U.S. patent application number 10/294621 was filed with the patent office on 2003-04-17 for dry production of a non-woven fibre web.
Invention is credited to Andersen, Jens Ole Brochner.
Application Number | 20030070262 10/294621 |
Document ID | / |
Family ID | 8159531 |
Filed Date | 2003-04-17 |
United States Patent
Application |
20030070262 |
Kind Code |
A1 |
Andersen, Jens Ole
Brochner |
April 17, 2003 |
Dry production of a non-woven fibre web
Abstract
A plant that includes two air-lay stations placed one after the
other serving for the dry production of a non-woven fiber web. Each
station includes a fiber feed duct for feeding fibers to the
station from a fiber source, an air-lay forming head connected to
the fiber feed duct and at least partly defined by a perforated
screen, and a suction box for successively sucking fibers in the
forming head through the screen. A separate fiber source is part of
each station. The first station furthermore has a fiber collector
placed under the screen of its forming head whereas the second
station has a forming wire placed under the screen of its forming
head. The two stations are connected to at least one conveyor for
conveying fibers from the fiber collector of the first station to
the forming head of the second station. By means of the plant, a
cotton fiber web on the basis of Cotton Linters Pulp and
thermobinding fibers can be produced which, considering its
quality, are price competitive with corresponding fiber webs based
on cellulose pulp. This cotton fiber web has a homogenous, nit-free
structure which is desirable for use in various products.
Inventors: |
Andersen, Jens Ole Brochner;
(Skanderborg, DK) |
Correspondence
Address: |
WINSTON & STRAWN
PATENT DEPARTMENT
1400 L STREET, N.W.
WASHINGTON
DC
20005-3502
US
|
Family ID: |
8159531 |
Appl. No.: |
10/294621 |
Filed: |
November 15, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10294621 |
Nov 15, 2002 |
|
|
|
PCT/DK01/00381 |
May 31, 2001 |
|
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Current U.S.
Class: |
19/296 ;
19/304 |
Current CPC
Class: |
D04H 1/732 20130101;
D04H 1/4266 20130101; D04H 1/5418 20200501; D04H 1/72 20130101;
D04H 1/425 20130101; D04H 1/542 20130101; D04H 1/736 20130101; D04H
1/5412 20200501 |
Class at
Publication: |
19/296 ;
19/304 |
International
Class: |
D01G 025/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 31, 2000 |
DK |
PA 2000 00857 |
Claims
What is claimed is:
1. A method for dry production of a non-woven fiber web that
includes at least relatively short and relatively long fibers,
wherein the method comprises the following process steps:
generating that a first air flow that contains short fibers from a
fiber source, passing the first air flow through a first perforated
screen having openings of a size that allow open, but not unopen,
short fibers to pass therethrough, passing the first air flow
through an air-permeable first forming wire running endlessly
during operation to form a non-woven layer of short fibers thereon,
generating a second air flow that contains short fibers from the
non-woven fiber layer that is formed on the forming wire,
generating a third air flow that contains long fibers from a fiber
source of same, passing the second and third air flows through a
second perforated screen having openings of a size that allow both
short and long fibers to pass therethrough, passing the second and
third air flows through an air-permeable second forming wire
running endlessly during operation to form a fiber layer on the
second forming wire, and preparing a non-woven fiber web from the
fiber layer from the second forming wire.
2. The method according to claim 1, wherein unopen, short fibers
are extracted from the first perforated screen.
3. A plant for dry production of a non-woven fiber web comprising
two air-lay stations placed after each other and each comprising at
least one fiber feed duct for feeding fibers to the station from a
fiber source, at least one air-lay forming head connected with the
fiber feed duct and at least partly defined by a perforated screen,
a suction box for successively sucking fibers through the screen, a
separate fiber source associated with each of the two stations, a
fiber collector associated with the first station and placed under
the screen of its forming head(s), a forming wire associated with
the second station and placed under the screen of its forming
head(s), and at least one conveyor associated with the two stations
for conveying fibers from the fiber collector of the first station
to the forming head of the second station.
4. The plant according to claim 3, wherein the fiber collector of
the first station is a forming wire.
5. The plant according to claim 3, wherein the fiber collector of
the first station is part of the suction box of the forming head
belonging to that station.
