EP2304104B1 - Method for producing a pattern on an endless belt - Google Patents

Abstract

The invention relates to a method for producing a topographical pattern from polymer material on an endless strip with a longitudinal direction and a transverse direction extending perpendicularly thereto, in which method a cylindrical rotary screen is used to apply the polymer material by the screen printing process to a circumferential side of the endless strip to be printed, wherein, when producing the pattern, the rotary screen, rotating repeatedly about its longitudinal axis, rolls on the circumferential side of the endless strip, whereby the pattern is applied to the circumferential side in at least one path running at least once uninterruptedly around the circumferential side in such a way that the beginning and the end of each revolution of the path are arranged along a common straight line, wherein, when rolling, the rotary screen performs N revolutions about its longitudinal axis during each revolution of the path on the circumferential side of the endless strip and N is a positive integer.

Description

The invention relates to a method for producing a topographic pattern of polymeric material on an endless belt.

In particular, for the production of tissue paper screens are used with decorative topographic patterns. As a result, tissue paper is produced, in which the topographic pattern of the sieve is imprinted.

In the prior art, various ways are known to apply the topographical pattern on an endless belt. For example, the topographical pattern is conceivable! a screen printing process or by means of extrusion nozzles.

Today's paper machine clothing often has widths of 10 meters or more. Printing screens are usually a maximum of one meter wide. Thus, the printing screens used in screen printing usually extend over only a portion of the width of the endless belt, which is why the topographic pattern in the known clothing usually from several juxtaposed web-like pattern sections is formed. The problem here is that the elements of juxtaposed pattern sections often have a strong offset relative to each other. This offset of the pattern elements of the individual pattern sections damages the visual impression of the tissue paper produced on such paper machine clothing.

The publication EP 1 690 981 A1 shows a method for producing a topographic pattern on or in a papermachine fabric, in which by means of a rotary screen, a topographic polymer pattern is generated. The rotary screen extends only over a partial width of a support structure of the cover and is moved relative to the topographical polymer pattern on the support structure relative to it so that the topographical polymer pattern is formed with respect to the width of the support structure by a plurality of juxtaposed topographic pattern sections which are at least in the plane of the support structure have an offset of 0.1 mm or less.

From the US 4,300,982 A Further, there is known a press felt for use in a paper machine having a raised pattern of substantially incompressible islands which provides at the back of the felt a storage volume for free drainage of water which has been squeezed out of the felt by press rolls.

It is the object of the present invention to propose a method for producing a topographical pattern of polymer material on an endless belt, in which the pattern elements of juxtaposed pattern sections have almost no or no offset to each other.

The object is achieved by the following method for producing a topographical pattern of polymer material on an endless belt:

An endless belt with a peripheral side to be printed is provided. The endless belt has a longitudinal direction and a perpendicularly extending transverse direction.

The method uses a rotary screen whose cylindrical surface has a perforation pattern defining the topographical pattern. The perforation pattern is viewed in the circumferential direction of the lateral surface, formed by a Perforationsmusterabschnitt or by several successive, mutually identical Perforationsmusterabschnitte.

To produce the topographical pattern on a peripheral side of the endless belt, the polymer material is pressed in the liquid or pasty state through perforations of the peripheral surface of the rotary screen, while the rotary screen, rotating several times about its longitudinal axis, with its lateral surface on the peripheral side of the endless belt in at least one at least once unrolled on the peripheral side of the endless belt continuously circulating path. A circulating path here has one or more circulations, each circulation has a beginning and an end.

The invention is characterized in that, for each orbit of the rotary screen on the peripheral surface of the endless belt, the beginning and the end of the respective web circulation are arranged along a common line and the rotary screen during unrolling during each orbit of the circumference of the endless belt N / M revolutions about its longitudinal axis, where N and M are each a positive integer, and where M indicates the number of perforation pattern sections, which are arranged in the circumferential direction of the lateral surface of the rotary screen one behind the other.

The set of positive integers here corresponds to the number set {1, 2, 3, 4, ...} in the mathematical sense.

The solution according to the invention ensures that the rotary screen performs N / M revolutions about its longitudinal axis during each web revolution on the circumferential side of the endless belt, M indicating the number of perforation pattern sections which are arranged one behind the other in the circumferential direction of the lateral surface of the rotary screen.

Since, when rolling the rotary screen on the peripheral side of the endless belt every time a perforation pattern section of the peripheral surface of the rotary screen completely rolls on the endless belt, a portion of the topographic pattern (hereinafter called "topographic pattern section") is formed on the peripheral side of the endless belt the solution according to the invention achieves that an integral multiple of consecutively arranged and mutually identical topographical pattern sections is produced on each peripheral web of the endless belt on each completed web circulation of the rotary screen.

Due to the fact that the beginning and the end of this orbit are arranged along a common straight line for each considered orbit, it is achieved that the end of the topographical pattern section last formed in the course of the orbital circulation in the direction of the circulation of the web after each orbit without offset at the beginning of the This topographical pattern is first followed by a topographic pattern section. The term "without offset" is to be understood here as meaning that, viewed in the direction of the circulation of the web, the end of the last formed topographical pattern section of a web circulation adjoins without any distance the top of the topographic pattern section first formed during this circulation of the web or that of the web circulation in question last formed topographical pattern section adjoins the first formed in this orbit topographic pattern section without overlapping it.

The solution according to the invention thus makes it possible to apply a topographical pattern without offset of the pattern elements forming the pattern on the endless belt.

Advantageous embodiments and further developments of the invention are specified in the subclaims.

It is conceivable that for different orbits at least two of the respective beginnings and ends defining straight lines offset from each other, in particular offset parallel to each other, run. Specifically, this may mean, for example, that for a first circulation the beginning and the end of the first circulation are arranged along a first straight line, with the beginning and the end of the second circulation passing along a second straight for a second circulation is arranged and wherein the first straight example. Parallel offset to the 2nd straight line.

It is conceivable according to a particularly preferred embodiment of the invention that the beginnings and the ends of all circulations are arranged along a common straight line.

It is conceivable that the endless belt is made endless by means of a connecting seam. The endless band can be flat or endlessly woven. For example, if the endless belt is flat-woven, it may be made endless by a woven seam joint, for example.

