U.S. patent application number 14/419485 was filed with the patent office on 2015-07-09 for device for hydrodynamically strengthening nonwovens, wovens or knitted fabrics.
The applicant listed for this patent is Trutzschler GmbH & Co. KG. Invention is credited to Peter Korner, Ullrich Munstermann.
Application Number | 20150191858 14/419485 |
Document ID | / |
Family ID | 48784228 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150191858 |
Kind Code |
A1 |
Munstermann; Ullrich ; et
al. |
July 9, 2015 |
DEVICE FOR HYDRODYNAMICALLY STRENGTHENING NONWOVENS, WOVENS OR
KNITTED FABRICS
Abstract
The invention relates to an apparatus for hydrodynamic
entanglement of non-wovens, wovens or knits, comprising a basic
drum (1) having a multiplicity of holes (4), on which basic drum
(1), spaced apart therefrom, there is arranged a structured drum
(6), the spacing between the basic drum (1) and the structured drum
(6) being arranged to be produced by a plurality of wires (5, 5',
5'', 5''', . . . ) which are arranged on the surface of the basic
drum (1) and which are at least in part in material-based
connection with the basic drum (1), the wires (5, 5', 5'', 5''', .
. . ) being arranged in parallel to one another on the surface of
the basic drum (1), characterised in that the wires (5, 5', 5'',
5''', . . . ) are arranged on the surface of the basic drum (1) at
an angle .alpha. of from 5.degree. to 45.degree., preferably
15.degree., relative to the longitudinal axis of the basic drum
(1).
Inventors: |
Munstermann; Ullrich;
(Egelsbach, DE) ; Korner; Peter; (Langen,
DE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Trutzschler GmbH & Co. KG |
Monchengladbach |
|
DE |
|
|
Family ID: |
48784228 |
Appl. No.: |
14/419485 |
Filed: |
July 9, 2013 |
PCT Filed: |
July 9, 2013 |
PCT NO: |
PCT/EP2013/002015 |
371 Date: |
February 4, 2015 |
Current U.S.
Class: |
28/104 ; 28/116;
492/28 |
Current CPC
Class: |
D04H 1/492 20130101;
D04H 18/04 20130101; D06B 23/026 20130101; D06C 29/00 20130101 |
International
Class: |
D06B 23/02 20060101
D06B023/02; D04H 1/492 20060101 D04H001/492; D04H 18/04 20060101
D04H018/04 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 23, 2012 |
DE |
10 2012 016 784.9 |
Claims
1. Apparatus for hydrodynamic entanglement of non-wovens, wovens or
knits, comprising a basic drum having a multiplicity of holes, on
which basic drum, spaced apart therefrom, there is arranged a
structured drum, the spacing between the basic drum and the
structured drum being arranged to be produced by a plurality of
wires which are arranged on the surface of the basic drum and which
are at least in part in material-based connection with the basic
drum, the wires being arranged in parallel to one another on the
surface of the basic drum, characterised in that the wires are
arranged on the surface of the basic drum at an angle .alpha. of
from 5.degree. to 45.degree., preferably 15.degree., relative to
the longitudinal axis of the basic drum.
2. Apparatus according to claim 1, characterised in that between
two to ten rows of holes are arranged between the wires.
3. Apparatus according to claim 1, characterised in that the wires
have a round, rectangular or contoured cross-section.
4. Apparatus according to claim 3, characterised in that the wires
have depressions and elevations.
5. Apparatus according to claim 1, characterised in that the wires
have a diameter of from 0.5 to 5 mm, preferably 1 to 3 mm,
especially from 1 to 2 mm.
6. Apparatus according to claim 1, characterised in that the wires
are soldered onto the surface of the structured drum.
7. Apparatus according to claim 1, characterised in that the
structured drum is nickel-plated together with the wires.
8. Apparatus for hydrodynamic entanglement of non-wovens, wovens or
knits, comprising a basic drum having a multiplicity of holes, on
which basic drum, spaced apart therefrom, there is arranged a
structured drum, characterised in that the spacing between the
basic drum and structured drum is arranged to be produced by at
least one pin having a head, which is arranged to be fixed in the
basic drum.