6. The plant according to claim 3, wherein the fiber source of the
first station consists essentially of relatively short fibers, and
that the openings in the screen of its at least one forming head
are of a size that mainly allow open, but not unopen short fibers
to pass through; that the fiber source of the second station
consists essentially of relatively long fibers, and that the
openings in the screen of its at least one forming head are of a
size that allow both the relatively short and the relatively long
fibers to pass through.
7. The plant according to claim 6, wherein the fiber source of the
first station consists essentially of Cotton Linters Pulp, and that
the fiber source of the second station consists essentially of
thermobinding fibers.
8. The plant according to claim 7, wherein the thermobinding fibers
are bicomponent fibers having a core that is surrounded by an outer
coating of a material having a lower melting point than that of the
core.
9. The plant according to claim 3, wherein the conveyor is a fiber
feed duct extending between the fiber collector of the first
station and the forming head of the second station.
10. The plant according to claim 3, wherein at least the first
station has at least one extraction duct and a conveyor fan for
extracting unopen fibers or nits from the screen of the at least
one forming head of that station.
11. A non-woven air-laid fiber web comprising a mixture of
thermobinding fibers and Cotton Linters Pulp which is mainly
screened of unopen fibers.
12. The non-woven air-laid fiber web according to claim 11, wherein
the thermobinding fibers are bicomponent fibers having a core
consisting essentially of a relatively strong material that is
surrounded by an outer coating having a lower melting point than
the core.
13. A non-woven air-laid fiber web obtainable by the method of
claim 7, such that the web comprises a mixture of thermobinding
fibers and Cotton Linters Pulp which is mainly screened of unopen
fibers.
14. The non-woven air-laid fiber web according to claim 12, wherein
the thermobinding fibers are bicomponent fibers having a core that
is surrounded by an outer coating of a material having a lower
melting point than that of the core.
15. In a method for producing a non-woven fiber web, the
improvement which comprises combining Cotton Linters Pulp together
with thermobinding fibers to produce the web.
16. The method of claim 15 wherein the thermobinding fibers are
bicomponent fibers having a core that is surrounded by an outer
coating of a material having a lower melting point than that of the
core.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of the US national stage
designation of International application PCT/DK01/00381 filed May
31, 2001, the content of which is expressly incorporated herein by
reference thereto.
BACKGROUND ART
[0002] The invention relates to a method for the dry production of
a non-woven fiber web of at least relatively short and relatively
long fibers. The invention also relates to a plant for the dry
production of a non-woven fiber web by means of two air-lay
stations placed one after the other and each comprising at least
one fiber feed duct to feed fibers to the station from a fiber
source, at least one air-lay forming head connected to the fiber
feed duct and at least partly defined by a perforated screen, and a
suction box for successively sucking fibers in the forming head
through the screen.
[0003] The invention moreover relates to a non-woven fiber web
produced by means of the method and the plant for dryly producing a
non-woven fiber web.
[0004] Finally, the invention relates to the use of Cotton Linters
Pulp (CLP), which is a relatively inexpensive by-product derived
from the seed coats of the cotton plant, for the dry production of
a relatively inexpensive non-woven air laid cotton fiber web.
[0005] The air-lay technique is known generally from GB Patent No.
1,499,687 which describes a plant for the dry production of a
non-woven fiber web. This plant has an air-lay forming head in form
of a box which is defined by a perforated base at the bottom. Above
the base are rows of rotating wings which distribute the fibers
during operation into flows across the perforated base. Below this
base is placed an air-permeable forming wire which is running
endlessly during operation for accommodating fibers which are drawn
through the openings of the perforated base by the negative
pressure in a suction box placed under the forming wire.
[0006] This plant is well suited for producing a non-woven fiber
web of like fibers or at least of fibers on the whole having the
same configuration. If the fiber web is to be made of fibers having
substantially different lengths, the plant can however not function
optimally, and the fiber web produced cannot obtain a completely
satisfactory quality.
[0007] These disadvantages can be assigned to the fact that it is
not possible to dimension the openings of the base so that they are
suited for both relatively short and relatively long fibers. It is
therefore necessary to choose openings having a size which is
between the optimum sizes for each of the two types of fibers. The
openings will then easily be too large for the short fibers and too
small for the long ones.
[0008] GB Patent application No. 2,031,970 describes an air-lay
plant having several forming heads of the above-mentioned type
placed in a row one after another above a joint forming wire. By
means of this arrangement, the plant is able to operate with both
short and long fibers with good results. Fibers of one specific
length are then distributed from a forming head having base
openings which are suited for exactly this fiber length. Layered
fiber webs can be produced by means of this technique as it also is
desired in some cases. The known plant is however not suited for
producing homogeneous fiber webs of fibers of different
lengths.
