MATERIAU A MAILLES CONSTITUE DE FILS, SON PROCEDE ET SON DISPOSITIF DE PRODUCTION, ET GAINE CONSTITUEE DE CE MATERIAU A MAILLES

SCREEN MATERIAL MADE OF WIRE, METHOD AND DEVICE FOR THE PRODUCTION THEREOF, AND A SLEEVE MADE OF SUCH SCREEN MATERIAL

Abrégé français

Matériau à mailles constitué de fils et destiné notamment aux cylindres d'impression au cadre, dans lequel les ouvertures (4) sont délimitées par des éléments filiformes (1) reliés les uns aux autres en certains points (2) de manière à obtenir une surface à mailles non tissée quasiment ou entièrement plate. Chacune des sections de fil voisines (3) comporte au moins deux éléments filiformes (1) s'étendant sensiblement dans le même sens, de préférence sans se croiser. On a également prévu un procédé et un dispositif de production dudit matériau.

Abrégé anglais

Screen material made of wire intended in particular for screen printing cylinders, in which the holes (4) are bounded in such a way by
wire pieces (1) which are joined to each other locally (2) that an at least virtually flat non-woven screen surface is obtained, adjacent wire
sections (3) each comprising two or more wire pieces (1) which extend preferably uncrossed in substantially the same direction; method
and device for the production thereof.

Revendications

-21 -
Claims
1. Screen material made of wire, suitable for screen
printing, characterized in that the holes (4; 7; 13; 17;
20; 23; 26) are bounded in such a way by wire pieces (1; 6
11, 12; 15, 16; 18'; 21') which are joined to each other
locally that an at least virtually flat non-woven screen
surface is obtained.
2. Screen material according to claim 1, characterized
in that adjacent wire sections (3; 5; 9, 10; 14; 18, 21),
each having two or more wire pieces (1; 6; 11, 12; 15, 16;
18'; 21'), extend uncrossed in substantially the same
direction.
3. Screen material according to claim 1 or 2,
characterized ir. that the screen material is made of zigzag
wire sections which are ]oined locally to each other at the
tips.
4. Screen material according to claim 1, characterized
in that the material comprises at least two groups (24, 25)
of wire sections, the wire sections in each group (24, 25)
running substantially parallel, and crossing those of
another group (24, 25) at one side, and in that the wire
sections (24, 25) are joined in such a way to each other at
the crossing points through fusion and/or merging that an
at least virtually flat screen surface is obtained.
5. Screen material according to claim 4, characterized
in that the wires are substantially linear.
6. Screen material according to one or more of the
preceding claims, characterized in that the wire material
and the method of joining are selected in such a way that
the screen material is dimensionally stable.
7. Screen material according to one or more of the
preceding claims, characterized in that the wire of the
screen material is made of a weldable material.
8. Screen material according to claim 7, characterized
in that the wire of the screen material is made of an
electrically conducting material
9. Screen material according to claim 8, characterized

- 22 -
in that the wire of the screen material is made of metal.
10. Screen material according to one or more of the
preceding claims, characterized in that the material has at
least 15 holes per linear cm.
11. Screen material according to claim 10,
characterized in that the material has at least 50 holes
per linear cm.
12. Cylinder made of screen material intended for
rotary screen printing, characterized in that the screen
material is a screen material according to one or more of
the preceding claims.
13. Method for the production of a screen material
according to one or more of claims 1-3, 6-11, characterized
in that wire sections are laid next to one another, the
wire sections are joined to each other locally, and the
screen holes are then formed through deformation of the
wire sections.
14. Method for the production of a screen material
according to one or more of claims 1-4, 6-11, characterized
in that wire sections are preformed and then joined point-
wise to optionally preformed wire sections.
15. Method according to claim 13 or 14, characterized
in that the wire sections are joined to each other on a
support.
16. Method according to claim 15, characterized in that
a roller is used as the support.
17. Method according to claim 16, characterized in that
one or more optionally preformed wires are wound around the
roller.
18. Method according to one or-more of claims 13-17,
characterized in that the wire sections are joined to each
other locally through laser welding.
19. Method for the production of a screen material
according to claim 4 or 5, characterized in that groups of
wire sections are laid in succession on a support at an
angle relative to each other, the wires being laid in such
a way per group that they run substantially parallel to
each other at some distance from each other, following
which the wire sections are joined to each other at

- 23 -
crossing points through fusion and/or merging.
20. Method according to claim 19, characterized in that
the wire sections of at least one group are made of
plastic.
21. Method according to one or more of claims 13-20,
characterized in that the screen material is subjected to a
flattening operation after production.
22. Method according to one or more of claims 13-21,
characterized in that the screen material is plated.
23. Screen material which is obtained by subjecting a
screen material according to one or more of claims 1-11 to
electrolysis in an electrolysis bath, which bath contains
at least one organic compound with at least one unsaturated
bond which does not belong to a
<IMG>
group, and has the properties of a class-two brightener,
the openings in the-final screen material essentially
corresponding to the openings in the starting material.
24. Wire material (39; 75) comprising essentially
linear wire sections which are joined to each other
locally, for use in the production of a screen material
according to one or more of claims 1-3, 6-11
25. Device for the continuous production of wire material
according to claim 24, at least comprising a frame with a
wire support, wire feed means for feeding wire sections to
the wire support, and joining means for joining the wire
sections to each other locally.
26. Device according to claim 25, characterized in that
the wire support is designed as a rotatable roller (36),
driving means (35) being present to rotate said roller
(36), so that wire can be wound onto said roller (36).
27. Device according to claim 26, characterized in that
said roller (36) is supported at one end only and that a
circumferential stop (38) is present near said supported
end.
28. Device according to one or more of claims 25-27,
characterized in that the wire feed means comprise at least