9. Apparatus according to claim 8, characterised in that the height
of the heads is between 1 to 10 mm.
10. Apparatus according to claim 8, characterised in that the heads
have an approximately semi-circular shape.
11. Apparatus according to claim 8, characterised in that the holes
in the basic drum have a diameter of from 2 to 10 mm.
12. Apparatus according to claim 8, characterised in that the holes
have a spacing of from 3 to 12 mm relative to one another.
13. Apparatus for hydrodynamic entanglement of non-wovens, wovens
or knits, comprising a basic drum having a multiplicity of holes,
on which basic drum, spaced apart therefrom, there is arranged a
structured drum, characterised in that the spacing between the
basic drum and the structured drum is arranged to be produced by
knobs which have been introduced into the basic drum by means of a
deformation process.
14. Apparatus according to claim 13, characterised in that the
spacing of the knobs is between 10 and 30 mm relative to one
another.
15. Apparatus according to claim 13, characterised in that the
knobs have a closed contour.
16. Apparatus according to claim 13, characterised in that the
diameter of the holes is between 4 to 10 mm, preferably 2 to 6
mm.
17. Apparatus according to claim 8, characterised in that the holes
in the basic drum have a diameter of from 3.5 to 5 mm.
18. Apparatus according to claim 8, characterised in that the holes
have a spacing of from 5 to 7 mm relative to one another.
19. Apparatus according to claim 1, characterised in that the holes
in the basic drum have a diameter of from 2 to 10 mm.
20. Apparatus according to claim 1, characterised in that the holes
have a spacing of from 3 to 12 mm relative to one another.
Description
[0001] The invention relates to an apparatus for hydrodynamic
entanglement of non-wovens, wovens or knits, wherein a liquid such
as, for example, water, is sprayed out from a multiplicity of
nozzles against the material for entanglement. The material for
entanglement runs over a rotating drum which is permeable to liquid
and to which negative pressure can additionally be applied in order
to draw off the water under suction.
[0002] Customarily, the drum consists of a cylindrical solid basic
drum having holes which ensure that a large amount of water flows
away. A structured drum is drawn over the basic drum, spaced apart
therefrom, which structured drum can have finely perforated
openings for entanglement of the fibres but which can also provide
the material being processed with a surface structure in the form
of a pattern.
[0003] A basic drum consisting of a solid cylindrical basic body is
known from EP 0223614 B2. Parallel to the longitudinal axis, a
multiplicity of grooves or depressions are cut into the basic body
by milling so that ridges which taper to a point remain. Many large
holes are made in the depressions, ensuring that a large volume of
water flows away. A thin structured drum having a multiplicity of
finely perforated openings is pushed over the ridges. The
structured drum customarily consists of a very thin cylindrical
metal plate and is highly susceptible to damage. The ridges
accordingly provide a spacing between the finely perforated
openings of the structured drum and the holes of the basic drum.
When hydrodynamically entangling non-wovens or wovens,
intermingling of the fibres is achieved as a result of the fibres
being pressed at least in part into the finely perforated openings
by means of water jets and intermingled. In the process, only
individual fibres enter the large openings in the basic drum, which
should not, because of the water flowing away, become blocked. The
basic drum shown in this prior art is very onerous to produce, as
the individual grooves have to be cut into a solid cylinder by
milling.
[0004] It is also known to apply to a basic drum a wire, in an
annular or helical arrangement, which produces the necessary
spacing relative to the structured drum. In that constructional
form it is disadvantageous that, when the structured drum is
demounted from the basic drum, the washed-off fibres that are
located between them cause jamming of the structured drum and basic
drum, so that the thin structured drum is damaged.
[0005] The problem of the invention is to provide an apparatus for
hydrodynamic entanglement of non-wovens, woven and knits which is
economical in construction and ensures that liquid flows away
reliably.
[0006] The invention solves the set problem by means of the
teaching of claims 1, 8 and 13; further advantageous embodying
features of the invention are characterised by the subordinate
claims.