Preferably, the endless belt with the topographical pattern is used as a paper machine clothing, in particular in the production of tissue paper, use.

There is further provided an endless belt, in particular a covering for a paper, board or tissue machine, which is produced by the method according to the invention.

The endless belt provided with the topographical pattern can be used here in particular as a DSP screen or as a TAD screen. The topographical pattern here preferably represents a decorative pattern by means of which a decorative pattern in the fibrous web is produced in the production and / or treatment of a fibrous web, in particular tissue web. As a result, the peripheral side to be printed may be the paper side of the endless belt.

If a wear volume is to be provided on the machine side of the endless belt by the topographical pattern, then the peripheral side to be printed may also be the machine side of the endless belt.

Preferably, the rotary screen is designed as a circular cylinder, in particular as a straight circular cylinder and extends in its length preferably only over a part of the width of the endless belt. The length of the rotary screen can, for example, between 0.2 and 3 meters, in particular between 0.3 and 1 meter; for example, be 0.5 meters.

Depending on how the rotary screen rolls on the peripheral side of the endless belt, different possibilities are conceivable, such as the beginning and the end of each web circulation can be arranged.

A first possibility provides that the common straight line, along which the beginnings and the ends of all web circulations are arranged, runs in the transverse direction of the endless belt. In this case, therefore, viewed in the longitudinal direction of the endless belt, the beginning and the end of each web circulation are always arranged at the same position.

This can be achieved, for example, by aligning the longitudinal axis of the rotary screen perpendicular to the longitudinal direction of the endless belt when the rotary screen rolls on the peripheral side.

Furthermore, it is particularly possible that the rotary screen in an uninterrupted helical path, in particular over the entire width of the endless belt to be printed rolls on the peripheral side and the rotary screen is moved when rolling on the peripheral side in the transverse direction of the endless belt, that the adjacent Loop orbits of the helical path complement the topographical pattern.

The helical path in this case is thus produced by moving the rotary screen in the transverse direction of the endless belt when the pattern is generated while rotating about its longitudinal axis aligned perpendicular to the longitudinal direction of the endless belt. The movement of the rotary screen in the transverse direction of the endless belt thus takes place here without a directed in the transverse direction of the endless belt rotary component.

In this case, it is particularly possible that the beginnings and the ends of all web circulations are arranged on a common, extending in the transverse direction of the endless belt straight lines, wherein viewed for each orbit whose beginning and end are offset by the width of the web to each other.

According to a further embodiment of the invention, it is conceivable that the rotary screen is unrolled in a plurality of juxtaposed webs on the peripheral side of the endless belt, each web on the peripheral side to be printed only makes a web circulation and the rotary screen between the application of two juxtaposed webs in the direction the width of the endless belt, in particular by the web width, is moved.

Also in this case, the rotary screen rotates about its longitudinal axis oriented perpendicular to the longitudinal direction of the endless belt, in which case movement in the transverse direction occurs only when the rotary screen has created a closed path and is brought into a position for producing an adjacent track got to.

In this embodiment of the invention, it is conceivable that the beginnings and the ends of all web circulations are arranged along a common straight line, wherein considered for each orbit whose start and end in the transverse direction of the endless belt are not offset from one another. Alternatively, it is conceivable that for different orbits at least two of the respective beginnings and ends extending and extending in particular in the transverse direction of the endless belt extending parallel lines with each other, for each orbit considered its beginning and end in the transverse direction of the endless belt are not offset from one another ,

Another possibility provides that the common straight line, along which the beginnings and the ends of all web circulations are arranged, encloses an angle of greater than 0 ° and less than 90 ° with the transverse direction of the endless belt. In this case, the beginnings and the ends of all web circulations are arranged on a common straight line extending obliquely to the transverse direction of the endless belt.

Also in this case, it is possible that the rotary screen rolls in an uninterrupted helical path, in particular over the entire width of the endless belt to be printed, on the peripheral side and the rotary screen is moved when rolling on the peripheral side in the transverse direction of the endless belt, that the adjacent trajectories of the helical path to the topographic pattern complement.

This can be achieved, for example, by the fact that the longitudinal axis of the rotary screen when rolling the rotary screen on the peripheral side is not aligned parallel, but obliquely to the transverse direction of the endless belt. This means that the rotary screen rotates when rolling on the peripheral side about its obliquely oriented to the transverse direction of the endless belt longitudinal axis.

In this case, therefore, the beginnings and the ends of all circulations are on one arranged common line, wherein viewed for each orbit, each whose beginning and end are offset by the width of the web to each other. The common straight line encloses an angle of greater than 0 ° and less than 90 ° with the transverse direction of the endless belt.

In the embodiments mentioned above, adjacent web circulations are preferably arranged in abutment with one another. This causes the adjacent orbits to complement the topographical pattern.

According to a specific embodiment of the invention, it is provided that the lateral surface of the cylindrical rotary screen moves when rolling on the peripheral side at a circumferential speed and that the endless belt rotates with a parallel to its longitudinal oriented transport speed to at least two mutually spaced and parallel aligned rollers. Here, the peripheral speed and the transport speed are coordinated so that the rotary screen in each revolution on the peripheral side of the endless belt N / M makes turns about its longitudinal axis and N and M is a positive integer.

The coordination between peripheral speed and transport speed is preferably carried out taking into account the quotient of the length of a web circulation and the length of one of the mutually identical perforation pattern sections of the lateral surface of the circular cylindrical rotary screen.

1. a) Die Längsachse des Rotationssiebs ist senkrecht zur Längsrichtung des Endlosbandes ausgerichtet:
   • In diesem Fall sind, in Längsrichtung des Endlosbandes betrachtet, der Anfang und das Ende jedes Bahnumlaufs an derselben Position angeordnet. In diesem Fall kann die Abstimmung zwischen Umfangsgeschwindigkeit der Mantelfläche des Rotationssiebs und der Transportgeschwindigkeit des Endlosbandes unter Berücksichtigung des Quotienten aus dem Umfang des Endlosbandes und der Länge eines Perforationsmusterabschnitts in Umfangsrichtung der Mantelfläche des zylindrischen Rotationssiebs erfolgen.

