U.S. patent application number 14/899288 was filed with the patent office on 2016-07-28 for entangled carbon-fiber nonwoven production method and assembly, three-dimensional-component nonwoven production method, and nonwoven fabric.
The applicant listed for this patent is GRIMM-SCHIRP GS TECHNOLOGIE GMBH, KARL MEYER AG. Invention is credited to Heinrich GRIMM, Tim RADEMACKER.
Application Number | 20160215422 14/899288 |
Document ID | / |
Family ID | 51224645 |
Filed Date | 2016-07-28 |
United States Patent
Application |
20160215422 |
Kind Code |
A1 |
RADEMACKER; Tim ; et
al. |
July 28, 2016 |
ENTANGLED CARBON-FIBER NONWOVEN PRODUCTION METHOD AND ASSEMBLY,
THREE-DIMENSIONAL-COMPONENT NONWOVEN PRODUCTION METHOD, AND
NONWOVEN FABRIC
Abstract
An entangled carbon-fiber non-woven production method for
producing an entangled carbon-fiber non-woven fabric from carbon
fibers up to a fiber length of 100 mm, with the following steps:
supplying carbon fibers; loosening/combing apart and
aerodynamically isolating the carbon fibers; aerodynamically
calming the isolated carbon fibers; introducing the calmed and
isolated carbon fibers into a vertically arranged air shaft (1),
wherein the carbon fibers are introduced at the upper end (12) of
the air shaft (1); mixing the carbon fibers within the air shaft
(1) in a contactless manner by air whirling by means of a plurality
of individual air flows; aerodynamically depositing the carbon
fibers onto a moving mold or deposit surface (2) arranged below the
air shaft (1), wherein the aerodynamic deposition is performed by
means of suctioning below the mold or the deposit surface (2),
wherein the air flows are varied and/or adjusted in the direction
and/or intensity thereof and the air flows are produced and varied
by means of one or more rotating and horizontally arranged air
nozzles (14). The invention further relates to an entangled
carbon-fiber non-woven production device, to a
three-dimensional-component non-woven production method, and to a
non-woven fabric
Inventors: |
RADEMACKER; Tim; (Stade,
DE) ; GRIMM; Heinrich; (Hildesheim, DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GRIMM-SCHIRP GS TECHNOLOGIE GMBH
KARL MEYER AG |
Hildesheim
Wischhafen |
|
DE
DE |
|
|
Family ID: |
51224645 |
Appl. No.: |
14/899288 |
Filed: |
June 13, 2014 |
PCT Filed: |
June 13, 2014 |
PCT NO: |
PCT/DE2014/100198 |
371 Date: |
March 28, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
D04H 1/732 20130101;
D04H 1/54 20130101; D04H 1/4242 20130101; D01G 25/00 20130101; D04H
1/542 20130101 |
International
Class: |
D04H 1/732 20060101
D04H001/732; D04H 1/4242 20060101 D04H001/4242; D04H 1/54 20060101
D04H001/54 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 20, 2013 |
DE |
10 2013 106 457.4 |
Claims
1. A process for producing a carbon fiber non-woven fabric from
carbon fibers up to a fiber length of 100 mm, comprising the steps
of: I. supplying carbon fibers; II. loosening/combing and
aerodynamic separating the carbon fibers; III. aerodynamic calming
the separated carbon fibers; IV. introducing the calmed and
isolated carbon fibers into a vertically arranged air shaft (1),
wherein the introduction takes place at the upper end (12) of the
air shaft (1); V. contactless mixing the carbon fibers within the
air shaft (1) by means of a plurality of individual air swirling
air streams; VI. aerodynamic depositing the carbon fibers onto a
moveable mold or a laying surface (2) arranged below the air shaft
(1), wherein the aerodynamic depositing if facilitated by a suction
below the mold or the laying surface (2), wherein the air flows are
varied or adjusted in their direction and/or strength, and the air
currents are produced and varied by one or more rotating and
horizontally arranged air nozzles (14).
2. The process according to claim 1, wherein the suctioning (step
VI.) is varied and/or adjusted in the suction power.
3. The process according to claim 1, wherein the mold or the laying
surface (2) is passed under the lower outlet (11) of the air shaft
(1), wherein the passing is guided linear or spatially, and wherein
the normal surface of the shape or laying surface (2) corresponds
in sections to the perpendicular of the air shaft (1).
4. The process according to claim 1, wherein the carbon fibers are
cut during feeding by means of a cross-cutter.
5. The process according to claim 1, wherein any one of the
preceding claims, the carbon fibers are supplemented by thermal
bonding fibers during feeding.