- 24 -
one wire reel (34) feeding wire (33) continuously.
29. Device according to claim 25, characterized in that
the wire support is designed as at least two rotatable
support wheels (50, 51) with radially extending projections
(53) and with a common axis (52), and that driving means
are present to rotate said wheels (50, 51).
30. Device according to claim 29, characterized in that
the wire feed means comprise at least one wire reel (61)
feeding wire (60) continuously, and that reciprocating
means (58) are present to guide the wire (60) from one
wheel to another and around the projections (53).
31. Device according to one or more of the claims 25-30,
characterized in that the joining means are designed as a
moveable laser welding device (40; 65)
32. Device for forming screen holes in a cylindrical
product made of wire material according to claims 1-12, at
least comprising a frame with a screen-hole-opening element
(46) comprising a conical bore, and moveable mounting means
for pulling the cylindrical product through the conical
bore in the direction in which the diameter of the bore
decreases, in which the conical bore and the mounting means
are designed in such a way, that at least a portion of the
cylindrical product can rotate relative to the screen-hole-
opening-element (46).

Description

WO 9~tl7306 PC~IN194100315
~17952g
Screen material made of Wile, method and device for the
production thereof, and a sleeYe made of such screen
o material.
The present invention relate5 in the f irst place to
a screen material made of wire, intended in particular for
screen printing.
Such a material is known and i5 generally made by
5 weaving, braiding, knitting or the like of a wire-type
material .
The f inal screen printing material is obtained by
pattern-wise masking of the holes, for example masking the
holes with a light-sensitive lacquer or the like, and then
10 pattern-wise exposure of the lacquer, following which the
exposed or non-exposed parts (~r~n~li nq on the type of
lacquer) are removed. The holes can also be masked with a
lacquer and, after it has cured, the lacquer is burnt away
pattern-wise by means of a laser or the like.
During screen printing a printing medium, such as
ink, is forced by means of a squeegee through the holes of
such a screen onto a substrate to be printed.
The printing quality with these woven, knitted or
braided screen materials is unsat;~f~l t~ry for many
applications, since the surface is relatively uneven and
r hAnn~l c can form between the screen wires and the
substrate to be printed, which gives rise to loss of
contour ~l.aL~ , due to undesirable running of the
printing medium over the ~ub~LLc-te.
Screen printing screens which do not have the
abv~ tioned disadvc...Lc-Jes are thin-walled flat metal
plates or s~ml ~cc thin-walled metal cylinders provided
with holes. This material can be made by providing a thin
metal plate or a thin ~ 11 ed metal cylinder with a light-
30 sensitive lacquer coating, which is exposed accordiny to
the desired hole pattern and developed, following which an
etching operation is carried out in order to obtain the
holes. This screen material can also be grown by
electroplating on ~I conducting substrate which has been

217g528
-- 2
provided suitably pattern-wise with an insulating lacquer.
For this latter operation a roller to which lac~uer is
applied locally, or a roller provided in a pattern-wise
manner with small holes in which the lac~uer is applied, is
used.
However, the above techni~ues are fairly complex,
envirnn -nt~l ly unfriendly and expensive.
The object of the present invention is to provide a
screen material made of wire which has the advantageous
printing properties of the last-mentioned metal screens,
but which can be made simply and cheaply and from a
multiplicity of materials. To this end, the screen material
according to the invention is characterized in that the
holes are bounded in such a way by wire pieces which are
joined to each other locally that an at least virtually
flat non-woven screen surface is obtained.
The screen material according to the invention can
be produced cheaply f rom a very wide variety of types of
wire, and both the dimensions and the shape of the hQles
can be set, while an at least virtually flat screen surface
i8 always obtained. As discussed earlier, this is desirable
in particular in the case of screen printing. The method
for producing the screen material is environmentally
friendly, since no etching or electroforming is required.
From W0-91/17006, a mesh material for security
windows and doors is known, made of preformed steel bars,
which are joined to form a planar assembly. This material
is not meant to be used as, nor is it suited f or, screen
materials for screen printing as it comprises relatively
3 0 large mesh holes . It is designed to be an obstacle against
inf ringing f orces .
The screen material according to the invention is
not restricted to screen printing, although it is essential
that it can be used as screen material for screen printing.
It can also be used suitably for, for example, filtration,
without the screen material being affected by contamination
which is difficult to remove, as in the case of woven,
braided or similar screen material. The screen material
according to the invention is also suitable for use as
~MENDED SHEEr

528
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heat-resistant filters, for example for flue gas
filtration, as wirè skeletons for catalyst compositions,
for use as embossing equipment and for all other purpose6
for which screen material can be used. ~he screen material
5 itself can also be applied to a support, following which
the holes are f illed with Lacquer and a screen material can
be grown by means of electro~?lating techniques on the
screen material according to the invention, in order to
produce ~he
AMENDED SHEET