If the rotary screen generates the topographical pattern in a helical path, then the following two cases can be distinguished, for example:

1. a) The longitudinal axis of the rotary screen is aligned perpendicular to the longitudinal direction of the endless belt:
   • In this case, as viewed in the longitudinal direction of the endless belt, the beginning and the end of each revolution of the web are located at the same position. In this case, the coordination between peripheral speed of the peripheral surface of the rotary screen and the transport speed of the endless belt taking into account the quotient of the circumference of the endless belt and the length of a Perforationsmusterabschnitts in the circumferential direction of the lateral surface of the cylindrical rotary screen.

• b) Die Längsachse des Rotationssiebs ist nicht senkrecht zur Längsrichtung des Endlosbandes ausgerichtet:
  • In diesem Fall sind, in Längsrichtung des Endlosbandes betrachtet, der Anfang und das Ende jedes Bahnumlaufs an unterschiedlichen Positionen angeordnet, und zwar abhängig davon an welcher Position sich das Rotationssieb in Querrichtung des Bandes betrachtet befindet. In diesem Fall kann die Abstimmung zwischen Umfangsgeschwindigkeit und Transportgeschwindigkeit, unter Einbeziehung des Umfangs des Endlosbandes, des Winkels den die Längsachse des Rotationssiebs und die Längsrichtung des Endlosbandes miteinander einschließen und der Länge eines Perforationsmusterabschnitts in Umfangsrichtung der Mantelfläche des zylindrischen Rotationssiebs erfolgen.

If the rotary screen produces the topographical pattern in a plurality of mutually juxtaposed webs, the coordination between the peripheral speed and the transport speed takes into account the circumference of the endless belt and the length of a perforation pattern section in the circumferential direction of the lateral surface of the cylindrical rotary screen.

• b) The longitudinal axis of the rotary screen is not aligned perpendicular to the longitudinal direction of the endless belt:
  • In this case, as viewed in the longitudinal direction of the endless belt, the beginning and the end of each web circulation are arranged at different positions, depending on which position the rotary screen is viewed in the transverse direction of the tape. In this case, the coordination between peripheral speed and transport speed, including the circumference of the endless belt, the angle which the longitudinal axis of the rotary screen and the longitudinal direction of the endless belt with each other and the length of a Perforationsmusterabschnitts in the circumferential direction of the lateral surface of the cylindrical rotary screen.

Preferably, the coordination between peripheral speed and transport speed is such that at a quotient of the length of a web circulation and the length of a Perforationsmusterabschnitts in the circumferential direction of the lateral surface of the cylindrical rotary screen, unlike a positive is integer, the peripheral speed and the transport speed are unequal. In this case, a difference between the peripheral speed and transport speed and a resulting relative movement at the moment of transfer of the polymer material from the rotary screen to the endless belt ensures that the rotary screen rotates about its longitudinal axis during unrolling during each web revolution on the circumferential side of the endless belt where N, M is a positive integer.

Specifically, this may mean that with a quotient with a decimal number less than 5, the peripheral speed is set smaller than the transport speed. Furthermore, this may mean that in the case of a quotient with a decimal number greater than 5, the peripheral speed is set greater than the transport speed.

Preferably, the rotary screen is disposed at a position where the endless belt is not guided around a roller. Furthermore, it is provided according to a specific embodiment of the invention that the rotary screen together with a counter-roller forms a gap through which the endless belt is passed for applying the polymer material.

In particular in order to ensure the lateral connection of web circulations arranged side by side in the transverse direction of the endless belt without displacement of the pattern elements, it makes sense if the perforation pattern of the rotary screen defining the topographical pattern is delimited by a single-end and another end-side end, viewed in the longitudinal direction of the rotary screen one-end end of the perforation pattern represents the continuation of the other end-side end of the perforation pattern. This aspect may also represent another aspect of the invention independent of the aspect of claim 1 and therefore does not necessarily have to be coupled with the aspect of claim 1.

As already stated, the endless belt can rotate around two mutually spaced, in particular parallel to each other arranged rollers at a transport speed. It is also conceivable that the rollers are mounted together with the rotary screen on a chair, wherein the rotary screen and the rollers are viewed in the machine direction of the stasis fixed to each other. Furthermore, it is conceivable for the rotary screen to be moved relative to the rolls in the cross-machine direction of the stiffening when the pattern is produced. When creating the pattern, the rotary screen may move continuously or stepwise in the cross machine direction of the chair.

Between the two spaced rollers, around which the endless belt revolves, rollers are preferably arranged, on which the endless belt is supported on at least one path between the two rollers.

In particular, the endless belt is supported on both paths, i. on the upper and lower tracks, between the rollers on the rollers. In this case, the endless belt comes into contact with the rollers on the upper path with its circumferential side opposite the peripheral side to be printed. Furthermore, the endless belt on the lower path with its printed peripheral side comes into contact with the rollers.

Since the rollers are each mounted rotatably about their Längsache the topographical pattern is spared on the lower route.

Preferably, the circumference of the endless belt is measured before the coordination between peripheral speed and transport speed.

According to a further embodiment of the invention can be provided that the endless belt, while it circulates around the rollers, is subjected to a heat treatment.

Furthermore, a preferred embodiment of the invention provides that the endless belt, while it revolves around the rollers, is under a tensile stress in its longitudinal direction. Preferably, this is the endless belt, during the heat treatment under a tensile stress, wherein the maximum tensile stress and maximum temperature during the heat treatment are lower than the maximum tensile stress and maximum temperature in a previous heat setting of the endless belt.

Typical values in this context are, for example, a max. Temperature during the heat treatment of approx. 160 ° C at a max. Tensile stress of approx. 1 kN / m, whereas in thermosetting the max. Temperature about 180 ° C and the max. Tensile stress is 1.5-2kN / m. The abovementioned values are particularly advantageous in the case of an endless belt designed as a spiral screen.

According to a further embodiment, the heat-setting endless belt, after it has been pulled with the maximum tensile stress in its longitudinal direction, can be pulled with a lower tensile stress than the maximum tensile stress. The lower tensile stress can be in this case, in particular in spiral screens, in the range of 0.5-1.0 kN / m.

If, for example, an endless belt designed as a woven fabric is used, then the maximum tensile stress during the heat treatment may increase up to 7 kN / m. Accordingly, a preferred embodiment of the invention provides that the endless belt in the heat treatment for curing the applied polymer material under a tensile stress in the range of 0.5-7.0 kN / m.