[0009] Attempts have been made to resolve the last-mentioned
problem by placing the forming heads on top of each other instead
of in a row one after the other. Such a plant is described in
published PCT application WO 96/10663. In this application, the
plant has three forming heads. The uppermost one is supplied with
Super Absorbent Powder (SAP) and has a base with openings that
exactly fit the size of the SAP. The middle forming head is
supplied with short cellulose fibers and has a base that exactly
fits the size of these short fibers, while the lowest forming head
is supplied with long thermobinding fibers and has a base that
exactly fits the size of these long fibers.
[0010] The base of the upper forming head forms an upper
delimitation to the middle forming head, and the base of this head
forms an upper delimitation to the lowest forming head. The
openings in the base of the lowest forming head are so large that
the SAP and the cellulose fibers can pass through the openings
simultaneously with the thermobinding fibers, and the openings in
the base of the middle forming head are so large that the SAP can
pass through these openings simultaneously with the cellulose
fibers.
[0011] Below the base of the lowest forming head is an
air-permeable forming wire which is running endlessly during
operation, and below this a suction box which is common to all
three forming heads. When the plant is running, the SAP is driven
via the openings in the base of the upper forming head down into
the middle forming head, the SAP and the cellulose fibers are
driven via the openings in the base of the middle forming head down
into the lowest forming head, and the SAP, the short cellulose
fibers and the long thermobinding fibers are driven via the
openings in the base of the lowest forming head down in a layer
onto the forming wire.
[0012] The SAP and the short cellulose fibers are first mixed in
the middle forming head and then the long thermobinding fibers in
the lowest forming head. By means of this mixing, a homogenous
fiber web should be obtainable. However, it is difficult to control
the different air flows of the process such that the resulting
fiber web obtains an acceptable homogeneity. This is among other
things due to the fact that the air flows inevitably will interfere
with each other. Thus, air is simultaneously blown in on both sides
of the base of both the upper and the middle forming head, and the
negative pressure from the suction box furthermore has to propagate
to the base of the middle forming head via the openings in the base
of the lowest forming head and to the base of the upper forming
head via the openings in the middle forming head. At the same time,
the SAP, the short cellulose fibers and the long thermobinding
fibers are moving in the opposite direction through the openings of
the respective bases, with those openings thereby randomly blocked
to the flow of the air to a greater or smaller extent.
[0013] When the forming heads are placed on top of each other
instead of in a row after each other, the plant will furthermore be
disproportionately high. Therefore, the plant known from the
published PCT application WO 96/10663 can rarely find room in
existing buildings, and new buildings for the plant will normally
look quite out of place in an otherwise harmonious group of
buildings. Furthermore, the great height means that it is difficult
to inspect the plant and control the process in this plant.
[0014] Today, dry-produced fiber webs are used extensively for many
different purposes, of which napkins, toilet paper, diapers,
sanitary napkins and absorbent products for people suffering from
incontinence can be mentioned.
[0015] In order to be able to keep the prices of these products at
a commercially acceptable level, a large part of the fibers that
form part of the air-laid fiber product are normally inexpensive
cellulose fibers which can be mixed with e.g., thermobinding fibers
depending on the application purpose just as the products also can
contain SAP to increase the ability of the products to absorb
liquids. However, for some purposes, products are desired that are
substantially softer than the products that are based on cellulose
fibers. Such a very soft, non-woven fiber product can be produced
by utilizing cotton fibers instead of cellulose fibers. Due to the
high price of the cotton fibers, however, the resulting products
will be too expensive for practical applications.
[0016] The production of cotton leaves a by-product called Cotton
Linters Pulp (CLP) which consists of short residual fibers from the
seed coats of the cotton plants. This by-product is far less
expensive than common cotton fibers. It is therefore possible to
use it for producing a very soft, non-woven cotton fiber web which,
considering its quality, would be able to compete on price with
fiber webs based on cellulose fibers. However, CLP consists of
fibers that are very fine, very short and also have a large content
of unopen fibers or nit. The above known plants and methods can
therefore not be used with a satisfactory result to produce a
nit-free, homogenous, non-woven fiber web of CLP-fibers and
thermobinding fibers. Thus, there is a need for improved products
of this type, and these are provided by the present invention.