6. The process according to claim 5, wherein after the application
of the mixture consisting of carbon fibers and thermal bonding
fibers to mold or laying surface (2), the thermal bonding fibers
are partially melted by application of energy.
7. A carbon fiber non-woven fabric production device for carbon
fibers up to a fiber length of 100 mm, to carry out the carbon
fiber non-woven fabric manufacturing processes according to claim
1, comprising: a supply arrangement for carbon fibers and,
optionally, a supply arrangement for thermal binding fibers; a
loosening/combing apart device or a fiber opener for combing,
separating, loosening and/or releasing the carbon fibers; an air
shaft (1), wherein this is arranged vertically and wherein the
carbon fibers are introduced at its upper end (12) and discharged
at the lower end (11); a transport and separation device for
separating and transporting the separated carbon fibers from the
loosening/combing apart device or the fiber opener to the air shaft
(1), including: including: a pipeline system (4); an entry area of
the pipeline system (4) to the loosening/combing apart device or a
fiber opener; a transport fan (41) inside the pipeline system for
transport of the carbon fibers to the air shaft; a calming section
(42), arranged downstream of the transport fan (41), designed as a
perforated tube, and an introduction section (43) for the
introduction of the carbon fibers into the air shaft (1); a
perforated deposit surface (2) arranged at the lower end (11) of
the air shaft (1), in particular a conveyor belt, or a three
dimensional shape for giving form to the carbon fibers to be
deposited thereon; a vacuum provided below the deposit shape or
surface (2), and an aerodynamic mixing system arranged in the air
shaft (1) for mixing the carbon fibers wherein the aerodynamic
system comprises a plurality of air nozzles (14) which generate a
plurality of air streams, wherein the air streams are variable
and/or adjustable in their direction and/or strength.
8. The device according to claim 7, wherein the air nozzles (14)
are rotated around one or more axes and/or swiveled and/or are
designed differently in their nozzle outlet.
9. The device according to claim 7, air nozzles (14) are arranged
on horizontally arranged and rotating rollers.
10. The device according to claim 7, wherein the neck area and/or
the pipe section has interior grooves and/or baffles which cause a
circular movement of the carbon fibers.
11. The device according to claim 7, wherein a robot arm device is
provided below the air shaft (1) for the movement of the mold,
wherein the robotic arm device allows three-dimensional movement of
the mold below the air shaft (1).
12. The device according to claim 7, wherein a heat source (15) is
arranged at the lower end (11) of the air shaft (1) so that the
thermal bonding fibers can be heated after application to the mold
or the laying surface (2).
13. A three-dimensional non-woven component manufacturing method
for manufacturing a non-woven fabric for a three-dimensional part
using a carbon fiber non-woven fabric production device according
to claim 7, wherein a three-dimensional mold of the component to be
produced is guided past a fiber output such that the fibers applied
from the fiber output onto the site of deposit are applied in the
orientation normal to the surface of the mold.
14. The method according to claim 13, wherein the speed of movement
of the mold and/or a suction of the device below the mold is
varied.
15. A non-woven fabric prepared by a carbon fiber non-woven fabric
production process according to claim 1.
Description
[0001] The invention relates to an entangled non-woven carbon fiber
fabric or material production process and a carbon fiber
manufacturing device for a random non-woven fabric or material of
carbon fibers up to a fiber length of 100 mm. Furthermore, the
invention relates to a method for producing a non-woven fabric or
material for a three-dimensional component.
[0002] The term non-woven fabrics or materials refers to structures
made of fibers of limited length, continuous fibers or chopped
fibers, which in some manner are assembled and in a suitable manner
joined together to form an entangled material, namely, a fibrous
sheet, a fibrous mat.
[0003] Different arrangements are known in the state of the art for
producing non-woven fabrics in a wide variety of
configurations.
[0004] From the document EP 1 774 077 B1 a method for producing a
multi-ply tissue is known, having at least one non-woven layer
formed by means of an air-laid process.
[0005] From the document DE 10 2011 079 525 A1 a method for
producing a fiber-reinforced plastic semi-finished product is
known, wherein, for manufacture, carbon fibers are directly
incorporated by a carding device, or from a feeder, into a
matrix.
[0006] From the document DE 101 14 553 A1 a method for producing a
thick, thermoformable, fiber-reinforced semi-finished product is
known, wherein dry reinforcing fibers are mixed together by means
of an air-laid or carding process to form a continuous web, wherein
the web obtained is solidified by needling.
[0007] From the document DE 10 2004 051 334 A1 a method for
producing a three-dimensional structure of a component is known,
the latter having a dimensionally stable textile structure.