In order to be able to keep the endless belt at constant width while it is tensioned around the rollers, a preferred embodiment of the invention provides that the endless belt under tension in its longitudinal direction is held in its transverse direction at a predetermined width or a predetermined width range by suitable means becomes. Holding the Endless belt in its transverse direction is particularly useful in a trained as tissue endless belt with thread creases.

Preferably, the polymer material is applied in a liquid or pasty state by means of the rotary screen on the endless belt and then subjected to its solidification of a thermal and / or a chemical activation treatment.

The polymeric material is preferably silicone or polyurethane.

The polymeric material, when applied to the endless belt, preferably has a viscosity in the range of 20000-80000 cps, more preferably in the range of 50000-60000 cps.

The polymer material applied to the endless belt can, for example, be thermally and / or chemically activated for its solidification.

During its rotation around the two rollers, the endless belt is preferably guided past a radiation source for thermal and / or chemical activation of the polymer material.

It should be mentioned in this context that liquid or pasty silicone can be solidified by means of heat treatment, for example by means of IR radiation. Furthermore, liquid or pasty polyurethane can be solidified by chemical activation, for example by means of UV radiation.

Preferably, the radiation source in this case has to be printed or at least partially printed peripheral side of the endless belt. In addition, a planar counter element can be provided, which is arranged opposite the radiation source in such a way that the endless belt is guided through a space bounded by the radiation source and the counter element. in this connection has the peripheral side facing away from the peripheral side of the tape to be printed on the counter element, that is, the endless belt is passed between the radiation source and the flat counter element. This method has proven itself in practice, in particular in a trained as a spiral wire endless belt.

In this case, the counter element can cause the heat emitted by the radiation source to be trapped and uniformly distributed in the space and / or the radiation emitted by the radiation source to be reflected in the direction of the endless belt.

The counter-element may, for example, be made of a material which reflects radiation more than it absorbs. The planar counter-element may, for example, be formed as a textile or non-textile fabric. By way of example, a fabric is used as the textile fabric. By way of example, a film or a sheet metal is used as a non-textile fabric. The counter element may, for example, be white on its side facing the endless belt.

In order to achieve a uniform longitudinal expansion over the width of the endless belt, it is particularly useful if the endless belt is uniformly exposed to the radiation over its entire width. This is particularly useful when the endless belt is heated by the radiation.

In order to obtain an accurate statement about the circumference of the endless belt, it is particularly useful if the endless belt is subjected to a heat treatment before the measurement of its circumference, wherein the circumference of the endless belt is measured after the circumference has adjusted to a constant value. Preferably, the circumference is measured before the topographical pattern is applied to the endless belt. This is particularly useful when the endless belt for solidification of the polymer material is subjected to a heat treatment.

Typically, the circumference of the endless belt is greater than 10 meters, in particular greater than 30 meters. Furthermore, the circumference of the lateral surface of the cylindrical rotary screen is typically less than 1 meter.

The endless belt is preferably a fabric or a spiral wire (called "spiral link fabric" in English). Preferably, the endless belt is made of at least one of the materials PET, PPS, PCT, PCTA.

In order to improve the control of the application of the polymer material and consequent reduction of the offset of pattern elements in the transverse direction of the endless belt, a further preferred embodiment of the invention provides that, during patterning, the position of the endless belt in a direction parallel to the transverse direction of the endless belt relative to one stationary reference position is measured, wherein in a change in the position of the endless belt parallel to its transverse direction, the position of the rotary screen is changed parallel to the transverse direction of the endless belt.

If the rollers and the rotary screen are arranged on a common stiffening as described above, provision can be made in particular for the position of the endless belt in the cross-machine direction relative to the stiffener to be measured during the production of the pattern, wherein when the position of the endless belt changes compared to a desired position , the position of the rotary screen is changed in the cross-machine direction of the belt or in the transverse direction of the endless belt. In other words, this means that when the change in the position of the endless belt relative to a desired position, to compensate for the change in position of the endless belt, the position of the rotary screen is corrected accordingly.

Preferably, the value and the direction of change of the position of the rotary screen correspond to the value and direction of the position of the endless belt in the cross-machine direction of the belt or in the transverse direction of the endless belt has changed.

A specific embodiment of the invention provides that the position of the endless belt is determined by the position of one of its longitudinal edges.

To determine the position of the endless belt, for example, a light barrier can be used with which the position of one of the longitudinal edges of the endless belt is measured.

Figur 1

eine Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens in Seitenansicht,

Figur 2

die Vorrichtung der Figur 1 in Draufsicht,

Figur 3

eine erste Variante des erfindungsgemäßen Verfahrens,

Figur 4

eine zweite Variante des erfindungsgemäßen Verfahrens,

Figur 5

eine dritten Variante des erfindungsgemäßen Verfahrens,

Figur 6

eine vierte Variante des erfindungsgemäßen Verfahrens,

Figur 7

das erfindungsgemäße Prinzip schematisch.

The invention will be further elucidated on the basis of schematic drawings which are not to scale. Show it

FIG. 1

a device for carrying out the method according to the invention in side view,

FIG. 2

the device of FIG. 1 in plan view,

FIG. 3

a first variant of the method according to the invention,

FIG. 4

a second variant of the method according to the invention,

FIG. 5

a third variant of the method according to the invention,

FIG. 6

a fourth variant of the method according to the invention,

FIG. 7

the principle of the invention schematically.

The FIG. 1 shows a device 1 for carrying out the method according to the invention in side view. The FIG. 2 shows the device 1 of FIG. 1 in plan view.

An endless belt 2 designed as a spiral screen with a peripheral side 3 to be printed is guided around two rollers 4, 5 spaced apart from one another and oriented parallel to one another. The endless belt has a longitudinal direction MD and a vertically extending transverse direction CMD.

The apparatus 1 comprises a perforated cylindrical rotary screen 6, rotatable about its longitudinal axis 8, by means of which a polymer material 9 can be screen-printed on the circumferential side 3 of the endless belt 2 to be printed, whereby a topographical pattern is formed on the peripheral side 3.

When applied, the polymer material 9 is in a liquid or pasty state and may have a viscosity in the range of 20000-80000 cps, more preferably in the range of 50000-60000 cps.