WO 95/17306 2 ~ ~ 9 5 2 8 PCrlrll9410031~
abovementioned thin walled metal products provided with
holes .
The wire used in the screen material according to
the invention is not particularly restricted, and can be of
5 round, oval, square, rectangular, triangular or other
desired cross-section, and it could even be approximately
strip-like .
In the present description, joining wires to each
other "locally" should be understood as meaning both point-
lO wise and over some distance, 6ince - as will be explained
later - a very wide variety of screen types can be obtained
through selection of a pattern of joining points, i.e.
points set up at a distance from each other, or groups of
points set up adjacent to each other, or continuous joining
15 over a fairly great distance.
Adjacent wire 6ections, each comprising two or more
wire pieces, preferably extend ul..;Lussed in substantially
the same direction.
Wire pieces should be understood as those wire
parts extending between two joining points. Wire sections
comprise a plurality of wire pieces.
Making adjacent wire sections run ul--iLos~d gives
rise to a ~ , at least virtually flat screen surface
which has adv~ L---J - printing properties.
When a part of the screen material of the above-
mentioned ` 'i- - L according to the invention is ~yA~n;n~
more closely, wire s-~ct; nnC running substantially parallel
to each other and joined locally to each other are clearly
visible .
3 0 The screen holes can be f ormed in many ways, but
the screen material i8 advantageously made of zigzag wire
s~ ~ ;nnCI which are joined to each other locally at the
tips. Such a material can be yL~,-luced in a 6imple and
L~L~ ;hl~ manner, as will be ~;crl-C5~ below. Zigzag
35 should be understood as being a sawtooth shape, a
5;~ C~ Al shape, a flattened sawtooth shape, or an
illt '; ate f orm of these .
According to another a6pect of the invention the
material comprises at least two groups of wire sections,
, , . _ .. . . . . . _ _ _ _ _ _ _ _

21'`~9~2~
-- 4
the wire sections in each grD,~l~ running substantially
parallel, and crossing those of another group at one side,
while the wire sections are joined in such a way to each
other at the crossing points through fusion and/or merging
that an at least virtually flat screen surface is obtained.
In the case of this embodiment a non-woven material
in which each group of wires extending in a particular
direction lies at one side of another group of wires is
obtained. This embodiment again provides a flat screen
surface, as is desirable in the case of screen printing in
particular .
Per se it is known from FR-A-2188501 to produce
non-woven screen materials, comprising several layers of
wires which extend parallelly. These layers of wire are not
joined by welding/merging, but by electroplating. Further
said material, therefore, consists of more layers and is
not f lat .
In particular, the wires are linear in this
embodiment, so that the number of holes per linear cm of
screen material, and thus the dimensions of the holes, can
be regulated in a simple manner. It will be clear that
squarQ openings are obtained with two groups of linear
wires, while with three groups of wires triangular and even
pentagonal and hexagonal openings can also be obtained.
The wire material used for the screen material
according to the present invention is not particularly
restricted, but this material and the method of j oining of
the wire pieces to each other are preferably selected in
such a way that the screen material finally obtained is
dimenæionally stable. This ensures that, for example, a
rotary screen printing cylinder made from the above-
mentioned screen material, or a screen plate, does not
deform in an~undesirable and irregular manner, thus
becoming unusable or producing uneven printing results.
The wire of the screen material is advantageously
made of a weldable material, and is particularly
advantageously made of an electrically conducting material.
Metal wire is preferred, because of its electrical
conductivity and durability, since screen material made of
AIUENOED SHEET

2179528
- 4a -
metal wire can easily be additiorlally reinforced by
electroplating, preferential or otherwise, or it can be
coated with a corrosion-resistant metal or provided with a
coating for ar,other purpose.
~he screen rrLaterial according to the in~rention
preferably has at least 15 holes per linear cm, and more
AhlENDED SHEET

` ~ 2179S28
preferably has at least so holes per linear cm. Such screen
materials are particularly suitable for screen printing.
The invention also provides a cylinder made of
screen material, intended for rotary screen printing, which
cylinder is characterized in that the screen material is a
screen material according to the invention.
The invention further provides a method for the
production of a screen material according to the invention,
which method is characterized in that wire sections are
laid next to one another, the wire sections are joined to
each other locally, and the screen holes are then formed
through deformation of the wire sections. Depending on the
way in which the wires are j oined, the wires are laid at a
æhort distance from each other or against each other. For
example, where soldering techniques are used, in the case
of which material is fed in at the position of the joint, a
certain distance between the wire parts . will not present a
problem, while if laser welding is used, the wire sections
preferahly rest against each other.
In another embodiment the method for the production
of a screen material according to the invention i9
characterized in that wire sections are preformed and then
joined pointwise locally to optionally preformed wire
sections .
Both methods provide a screen material ~nade of wire
sectlons which extend uncrossed and essentially in the same
direction .
The wire sections are preferably joined to each
other on a support, it being particularly preferable for
the support used to be a roller. P, cylindrical screen
material can be obtained in this way. For this purpose, one
or more optionally pre~ormed wires are wound around the
roller, the number of wires, the cross-æectional dimension
of the wires in s~uestion and the winding method determining
the pitch. Unclosed ring-shaped wire sections can also be
laid on the roller and then joined locally, and the screen
holes are finally formed.
In particular, the wire sections are joined to each
other locally through laser welding, in which case the
~ENoED SHEE~ '

~1~9528
WO 9~/17306 PCTIN194/00315
'
-- 6 --
laser can operate continuously or intermittently ( in a
pulsed manner). Apart from welding, all kinds of other
joining tprhniqupe such as soldering, gluing, merging etc.
may be mentioned.
The invention also provides a method for the
production of a screen material according to the invention,
which r~ethod is characterized in that groups of wire
~Pct i nnC are laid in s~lrcP~cin~ on a support at an angle
relative to each other, the wires being laid in such a way
per group that they run substantially parallel to each
other at some distance from each other, following which the
wire sPrtinnC are joined to each other at the crossing
points through fusion and/or merging.
Here again, for the production of a SPAml PCC
cylinder made of screen material it is preferable to wind
wires onto a roller, in which case the distance between the
wires of each group, and thus the number of holes per
linear cm of the screen mal:erial finally ~L-,-Iuced, can be
set by setting the pitch o~ wires to be wound. Fusion
and/or merglng can be carried out under the influence of
t. _ ~ILUL~= increase and/or E,L.:anuL~: increase or t_e like.
In the case of this method it is preferable to
subject the screen material to a flattening operation, for
example, planing, polichin~ or gauging, after proA1lr~;nn.
In order to simplify the abovementioned fusion
and/or merging, the wire sec~i nnC of at least one group are
preferably made of plastic. If desired, after completion of
the screen material, such plastic wire parts can be
provided with a metal layer in a manner known to those
skilled in the art.
In order to give a~ditional strength to the screen
material according to the invention, or to coat it for
another purpose, it is preferable to carry this out by
electroplating tPrhniqllPc which are known to those skilled
in the art. A tPrhniqllP suitable for this purpose is
pref erential growth of a metal layer .
The wire material used in the method according to
the invention is preferably a hardenable or curable
material. Examples are metals which can be hardened by, for