[0007] In accordance with the technical teaching according to claim
1, the apparatus for hydrodynamic entanglement of non-wovens,
wovens or knits comprises a basic drum having a multiplicity of
holes, on which basic drum, spaced apart therefrom, there is
arranged a structured drum, the spacing between the basic drum and
the structured drum being arranged to be produced by a plurality of
wires which are arranged on the surface of the basic drum and which
are in material-based connection with the basic drum, the wires
being arranged parallel to one another on the surface of the basic
drum. The material-based connection with the basic drum can be
accomplished in partial manner, for example at spaced-apart points
or in sections where relatively long regions between the wire and
basic drum are connected to one another, there then following a
section without a material-based connection. Furthermore, the
material-based connection with the basic drum can be provided over
the entire length of the wire. A result of the wires being arranged
on the surface of the basic drum at an angle .alpha. of from
5.degree. to 45.degree., preferably 15.degree., relative to the
longitudinal axis of the basic drum is that, in technical
co-ordination with the nozzle bars, the sprayed-on liquid is
removed very well. In contrast to the prior art, a complete row of
water jets does not hit the spacer between the basic drum and the
structured drum, causing marked and disruptive rebound of the
complete row of water jets, but rather only one water jet at a
time. When the structured drum is demounted, washed-in fibres
cannot cause clogging and/or jamming between the structured drum
and basic drum because the space between the individual wires at
the end faces is open and the fibres or dirt particles can be
removed by way thereof. The structured drum can be twisted off or
screwed off the basic drum as with a very steeply angled
thread.
[0008] The invention makes possible economical and flexible
production of the basic drum, wherein the recesses no longer need
to be machined out from a solid cylinder. The material-based
connection between the wires and basic drum and/or metal plate
makes possible an economical and durable connection which
withstands a high degree of impact of liquid from the nozzle
bars.
[0009] It is advantageous that between two to ten rows of holes can
be arranged between the wires, which can be dependent on, inter
alia, the diameter of the holes and of the wires. As a result, in
dependence on the diameter of the basic drum, an optimal
combination is obtained between the number of wires, which keep the
structured drum spaced apart therefrom, and the number of holes, by
way of which the sprayed-on liquid is removed.
[0010] In a preferred embodying form, the at least one wire can
have a round, rectangular or contoured cross-section. The
production costs and also production methods can be varied in
accordance with requirements by means of the wire
cross-section.
[0011] It is especially advantageous for the at least one wire to
have depressions and elevations, which results in liquid flowing
away especially well, because the wires do not then form enclosed
segments but rather the liquid can flow away over a relatively
large circumferential extent of the basic drum.
[0012] In an advantageous embodiment, the at least one wire has a
diameter of from 0.5 to 5 mm, preferably 1 to 3 mm, especially from
1 to 2 mm. This creates a necessary spacing between the basic drum
and structured drum, but without at the same time the cross-section
of the wire being so large that holes are covered excessively. By
virtue of the preferred round shape of the wires, it is possible,
in the case of a large wire diameter, for the holes to be partly
covered without the water removal being notably impaired.
[0013] In a further advantageous embodying form, the wires are
soldered onto the surface of the basic drum. Especially in the case
of thin basic drums, this does not give rise to the problem of heat
distortion as it does in the case of welding, following which the
basic drum has to be straightened out again. Soldering the wires to
the basic drum in sections further reduces the heat loading.
[0014] In order to close the small gaps which are then formed, in
which fibres can become lodged, the basic drum is nickel-plated
together with the wires. In addition to the corrosion resistance,
the nickel-plating also produces a further connection between the
basic drum and the wires.
[0015] In an alternative second embodying form, the apparatus for
hydrodynamic entanglement of non-wovens, wovens or knits comprises
a basic drum having a multiplicity of holes, on which basic drum
there is arranged, spaced apart therefrom, a structured drum,
wherein in accordance with the invention the spacing between the
basic drum and structured drum is arranged to be produced by at
least one pin having a head, which is arranged to be fixed in the
basic drum. The pins can be very simply inserted and fixed in the
basic drum so that the heads provide the necessary spacing relative
to the structured drum. It is advantageous that the liquid sprayed
on for the purpose of entanglement can distribute itself between
the pins over the entire circumferential extent of the basic drum
and is removed by way of the holes. Furthermore, the apparatus for
hydrodynamic entanglement can be matched in highly flexible manner
to customer requirements by means of different pins and by means of
the number of pins used.