[0008] Furthermore, from document US 2013/0108831 A1, a non-woven
fabric with randomly arranged fibers is known which is produced in
the air-laid method.
[0009] Also, from the document DE 100 52 223 A1 a multilayer,
flexible, carbon-containing layer of paper is known which is
produced in the air-laid process.
[0010] In the publication by H. Fuchs, W. Albrecht "Nonwovens",
published by Wiley-VCH GmbH (ISBN 978-3-527-31519-2 Print), 2nd
edition 2012, page 158-171, non-woven mats and their manufacturing
method is disclosed, where different systems are shown to produce
these mats, and in particular the air-laid method is described.
[0011] Also known are alternative applications for a tuft feeder as
disclosed in the publication Melliand Textilberichte 7-8/2001, page
567-570 of S. Schlichter, B. Rubenach, Trutzschler GmbH & Co.
KG.
[0012] A problem with the previously known non-woven fabrics of
carbon fibers is non-uniformity with respect to the distribution of
the carbon fibers within the mat. There are formed thickened areas
and areas in which far too little carbon fibers are provided within
a prepared mat. This non-uniformity leads to mats produced from the
non-wovens parts that do not have the necessary stability over
their entire structure and so quickly fail under the set
requirements.
[0013] Generally known for the production of non-woven fabrics from
a variety of starting fibers are in particular the wet-laid
process, wherein the fibers are present in a water bath and are
formed out of this into a mat, which is generally applied for the
production of carbon fiber non-wovens, and the air-laid process,
where with the aid of air and needle devices or needle equipped
rollers fibers are made into non-woven fabrics, but this is not
applicable to carbon fibers. The application of the air-laid
process to carbon fibers results in particular in mechanical
operations on the fiber and, ultimately, thereby impairment of the
high performance fiber.
[0014] The present invention is based on the object of disclosing
an arrangement and a method for producing non-woven fabrics, which
make it possible to treat the fibers to be processed gently during
manufacture and in particular homogeneous and to impart
requirements to the fiber in a non-woven fabric form.
[0015] These objects are achieved with a method according to claim
1, an arrangement according to claim 7 as well as a further method
of claim 13 and a non-woven fabric according to claim 15.
[0016] The process of production of carbon fiber non-woven fabrics
from carbon fibers up to a fiber length of 100 mm comprises the
steps of:
[0017] I. supplying carbon fibers;
[0018] II. loosening/combing apart and aerodynamic separating the
carbon fibers;
[0019] III. aerodynamic calming the separated carbon fibers;
[0020] IV. introducing the calmed and isolated carbon fibers into a
vertically arranged air shaft, wherein the introduction is carried
out at the upper end of the air shaft;
[0021] V. contactless mixing the carbon fibers within the air shaft
by means of a plurality of individual air swirling air streams;
[0022] VI. aerodynamic depositing the carbon fibers on a movable
mold or laying surface arranged below the air shaft, wherein the
aerodynamic depositing is facilitated by a suction below the mold
or the laying surface.
[0023] Through the above-indicated procedures there occurs a
non-contact mixing and calming, with gentle material handling,
depositing of the carbon fibers on a laydown surface or on a form,
wherein during mixing no mechanical interventions take place which
could damage the carbon fibers.
[0024] Inside the air shaft, following the aerodynamic or
contactless mixing, a gravity-assisted trickle down of fibers takes
place.
[0025] The step II according to the invention, namely, the
loosening/combing apart and aerodynamic separation of the carbon
fibers, can also be realized by means of an aerodynamic separation
method or arrangement, wherein the loosening/combing apart is
accomplished by corresponding air rollers. Alternatively,
commercially available openers can be used to open the delivered
carbon fiber bundles, to loosen/comb apart, in order to prepare
them for further processes. A traditional opener in this case has
two counter-rotating needle rollers, which are preferably formed in
the case of carbon fibers with a spherical head at the needle
tip.
[0026] The contactless mixing of the carbon fibers is effected
within the vertically arranged air shaft (Step V.) by air swirling
by a plurality of individual air streams, said air streams being
varied and/or adjusted in their direction and I or strength.
[0027] The air streams in this case can be realized by a plurality
of individual nozzles, wherein it is crucial that a turbulent or
chaotic and especially not directed flow is formed within the air
shaft.
[0028] In a particular embodiment, the air streams are generated by
one or more rotating and horizontally arranged air rollers, in
particular arranged within one or more planes. These can also be
variably adjusted. The air rollers are designed as rotating
pressure pipes, on the outer circumference of which a plurality of
nozzles are arranged. Driven by respective electric motors, the air
rollers are rotated, so that via the thereupon arranged nozzles,
which can have different discharge angles, the discharged air is
spatially distributed, so that within the air shaft to a mixing of
the carbon fibers occurs.