WO 95/17306 217 9 ~ 2 g PCT1~194100315
-- 7 --
example, nitriding, or cuL-able plastics. The above is
particularly advantageous if the wire has to be wound, for
example, prior to joining, so that some flexibility of the
wire is desirable. The ability to be hardened or cured
5 makes it pnC~ihlP to give the final product the required
strength, dimensional stability, hardness or wear
resistance .
The invention also provides a screen material
which is obt~;n~ by subjecting a screen material according
lO to the invention to electrolysis in an electrolysis bath,
which bath contains at least one organic ~ _ ' with at
least one u..s.Lu~4Led bond which does not belong to a
=C-S=O
group, and has the properties of a class-two brightener,
the 9p~-nin~C in the final screen material essentially
~:UL L ~ ; n~ to the openings in the starting screen
material. In this rnnn~t tinn reference is made to
20 ~rpli~n~'s EP-B-0 038 104, which r1icclns~c a method for
preferential growing of a metal on a screen skeleton in an
electrolytic bath. With this method the growth can take
place essentially at right angles to the plane of a screen.
The invention fur1:her provides a wire material,
25 comprising essentially linear wire ~ert;nnc which are
joined to each other locally, which material is intended
~or use in the pro~ rtinn of a screen material according to
the invention. In the ca5e of this wire material the screen
holes have not yet been formed through deformation of the
30 wire sections, but all wire sections lie essentially next
to each other.
The invention finally provides a device for the
rnnt; n--nl1c production of wire material according to the
invention, at least comprising a frame with a wire support,
35 wire feed means for feeding wire se~ ~; nn~c to the wire
support, and joining means for ~oining the wire sections to
each other locally. Such a device according to the
invention can be d~cign~ in di~ferent ways.
Preferably the wire support is ~l~cign~ as a
40 rotatable roller, driving means being present to rotate

WO 95/17306 PCT/NL94/00315
~17g528
said roller, so that wire can be wound onto said roller.
More preferably 6aid roller is DU~ Jl Led at one end
only and a circumferential stop is present near said
supported end.
Advantageously the wire feed means comprise at
least one wire reel feeding wire continuou61y.
Thus, wire can be wound onto the roller in such a
manner, that the wire is wound onto the roller between the
wire already present on the roller surface, and the
circumferential stop near the supported end. Thereby, the
wire present on the roller is pu6hed to the UIIDII,UUUl Ltd
end. Before leaving the roller, the wire sections are
~oined to each other locally, e.g. by welding or the like.
It will be clear, that the shape of the roller is
not critical, and depends on the final application of the
material p, u~ ed. In the case of cilindrical screens for
rotary screen printing a roller with a circular cross
3ection is preferred, although other cross section are also
feasible for other purposes.
2 0 In another aspect of the device according to the
invention, the wire support is designed as at least two
rotatable support wheels with radially extending
projections, and with a common axis, driving means being
present to rotate said wheels. In this case advantageously
the wire feed means comprise at least one wire reel feeding
wire cnn~;m~n~ y~ and whereby reciprocating means are
present to guide the wire from one wheel to another, and
around the projections.
The wheels are provided with radially extending
projections, being spikes, pins or the like, such that the
wire can be carried between the wheels in a zig-zag winding
around the respective projections on the wheels.
That is, the wire is guided to a wheel, bent around a
pro; ection of said wheel, guided to the other wheel and
bent around a projection of the respective wheel back to
the ~irst wheel again etc. The means which guide the wire
rrom one wheel to another need to reciprocate, whereas the
wheels rotate, which movements together position the wire
in a zig-zag condition between the wheels. This will be

~1 79528
. 9.. , l l ~
explained in more detail with reference to the drawing.
Pre:Eerably the j oining means are designed as a
movable laser welding device.
The wire material produced with the device
5 according to the invention must be deformed, to open the
screen holes. This can be achieved by drawing in the
correct direction. In the case of a cylindrical product
this opening of the holes can be advantageously achieved by
a device for~forming screen holes in a cylindrical product
10 made of wire material according to the invention, at least
comprising a frame with a screen-hole-opening-element,
comprising a conical bore, and moveable mounting means for
pulling the cylindrical product through the conical bore in
the direction in which the diameter of the ~ore decreases,
15 in which the conical bore and the mounting means are
designed in such a way, that at least a portion of the
cylindrical product can rotate relative to the screen-hole-
opening- element .
The invention will be explained in greater detail
20 below with reference to the appended drawing, in which:
Fig. 1 shows an embodiment of screen material
according to the invention;
Fig. 2 shows the screen material according to Fig.
1 which has been subj ected to additional de~ormation in the
25 horizontal direction;
Fig. 3 shows another embodiment of the screen
material according to the invention;
Fig. 4 shows yet another embodiment o~ the screen
t~r; i~l according to the invention with zigzag wires and
3 o linear wires;
Fig. 5 shows yet another embodiment o~ the screen
material according to the invention with rectangular holes;
Figs. 6 a-e show examples of wire cross-sections;
Fig. 7 shows a diagrammatic view of adjacent,
35 contacting wire sections with round cross-section which are
welded to each other;
Fig. 8 shows a section of Fig. 7 along the line
VIII-VIII;
Fig. 9 shows screen material according to the
A~liENDED SffEEr

