Band-shaped composite body, as well as device and method for its production

Abstract

The invention relates to a device (1) for producing a band-shaped composite body (2) with a base body (4) with at least a first layer (6) and a second layer (8) of polymeric material and at least one reinforcement layer (10) arranged between the first layer (6) and the second layer (8), wherein a left side strip (12) and / or right side strip (12) made of polymeric material at least partially closes the cross-section of the base body (4) on the left side and / or the right side, wherein the device (1) has a rotatably mounted and temperature-controlled cylindrical forming wheel (14) and a band (16), wherein the forming wheel (14) has a pressing device (18) for exerting an axial force in a transverse direction (Y) on the left side strip (12) and / or the right side strip (12).

Description

The invention relates to an apparatus for producing a ribbon-shaped composite body according to the preamble of claim 1, the invention also relates to the use of the apparatus according to the invention for producing a ribbon-shaped composite body according to the preamble of claim 6, a method for producing a ribbon-shaped composite body according to the preamble of claim 7, and a ribbon-shaped composite body according to the preamble of claim 8.Strip-shaped composite bodies, in particular conveyor belts, made of polymeric material are usually vulcanized or shaped in sections in vulcanization presses. After a first length section has been vulcanized, a second length section adjoining it is placed in the vulcanization press and vulcanized analogously to the first length section. The steps are repeated until the conveyor belt has been vulcanized over the entire length. A disadvantage of such a discontinuous vulcanization process is very time- and energy-consuming due to the required heating and cooling processes between the individual vulcanization processes. Also, undesired changes in the material properties can occur locally in the joint regions of the individually vulcanized length sections due to the additional thermal load there of two successive vulcanization processes.The disadvantages associated with the batch vulcanization molding process can be improved or solved by a continuous vulcanization molding process with a rotary vulcanizing device (AUMA). An AUMA has a rotatable and heatable cylindrical forming wheel which is surrounded by a circumferential belt over preferably 270° of the circumference. The belt is usually designed endless and, after running off from the forming wheel, can be guided again via deflection rollers to the inlet of the forming wheel. DE 32 35 740 A1 and DE 10 2013 102 148 A1 describe a rotary vulcanization method or a device suitable therefor, in which a multilayer structure to be vulcanized is introduced into a gap between the belt and a cylindrical, rotatably mounted forming wheel and is formed into a composite material during the circulation around the tempered forming wheel between the belt and the forming wheel. The parameters time, pressure and temperature responsible for the vulcanization or molding process can be adjusted by the rotational speed or the rotational speed of the mold wheel, the contact pressure force of the belt and the regulation of the temperature of the mold wheel.In particular in the case of products which are exposed to external environmental influences in their use, it is of great importance to close the cross section which is exposed in the left and right side regions, in order thus to protect the inner structure of the composite body from the harmful effect of external environmental influences.The object of the invention is to provide a device for the continuous production of a composite body, wherein a laterally exposed cross section of the composite body can be closed by the device. Additionally or alternatively, a method for producing such a composite body is intended to be provided.This object is achieved by a device having the features of independent claim 1.Further solutions result from the use of the device according to the invention for producing a strip-shaped composite body having the features of claim 6, a method for producing a strip-shaped composite body having the features of claim 7 and by a strip-shaped composite body according to claim 8.Further advantageous embodiments are disclosed in the dependent claims, as well as in the general description and the exemplary embodiments.The invention relates to a device for producing a strip-shaped composite body, wherein the composite body has a base body with at least a first layer and a second layer of polymeric material and at least one reinforcing layer arranged between the first layer and the second layer, wherein a left side strip and or right side strip of polymeric material at least partially closes the cross section of the base body on the left side and or the right side. The device has a rotatably mounted and temperature-controllable cylindrical forming wheel and a belt, wherein the first layer, the reinforcing layer and the second layer are arranged one above the other in layers, and the side strip wraps around the forming wheel in a gap between the forming wheel and the belt and can be formed into the composite body. The forming wheel has a pressing device for applying an axial force in a transverse direction to the left side strip and or the right side strip.In other words, the layer-by-layer arrangement