[0029] The suction step (Step VI.) is varied and/or adjusted in the
suction capacity, whereby the density of the web can be adjusted or
varied accordingly. A further possibility of the density variation
is adjusting the speed of an appropriately provided belt conveyor
or a moving of the shape by the deposit zone by so that the density
decreases with higher speed and with a reduced speed the density of
the carbon fibers increases.
[0030] The shape or the deposit surface is moved past the lower
outlet, the deposit zone, the air shaft, wherein the passage is
guided linear or spatially, wherein the normal surface of the shape
or laying surface corresponds in sections to the perpendicular of
the air shaft. This means that the carbon fibers trickling down
always land vertically incident on the surface of the mold and
there lie down according to the surface, thereby forming a
non-woven product, which corresponds exactly to the surface
curvature or surface shape of the mold. The problem of the
subsequent bending of a two-dimensionally generated fleece to a
three-dimensional surface is hereby bypassed altogether, since a
three-dimensional non-woven mat is produced directly on the form,
which can be further processed as appropriate with plastics to
produce a carbon fiber-plastic matrix. In the application of the
fibers, these particularly preferably include a thermal bonding
fiber, such as polyamide fibers, wherein the fiber mixture of
carbon fibers and thermal bonding fibers are solidified immediately
after the depositing on the mold by an energy or heat source such
that upon further movement of the mold a changing the position of
the fibers relative to each other is prevented or excluded. For
this a partial melting of the thermal bonding fibers at the surface
of the mat occurs, so that an advancing envelope is produced above
the fabric. The composition of the fibers is here however not
changed.
[0031] The carbon fibers are cut during feeding by means of a
cross-cutting. In particular, carbon fibers from recycling
processes are used for non-woven mat production, which are brought
to a predefined length, first by means of a cross-cutting, so that
overall only fibers are present with a maximum length of, for
example, 60 mm.
[0032] The carbon fibers are supplemented with thermal bonding
fibers during feeding. The thermal bonding fibers are partially
melted by application of energy after the application of the
mixture comprising carbon fibers and thermal bonding fibers onto
the form or laying surface.
[0033] A carbon fiber-entangled non-woven production arrangement
for carbon fibers up to a fiber length of 100 mm, but in particular
for fiber lengths up to 60 mm, for carrying out the production
method of the invention, comprises: [0034] a supply arrangement for
carbon fibers and, optionally, a supply arrangement for thermal
binding fibers; [0035] a loosening/combing apart device or a fiber
opener for combing, separating, loosening and/or releasing the
carbon fibers; [0036] an air shaft, wherein this is arranged
vertically and wherein the carbon fibers are introduced at its
upper end and discharged at the lower end; [0037] a transport and
separation device for separating and transporting the separated
carbon fibers from the loosening/combing apart device or the fiber
opener to the air shaft, including: [0038] a pipeline system;
[0039] an entry area of the pipeline system to the
loosening/combing apart device or a fiber opener; [0040] a
transport blower or fan inside the pipeline system for transport of
the carbon fibers to the air shaft; [0041] a calming section,
arranged downstream of the transport fan, designed as a perforated
tube, and [0042] an introduction section for introducing the carbon
fibers in the air shaft; [0043] a perforated deposit surface
arranged at the lower end of the air shaft, in particular a
conveyor belt, or a three dimensional shape for giving form to the
carbon fibers to be deposited thereon; [0044] a vacuum provided
below the depositing shape or surface, and [0045] an aerodynamic
mixing system arranged in the air shaft for mixing the carbon
fibers.
[0046] By means of the previously disclosed arrangement, it is
possible on the one hand to realize the processes or process
sections in such a way that contactless and without mechanical
intervention a mixing the carbon fiber occurs in the free-flow
zone, namely within the air shaft.
[0047] The aerodynamic thorough-mixing system comprises a plurality
of air nozzles that generate a plurality of air streams, the air
streams being variable and/or adjustable in the direction and/or
strength. The air jets can for this purpose be tapered or straight
and arranged differently, especially in their orientation or
direction of the jet. In addition, the beam width of the nozzle can
vary from nozzle to nozzle. In a particularly preferred embodiment,
no engagement of the air flows within each other takes place, so
that the air turbulence or air flow within the air shaft while
causing a very good mixing of the fibers does not prevent their
precipitation downward.
[0048] With respect to the aerodynamic through-mixing system, for
this purpose, a variety of possible spray shapes are available for
generating an optimal vortex within the air shaft, so that the
fibers can be optimally mixed and uniformly, in particular with
uniform concentration, trickle down.