[0016] In a preferred embodying form, the height of the heads is
between 1 to 10 mm. Modification of the spacing between the
structured drum and basic drum is accordingly more flexible than in
the case of the first embodying form having the wire. Especially
having regard to the spacings from the holes it is possible to use
a variety of small or larger heads.
[0017] A shape which is very favourable to flow for directing away
the sprayed-on liquid is achieved as a result of the heads having
an approximately semi-circular shape.
[0018] For the first and second embodying forms, the holes in the
basic drum have a diameter of from 2 to 10 mm, preferably from 3.5
to 5 mm. As a result, in dependence on the material being
processed, good removal of the sprayed-on liquid can be
achieved.
[0019] In conformity therewith, the holes have a centre-to-centre
spacing of from 3 to 12 mm, preferably from 5 to 7 mm, relative to
one another so that sufficient stability of the basic drum and/or
of the fabric is ensured.
[0020] In a third embodying form of the invention, the spacing
between the basic drum and the structured drum is produced by knobs
having been introduced into the basic drum by means of a
deformation process. In contrast to the first two embodying forms,
the basic drum becomes more torsion-resistant and accordingly can
be of lighter construction.
[0021] In a preferred embodying form, the spacing of the knobs can
be between 10 and 30 mm relative to one another. This results in a
very open structure between the basic drum and structured drum, by
way of which the sprayed-on liquid can rapidly flow away.
[0022] It is advantageous for the knobs to have a closed contour so
that the fibres do not catch in the holes in the basic drum in the
course of hydrodynamic entanglement.
[0023] Preference is given to the diameter of the holes being
between 3 to 10 mm, preferably 2 to 6 mm, so that having regard to
the knob spacings it is ensured that the liquid flows away
optimally.
[0024] According to the prior art, the basic drum is customarily
produced from normal stainless steel, the toughness of which is too
great for such a deep-drawing process and which is correspondingly
expensive. The possibilities of the deformation process are
correspondingly limited, because in the event of excessive
deformation the material develops cracks.
[0025] In accordance with the invention, in this embodying form,
the basic drum is produced from a deep-drawable metal having a high
deformation capability and is subsequently provided with a surface
coating in order to achieve the required corrosion protection.
Nickel can be used as a suitable surface coating, which at the same
time has a high degree of resistance to wear. The deep-drawable
materials may also include non-rusting steels that are suitable for
deep-drawing.
[0026] The invention is explained in greater detail hereinbelow
with reference to a possible embodying example shown in
diagrammatic form.
[0027] FIG. 1: is a perspective view of a basic drum according to a
first embodying example;
[0028] FIG. 2: is a section through a basic drum having different
wire shapes;
[0029] FIG. 2a: is a longitudinal section from FIG. 2 along a
wire;
[0030] FIG. 3: is a perspective view of a basic drum according to a
second embodying example;
[0031] FIG. 3a: is a section through a basic drum according to the
second embodying example;
[0032] FIG. 4: is a section through a basic drum according to a
third embodying example.
[0033] FIG. 1 shows a basic drum 1, which has on its surface a
multiplicity of holes 4. The basic drum 1 can be constructed as a
solid cylindrical component or as a component having a plurality of
cylindrical supports 3, onto which there is drawn a metal plate 2
or a fabric having a multiplicity of holes 4. In this embodying
example, a metal plate 2 is drawn onto two cylindrical supports 3,
although only one support 3 is shown. The supports 3 are arranged
in the region of the end faces of the basic drum 1 and are
constructed to take a mounting means (not shown) at both ends. The
wall thickness of the solid basic drum 1 can be between 2 to 10 mm.
