example only with reference to the accompanying
drawings in which:-
Fig.1 is a side elevation of one fabric in accordance with the invention; and
Fig.2 is a side elevation of a second fabric in accordance with the invention.
[0020] Referring to Fig.1 a fabric 10 comprises a single layer of relatively large and small
cross machine direction yarns arranged alternately. A first machine direction yarn
11 extends above two large cross machine direction yarns 12,13 and a small cross machine
direction yarn 14 located therebetween so as to form a float. The yarn then passes
below a small cross machine direction yarn 15 to form a knuckle and then over a further
pair of large cross machine direction yarns 16,17 and a small cross machine direction
yarn 18. The majority of the machine direction yarn 11 is thus located at the upper
surface of the fabric. The parts of the machine direction yarn 11 forming the knuckles
do not extend as far as the lower surface of the fabric. The other machine direction
yarns 19 provided at the upper surface of the fabric are arranged in the same manner.
The machine direction yarns 20 provided at the lower surface of the fabric float below
two large cross machine direction yarns and one small cross machine direction yarn
located therebetween. The yarn then extends over a small cross machine direction yarn
so as to form a knuckle and then over two further large cross machine direction yarns
and an intermediate small cross machine direction yarn. The machine direction yarns
provided at the lower surface of the fabric do not therefore extend to the upper surface
of the fabric. In use the fabric is formed into a belt for a paper dryer machine.
The yarns on one surface of the fabric support the paper and are typically made from
PPS, PEN, PEEK or PCTA which exhibit good resistance to degradation by heat, steam
and wear. The yarns at the other surface of the fabric are typically made from polyester
which exhibits good resistance to dry heat degradation.
[0021] Fig.2 shows a further fabric 21 in accordance with the invention having two layers
22,23 of cross machine direction yarns, each layer comprising relatively large and
small cross machine direction yarns arranged alternately. The cross machine direction
yarns of the two layers are preferably, but not exclusively stacked in a manner such
that a small cross machine direction yarn is located above a large cross machine direction
yarn and a large cross machine direction yarn is located above a small cross machine
direction yarn.
[0022] A machine direction yarn 24 floats over two large cross machine direction yarns 25,26
at the upper surface and an intermediate small cross machine direction yarn 27. The
yarn then passes below a small cross machine direction yarn 28 in the upper layer
22, and a small cross machine direction yarn 29 in the lower layer 23 and a further
small cross machine direction yarn in the upper layer 30. The machine direction yarn
24 then repeats this weave pattern along the length of the fabric. The other machine
direction yarns 31 at the upper surface are similarly arranged. The machine direction
yarns 32,33 provided at the lower surface are arranged in a mirror image to the upper
cross machine direction yarns.
[0023] As before the machine direction yarns defining floats at the base of the fabric do
not extend to the upper surface and the machine direction yarns defining floats at
the top surface of the fabric do not extend to the lower surface of the fabric.
[0024] It is to be understood that the above described embodiments are by way of illustration
only. Many modifications and variations are possible within the scope of the appended
claims.
1. A papermakers fabric woven from machine direction yarns (11,19,20;24,31-33) and one
or more layers (22,23) of cross-machine direction yarns, (12-18;25-30) the cross-machine
direction yarns (12-18;25-30) in at least one of the layers (22,23) comprising relatively
large (12,13,16,17;25,26) and small (14,15,18 ; 27-30) yarns and the machine and cross
machine direction yarns being arranged such that the machine direction yarns (11,19,20
; 24,31-33) define outer floats or knuckles on one of the faces of the fabric and
inner floats or knuckles below said one face around small cross machine direction
yarns (14,15,18 ; 27-30) in one of the cross machine direction yarn layers (22,23)
wherein the parts of the machine direction yarns (11,19,20 ; 24,31-33) defining the
inner floats or knuckles below said one face do not extend to the plane of the obverse
face of the fabric, characterized in that the parts of the machine direction yarns
(11,19,20 ; 24,31-33) defining the inner floats or knuckles below said one face are
spaced from the plane of the observe face of the fabric by air.
2. A papermakers fabric as claimed in claim 1, wherein all of the layers (22,23) of cross
machine direction yarns (25-30) comprise relatively large (25,26) and small (27-30)
yarns.
3. A papermakers fabric as claimed in claim 1 or claim 2, wherein machine direction yarns
(11,19 ; 24,31) floating on said one face of the fabric are made of the same material
to machine direction yarns (20 ; 32,33) floating on the obverse face of the fabric.
4. A papermakers fabric as claimed in claim 1 or claim 2, wherein machine direction yarns
floating (11,19 ; 24,31) on said one face of the fabric are made of a different material
to machine direction yarns (20 ; 32,33) floating on the obverse face of the fabric.