[0049] The fibers are blown and swirled by the aerodynamic
through-mixing system from various quarters.
[0050] The laying surface is formed perforated, wherein a vacuum or
suction device, for example, a transport fan, is provided below the
laying surface, which quasi suctions the trickling and isolated
carbon fibers onto the laying surface. Of course, this suctioning
of the fibers is carried out only on a defined area below the
trickle zone.
[0051] The air nozzles are rotated about one or more axes and/or
swiveled and/or are designed differently in their nozzle
outlet.
[0052] The air nozzles are provided on horizontally arranged
rotating rollers. The air nozzles in particular are arranged on the
rotating rollers to form air rollers according to the invention,
which are rotated by means of motors arranged on the outside of the
air shaft, in particular electric motors.
[0053] In a particular embodiment of the air rolls, the air nozzle
can simply radiate into the upper portion, which this is realized,
for example, by the fact that, essentially semicircular formed
sheets are positioned inside the rotating rollers, a hollow tube,
which during the rotation of the air rollers prevent air flow to
the nozzles arranged on the rotating rollers, in that they block
access to the nozzles arranged on the rotating rollers. In this way
the air flow generated is directed only in the direction of the
upper part of the air shaft. Below the rollers, thus, unimpeded air
settling of the fibers on the mold or laying surface and the
conveyor belt is possible.
[0054] As a further special embodiment of the air rollers, their
complete rotation can be mentioned, which air is emitted in all
directions through their full range of rotation. The air can be
emitted at low speeds from the nozzles, however, due to the large
number of provided nozzles, lead to an optimal turbulence.
[0055] The neck area and/or the pipeline section has internal
grooves and/or baffles which cause a circular movement of the
carbon fibers. Due to the clever arrangement of the extension
portion of the pipeline system to the opener or the
loosening/combing device, namely the lateral discharge of the
opened fibers from the loosening/combing device in a pipeline
system, the transport is carried out freely because of air
turbulence, namely the fibers are airborne. This is done in
particular by the rotating flow that comes about due to the grooves
in the pipe wall.
[0056] In the calming tube section, which is arranged after the
transport fan, calming of the fibers is carried out, so that their
kinetic energy is reduced considerably. The calming tube section is
designed as a sheathed perforated pipe and flows into an
introductory section, which fans out, for example, of a round
transport tube into a rectangular opening in the air shaft and so
introduces calmed fibers in the air shaft.
[0057] Within the air shaft, an appropriate aerodynamic mixing
takes place, so that the fibers can trickle freely downwards to the
lower part of the air shaft.
[0058] Within the air shaft an air roller unit may be provided
arranged in the lower part, to which end two or more air rollers
are arranged parallel to each other. In one particular embodiment,
five air rollers are arranged side by side.
[0059] In a further embodiment, in a further level above the first
air roller unit, which is located near the lower portion of the air
shaft, a second and/or third air roller unit can be provided, in
which case in each case provided at least one or more air rollers
respectively are disposed parallel to each other. The pre-levels
are used for pre-mixing of the fibers.
[0060] Further, baffles can be arranged inside the air shaft, which
first produce a concentration of the fibers in one area, which
fibers are then better distributed by the arranged air rollers.
[0061] Further, rotating or stationary nozzles having identical or
preferably differently streaming properties may be arranged on the
inner wall of the air shaft, to optimize the mixing without
mechanical intervention, in further another embodiment.
[0062] For the movement of the mold or shape below the air shaft a
robotic arm device is provided, wherein the robotic arm device
allows three-dimensional movement of the mold below the air
shaft.
[0063] A heat source is disposed at the lower end of the air shaft
so that the thermal bonding fibers can be heated after settling on
the form or the laying surface to solidify the surface of the web.
Such heat sources may be, for example, infrared emitters and
microwave emitters.
[0064] In one embodiment, the carbon fibers and the thermal bonding
fibers can be applied separately from each other onto the laying
surface, wherein first the carbon fibers and, following in the
transport direction of the conveyor belt, the thermal bonding
fibers settle. Here, it is also possible that the thermal bonding
fibers are provided in the air shaft homogenized using conventional
nail rollers and sprinkled on the surface.