In addition to the rotary screen 6, a counter-roller 7 is provided, which forms a gap together with the rotary screen 6, through which the endless belt 2 is passed for applying the polymer material 9.

In the present case, the rotary screen 6 is arranged at a position at which the endless belt 2 is not guided around one of the two rollers 4, 5.

The device 1 has, between the two spaced rollers 4, 5 around which the endless belt 2 revolves, rollers 10, 11 on which the endless belt 2 extends on both paths, i. supported on an upper path 12 and on a lower path 13 between the rollers 4, 5.

Here, the endless belt 2 comes on the upper path 12 with its side facing the circumferential side 3 to be printed on the peripheral side 14 with the rollers 10 in contact. Furthermore, the endless belt 2 comes on the lower path 13 with its at least partially printed peripheral side 3 with the rollers 11 in contact. The rollers 10, 11 are rotatable about their longitudinal axis.

The endless belt 2, while it revolves around the rollers 4, 5, subjected to a heat treatment. As a result of the heat treatment, the polymer material 9 applied to the endless belt 2, in the present case silicone, is thermally activated, as a result of which it solidifies.

For the heat treatment, the endless belt 2, as it passes around the two rollers 4, 5, is guided past a radiation source 17, which in the present case generates IR radiation and emits the radiation in the direction of the peripheral side 3.

In addition, a planar counter element 15 is provided, which is arranged opposite the radiation source 17 in such a way that the endless belt 2 is guided through a space 16 delimited by the radiation source 17 and the counter element 15. In this case, the circumferential side 14 pointing away from the circumferential side 3 of the band 2 to be printed faces the counter-element 15, which is designed as a white screen. The endless belt 2 is passed between the radiation source 17 and the screen 15.

The counter element 15 in the present case causes at least part of the heat generated by the radiation source 17 to be trapped and evenly distributed in the space 16 and / or at least part of the radiation emitted by the radiation source 17 to be reflected in the direction of the endless belt 2.

In order to achieve a uniform longitudinal expansion of the endless belt 2 on its width, it is particularly useful if the endless belt 2 is uniformly exposed to the radiation over its entire width. This is particularly useful when the endless belt is heated by the radiation.

When creating the pattern, the rotary screen 6, rotating several times about its longitudinal axis 8, rolls on the peripheral side 3 of the endless belt 2, whereby on the peripheral side 3 at least a part of the pattern in such a at least once on the peripheral side 3 continuously circulating path B such is applied, that the beginning A and the end E of each circulating track BU along a common line 18 are arranged (see Figures 3-5 ).

Here, the rotary screen 6 is moved either continuously or stepwise in the transverse direction CMD of the endless belt.

The device 1 furthermore has a light barrier 19, by means of which, during the generation of the pattern, the position of the endless belt 2 relative to a stationary reference position in a direction parallel to the transverse direction CMD of the endless belt 2 is measured. The reference position can be determined, for example, by a position in the cross-machine direction of the machine frame, not shown, on which the rollers 4, 5 and the holder of the rotary screen 6 are mounted. Both the light barrier 19 and the trajectory with which the rotary screen in the cross-machine direction of the chair or in the transverse direction of the endless belt 2 (Bem: the cross-machine direction of the chair and the transverse direction of the endless belt coincide here) are connected to a control device means 20. The control means causes a position change of the endless belt 2 parallel to its transverse direction CMD to change the position of the rotary screen 6 parallel to the transverse direction of the endless belt 2, wherein in the present case the value and the direction of change of the position of the rotary screen 6 in CMD is the value and corresponds to the direction that the position of the endless belt 2 has changed in the transverse direction CMD of the endless belt.

As from the representation of FIG. 2 can be seen, the position of the endless belt 2 is determined based on the position of one of its longitudinal edges 21 here.

In the in the Figures 2-6 shown representations, the peripheral side 3 of the endless belt 2 is only partially provided with the pattern. The areas with the pattern are dotted, with the dots representing the pattern.

The FIG. 7 shows the principle of the invention schematically. To recognize is on the upper straight line circulation Bu which extends from a beginning A to an end E. The middle straight line shows on the one hand the distance WR, which covers the rotary screen when it makes a revolution when it rolls on the peripheral side of the endless belt. On the other hand, the average straight line indicates the number N / M of revolutions made by the rotary screen 6 during unrolling on the peripheral side 3 of the endless belt 2 during a circulating track BU.

Since the lateral surface of the rotary screen viewed in the circumferential direction of the lateral surface is formed by M consecutively identical perforation pattern sections, where M is four in the present case, the rotary screen 6 according to the invention unrolled on the peripheral side 3, that this at each circulating track BU on the peripheral side 3 of Endless band N / M revolutions, here 9/4 = 2¼ revolutions, about its longitudinal axis 8, where N, M is a positive integer.

As a result of the solution according to the invention, the rotary screen 6 rolls a plurality of perforation pattern sections on the circumferential side of the endless belt during each circulating circulation BU on the peripheral side 3 of the endless belt 2. This ensures that at the end E of each web circulation BU a number of perforation pattern sections are unrolled on the peripheral side of the endless belt. Since the individual perforation pattern sections are identical to one another, they also form topographical pattern sections which are identical to one another. This ensures that the topographical pattern section at the beginning A of the web circulation BU without offset is followed by the identical topographic pattern section at the end E of the web circulation BU.

In the in the FIG. 7 In the example shown, the rotary screen 6 makes ¼ revolutions about its longitudinal axis 8 during a circulatory travel BU. This means that BU = N / M × WR, where N, M is a positive integer.

The lower straight in the FIG. 7 indicates the circumference UR of the lateral surface of the rotary screen. As can be seen, the circumference UR is greater than the distance WR which the rotary screen has to cover during one revolution of the rotary screen, so that the rotary screen rotates N / M times around its longitudinal axis in the case of a circulating track BU. The circumference of the lateral surface of the rotary screen is composed of the lengths LP1-LP4 of the mutually identical and in the circumferential direction successive Perforationsmusterabschnitte together. Consequently, the lengths LP1-LP4 are all the same.