~ 528
- 9a -
invention, obtained by formin~ the holes o~ the welded
AMENDED SHEET

WO 95/17306 ~ 1 7 ~ 5 2 8 PCrlNI~ 0315
-- 10 --
material according to Fig. 7;
Fig. lo shows a diagrammatic view of wire s~innc
with oval cross-section which have been welded to each
other locally;
Fig. ll shows a section of Fig. 10 along the line
XI-XI;
Fig. 12 shows screen material according to the
invention which has been obtained by forming the holes of
the welded material according to Fig. 10;
Fig . 13 shows an ~ ' i L of screen material
according to the invention with crossing wires;
Fig. 14 shows a section of Fig. 13 along the line
XIV--XIV;
Fig. 15 shows a section of Fig. 13 along the line
XV-XV;
Fig. 16 shows a diagrammatic view of a device ~or
producing a ~in~lcsirlAl wir~;
Fig. 17 shows a diagrammatic view of a device for
winding wire around a roller and joining adjacent wires
locally;
Fig. 18 shows a diagr~mmatic view of the winding of
A plurality of wires;
Fig. l9a shows a diagrammatic view of a
continuously operating device for the pro~ t;nn of screen
material according to the invention prior to the formation
of the holes;
Fig. l9b shows a section of the bearing arm with
wound and welded cylindrical material;
Fig. l9c shows a section of another ~nho~; ~ of
the bearing arm from Fig. l9a;
Fig. 20 shows a diagrammatic view of a device for
f orming screen holes; and
Fig. 21 shows a diagrammatic view of a continuously
operating device for the prsr~ t;nn of flat screen material
according to the invention prior to the formation of the
holes .
Fig. 1 shows a first: ' '; of a screen
material accordihg to the inventiorl made o~- iron wire, with
wire pieces 1 and junction points 2. A wire section 3 is

-
W0 95117306 2 1 7 ~ ~ ~ 8 ~ = PCTJN194~00315
indicated by hatching. In the case of this . i ~ of
the screen material, wire sections 3 comprising several
wire pieces 1 are ~oined lto each other by welding at
junction points 2 . This - ; L can be ,uL u~ ced by
5 placing linear wire sections 3 next to one another, then
joining them point-wise in a suitable manner, for example
by laser welding, and subjecting the material thus formed
to a tensile force e6sentially at right angle6 to the wire
secttonc, in order to form the 6creen hole6 4. Wire
10 8~rt 1 nn-: 3 which have been provided bef orehand with a
zigzag 6hape can al60 be welded to each other at the tip6,
with the re6ult that the Eormation of the holes i6 not
n~ c_", y,
Fig. 2 6how6 the ~aterial according to Fig. l with
15 the ~ormation of the hole6 being cnnti n-1~d through drawing
in the horizontal direction in the figure, 60 that the
screen holes 4 have become lozc.-y_ shaped.
Fig. 3 6how6 an: `i L of the 6creen material
according to the invention in which the wire section6 5 are
20 cim--niAAl and are made oE wire pieces 6 which bound screen
hole8 7. The ~in---oi~l wire sections 5 are joined to each
other at the tips at 8.
Fig . 4 show6 anotl~er ~ho~l i L of the 6creen
material according to the invention, comprising wire
25 6~rtinn~ 9 and lO with respective wire piQces ll and 12.
~he wire s~r~innc g are linear, and the wire ~ectinnC lO
are ~inll~oirlAl~ It will be clear that thi6: ~i-
cannot be ~Ludu~-:d by placing wire 6~ctionc next to each
other, joining them point-wi6e, and then forming the screen
30 hole6, but that the wire 6ectinnC lO must be provided with
the aLu~c inn~l sinusoidal shape prior to being joined
to the wire 6ections ll.
Fig. 5 shows an ~ i t ~:ULL~ in~ to Fig. 1
with wire s~-rti onC 14, which comprise two types of wire
35 pieces 15 and 16 respectively of differing lengths which
bound rDrtAn~lAr screen 11oles 17. This ~ho~i- L can be
obtained by laying wire sections next to one another and
joinir~s them point-wise in ~ suitable patter1~.
In the light of t1le above, it will be clear that