[0065] A further particular embodiment, in relation to the
invention, is given when a method for producing a non-woven fabric
for a three-dimensional component includes a step, in that a shape
of the three-dimensional component is guided past a fiber output,
in particular with an arrangement according to the invention,
wherein the fibers are applied from the fiber output on the
incidence of mold in the direction normal of the surface. This
ensures that the downward trickling fibers form a mat on the
surface of the mold, which exactly follows in accordance with the
shape of the mold, with no tension of the fibers caused by, for
example, buckling, bending or the like, which is usually occurs
when laying a two-dimensionally manufactured fleece on a curved
shape. Conventionally corresponding three-dimensionally formed
shapes are covered with a two-dimensional non-woven mat and then
processed with a plastic into a fiber plastic matrix. Such
components can be, for example, the floor of a vehicle or doors of
baggage compartments of overhead compartments on planes, wherein
these embodiments are to be considered only by way of non-limiting
examples. Since the fibers are formed into a non-woven mat exactly
adapted to the shape during laying, in this way the production of a
nearly tension-free component is accomplished.
[0066] The speed of movement of the mold can be varied and/or a
suction device below the mold can be varied. As a result, the
density of the web is adjustable. At higher suction the material in
the form of fibers flowing in the trickle zone increases, so that
the density of the web increases. At faster movement of the mold,
the density is locally reduced, since fewer fibers can trickle per
time onto the mold.
[0067] It is also possible during the passage of the mold passing
below the trickle zone to apply suction to only specific portions
of the mold, so as to bias attachment of the fibers at defined
locations of the mold. Alternatively, individual sections of the
form can have greater application of suction, to provide localized
sections of the fleece with a higher density of carbon fibers.
[0068] The most important aspects of this invention can be
summarized in: [0069] gentle treatment of the fibers within the
trickle zone while being mixed homogeneously, [0070] prevention of
fiber breaks, [0071] production of a homogeneous isotropic
non-woven mat or fleece.
[0072] In the following, exemplary embodiments of the invention
will be explained in greater detail with reference to the
accompanying drawings.
[0073] Therein:
[0074] FIG. 1 is a schematic representation of a first embodiment
of the inventive device for manufacturing a two-dimensional
non-woven fabric;
[0075] FIG. 2 is a schematic representation of a second embodiment
of the inventive arrangement for manufacturing a two-dimensional
non-woven fabric;
[0076] FIG. 3 is a detailed representation of an embodiment of the
air shaft in a side view;
[0077] FIG. 4 is a detailed representation of the air shaft in
accordance with the illustrative embodiment according to FIG. 3 in
a schematic front view;
[0078] FIG. 5 shows a detailed representation of the air shaft in
accordance embodiment corresponding to FIG. 3 and FIG. 4 is a
schematic plan view;
[0079] FIG. 6 is a schematic representation of a third embodiment
of the inventive device for manufacturing a two-dimensional
non-woven fabric; and
[0080] FIG. 7 is a schematic representation of an embodiment of the
inventive device for producing a three-dimensional non-woven
fabric.
[0081] In FIG. 1 a schematic representation of a first embodiment
of the device according to the invention for producing a
two-dimensional non-woven fabric 5, wherein the non-woven fabric
has thermal bonding fibers 51 fused on the surface.
[0082] The device includes an air shaft 1 with a lower end 11 and
an upper end 12. Inside the air shaft 1 there are air rollers
fitted with air nozzles 14, with direction of rotation indicated
with R. The rotation of the air rollers 14 takes place by means not
shown electric motors, arranged on the outside of the air shaft 1.
At the upper end of the air shaft in the area of the port 43 is an
inlet pivot-nozzle distributor device 121, which promotes better
admission and better guidance in the air shaft 1. In the side walls
of the air shaft 1 shaft-pivot-nozzle distributor 122 are provided,
which effect also with compressed air a better fiber distribution.
The pivoting nozzle manifolds 121, 122 are in this case provided
automatically pivoting.
[0083] Next, at the lower end 1 of the air shaft, a heat source 15
is provided, which may be embodied as infrared radiating, microwave
radiating or the like.
[0084] Below the air shaft 1, which namely serves for the
percolation or trickling of separated fibers, namely carbon fibers
as the main component, a laying surface 2 is formed in the form of
a depositing conveyor belt 21, wherein the depositing conveyor belt
is formed with perforations and has a suctioning withdrawing of
air, or for vacuum assisted depositing of the fibers onto the
depositing conveyor belt 21.
[0085] Following the depositing conveyor belt 21 a non-woven fabric
removal conveyor belt 22 is provided.
[0086] Further, the device includes an opener 3, shown here as a
classic opener with two counter-rotating needle rollers. The opener
3 is supplied by a supply of carbon fibers 31, in particular from
recycled carbon short fibers. The carbon fibers are here
transported by conveyor 312 to the opener 3. Next, a supply of
thermal binder fibers 32, for example, polyamide fibers, is
provided parallel thereto, which fibers are conveyed via a conveyor
322 to the opener 3.