When a metal plate 2 is used, the wall thickness can be between 1
and 6 mm.
[0034] The holes 4 are usually of cylindrical construction and can
have a diameter of from 2 to 10 mm, preferably 3.5 to 5 mm. The
contour of the holes 4 can also be oval, square or of another
shape. Furthermore, the cross-section of the holes 4 can change
through the depth of the metal plate 2 and, for example, have a
conical shape. The centre-to-centre spacings of the holes 4 can be
in the range from 3 to 12 mm, preferably in the range from 5 to 7
mm. In this embodying example, holes 4 having a diameter of 5 mm
and having a centre-to-centre spacing of 7 mm are used. The holes 4
can be arranged in a line, arranged at an angle .alpha. of, for
example, 5.degree. to 45.degree. relative to the longitudinal axis
of the basic drum 1. In this embodying example, the angle .alpha.
is 15.degree. relative to the longitudinal axis of the basic drum
1.
[0035] Arranged along this line, on the surface of the basic drum 1
between the holes 4, are wires 5, 5', 5'', 5''', which are, over
part of or all of their length, in material-based connection with
the basic drum 1. The wires 5, 5', 5'', 5''' are accordingly
arranged at an angle of, for example, from 5.degree. to 45.degree.
relative to the longitudinal axis of the basic drum 1 in such a way
that, as far as possible, none of the holes 4 are covered by a wire
5, 5', 5'', 5''' or, if so, only partly covered. In this embodying
example, the angle at which the wires 5, 5', 5'', 5''' are arranged
between the holes 4 is also 15.degree. , therefore always in
between, for example, a row of holes 4. The number of wires 5, 5',
5'', 5''' arranged on the surface of the basic drum 1 depends,
inter alia, on the diameter of the basic drum 1, on the structured
drum 6 mounted on the basic drum 1 and on the material for
processing which is to be hydrodynamically entangled. Even though
only four wires 5, 5', 5'', 5''' are shown here, it is clear that
the wires 5, 5', 5'', 5''' are arranged at regular intervals around
the entirety of the basic drum 1 in order to fix the mounted
structured drum 6 at a constant spacing.
[0036] In this embodying example the wires are arranged at a
spacing relative to one another such that six rows of holes 4 are
located between every two wires (5 and 5'; 5' and 5''; 5'' and
5'''). The wires 5, 5', 5'', 5''' are in material-based connection
with the surface of the basic drum over part, at least, or all of
their length, for example by means of a welding or soldering
procedure and/or by surface coating such as, for example,
nickel-plating. The wires 5, 5', 5'', 5''' can have a diameter of
from 0.5 mm to 5 mm, preferably 1 to 3 mm, especially 1 to 2 mm,
the diameter of the wires 5, 5', 5'', 5''' being dependent on the
spacing of the holes 4 relative to one another because as a rule
covering of the holes 4 is to be avoided as far as possible, or the
holes being only partly covered.
[0037] A further preferred embodying form are holes 4 in a
triangular arrangement which also at the same time form a row of
holes in one line. As a result of the rows of holes being offset
relative to one another, three holes accordingly form an
equilateral triangle.
[0038] However, there are also embodying forms in which the holes 4
have a diameter of, for example, 2 mm and the spacing relative to
the structured drum 6 has to be maintained using wires 5, 5', 5'',
5''' having a diameter of, for example, 5 mm. In this case it is
clear that the wires 5, 5', 5'', 5''' do, at least in part, cover
the holes 4.
[0039] In accordance with FIG. 2, the cross-section of the wires 5
can be round, rectangular or square 5' or contoured 5''. Of course,
other cross-sections such as, for example, triangular, are also
possible.
[0040] The use of wires 5 of round cross-section makes possible
very economical manufacture because wires of round cross-section
are standard and can be purchased very economically. Furthermore,
these wires can be connected to the metal plate 2 especially well
by means of soldering or nickel-plating.
[0041] Wires 5' having a rectangular cross-section are likewise
very suitable for the material-based connection because they have a
large surface contacting the basic drum 1 or metal plate 2. They
can be fixed to the metal plate 2 well, especially by means of
induction welding and soldering.