5. A papermakers fabric as claimed in any preceding claim, wherein the fabric comprises
a plurality of layers (22,23) of cross machine direction yarns (25-30) and different
materials are used for the cross machine direction yarns (25-30) provided at the said
one face and obverse face of the fabric.
6. A papermakers fabric as claimed in any preceding claim, wherein machine direction
yarns (11,19 ; 24,31) floating on one face of the fabric comprise polyester and machine
direction yarns (20 ; 32;33) floating on the obverse face of the fabric comprise PPS,
PEN or PEEK.
7. A papermakers fabric as claimed in any preceding claim, wherein there is a difference
in the diameter of the relatively large (12,13,16,17 ; 25,26) and small (14,15,18
; 27-30) cross machine direction yarns in the range from 0.1mm to 0.6mm.
8. A papermakers fabric as claimed in any preceding claim, wherein the relatively large
(12,13,16,17 ; 25,26) and small (14,15,18 ; 27-30) cross machine direction yarns are
provided in alternating fashion in any single cross machine direction yarn layer (22,23).
9. A papermakers fabric as claimed in any preceding claim, wherein the fabric comprises
more than one cross machine direction yarn layer (22,23) and the relatively large
(12,13,16,17 ; 25,26) and small (14,15,18;27-30) cross machine direction yarns are
provided in alternating fashion vertically in adjacent layers (22,23).
10. A papermakers fabric as claimed in any preceding claim, wherein the fabric further
comprises additional stuffer cross machine direction yarns.
11. A papermakers fabric as claimed in claim 10, wherein the stuffer yarns are non-circular
in cross section.
12. A papermakers fabric as claimed in any preceding claim, wherein the machine direction
yarns (11,19,20 ; 24,31-33) are non-circular in cross section.
13. A papermakers fabric as claimed in claim 12, wherein the machine direction yarns (11,19,20
; 24,31-33) are flat monofilaments having an aspect ratio in the range from 2:1 to
4:1.
14. A papermakers fabric as claimed in claim 12, wherein the machine direction yarns (11,19,20
; 24,31-33) are "D" shaped, the curved surfaces thereof facing into the body of the
fabric.
15. A papermakers fabric as claimed in any preceding claim, wherein the fabric contains
different machine direction yarns (11,19,20 ; 24,31-33) having different cross-sectional
sizes and/or shapes.
16. A papermakers fabric as claimed in any preceding claim, wherein the fabric is a dryer
fabric.
1. Papiermaschinengewebe mit in Maschinenrichtung liegenden Fäden (11, 19, 20, 24, 31
bis 33) und einer oder mehreren Lagen (22, 23) von in Maschinenquerrichtung liegenden
Fäden (12 bis 18; 25 bis 30), wobei die in Maschinenquerrichtung liegenden Fäden (12
bis 18; 25 bis 30) in mindestens einer Lage (22, 23) relativ dicke Fäden (12, 13,
16, 17, 25, 26) und relativ dünne Fäden (14, 15, 18, 27 bis 30) aufweisen und die
in Maschinenrichtung sowie die in Maschinenquerrichtung liegenden Fäden derart angeordnet
sind, daß die in Maschinenrichtung liegenden Fäden (11, 19, 20; 24, 31 bis 33) äußere
Flottierungen oder Hügel auf einer Seite des Gewebes und unter dieser Gewebeseite
innere Flottierungen oder Hügel um in Maschinenquerrichtung liegende dünne Fäden (14,
15, 18, 27 bis 30) in einer der Lagen (22, 23) von in Maschinenquerrichtung liegenden
Fäden bilden, und wobei sich die Abschnitte der in Maschinenrichtung liegenden Fäden
(11, 19, 20, 24, 31 bis 33), die unter dieser Gewebeseite die inneren Flottierungen
oder Hügel bilden, nicht bis zur Ebene der gegenüberliegenden Gewebeseite erstrecken,
dadurch gekennzeichnet, daß die Abschnitte der in Maschinenrichtung liegenden Fäden
(11, 19, 20, 24, 31 bis 33), welche die inneren Flottierungen oder Hügel unter der
einen Gewebeseite bilden, von der Ebene der gegenüberliegenden Gewebeseite durch Luft
getrennt sind.
2. Papiermaschinengewebe nach Anspruch 1,
wobei alle Lagen (22, 23) von in Maschinenquerrichtung liegenden Fäden (25 bis 30)
relativ dicke Fäden (25, 26) und relativ dünne Fäden (27 bis 30) aufweisen.