WO 95tl7306 PCr/N~94/00315
2~ 9528 `
-- 12 --
the shape and rli- -ion~: of the screen holes can be varied
in a very wide variety of ways through selection of the
wire thirknQr~, the wire material, the position of the
junction points, the aperture of the screen holes etc.
The wire shape used in the screen material
~ccording to the invention is not very restricted. Figs.
6a-e show a round, square, triangular, rectangular and oval
wire ~.v~ 3e:_Lion, all of which are suitable for use in
the invention. The triangular and oval :LV~ s~_LiOns are
preferable, the latter being mo6t preferable. Use of a
triangular wire .;Lvs~ Lion will produce a screen with an
approximately conical hole shape at one side, which during
use of the screen easily releases material to be screened
and does not become blocked when material is ~-lrPl i ~d to
the flat side, r ' hin~ which is also an a~vc.nLaye during
use for screen printing. Use of an oval vLvcia s~ction
~. vduC:t~6 a screen material which is very similar to the
screen materials obtained by electroplating and d i ~r~ ^d
in the introductory section of the description, which
screen materials have particularly good printing
properties .
Fig . 7 shows metal wire s~rti ~ n~ 18 placed next to
one another and having weld points 19, a section of which
is shown along the line VIII-VIII in Fig. 8. If the
25 inteL~ vl.e.;Led wire sections 18 from Fig. 7 are deformed in
the direction indicated by the arrows, the ~LL~-~LuLæ
indicated diagrammatically in Fig. 9 i8 obtained, with
screen holes 20. It will be clear that the shape of the
holes can be suitably varied, as was ~ ~r~ o~ earlier.
Fig. 10 shows diagrammatically wire sections 21
situated adjacent to each other and i~lLeL r l ~d over
~ome length at 2 2 .
Fig. 11 shows a sectional view along the line XI-XI
in Fig. 10, in which it can be seen clearly that the wire
s~c~rnP~ have an oval ~;Lv:i8 G~_Lion.
Pig. 12 shows a preferred ~mho~li L of screen
material according to the invention, which is obtained by
subjecting the wire material according to Fig. lo to a
tensile force in the direction of the arrows, so that the

WO 95~17306 2 1 ~ 8 PCTIN194100315
-- 13 --
screen holes are formed. These hc~Y~rlnAl screen holes, in
particular in combination with an oval wire L:L~I5s-s~_Lion,
have very advantageous characteristics for screen printing,
since hf-Y~ l holes approach the traditional shape of
5 screen printing stencils, ~md optimum distribution of
screen holes is also obtained over the surface, with
additional strength compared with differently shaped holes.
The wire pieces 21' are joined to each other over a
short length by weld points. It will be clear that a
lO smaller number of weld points situated further apart or a
continuous weld can also be used. A wire piece 21'
comprises a wire section going out from the centre of a
weld to the centre of an adjoining weld in the same wire
section 21. If the h~YA~-~n~l ~Lru~ LuLe from Fig. 12 is
15 stretched (opened) further, an ~ccDnti ~lly r~-rt~ng~ r hole
shape will be obtained, the holes being arranged in a
staggered manner (brickwork ~LL.~.LULe).
For the joining of metal wires, a soldering medium
such as tin, lead, lead-tin, brass, silver or the like can
20 also be fed in during the welding, with or without a flux.
Of course, a . 0LL~ in~ t~ hniql-~ can also be used for
joining wires made of other materials.
Fig . 13 shows another ` ' i ~ of screen material
according to the invention, showing two groups of wire
25 seoti nnc 24 and 25 which are joined to each other at the
crossing points through fusion and/or merging, through
which screen holes 26 are formed.
Figs . 14 and 15 show the s~ n~ l view along the
line XIV-XIV and the line XV-XV. As i8 clear, a screen
30 material with an erE^-ti~l ly flat screen surface is also
obtained in the case of this ~ L.
The joining of such crossing wires can be carried
out by te~~hniq~ which are known to those skilled in the
art. For eYample, the wires can merge with each other at
35 the crossing points through welding or the like, or through
the application of PLe~UL;' locally at raised ' ~LUL~
or otherwise, i . e. by setting up the groups of wire
SëCtiOnS 24 and 25 so that they cross each cther and then
e~sing them between heated or unheated ~LeS~uLè plates
_ _ _ _: _ _ _ _ _ _ _

WO 95/17306 PCrlr;194100315
z~952a
or the like. A lauartz lamp can also be used for forming
connections at the crossing points through fusion and/or
merging .
ThQ material of the wire used for the screen
5 material according to the invention is not very limited,
but in particular f or the production of screen printing
material it is preferable to use metal wire, since the
latter i8 easily joined locally by welding by means of, for
example, a laser, and any curves made in advance in metal
10 wire are tli io~Al ly stable. Examples of suitable metals
are: iron, steel, copper, nickel, ~1~ ill~ etc.
In the i- L shown in Fig. 13 it is preferable
for at least one of the groups to be made of plastic, so
that the _ is simplified through merging at the
15 position of the crossing points.
The screen material according to the invention can
be subjected to additional coating steps after its
pro~lrtin~, for example in order to strengthen it. For
instance, after its surface has been made rl nAIlr~inq if
20 desired, in the case of plastic wire, the screen material
can be plated with a suitable metal in a known manner.
After prof'~llrtinn and before possible lli7ation~
the material can also be subjected to a flattening
operation, in order to remove uneven points. Examples are
2 S planing, pol i s:h i n g ~ gauging etc .
Fig. 16 shows diagrammatically a device with two
gear wheels 27 and 28, between which a wire 29 is conveyed
by way of guide rollers 30 and 31. A zigzag-shaped wire is
nh~:~inc-d by driving the ab-.. inn~S gear wheels 27, 28
in the direction indicated. If the wire is a metal wire, it
may if desired be subjected to a heat LL~S!i; ' after the
deformation operation, in order to give the wire
inn~l gtability, as a result of the hardening
properties of the chosen material.
Fig. 17 shows diagrammatically a device for the
production of screen material according to the invention,
in which a wire 33 is wound around a roller 32. The roller
is rotate~ in the direction of th~ arrow, and the wire ~3
is drawn off a reel 34. During the windins, the reel 34 can
.