• Die Mantelfläche des Rotationssiebs 6 dreht sich beim Abrollen des Rotationssiebs 6 auf der Umfangsseite 3 des Endlosbandes 2 mit einer Umfangsgeschwindigkeit Vu. Ferner läuft das Endlosband 2 mit einer parallel zu seiner Längsrichtung MD orientierten Transportgeschwindigkeit Vt um die zwei zueinander beabstandeten und parallel zueinander ausgerichteten Walzen 4, 5 um. Hierbei sind die Umfangsgeschwindigkeit Vu und die Transportgeschwindigkeit Vt so aufeinander abgestimmt, dass das Rotationssieb 6 bei jedem Bahnumlauf BU auf der Umfangsseite 3 des Endlosbandes N/M Umdrehungen um seine Längsachse 8 macht und N und M jeweils eine positive ganze Zahl ist.

To achieve this, for example, the following can be done:

• The lateral surface of the rotary screen 6 rotates when rolling the rotary screen 6 on the peripheral side 3 of the endless belt 2 with a peripheral speed Vu. Furthermore, the endless belt 2 runs with a transport speed Vt oriented parallel to its longitudinal direction MD around the two rollers 4, 5 spaced apart from one another and oriented parallel to one another. Here, the peripheral speed Vu and the transport speed Vt are coordinated so that the rotary screen 6 makes at each circulating track BU on the peripheral side 3 of the endless belt N / M revolutions about its longitudinal axis 8 and N and M are each a positive integer.

Taking into account the quotient of the length of a web circulation BU and the circumference UR of the lateral surface of the circular cylindrical rotary screen 6 and the number M of the identical perforation pattern sections arranged one behind the other in the circumferential direction of the lateral surface, the coordination between circumferential speed Vu and transport speed Vt takes place.

If, for example, the length of the circulating track BU is identical to the circumference of the endless belt, then the coordination between peripheral speed Vu and transport speed Vt takes place, taking into account the quotient of the circumference of the endless belt 2 and the circumference UR of the lateral surface and below Considering the number M of the circumferential direction of the lateral surface successively arranged identical perforation pattern sections of the circular cylindrical rotary screen. 6

The various possibilities of generating the pattern will be described in more detail below. It should be noted here that a circulating track BU, depending on the method used, can extend parallel to the longitudinal direction MD of the endless belt 2 or obliquely thereto.

The FIG. 3 shows a first variant of the method according to the invention.

When in the FIG. 3 illustrated variant, the rotary screen 6 rolls in an uninterrupted helical path B on the peripheral side 3 from. The web B is formed by a multiplicity of contiguous web circulations, of which the web circulations BU1 and BU2 are specified in greater detail in the present case. Each orbit revolution BU1, BU2 is limited in length by a start A and an end E. Thus, for example, the path of circulation BU1 is limited in its length by the start A1 and the end E1. As from the representation of FIG. 3 can be seen, the ends E1, E2 and the beginnings A1, A2 of all circulating trains BU1, BU2 on a common straight line 18 with the longitudinal direction MD of the endless belt 2 forms an angle α # 90 °. In this case, therefore, the beginnings A1, A2 and the ends E1, E2 all Bahnumläufe BU1, BU2 on a common obliquely to the longitudinal u. Transverse direction of the endless belt 2 extending common line 18 is arranged. The beginning A1, A2 and the end E1, E2 of each web circulation BU1, BU2 is in this case each offset by the width BB of the web B to each other.

When unwinding the rotary screen 6 on the peripheral side 3, this is displaced in the transverse direction CMD of the endless belt 2 in such a way that the adjacent web circulations BU1, BU2 of the helical path B complement the topographical pattern. In this case, adjacent web circulations BU1, BU2 are arranged in abutment with one another.

In the present case, the longitudinal axis 8 of the rotary screen 6 when rolling the rotary screen 6 on the peripheral side 3 is not parallel, but obliquely aligned with the transverse direction CMD of the endless belt 2. In the present case, the longitudinal axis 8 of the rotary screen 6 encloses the angle α with the longitudinal direction MD of the endless belt 2. This means that the rotary screen 6 when rolling on the peripheral side 3 about its obliquely to the longitudinal u. Transverse direction of the endless belt 2 oriented longitudinal axis 8 rotates.

In the in the FIG. 3 In the case shown, the beginning and end of each circulating belt BU are viewed at different positions in the longitudinal direction MD of the endless belt, ie, with each revolution of the endless belt 2 around the two rollers 4, 5, the position of the beginning A and B, viewed in the longitudinal direction MD of the endless belt the end E of the web circulation BU and indeed depending on where the rotary screen 6 is viewed in the transverse direction CMD of the endless belt 2.

When in the FIG. 3 shown variant, the coordination between peripheral speed Vu and transport speed Vt, taking into account the circumference of the endless belt 2, the angle α the longitudinal axis 8 of the rotary screen 6 and the longitudinal direction MD of the endless belt 2 together and the length of the circumferential direction of the lateral surface arranged in succession identical Perforation pattern sections of the circular cylindrical rotary screen 6.

The FIG. 4 shows a second variant of the method according to the invention.

When in the FIG. 4 illustrated variant, the rotary screen 6 rolls in an uninterrupted helical path B on the peripheral side 3 from. The web B is formed by a plurality of adjacent web circulations BU, of which the web circulations BU1 'and BU2' are specified. Each orbit revolution BU1 ', BU2' is defined in length by a start A and an end E limited. For example, the web circulation BU1 'is limited in its length by the beginning A1' and the end E1 '. As from the representation of FIG. 4 it can be seen, are the ends E1 ', E2' and the beginnings A1 ', A2' all orbits on a common straight line 18 'with the longitudinal direction MD of the endless belt 2 forms an angle α = 90 °. In this case, therefore, the beginnings A1 ', A2' and the ends E1 ', E2' all Bahnumläufe BU1 ', BU2' on a common parallel to the transverse direction CMD of the endless belt 2 extending straight line 18 'are arranged. The beginning A1 ', A2' and the end E1 ', E2' of each circulating track BU1 ', BU2' are in this case offset in the transverse direction CMD of the endless belt by the width BB of the track B offset from one another, ie, for example. of the web circulation BU1 'viewed in the transverse direction CMD of the endless belt 2 is arranged offset by the web width BB to the end E1 "of the web circulation BU1".