[0087] The device further includes a pipeline system 4, which
allows the opened fibers to be conveyed from the opener 3 to the
air shaft 1. The piping system 4 includes, in addition to the
transport pipes, which are formed as spiral ducting, a transport
fan 41, a calming pipe section 42, this being designed as a
perforated plate with a vacuum envelope, and an introduction
section 43, wherein the introduction section 43 forms a transition
from a round tube to a square introduction section at the upper end
12 of the air shaft 1.
[0088] Next, the sequence of the non-woven fabric production is
illustrated by this figure:
[0089] First, thermal bonding fibers and carbon fibers are
transported on conveyors 312, 322 in accordance with the direction
of transport X.sub.TF and X.sub.CF from the respective stocks 31,
32 to the opener 3. In the opener 3 the opening of fibers is
carried out in the traditional manner by counter-rotating needle
rollers. In a specific embodiment, the needle rollers have a round
or hemispherical head region.
[0090] After opening, the fibers are introduced laterally into the
pipe system 4 in such a manner that the fibers are transported in
the direction of transport XO (into the plane of the figure)
through the pipeline system 4 with swirling parallel to the opener
3 whereby the singled out or opened fibers are free to move
along.
[0091] A transport fan 41 is provided for transportation of the
fibers in the direction of transport X.sub.F through the circular
part of the pipeline system 4.
[0092] In addition, to calm the fibers, a calming pipe section 42
is provided, where air exits through the holes of the perforated
metal pipe. Here, the air can also be suctioned out via a further
closed tube element enclosing a perforated tube.
[0093] After the calming of the fibers, the introduction of the
fibers into the air shaft 1 takes place through the introduction
section 43.
[0094] Inside the air shaft 1, the fibers trickle downwards due to
gravity and by suction below the depositing conveyor belt 21. Here,
the fibers are mixed exclusively non-contact, by means of an
aerodynamic air mixing system, namely, an array of air five rollers
14, which are arranged in the lower region of the air shaft 1.
[0095] After the aerodynamic and non-contact mixing of the fibers,
these trickle through rollers 14 to the depositing conveyor belt
21, wherein this is amplified by the corresponding suction below
the depositing conveyor belt 21.
[0096] The depositing conveyor belt 21 continuously moves on so
that initially a non-woven fabric 5 is produced. The non-woven
fabric 5 comprising carbon fiber and thermal bonding fibers,
present in a homogeneous mixture, is conveyed to a heat source 15,
where the web is superficially solidified by melting the thermal
bonding fibers 51.
[0097] Furthermore, a transfer of the non-woven fabric 51 to a web
transport conveyor 22 is effected.
[0098] In the following the same reference numerals are used for
like components, and reference is made to their fundamental
function to the previous embodiments.
[0099] FIG. 2 shows a schematic representation of a second
embodiment of the inventive device for manufacturing a
two-dimensional non-woven fabric 5 consisting solely of carbon
fibers.
[0100] In this embodiment, only carbon fibers are supplied to the
opener 3 and accordingly fed to the air shaft 1.
[0101] The air shaft 1 has, in this embodiment, two levels of air
rollers 14, 16, which are each arranged horizontally in the air
shaft 1. The upper level air rollers 16 first cause a pre-mixing of
the fibers within the calmed air shaft 1 and then supply the
already relatively homogeneously to the lower air roller device
14.
[0102] What is important to all the embodiments of this application
is the contactless handling of the carbon fibers within the air
shaft 1 by means of air rollers 14, 16, 19 and air nozzles 121,
122. Graphically illustrated as the air rollers 14, 16, 19 is
always the rotating air roll per se as well as the air flows
emerging from the nozzles arranged on the rotating air rollers.
[0103] After the settling of the carbon fibers on the depositing
conveyor belt 21, facilitated by the generated suction, the
homogeneous non-woven fabric 5 is moved in the transport direction
X.sub.V and past on to the removal conveyor belt 22.
[0104] In FIG. 3 a detailed representation of an embodiment of the
air shaft 1 is shown in a side view.
[0105] The duct 1 has again two levels of air rollers 14 and 16,
wherein in this embodiment three horizontally arranged air rollers
are arranged side by side, which are also supported by baffles 17
on the edge of the air shaft 1, so that the trickling of the carbon
fibers occurs in a more concentrated manner.
[0106] FIG. 4 is a detailed representation of the air shaft 1
according to the embodiment shown in FIG. 3 illustrated in a
schematic front view.
[0107] Here, the differently designed nozzles of the air rollers
14, 16 can be seen. The nozzles of the air rollers 14, 16 are shown
arranged near the upper side only by way of example, they are
however in a preferred embodiment located circumferentially on all
sides on the surface of the air rollers 14, 16, so that mixing can
be achieved in the entire duct 1.