WO 9S/l7306 Z~ ~ 7 9 ;r~ 2 8 ; PC1~194l00315
-- 15 --
be moved parallel to the roller 32 in the direction of
winding. Reference number 35 indicates a moving laser
device which locally welds the wire 33 wound around the
roller 32. The laser device advantageously comprises
positioning means which can comprise a tracer for
dQt~ormininr~ the mutual position of the weld points in
relation to the wire sections, on the basis of which the
position of the laser can be set by means of suitable laser
~. L means. After the roller 32 has been provided with
wire 33 over its full length and local welding has been
carried out, the material thus ~lodu~ ed is removed from the
roller 32 and subjected to a tensile force in the
lengthwise direction, as a result of which the length of
the cylinder increases, the diameter decreases, and the
screen holes are formed. It will be clear that the
r~ rti nn in diameter or the increase in length of the
screen cylinder and the hole shape and hole size depend on
the mutual position and rli -ionc of the junctions, the
wire diameter and the degree of deformation.
If the wire 33 is conveyed through the device of
Fig. 16 prior to winding, the final material need not be
subjected to a deformation treatment. The mutual
positioning of the tips o E the already wound wire relative
to the wire yet to be wound can be regulated by regulating
the wire tension in a suitable manner in the inlet during
winding .
Fig. 18 shows the same roller 32, winding here
taking place simultaneously with a plurality of wires 33,
of the same or different type and shape, as a result of
which the surface of the ~oller can be covered with wire
more quickly at the same speed of rotation. During winding
involving a plurality of wires in this way, the winding
pitch will increase for each individual wire.
The result of this is that when the screen holes
are formed in the screen material removed from the roller
32 after welding, by a tensile force in the lengthwise
direction, the material will have an inherent twist. This
mean~ that during drawing at thP ends o~ th~ screen
cylinder, at least one of the attachment ~ - Ls must be

Wo 95117306 ~ ~ PCT/NL941003l5
~79~28`
-- 16 --
set up in a rotatable manner.
Fig. l9a shows diagrammatically a device for the
continuous production of screen material according to the
invention. It contains a reel 34 from which wire 33 i5
unreeled. Although one reel is shown, it is, of course,
po~sihle, aS ~1iFC~lcc~ earlier, for a plurality of wires to
be wound simultaneously.
Reference number 35 shows a drive - -niF- of a
mandrel 36, onto which the wire 33 is wound. The wire 33 i8
guided through a wire feed control unit 37 to the mandrel
36. The wire 33 is guided between a stationary stop 38 and
the already wound material, with the result that during the
winding the already wound material is forced to the left in
the f igure . During the abovementioned . . , the wire is
welded locally by means of a laser 40 set up in a fixed
position. Many types of lasers are suitable for this
purpose . DPrPn~l ~ ng on the wire pitch, the winding speed,
the type of weld and the weld pattern, the laser can
operate continuously or intermittently.
The mandrel 36 used is preferably illL-:L ~ J-~ble,
~o that cylinders 39 of different diameters, with the same
number of standard ~ L (pattern repeat
) and UL-Ji~ cLion shape6, can be ~L~-Iuced.
Different .:Lo~ e_Lion 6hapes should be u..~e~Lood as
25 meaning oval, triangular, square etc. croSs-sectinnc.
Reference number 41 indicates a movable trestle,
which by means of a bearing arm 42 serves to support the
material 39 moving from the roller 36.
The bearing arm 42 of the trestle 41 is preferably
30 in the form of a freely rotating roller, and more
preferably the beariny arm is ~ n~d in such a way that
it has several freely rotatable rollers ~iRr~5~-1 around the
inner periphery of the cylinder ~Lcduced, so that the
cylinder material ~L~,-luced can be supported at several
35 points. Fig. l9b shows a section of the bearing arm 42 from
Fig. l9a with cylindrical material 39 which has been
produced. Fig. l9c 6hows a preferred _ ir L of the
b~aring arm 42 in section, which has four supporting
rollers 44 for supporting the material 39. The mutual

W0 95ll7306 PCrlr~194~00315
~ ~9;~2~
-- 17 --
position of the rollers advantageously is adjustable.
With the device Acrnr~l;n~ to the invention the
pitch can be regulated by, for example, placing a ring-
shaped stop with an oval ~:L~JSS section at a suitable angle
5 around the mandrel.
Reference number 43 indicates diagrammatically a
cutting device which also moves along and serves to cut off
a certain length of material after it has formed. After
cutting, said cylindrical material can be moved by mean& of
10 the trestle 41. Thereafter, the arm of another trestle can
be placed in the material 39 moving off the roller 36. ~he
supporting arm 42 on the trestle 41 can be suitably
adjusted in height, for e~ample by means of a screw spindle
45 or the like.
Lengths of the cylindrical material to be obtained
can also be separated from each other in another way. For
ex~mple, if the laser is i~ LLU~Led for some time after a
certain period of operation of the device, a number of
windings of wire are not welded. This number can be
20 sala~to~ in such a way that at a suitable moment the
cylindrical material already ~-.,duced can be removed from
the mandrel, in which case the wound wire material not
welded is drawn as a coil and can be severed. The advantage
of this is that only one wire need be cut through, as
25 against the _ l eta severing of a cylinder.
Fig. 20 shows diagrammatically a device for forming
screen holes, comprising a forcing device 46 as a screen-
hole-opening element. With this device 46 the material 39
in which screen holes are not yet formed is forced, as
30 shown diayL tically at 47, in the direction of the
arrow, as a result of which the screen holes are formed in
the material 39, as indicated at 48. It will be clear that
the drawing section (not shown) by means of which the
material 39 is moved through the forcing device or the
35 forcing device itself must be set up in a rotatable manner,
since a certain degree of rotation, ~laran~lin~ on the method
of winding the wire (or wires), will occur during the
formation of the screen hol~. It may be advanL~yc:ous
during the formation of the holes by means of the forcing