When unwinding the rotary screen 6 on the peripheral side 3, this is displaced in the transverse direction CMD of the endless belt 2 in such a way that the adjacent web circulations BU1 ', BU2' of the helical path B complement the topographical pattern. In this case, adjacent web circulations BU1 ', BU2' are arranged in abutment with one another.

In the present case, the longitudinal axis 8 of the rotary screen 6 is aligned parallel to the transverse direction CMD of the endless belt 2 during unwinding of the rotary screen 6 on the peripheral side 3. In the present case, consequently, the longitudinal axis 8 of the rotary screen 6 with the longitudinal direction MD of the endless belt 2 encloses the angle α = 90 °. This means that the rotary screen 6 rotates when rolling on the peripheral surface 3 about its parallel to the transverse direction CMD of the endless belt 2 oriented longitudinal axis 8.

In the in the FIG. 4 In the case shown, the beginning and end of each circulating track BU, viewed in the longitudinal direction MD of the endless belt, are always at the same point, ie, each revolution of the endless belt 2 about the two rollers 4, 5 also completes a circulating belt BU, irrespective of where the rotary screen 6 viewed in the transverse direction CMD of the endless belt 2 located.

The FIG. 5 shows a third variant of the method according to the invention.

When in the FIG. 5 illustrated variant, the rotary screen 6 rolls in a plurality of juxtaposed webs B on the peripheral side 3 of the endless belt 2, wherein each web B makes on the peripheral side to be printed 3 only a circulating track BU. In other words, each web circulation BU generates a web B. Furthermore, between the application of two webs BU1 ", BU2", BU3 "arranged next to one another in the transverse direction of the endless belt 2, the rotary screen 6 is displaced by the web width BB.

When in the FIG. 5 shown variant, the beginning A1 ", A2" and the end E1 ", E2" of each orbit circulation BU1 ", BU2" viewed in the transverse direction CMD of the endless belt 2 are not offset from one another.

As from the representation of FIG. 5 can be seen, are the ends E1 ", E2" and the beginnings A1 ", A2" all orbits on a common straight line 18 "which includes an angle α = 90 ° with the longitudinal direction MD of the endless belt 2. In this case, therefore Beginnings A1 ", A2" and the ends E1 ", E2" all orbits BU1 ", BU2" on a common parallel to the transverse direction CMD of the endless belt 2 extending common line 18 "arranged.

Between the generation of successive web circulations BU1 ", BU2", the rotary screen 6 on the peripheral side 3 is displaced in the transverse direction CMD of the endless belt 2 such that the adjacent web circulations BU1 ", BU2" complement the topographical pattern. In this case, adjacent web circulations BU1 ", BU2" are arranged in abutment with one another. During the generation of the web circulations BU1 ", BU2", the rotary screen 6 is not displaced in the transverse direction CMD of the endless belt 2. A movement of the rotary screen 6 in the transverse direction CMD thus takes place only when the rotary screen a closed Bahn BU1 ", BU2" has generated and must be brought into a position for the generation of an adjacent track.

In the present case, the longitudinal axis 8 of the rotary screen 6 is aligned parallel to the transverse direction CMD of the endless belt 2 during unwinding of the rotary screen 6 on the peripheral side 3. In the present case, consequently, the longitudinal axis 8 of the rotary screen 6 with the longitudinal direction MD of the endless belt 2 encloses the angle α = 90 °. This means that the rotary screen 6 rotates when rolling on the peripheral side 3 about its parallel to the transverse direction CMD of the endless belt 2 oriented longitudinal axis 8.

In the in the FIG. 5 In the case shown, the beginning and end of each circulating belt BU, viewed in the longitudinal direction MD of the endless belt, are always at the same point, ie, each time the endless belt 2 revolves around the two rollers 4, 5, a web revolution BU is completed, regardless of where the rotary screen 6 is viewed in the transverse direction CMD of the endless belt 2.

The FIG. 6 shows a fourth variant of the method according to the invention.

When in the FIG. 6 illustrated variant, the rotary screen 6 rolls in a plurality of juxtaposed webs B on the peripheral side 3 of the endless belt 2, wherein each web B makes on the peripheral side to be printed 3 only a circulating track BU. In other words, each web circulation BU generates a web B. Furthermore, between the application of two webs BU1 ", BU2", BU3 "arranged next to one another in the transverse direction of the endless belt 2, the rotary screen 6 is displaced by the web width BB.

When in the FIG. 6 the variant shown are the beginning A1 "'and the end E1"' of the circulating track BU1 "'on a common line 18 ₁ "'. Further, the beginning A2 "'and the end E2"' of the circulatory track BU2 '"are on a common Straight line 18 ₂ "'which runs parallel to the straight line 18 _i ''' in contrast to that in the FIG. 5 embodiment shown are in the embodiment of FIG. 6 not all beginnings and ends of the circulations on a common straight line, but only the beginning and the end of each circulating train BU1 "", BU2 '"taken separately.

In the present case, the straight line 18 _i '"and 18 _2"' in the longitudinal direction MD of the endless belt 2 viewed by the length of an applied on the peripheral side of the endless belt 2 topographical pattern portion MA -general offset by an integer multiple of the length of a topographical pattern portion to each other.

In the present case-as in the embodiment of FIG. 5 - The longitudinal axis 8 of the rotary screen 6 when rolling the rotary screen 6 on the peripheral side 3 parallel to the transverse direction CMD of the endless belt 2 aligned. In the present case, consequently, the longitudinal axis 8 of the rotary screen 6 with the longitudinal direction MD of the endless belt 2 encloses the angle α = 90 °. This means that the rotary screen 6 rotates when rolling on the peripheral side 3 about its parallel to the transverse direction CMD of the endless belt 2 oriented longitudinal axis 8.