SUMMARY OF THE INVENTION
[0017] The present invention provides a method and a plant for the
dry production of a non-woven fiber web of at least relatively
short and relatively long fibers, by means of which a homogenous,
nit-free, non-woven fiber web can advantageously be produced on the
basis of CLP-fibers and thermobinding fibers.
[0018] The invention also provides a non-woven fiber web that has a
homogenous and substantially nit-free structure and which is
produced by the method and plant.
[0019] The invention further provides CLP as base material for the
dry production of a non-woven cotton fiber web which can be used to
make a wide variety of absorbent materials.
[0020] The novel and unique features of the method according to the
invention are based on generating a first air flow with short
fibers from a fiber source, passing the first air flow through a
first perforated screen having openings of a size that mainly allow
open, but not unopen short fibers to pass therethrough, passing the
first air flow through an air-permeable first forming wire running
endlessly during operation thus forming a non-woven layer of short
fibers on the forming wire, passing the first air flow through an
air-permeable first forming wire running endlessly during operation
to form a non-woven layer of short fibers thereon, generating a
second air flow that contains short fibers from the non-woven fiber
layer that is formed on the forming wire, generating a third air
flow that contains long fibers from a fiber source of same, passing
the second and third air flows through a second perforated screen
having openings of a size that allow both short and long fibers to
pass therethrough, passing the second and third air flows through
an air-permeable second forming wire running endlessly during
operation to form a fiber layer on the second forming wire, and
preparing a non-woven fiber web from the fiber layer with further
treatment.
[0021] By using this method, a non-woven fiber web of short and
long fibers obtains a homogenous structure which at the same time
is free of nits when the unopen short fibers or nits are extracted
from the first perforated screen.
[0022] The novel and unique features of the plant according to the
invention are the fact that a separate fiber source belongs to each
station, that the first station has a fiber collector placed under
the screen of its at least one forming head, that the second
station has a forming wire placed under the screen of its at least
one forming head, and that the two stations are connected by at
least one conveyor for conveying fibers from the fiber collector of
the first station to the forming head of the second station.
[0023] When the screen openings of the first station have a size
that fit the short fibers which e.g. can be CLP-fibers, and the
screen openings of the second station have a size that fit the long
fibers which e.g. can be thermobinding fibers, the plant can be
utilized for producing a non-woven fiber web having a homogenous
structure.
[0024] The first station is then fed short fibers whereas the
second station is fed both long fibers and short fibers having
passed the screen openings of the first station. The short and long
fibers thereby obtain being carefully mixed in the second station
and can thereby form a fiber layer having a homogenous structure on
the forming wire of the second station.
[0025] By means of the above arrangement, unopen fibers or nits can
selectively be extracted from the first station so that the
resulting fiber web also becomes at least essentially free of
nit.
[0026] The conveyor that can be used for connecting the first and
second stations together can be a belt conveyor but can in an
advantageous embodiment be a fiber feed duct connecting the fiber
collector of the first station to the forming head of the second
station. By means of a fan generating an air flow through the fiber
feed duct, the fibers are sucked from the fiber collector of the
first station up into the fiber feed duct in order to then via this
being blown into the forming head of the second station.
[0027] The fiber collector of the first station can be of any
expedient kind. In an advantageous embodiment the fiber collector
can quite simply be part of the suction box of the first station
whereby the extraction from the suction box takes place by means of
the fiber feed duct which connects the two stations. In a second
advantageous embodiment the fiber collector can be a forming wire
which then acts as a travelling filter for filtering off the short
fibers from the air flow through the screen openings of the first
station.
[0028] The novel and unique features of the fiber web according to
the invention are the fact that it comprises a mixture of
thermobinding fibers and CLP-fibers screened of unopen fibers or
nit, and that it has a homogenous and nit-free structure. Such a
web has an extraordinarily great softness which is wanted for many
purposes. Furthermore, fiber webs on cotton basis are good for the
skin and non-allergenic.
[0029] The novel and unique features of the invention include the
use of CLP as base material to produce a non-woven air-laid cotton
fiber web together with thermobinding fibers. Thus, in a method for
producing a non-woven fiber web, the invention relates to the
improvement which comprises combining CLP together with
thermobinding fibers to produce the web.
[0030] A cotton fiber web based on conventional cotton fibers will
be too expensive for practical application due to the relatively
high price of these fibers. By using CLP as base material instead,
an inexpensive product is obtained having the same advantages of
the cotton fiber web based on conventional cotton fibers. However,
the CLP fibers are relatively short and weak. The strength of the
web is therefore obtained by binding the fibers together by means
of thermobinding fibers using the method and plant according to the
invention.