of the first layer, the reinforcing layer and the second layer, and of the side strips, can be fed to the gap at the inlet of the apparatus between the forming wheel and the belt. During the revolution around the forming wheel, preferably over a wrap angle of 180° to 270°, under a pressure of 2 to 12 bar, the composite body is formed, which leaves the gap at an outlet lying at the end of the wrap angle of the forming wheel. Via the wrap angle, the belt surrounds the composite body and ensures a sufficiently high contact pressure force of the composite body in the radial direction or vertical direction on the forming wheel. The speed of the belt may be synchronized with the speed of the forming wheel. The temperature is preferably between 100 and 250° C. The pressing device according to the invention can counteract a material displacement in the transverse direction as a result of the force exerted by the belt in the vertical direction or radial direction. In this way, a particularly good geometric dimensional stability of the composite body can be ensured. In addition, the axial force effect of the pressing device on the side strip can improve its adhesion to the base body. The first side strip and or the second side strip can additionally be connected to the base body of the composite body using adhesion promoters.The polymeric material may be formed as an elastomeric material or a thermoplastic elastomer. Preferably, the elastomeric material of the first layer and or of the second layer can be plate-shaped. Alternatively, the polymeric material may be extruded immediately prior to the nip at the entrance of the forming wheel.The reinforcing element layer can be designed, for example, as a woven fabric layer or can have cords or tension members made of steel or aramid or carbon.The polymeric material of the first layer and or of the second layer and or of the first side strip and or of the second side strip can be supplied to the device in an unvulcanized state or already vulcanized. In the case of an unvulcanized polymeric material, vulcanization or crosslinking takes place on the molding wheel under the influence of pressure and a temperature above the vulcanization temperature of the polymeric material. Alternatively, the shaping of the composite body comprising a thermoplastic elastomer can be effected by cooling the thermoplastic elastomer extruded onto the molding wheel.The composite body produced by the apparatus according to the invention can have a high dimensional accuracy due to the continuous forming process. Due to the laterally closed cross section through the side strips, the inner structure of the composite body can be protected as much as possible from external environmental influences, which can impart a high mechanical strength and load-bearing capacity to the composite body over the long term. In this case, at least the reinforcing layer which is exposed in the lateral cross section of the composite body is covered by the side strip. Preferably, the side strip can cover or close the entire cross section of the base body. Preferably, the side strips extend in the vertical direction.According to a further aspect of the present invention, the pressing device is axially or radially and axially adjustable. The pressing device can advantageously be adjustable in such a way that the axial force can be exerted on the left side strip and or on the right side strip only in the region of the angle of wrap of the composite body around the forming wheel. The pressing device can be adjusted in the region of the inlet into the gap between the forming wheel and the belt and or in the region of the outlet upon leaving the composite body from the forming wheel such that no force or only an extremely low force is exerted on the left side strip and or the right side strip by the pressing device. In this way, low-stress ingress and egress of the composite body into or from the device can be ensured.According to a further aspect of the present invention, the apparatus has at least one pressure roller for exerting a radial force on the pressure device, as a result of which the pressure device is radially and axially adjustable. The pressing device can be designed as a so-called toggle lever, wherein at least a first and a second lever are connected to one another by a joint. The first and second levers may be disposed at a variable angle to each other through the hinge. A change in the angle between the first lever and the second lever has the effect that the toggle lever is simultaneously adjusted in the radial and axial direction. For example, a movement of the toggle lever from an angle of 20° to an angle of 180° between the first lever and the second lever leads to the toggle lever spreading or expanding in the axial direction, while the height of the toggle lever decreases in the radial direction, or vice versa. This adjusting movement can be effected by exerting a radial force on the pressing device through the belt and additionally through the pressing roller. The pressure roller can preferably exert a radial force on the strip, wherein the strip acts directly on the pressure device. Starting from an angle between the first lever and the second lever of preferably more than 180°, the toggle lever can lock. The locking mechanism can be released and thus the toggle lever can be adjusted only after a certain force is exceeded, so that an undesired adjustment of the toggle lever can be avoided with a small