In the in the FIGS. 4 . 5 and 6 the variants shown, the coordination between the peripheral speed Vu of the lateral surface of the rotary screen 6 and the transport speed Vt of the endless belt 2 taking into account the quotient of the circumference of the endless belt 2 and the length of the circumferential direction of the lateral surface successively arranged identical perforation pattern sections of the circular cylindrical rotary screen. 6

Claims (15)

1. Method for producing a topographical pattern of polymer material (9) on an endless strip (2) which has a longitudinal direction (MD) and a transverse direction (CMD) extending perpendicularly thereto, in which use is made of a rotary screen (6), the cylindrical surface area of which has a perforation pattern which defines the topographical pattern and, viewed in the circumferential direction of the surface area, is formed by one perforation pattern section or by a plurality of consecutive perforation pattern sections identical to one another and, to produce the pattern on a circumferential side (3) of the endless strip (2), the polymer material (9) in the liquid or pasty state is pressed through perforations in the surface area of the rotary screen (6), while the rotary screen (6), rotating repeatedly about the longitudinal axis (8) thereof, rolls on the circumferential side (3) of the endless strip (2) in at least one revolving path (B) uninterrupted at least once on the circumferential side (3) of the endless strip (2), characterized in that for each path revolution (BU, BU1, BU1'...) of the rotary screen (6) on the circumferential surface (3) of the endless strip (2), it is the case that the beginning (A, A1, A1', A1"...) and the end (E, E1, E1', E1 "...) of the respective path revolution (BU, BU1, BU1'...) is arranged along a common straight line (18, 18', 18₁, 18₂) and, when rolling, the rotary screen (6) makes N/M revolutions about the longitudinal axis (8) thereof during each path revolution (BU, BU1, BU1'...) on the circumferential side (3) of the endless strip (2), with N and M each being a positive whole number, and with M indicating the number of perforation pattern sections which are arranged consecutively in the circumferential direction of the surface area of the rotary screen (6).
2. Method according to Claim 1, characterized in that the beginnings (A, A1, A1'...) and the ends (E, E1, E1'...) of all of the path revolutions (BU, BU1, BU1') are arranged along a common straight line (18, 18', 18₁, 18₂).
3. Method according to Claim 2, characterized in that the common straight line (18, 18', 18₁, 18₂), along which the beginnings (A, A1, A1'...) and the ends (E, E1, E1'...) of all of the path revolutions (BU, BU1, BU1') are arranged, runs in the transverse direction (CMD) of the endless strip (2).
4. Method according to Claim 2, characterized in that the common straight line (18, 18', 18₁, 18₂), along which the beginnings (A, A1, A1'...) and the ends (E, E1, E1'...) of all of the path revolutions (BU, BU1, BU1') are arranged, encloses an angle (α) of greater than 0° and smaller than 90° with the transverse direction (CMD) of the endless strip (2).
5. Method according to one of the preceding claims, characterized in that the rotary screen (6) extends only over part of the width of the endless strip (2).
6. Method according to one of Claims 1, 2, 3 or 5, characterized in that, during rolling of the rotary screen (6) on the circumferential side (3), the longitudinal axis (8) of the rotary screen (6) is oriented perpendicularly to the longitudinal direction (MD) of the endless strip.
7. Method according to Claim 6, characterized in that the rotary screen (6) rolls on the circumferential surface (3) in an uninterrupted, helical path (B), in particular over the entire width of the endless strip (2), and, when rolling on the circumferential side (3), the rotary screen (6) is displaced in the transverse direction (CMD) of the endless strip (2) in such a manner that the adjacent path revolutions (BU, BU1, BU1'...) of the helical (B) path are added to the topographical pattern.
8. Method according to Claim 6, characterized in that the rotary screen (6) is rolled on the circumferential side (3) of the endless strip (2) in a plurality of paths (B) arranged next to one another, with each path (B) making only one path revolution (BU, BU1, BU1'...) on the circumferential side (3) to be printed, and, between the application of two paths (B) arranged next to each other, the rotary screen (6) is displaced in the direction of the width of the endless strip (2), in particular by the path width (BB).
9. Method according to one of Claims 1, 2, 4 or 5, characterized in that, during rolling of the rotary screen (6) on the circumferential side (3), the longitudinal axis (8) of the rotary screen (6) is oriented at an angle (α) of greater than 0° with respect to the transverse direction (CMD) of the endless strip (2).
10. Method according to Claim 9, characterized in that the rotary screen (6) rolls on the circumferential surface (3) in an uninterrupted, helical path (B), in particular over the entire width to be coated of the endless strip (2), and, when rolling on the circumferential side (3), the rotary screen (6) is displaced in the transverse direction (CMD) of the endless strip (2) in such a manner that the adjacent path revolutions (BU, BU1, BU1'...) of the helical path (B) are added to the topographical pattern.
11. Method according to one of the preceding claims, characterized in that, when rolling on the circumferential side (3), the surface area (M) of the rotary screen (6) rotates at a circumferential speed (Vu) while the endless strip (2) revolves at a transport speed (Vt), which is oriented parallel to the longitudinal direction (MD) thereof, about at least two rolls (4, 5) which are spaced apart from each other and are oriented parallel to each other, the circumferential speed (Vu) and the transport speed (Vt) being coordinated with each other in such a manner that the rotary screen (6) makes N/M revolutions about the rotational axis (8) thereof during each revolution on the circumferential surface (3) of the endless strip (2), with N and M each being a positive whole number, and with M indicating the number of perforation pattern sections which are arranged consecutively in the circumferential direction of the surface area of the rotary screen (6).
12. Method according to one of the preceding claims, characterized in that the circumferential speed (Vu) and transport speed (Vt) are coordinated taking into consideration the quotient of the length of a path revolution (BU, BU1, BU1'...) and the length of one of the identical perforation pattern sections (LP1, LP2, LP3, LP4...) of the surface area of the cylindrical rotary screen (6).
13. Method according to Claim 12, characterized in that the circumferential speed (Vu) and transport speed (Vt) are coordinated in such a manner that, given a quotient of the length of a path revolution (BU, BU1, BU1'...) and the length of one of the identical perforation pattern sections (LP1, LP2, LP3, LP4...) of the surface area of the cylindrical rotary screen (6) that is not equal to a positive whole number, the circumferential speed (Vu) and the transport speed (Vt) are not equal.
14. Method according to one of the preceding claims, characterized in that the rotary screen (6) is arranged at a location at which the endless strip (2) is not guided around a roll (4, 5).
15. Method according to one of the preceding claims, characterized in that the perforation pattern of the rotary screen (6) which defines the topographical pattern, as viewed in the longitudinal extent of the rotary screen (6), is delimited by an end on one end side and an end on the other end side, the end on one end side of the perforation pattern constituting the continuation of the end on the other end side of the perforation pattern.

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