[0042] Wires 5'' having a contoured cross-section, for example
having an overall rectangular cross-section but with a rounded
surface facing the structured drum 6, give the structured drum 6 a
high degree of stability because of the better contact surface.
[0043] Furthermore, as shown in FIG. 2a, the use of wires 5'''
having an indented surface, that is to say an alternating spacing
away from the surface of the basic drum 1, is expedient. Along its
longitudinal extent, the wire 5''' has alternating elevations 5b'''
and depressions 5a'''. As a result, liquid sprayed out from the
nozzle bars and onto the material being processed can flow away
especially well in the region of the depressions 5a''. As a result,
in the regions between the wires no enclosed segments are formed
where the liquid can flow away only through the holes 4 bounded by
two wires, but rather the liquid can, over a relatively large
circumferential extent of the basic drum 1, distribute better and
flow away into those regions which are not at the time being
sprayed with water by the nozzle bars. For reasons of clarity, the
perforation of the structured drum 6, that is to say its fine
holes, is not shown in the illustrations of FIGS. 2 and 2a.
[0044] The invention according to the first embodying example of
FIGS. 1 to 2a makes possible very economical and rapid production
of the basic drum 1, the depressions no longer having to be
machined out from the solid cylinder. By varying the wire diameter
and wire cross-sections, it is possible to match a basic drum 1 to
customer requirements in very flexible manner. The material-based
connection between the wires 5, 5', 5'', 5''' and the basic drum 1
or metal plate 2 makes possible an economical and durable
connection which withstands a high degree of impact of liquid from
the nozzle bars. The construction of the basic drum 1 from the
supports 3 onto which the metal plate 2 with the wires 5, 5', 5'',
5''' is drawn makes it possible to produce a light basic drum 1
which can be operated using reduced drive power compared to the
prior art.
[0045] In accordance with the second embodying example according to
FIGS. 3 and 3a, the basic drum 1 is constructed in the same manner
as in the first embodying example. The basic drum 1 has, over its
entire surface, a multiplicity of holes 4, only individual regions
of which have been shown in the drawing. The basic drum 1 can
likewise be constructed as a solid cylindrical component or as a
component having a plurality of cylindrical supports 3, onto which
there is drawn a metal plate 2 or a fabric having a multiplicity of
holes 4. In this embodying example, a metal plate 2 is drawn onto
two cylindrical supports 3, although only one support 3 is shown.
The supports 3 are arranged in the region of the end faces of the
basic drum 1 and are constructed to take a mounting means (not
shown) at both ends.
[0046] The holes 4 are usually of cylindrical construction and can
have a diameter of from 2 to 10 mm, preferably 3.5 to 5 mm. The
centre-to-centre spacings of the holes 4 can be in the region of
from 2 to 12 mm, preferably in the region of from 5 to 7 mm. In
this embodying example there were used holes 4 having a diameter of
5 mm and having a centre-to-centre spacing of 7 mm. The holes 4 in
this embodying example are not arranged in a line but rather,
preferably, in a six-hole arrangement where six holes 4 are
arranged around a hole 4. This makes it possible to accommodate the
maximum number of holes 4 on a surface. However, other arrangements
of holes 4 are of course also possible, for example in a line as in
accordance with the first embodying example. Between the holes,
pins 7 are fixed in the basic drum 1 or metal plate 2, which pins 7
can be in form of grooved pins or rivets. The heads 7a of the pins
7 produce the necessary spacing relative to the structured drum 6,
which can be between 1 to 10 mm.
[0047] The number of pins 7 relative to the number of holes 4 can
be, for example, between one to four pins 7 to seven holes 4, that
is to say for every 6-hole structure comprising seven holes one to
four pins 7 can be arranged in the basic drum 1 or metal plate 2.
In this embodying example too, the pins 7 are so arranged that they
do not cover any holes 4. Of course, the number of pins 7 can also
be significantly higher or lower.