3. Papiermaschinengewebe nach Anspruch 1 oder 2,
wobei in Maschinenrichtung liegende, auf der einen Seite des Gewebes flottierende
Fäden (11, 19; 24, 31) aus demselben Material hergestellt sind wie in Maschinenrichtung
liegende flottierende Fäden (20; 32, 33) auf der gegenüberliegenden Seite des Gewebes.
4. Papiermaschinengewebe nach Anspruch 1 oder 2,
wobei in Maschinenrichtung liegende, auf der einen Seite des Gewebes flottierende
Fäden (11, 19, 24, 31) aus unterschiedlichem Material hergestellt sind als in Maschinenrichtung
liegende flottierende Fäden (20, 32, 33) auf der gegenüberliegenden Seite des Gewebes.
5. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei das Gewebe mehrere Lagen (22, 23) von in Maschinenquerrichtung liegenden Fäden
(25 bis 30) aufweist und für die in Maschinenquerrichtung liegenden Fäden (25 bis
30) auf der einen Seite und auf der gegenüberliegenden Seite des Gewebes unterschiedliche
Materialien verwendet werden.
6. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei in Maschinenrichtung liegende, auf einer Seite des Gewebes flottierende Fäden
(11, 19, 24, 31) aus Polyester und in Maschinenrichtung liegende, auf der gegenüberliegenden
Seite des Gewebes flottierende Fäden (20, 32, 33) aus PPS, PEN oder PEEK hergestellt
sind.
7. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei die in Maschinenquerrichtung liegenden relativ dicken Fäden (12, 13, 16, 17;
25, 26) und relativ dünnen Fäden (14, 15, 18; 27 bis 30) eine Differenz im Durchmesser
von 0,1 mm bis 0,6 mm aufweisen.
8. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei die in Maschinenquerrichtung liegenden relativ dicken Fäden (12, 13, 16, 17;
25, 26) und relativ dünnen Fäden (14, 15, 18, 27 bis 30) in jeder einzelnen Lage (22,
23) von in Maschinenquerrichtung liegenden Fäden wechselweise angeordnet sind.
9. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei das Gewebe mehr als eine Lage (22, 23) von in Maschinenquerrichtung liegenden
Fäden aufweist und die in Maschinenquerrichtung liegenden relativ dicken Fäden (12,
13, 16, 17, 25, 26) und relativ dünnen Fäden (14, 15, 18, 27 bis 30) benachbarter
Lagen (22, 23) in vertikaler Richtung abwechselnd angeordnet sind.
10. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei das Gewebe außerdem zusätzliche in Maschinenquerrichtung liegende Füllfäden
aufweist.
11. Papiermaschinengewebe nach Anspruch 10,
wobei die Füllfäden im Querschnitt nicht kreisförmig sind.
12. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei die in Maschinenrichtung liegenden Fäden (11, 19, 20; 24, 31 bis 33) im Querschnitt
nicht kreisförmig sind.
13. Papiermaschinengewebe nach Anspruch 12,
wobei die in Maschinenrichtung liegenden Fäden (11, 19, 20; 24, 31 bis 33) flache
Monofilamente sind, deren Verhältnis Breite zu Höhe zwischen 2:1 und 4:1 liegt.
14. Papiermaschinengewebe nach Anspruch 12,
wobei die in Maschinenrichtung liegenden Fäden (11, 19, 20, 24, 31 bis 33) eine D-Form
aufweisen, deren Krümmung sich in den Körper des Gewebes hinein erstreckt.
15. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei das Gewebe unterschiedliche in Maschinenrichtung liegende Fäden (11, 19, 20,
24, 31 bis 33) mit unterschiedlichen Profilgrößen und/oder Profilformen enthält.
16. Papiermaschinengewebe nach einem vorhergehenden Anspruch,
wobei das Gewebe eine Trockenpartie-Bespannung ist.
1. Tissu pour la fabrication de papier tissé à partir de fils orientés selon une direction
de la machine (11, 19,20,24,31 à 33) et une ou plusieurs couches (22, 23) de fils
orientés transversalement à la direction de la machine (12 à 18; 25 à 30), les fils
orientés transversalement à la direction de la machine (12 à 18; 25 à 30) comprenant
dans au moins l'une des couches (22,23) des fils relativement gros (12, 13, 16, 17,
25, 26) et petits (14, 15, 18, 27, 30) et les fils orientés selon la direction de
la machine et transversalement à la direction de la machine étant agencés de sorte
que les fils orientés selon la direction de la machine (11, 19, 20; 24, 31 à 33) définissent
des flottés ou boucles extérieures sur l'une des faces du tissu et des flottés ou
boucles intérieures sous ladite face autour de petits fils orientés selon la direction
de la machine (14, 15, 18; 27 à 30) dans l'une des couches de fils orientés transversalement
à la direction de la machine (22, 23), dans lequel les parties des fils orientés selon
la direction de la machine (11, 19, 20, 24,31 à 33) définissant les flottés ou boucles
intérieures sous ladite face ne s'étendent pas jusqu'au plan de la face apparente
du tissu, caractérisé en ce que les parties des fils orientés selon la direction de
la machine (11, 19, 20, 24, 31 à 33) définissant les flottés ou boucles intérieures
sous ladite face sont espacées du plan de la face apparente du tissu par de l'air.