[0108] In FIG. 5 a detailed representation of the air shaft 1
according to the embodiment corresponding to FIG. 3 and FIG. 4 is
shown in a schematic plan view.
[0109] In FIG. 6 a schematic representation of a third embodiment
of the inventive device for manufacturing a two-dimensional
non-woven fabric 5 is shown.
[0110] In this embodiment, the carbon fibers are trickled onto the
laydown conveyor 21 by means of the inventive device, analogous to
FIG. 2. Herein, the mixing takes place inside the air shaft 1 by
means of air rollers 14 or appropriately arranged nozzles.
[0111] The thermal bonding fibers are supplied subsequent to the
application of the carbon fibers via a separate duct, in which duct
the thermal bonding fibers are homogenized and mixed via known
prior art needle rollers.
[0112] Subsequently, the layered fibers, namely the carbon fibers
at the bottom of and the thermal binder fibers above, are supplied
to a heat source 15, which partially melts the thermal bonding
fibers, so that a carbon non-woven fabric 5 is formed with an
almost solid surface made from partially fused thermal bonding
fibers 51.
[0113] FIG. 7 is a schematic representation of an embodiment of the
device according to the invention for producing a three-dimensional
non-woven fabric.
[0114] In this embodiment, the embodiment of FIG. 1 is again
generally incorporated, wherein carbon fibers and thermal bonding
fibers mixed together and homogenized in the duct 1 and are
sprinkled onto a laying surface 2.
[0115] Within the air shaft 1 now three roll air levels 14, 16, 19
are provided, which are each different. There occurs respectively
an improved separation and mixing of the fibers, which are then
ultimately sprinkled onto a three-dimensional shape to be covered
23.
[0116] The three-dimensional shape to be covered 23 is disposed on
a multi-axis robotic arm 24 so that the mold, starting one side, is
guided past the trickle zone of the air shaft 1. Here, the mold 23
is so guided past with the aid of the robot arm 24, which is driven
for example via a corresponding software programmable controller,
so that the trickling fibers are trickled perpendicular to each
point of the three-dimensional shape 23.
[0117] In order that the settled deposited fibers not slip or even
fall off during further movement of the mold 23 by means of the
robot aim 24, by means of the heat source 15 a partial melting of
the thermal bonding fibers to the surface is accomplished, so that
a non-woven fiber 51 is produced on the three-dimensional shape
23.
[0118] All produced webs 5, 51 can be further processed with
appropriate processing method, so that, for example, carbon fiber
reinforced plastic components arise.
LIST OF REFERENCE NUMBERS
[0119] 1 airshaft
[0120] 11 lower end
[0121] 12 upper end
[0122] 121 inlet pivot-nozzle distributor
[0123] 122 shaft pivot-nozzle distributor
[0124] 13 over-pressure vent
[0125] 14 air rollers with fitted air nozzles/air nozzles
[0126] 15 heat source/infrared radiator/microwave radiator
[0127] 16 second row of air rollers fitted with air nozzles
[0128] 17 air deflectors or baffles
[0129] 18 airshaft with nails rolls
[0130] 19 third row of air rollers fitted with air nozzles
[0131] 2 laying surface
[0132] 21 depositing conveyor belt with suction
[0133] 22 non-woven fabric removal conveyor belt
[0134] 23 mold to be covered
[0135] 24 robotic arm
[0136] 3 opener
[0137] 31 supply of carbon fiber/recycled-carbon short fibers
[0138] 312 conveyor device for carbon fibers
[0139] 32 supply of thermal binder fiber/polyamide fibers
[0140] 322 conveyor device for thermal bonding fibers
[0141] 4 pipe system
[0142] 41 transport ventilator
[0143] 42 calming section/perforated sheet
[0144] 43 introduction section
[0145] 5 non-woven fabric
[0146] 51 non-woven fabric with superficially fused thermal bonding
fibers
[0147] R rotation of air rollers
[0148] X.sub.B transport direction calmed fibers
[0149] X.sub.CF transport direction carbon fibers from supply to
opener
[0150] X.sub.TF transport direction thermal bonding fibers from
supply to opener
[0151] X.sub.O transport direction of the fibers subsequent to the
opener (parallel to the opener and circular motion)
[0152] X.sub.F transport direction fibers (in the circular
section)
[0153] X.sub.V transport direction depositing conveyor belt with
fleece
[0154] X.sub.L main transport direction of the carbon
fibers/thermal bonding fibers within the air shaft
* * * * *