[0031] An especially good strength is obtained according to the
invention when the thermobinding fibers are bicomponent fibers of
the kind that each has a core consisting of a rather strong
material and that is surrounded by an outer coating having a lower
melting point than the core. During the production of the fiber
web, the outer coating will melt readily and effectively together
with both each other and the short and weak CLP fibers, and
especially in nodal points whereby the advantageous properties of
the CLP cotton fibers are completely maintained whereas the core of
the bicomponent fibers transfers its great strength to the cotton
fiber web.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] The invention will be explained in greater detail below,
describing only exemplary embodiments with reference to the drawing
figures, in which
[0033] FIG. 1 is a diagrammatic view of a first embodiment of a
plant according to the invention,
[0034] FIG. 2 is a diagrammatic view of a second embodiment of a
plant according to the invention,
[0035] FIG. 3 is a diagrammatic view of a third embodiment of a
plant according to the invention, and
[0036] FIG. 4 is a diagrammatic view of a fourth embodiment of a
plant according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] In the following the invention is described on the
assumption that a homogenous and nit-free cotton fiber web of
CLP-fibers and thermobinding fibers is to be made.
[0038] CLP has very fine and short fibers and also a large content
of unopen fibers or nit. Therefore, it has so far not been possible
in practice to use CLP for producing a cotton fiber web of
satisfactory quality.
[0039] The fine and short CLP-fibers are bound to the thermobinding
fibers in a manner known per se in order to thereby give the fiber
web the necessary strength. The resulting cotton fiber web is
relatively inexpensive to produce and has a very soft structure.
There is thus a considerable market for such a product.
[0040] The plant according to the invention in FIG. 1 has a first
air-lay station 1 for CLP-fibers and a second air-lay station 2 for
both thermobinding fibers and CLP-fibers which have been screened
of nits in the first station. If the thermobinding fibers are mixed
with unscreened CLP-fibers, the result is a fiber web of
unsatisfactory quality.
[0041] The main components of the first station 1 is a hammer mill
3 for defibrating CLP from a roller 4, and a first forming head 5
having a first perforated base 6, a first set of rotatable wings 7
placed in rows above the base 6, and a first suction box 8 placed
under the base 6.
[0042] When the first station is operating, the forming head 5 is
supplied with defibrated fibers from the hammer mill 3 via first
feed duct 9 having a first feed fan 10.
[0043] The wings 7 are sweeping the supplied CLP-fibers across the
base 8 in continuous flows. During this, the fibers are sucked
successively down into the suction box 8 via the openings 11 of the
base 8 by a second feed fan 12 which is connected to the suction
box via the second feed duct 13.
[0044] The openings 11 of the base 8 are arranged with a size that
allows the fine, short CLP-fibers to pass but not the coarser
nit.
[0045] A return fan 14 serves for returning the nits to the hammer
mill 3 via a return duct 15 where the nits can be open.
[0046] The screened fibers are collected in the suction box which
thus simultaneously acts as fiber collector.
[0047] The main components of the second station 2 are a fiber
source 16 with a bale breaker 17 for breaking up the thermobinding
fibers from a bale of thermobinding fibers 18, and a second forming
head 19 having a second perforated base 20, a second set of
rotatable wings 21 placed in rows above the base 20, a forming wire
22 placed under the base 20, and a second suction box 23 placed
under the forming wire 22 and via a suction duct 24 connected to a
fan 25 for creating a negative pressure in the suction box.
[0048] When the second station is operating, the second forming
head 19 is supplied with screened CLP-fibers from the first suction
box 8 via the second feed duct 13 by means of the second feed fan
12.
[0049] The second forming head 19 is simultaneously supplied with
thermobinding fibers from the fiber source 16 via a third feed duct
26 with a third feed fan 27.
[0050] In the second forming head 19, the supplied with CLP-fibers
are mixed with the supplied thermobinding fibers. The second set of
wings 21 are sweeping the now mixed fibers across the second
perforated base 20 in continuous flows. During this, the fibers are
sucked successively down into a layer on the forming wire 22 via
the openings 28 of the base by means of the fan 25 which is
connected to the suction box 23 via the suction duct 24.
[0051] The openings 28 of the second base 20 are arranged with a
size that allow both CLP-fibers and thermobinding fibers to
pass.