[0048] The semi-circular shape of the heads 7a results in a shape
that is very favourable to flow, wherein the liquid can flow away
with little resistance. A further advantage compared to the prior
art is that the liquid does not have to flow away through the holes
4 in separate regions or segments but can distribute itself in the
entire region between the basic drum 1 and structured drum 6.
[0049] It is furthermore advantageous for the basic drum 1--in this
embodying example the supports 3 together with the metal plate 2
and the pins 7--to be subjected to surface treatment, for example
nickel-plated, so as to avoid the small gaps which are formed
between the heads 7a of the pins 7 and the metal plate 2, in which
the fibres of the material being processed can catch. A continuous
smooth surface is obtained as a result.
[0050] In a third embodying example according to FIG. 4, the metal
plate 2 of the basic drum 1 consists of, for example, a steel plate
having a wall thickness of from 1 to 6 mm, in which a multiplicity
of holes 4 are arranged, between which elevations in the form of
knobs 8 have been pressed out from the inside of the basic drum 1.
These elevations can be produced with a stamp in the course of
metal plate working. Because, in the course of metal plate working,
particular radii have to be adhered to during the forming process,
the number of knobs 8 for a given height of knob 8 cannot be too
large, that is to say the spacings between the knobs 8 are greater
than can be attained in the case of the embodiment with the pins 7.
In this embodying example, the spacing of knobs 8 relative to one
another is between 15 and 30 mm, the holes 4 being arranged between
the knobs 8.
[0051] The holes 4 are usually of cylindrical construction and can
have a diameter of from 2 to 10 mm, preferably 3.5 to 5 mm. The
centre-to-centre spacings of the holes 4 relative to one another
can be based on the spacing of the knobs 8 relative to one another,
with its being possible, for example, for there to be two knobs 8
for one hole 4 or also, alternatively, for one hole 4 to be
surrounded by four knobs 8. Of course, the ratio of holes 4 to
knobs 8 can be greater or smaller depending on the non-woven or
woven to be produced. In this shown embodying form, the diameter of
the holes 4 is in the range from 4 to 10 mm. When a plurality of
holes 4 are arranged in an area surrounded by four knobs 8, the
preferred diameter of the holes is somewhat smaller, for example
from 2 to 6 mm.
[0052] Because of the tolerances in material deformation, the knobs
8 can have differing heights, which can be evened out by subjecting
the basic drum 1, over the circumference of the cylinder, to
grinding or turning. The heads of the knobs 8 rounded by the
deformation can as a result be removed at least in part. After
reducing the height of the knobs 8 by grinding or turning, the
remaining height can consequently be between 2 to 10 mm. When
reducing the height of the tips of the knobs 8 by grinding or
turning, it must be ensured that the knobs have a closed contour,
that is to say they are not reduced to the extent that an opening
is produced. Depending on the non-woven or woven to be produced,
such an opening may be undesirable because fibres of the woven
being processed may catch therein and result in partial clogging of
the perforated structured drum 6. Here too, surface coating, for
example as a result of nickel-plating, is also advantageous,
because it is a reliable corrosion protection, and cracks and
irregularities in the surface of the basic drum 1 are removed, and
the surface, including the sharp edges, is made smooth.
[0053] Besides the advantage of economical production, producing
the basic drum 1 from a metal plate by deformation also has the
advantage that the metal plate 2 is integrally constructed with the
elevations. The basic drum 1 is, as a result, more
torsion-resistant and can be of lighter construction.
[0054] All three embodying forms have the advantage that production
is very economical without having to cut depressions or grooves in
a solid body by milling. Furthermore, very small spacings between
the basic drum 1 and structured drum 6 are possible by simple means
and can be rapidly matched, using manufacturing technology, to the
characteristics of the material to be processed.
REFERENCE NUMERALS AND LETTERS
[0055] 1 Basic drum [0056] 2 Metal plate [0057] 3 Support [0058] 5
Hole [0059] 5, 5', 5'' , 5''', Wire [0060] 5a Depression [0061] 5b
Elevation [0062] 6 Structured drum [0063] 7 Pin [0064] 7a Head
[0065] 8 Knob [0066] .alpha.Angle
* * * * *