Wo 95/17306 PCr/NL94/00315
21795~8
-- 18 --
device 4 6 to set up a support element in the product, in
order to be able to carry out this operation in a
L C.~L ~,ducible manner .
If in a prnA~rtinn process large numbers of wire
5 cylinders whose holes haYe not yet been formed are being
produced, in successive wire cylinders the 5creen holes can
be formed to a gradually increasing extent, which means
that successively cylinders with slightly decreasing
t~L are produced and can be pushed into one another.
10 The ~Lcl]lD~uL ~ILion and storage thereof is thus greatly
simplified. The screen holes in the desired final form can
then be made in these cylinders at a desired time. The same
applies for wire material wound in the lengthwise direction
of a roller, where the rli ~ L increases and the length
15 de~:L ?_-- during formation of the screen holes.
In the case of cylindrical screen material the wire
can also be wound in the lengthwise direction of a roller,
in which case projections, for example, such as pins, can
be present around the periphery at the ends of the roller,
2 0 so that the wire can be wound to and f ro in the lengthwise
direction. For winding in the lengthwise direction, the
wire can also be wound so as to cross over the end f aces of
the roller. When such a cylinder made of wire material is
welded locally, during formation of the screen holes a
Z5 di~meter increase and a length reduction of the cylinder
will be the result, contrasting with what has been
described above. For this operation it is pnc:cihl~ to u5e,
for example, an ~y~An~lAhl~ core, or the wound wire material
can be moved in the oppo6ite direction over the f orcing
30 device 46 from Fig. 20, in order to form the screen holes.
For the production of the: i- L of the screen
material according to Fig. 13 in cylindrical form, a wire
can be wound at such a pitch in one direction around a
support, as shown, for example, in Fig. 17 ar 18, that wire
35 8~ctinn~ pn~l~rl at a distance from each other are
nht;~in~ following which the same wire may if desired be
wound over the f irst group of wire sections in the opposite
direction with UULL ~ lin~ d~sired pitch. Furthermore,
several groups of wires can be wound, following which the
_ _ _ _ _ _ . _

W0 9S/17306 ` ' ;` pCl~g410031S
-- 19 --
wires are joined to each other at the crossing points by
means of suitable techniques known to those skilled ln the
art, such as welding or pressing at elevated t~ elLUL~
through fusion and/or merging.
By means of the method described above, screen
material according to the invention can be pL u~luuc:~l with a
very wide range of numbers of holes per linear cm and of
hole shapes, while f lat screens can also be produced in a
CuLL~ nq manner. These can be ~Lu~luc;Qd directly or by
cutting open cylinders according to the invention in the
lengthwise direction.
It is also pointed out that although essentially
symmetrical screen materials are described above, the
invention is not limited thereto, since any desired
deformed wires can be joined to each other in any desired
way, 80 that flat screen material is obtained with any
desired shape of holeg and any degired tl1 -ion~, which
can be a~lv~-lL~g~uu~ ror certain applications. The so-called
moiré efrects in particular are au~.ess~d in this case.
Screen material can also be ~Lu~lucea in flat form by
laying wire sections which may consist of one and the same
wire next to each other on a flat support, then joining
them locally, and s~ ntly forming the screen holes.
Finally fig. 21 shows a diagrammatic view of a
continuously operating device for the production of flat
screen material according to the invention, prior to the
formation of the holes. Said device comprises at least two
rotatable support wheelS 50, 51 with a common axis 52 and
radially extending projections designed as pins 53. These
pins 53 arQ shown in an enlarged view A in fig. 21.
The wheels support endless belts 55 and 56 provided
with op~nin.'JS 57 into which the pins 53 fit. It will be
clear that the belts are endless belts and guided over an
additional pair of driving wheels (not shown), also
comprising pins or the like.
A guide bar 58 is present forming the reciprocating
means to guide a wire 60 from wheel 51 to wheel 50 and
back, around the respective pinc 53. Thus, a 2ig-zag
- L of the wire is provided. The driving means of said

WO 95/17306 PCr/NL94/00315
2179528
-- 20 --
guide pin are not shown for clarity reasons.
The wire 60 is unreeled from a reel 61 provided
with a slip-coupling 62 to provide the necessary wire
tension .
65 schematically shows a laser welding device which
is moveable along a slit 66 ln guide means 67. In the la6er
welding device a laser beam 68 i8 passed through a
focussing optic 6g and impacts on the zig-zag wire material
at a focal point 70. Very close to said focal point 70 a
10 wedge 71 is present, which is 6hown in the enlarged cross-
section B. Said wedge 71 can be moved in the direction of
the arrow 72 to move the wire section 73 against the wire
material 74 already locally welded in the direction of
arrow 78. Said wedge 71 is provided with drive means (not
15 shown) to follow the ~c L of the focal point of the
laser welding device, assuring that at the focal point the
wires are positioned against each other for accurate
welding .
The wire material 75 being locally welded is
20 supported by the driving belts 55 and 56 and further by an
additional ~U~ 2rVL belt 76 driven by a drive roller 77 and
another CV1L 1~.,...1;nq drive roller, not shown.
Por the purpose of clarity only the i LallL
details are shown in fig. 21 and of course many
modifications can be made.
The drive belts 55 and 56 do not only drive the
wheels 50 and 51, and support the wire material 75, but
also assure that the welded wire material 75 is removed
from the pins 53.
Preferably mean6 are present between the guide bar
and the reel 61 to te for differences in length of
the wire 60 fed to the pins of the wheels, due to the
reciprocating ~ L of the guide bar 58. This can be
achieved by moving the reel 61 together with the guide bar
58, or by spring loaded wheels or the like.
After mal-u~a-LuL.: of the wire material 75 the
screen holes can be opened by suitable deformation of the
material as ~iiccllcserl with reference to earlier figures.

Dessin représentatif