[0052] Thereby, a fiber layer of CLP-fibers and thermobinding
fibers is made on the forming wire 22, said fiber layer has a
homogenous and nit-free structure. In a known subsequent process
(not shown), the fiber layer is finally converted into the desired
fiber web which among other things can be dust bonded by means of a
layer of latex.
[0053] The plant according to the invention shown in FIG. 2
corresponds essentially to the one shown in FIG. 1 and referred to
above. Like parts are therefore designated by the same reference
numerals.
[0054] In this case, the fiber collector of the first station is
however a forming wire 29 acting as a travelling filter for
filtering off the CLP-fibers from the air flow through the base
openings 11 of the first station 1.
[0055] The CLP-fibers are sucked successively down onto the forming
wire 29 via the openings 11 of the first base by means of a fan 30
which is connected to the suction box 8 via a suction duct 31. An
evenly distributed CLP-fiber layer 32 settling on the forming wire
29 is successively conveyed with this wire towards the inlet
openings 33 of the second feed duct 13 and supplied in a continuous
flow into the second forming head 19 via the second feed duct 13 by
means of the second feed fan 12.
[0056] This solution has especially the advantage that the feeding
of screened CLP-fibers in the second forming head 19 is controlled
very accurately, and that the resulting cotton fiber web therefore
can obtain a very uniform structure in the longitudinal
direction.
[0057] The plant according to the invention shown in FIG. 3
corresponds essentially to the one shown in FIG. 2 and referred to
above. Like parts are therefore designated by the same reference
numerals.
[0058] In this embodiment both stations use a known forming head in
form of a drum-shaped screen 41 having horizontal brushes 42 for
distributing the fibers over the screen. Each station has two
forming heads.
[0059] Moreover, the functioning of the embodiment shown in FIG. 3
of a plant according to the invention corresponds to the one shown
in FIG. 2 and referred to above and will therefore not be mentioned
any further here.
[0060] FIG. 4 is a very diagrammatic view of a plant according to
the invention having a first station 34 with one forming head 35
for CLP-fibers placed above a forming wire 36, and a second station
37 with three forming heads 38a,b,c for screened CLP-fibers and
other fibers placed above a joint forming wire 39.
[0061] The two stations are connected to a fiber conveyor 40 for,
as indicated by the arrows, conveying screened CLP-fibers from the
forming wire 36 of the first station 34 into the forming heads
38a,b,c of the second station.
[0062] This plant can be used for producing cotton fiber webs
having a composition that varies depending upon the supply of
fibers to the different forming heads of the second station.
[0063] For example, the plant can be used for producing laminated
cotton fiber webs, and cotton fiber webs that also comprises a
powder for example SAP, and synthetic fibers such as PET.
[0064] Two different, known forming heads are mentioned above and
shown in the drawing that can form part of a plant according the
invention. However, this is only to be taken as an example as the
plant within the scope of the invention can function with any other
kind of forming head just as two or several different types of
forming heads can form part of the same plant.
[0065] The invention is furthermore described on the assumption
that the short fibers forming part of the fiber web according to
the inventions are CLP.
[0066] This is also only to be taken as an example as the method
and the plant according to the invention advantageously can be used
to produce fiber webs having a content of other types of short
fibers, for example cellulose fibers.
[0067] The first air-lay station of the plant can furthermore have
more than one forming head for short fibers.
[0068] The first station can thus have one forming head for short
cellulose fibers and a second for CLP-fibers whereby a homogenous,
nit-free, non-woven cotton fiber web can be produced that has an
acceptable softness and is relatively inexpensive.
EXAMPLES
[0069] The following non-limiting examples illustrate preferred
embodiments of the present invention.
[0070] A web having the advantageously soft properties of the
relatively short and weak CLP fibers and the advantageously great
strength of the thermobinding fibers can for example be obtained
with the following compositions.
Example 1
[0071] A fiber web consisting of 60 weight percentage CLP fibers
and 40 weight percentage thermobinding fibers.
Example 2
[0072] A fiber web consisting of 95 weight percentage CLP fibers
and 5 weight percentage bicomponent fibers.
Example 3
[0073] A fiber web consisting of a multilayer; for example a
three-layer product where the top and base layer consist of 60
weight percentage CLP-fibers and 40 weight percentage bicomponent
fibers. The middle layer consists of 95 weight percentage
CLP-fibers and 5 weight percentage bicomponent fibers but can just
as well comprise SAP, SAF or pulp within the scope of the
invention.
* * * * *