2. Tissu selon la revendication 1, dans lequel toutes les couches (22, 23) de fils orientés
transversalement à la direction de la machine (25, 30) comprennent des fils relativement
gros (25, 26) et petits (27 à 30).
3. Tissu selon la revendication 1 ou 2, dans lequel des fils orientés selon la direction
de la machine (11, 19; 24, 31) flottant sur ladite face du tissu sont réalisés dans
le même matériau que des fils orientés selon la direction de la machine (20; 32, 33)
flottant sur la face apparente du tissu.
4. Tissu selon la revendication 1 ou 2, dans lequel des fils orientés selon la direction
de la machine (11, 19, 24, 31) flottant sur ladite face du tissu sont réalisés en
un matériau différent des fils orientés selon la direction de la machine (20,32,33)
flottant sur la face apparente du tissu.
5. Tissu selon l'une quelconque des revendications précédentes, dans lequel le tissu
comprend plusieurs couches (22, 23) de fils orientés transversalement à la direction
de la machine (25 à 30) et des matériaux différents sont utilisés pour le fils orientés
transversalement à la direction de la machine (25 à 30) prévus au niveau de ladite
face et sur la face apparente du tissu.
6. Tissu selon l'une quelconque des revendications précédentes, dans lequel des fils
orientés selon la direction de la machine (11, 19; 24, 31) flottant sur une face du
tissu comprennent du polyester et des fils orientés selon la direction de la machine
(20; 32, 33) flottant sur la face apparente du tissu comprennent du PPS, du PEN ou
du PEEK.
7. Tissu selon l'une quelconque des revendications précédentes, dans lequel il existe
une différence de diamètre entre les fils orientés transversalement à la direction
de la machine relativement gros (12, 13, 16, 17; 25, 26) et petits (14, 15, 18; 27
à 30) qui est comprise dans la plage allant de 0,1 mm à 0,6 mm.
8. Tissu selon l'une quelconque des revendications précédentes, dans lequel les fils
orientés transversalement à la direction de la machine relativement gros (12, 13,
16, 17; 25; 26) et petits (14, 15, 18; 27 à 30) sont prévus de manière alternée dans
chaque couche unique de fils orientés selon la direction de la machine (22, 23).
9. Tissu selon l'une quelconque des revendications précédentes, dans lequel le tissu
comprend plus d'une couche de fils orientés transversalement à la direction de la
machine (22, 23), et les fils orientés transversalement la direction de la machine
relativement gros (12, 13, 16, 17; 25, 26) et petits (14, 15, 18; 27 à 30) sont prévus
de manière alternée verticalement dans des couches adjacentes (22, 23)
10. Tissu selon l'une quelconque des revendications précédentes, dans lequel le tissu
comprend en outre des fils additionnels de remplissage orientés transversalement à
la direction de la machine.
11. Tissu selon la revendication 10, dans lequel les fils de remplissage sont de section
transversale non circulaire.
12. Tissu selon l'une quelconque des revendications précédentes, dans lequel les fils
orientés selon la direction de la machine (11, 19, 20; 24, 31 à 33) sont de section
transversale non circulaire.
13. Tissu selon la revendication 12, dans lequel les fils orientés selon la direction
de la machine (11, 19, 20; 24, 31 à 33) sont des monofilaments plats ayant un rapport
d'aspect compris dans la plage allant de 2:1 à 4:1.
14. Tissu selon la revendication 12, dans lequel les fils orientés selon la direction
de la machine 19, 20, 24, 31 à 33) sont en forme de "D", les surfaces courbes de ceux-ci
étant orientés à l'intérieur du corps du tissu.
15. Tissu selon l'une quelconque des revendications précédentes, dans lequel le tissu
comprend différents fils orientés selon la direction de la machine (11, 19, 20; 24,
31 à 33) ayant des dimensions et/ou des formes en section transversale différentes.
16. Tissu selon l'une quelconque des revendications précédentes, dans lequel le tissu
est un tissu de séchage.