force effect. To adjust the force exerted by the pressure roller on the pressure device, the pressure roller can be adjusted radially. In particular, the presence of one or more pressure rollers can additionally improve the pressure distribution in the radial direction on the side strips. As a result, the adhesion of the side strips to the base body and or the geometric dimensional stability of the composite body can be additionally improved.According to a further aspect of the present invention, the pressing device has individual segments, wherein the individual segments can be positioned in a first closed position via the angle of wrap of the composite body around the forming wheel. The individual segments of the pressing device can be arranged distributed over the circumference of the forming wheel. At least in the region of the inlet into the gap between the forming wheel and the belt and or in the region of the outlet upon leaving the composite body from the forming wheel, the individual segments can be positioned in a second, open position. In this case, the individual segments can be adjusted axially to such an extent that no or only an extremely low axial force is exerted on the composite body or the side strips outside the angle of wrap of the composite body around the forming wheel. The individual segments can be positioned in the first closed position via the angle of wrap of the composite body around the forming wheel, so that an axial force can be exerted on the composite body or the side strips.According to a further aspect of the present invention, the individual segments can be positioned spring-loaded or pneumatically or hydraulically into the first position and or a second open position. In particular, a spring-loaded adjustment of the individual segments represents a structurally simple and robust mechanical solution which requires no additional sensors and actuators and is therefore also particularly cost-effective to implement.The present invention also relates to the use of the device according to the invention for producing a strip-shaped composite body, having a base body with at least a first layer and a second layer of polymeric material and at least one reinforcing layer arranged between the first layer and the second layer, wherein a left side strip and or right side strip of polymeric material at least partially closes the cross section of the base body on the left side and or the right side.The present invention also relates to a method for producing a strip-shaped composite body using a device according to the invention, wherein the composite body has a base body having at least a first layer and a second layer of polymeric material and at least one reinforcing layer arranged between the first layer and the second layer, wherein a left side strip and or right side strip of polymeric material at least partially closes the cross section of the base body on the left side and or the right side. The method is characterized by the following method steps: a) arranging the first layer, the reinforcing layer and the second layer one above the other in layers, b) applying the left side strip and or the right side strip, respectively, c) introducing the arrangement of method step a) in layers and the side strips of method step b) into a gap between a forming wheel and a belt, d) applying an axial force in a transverse direction to the left side strip and or the right side strip by a pressing device, wherein the pressing device is adjusted axially or radially and axially, e) forming the composite body under a pressure of 2 to 12 bar at a temperature between 100° C. to 250° C.In the case of an unvulcanized polymeric material, vulcanization or crosslinking takes place on the molding wheel under the influence of pressure and a temperature above the vulcanization temperature of the polymeric material. Alternatively, the shaping of the composite body comprising a thermoplastic elastomer can be effected by cooling the thermoplastic elastomer extruded onto the molding wheel. The pressing device can counteract a material displacement in the transverse direction as a result of the force exerted by the belt in the vertical direction or radial direction. In this way, a particularly good geometric dimensional stability of the composite body can be ensured. In addition, the axial force effect of the pressing device on the side strip can improve its adhesion to the base body.The present invention also relates to a belt-shaped composite body, preferably a transport belt or a drive belt, produced in a method according to the invention. The aforementioned properties and advantages can thus be transferred to a wide variety of ribbon-shaped composite bodies. In particular, the method according to the invention can produce a composite body which has a high dimensional stability on account of the continuous vulcanization process. Due to the cross section through the side strips that is laterally closed at least partially in the region of the reinforcing layer, the inner structure of the composite body is protected as much as possible from external environmental influences, which gives the composite body a high mechanical strength and load-bearing capacity over the long term.It is expressly pointed out that the embodiments of the invention explained above can each be combined with one another individually or in any technically meaningful combination, in each case with the subject matter of the independent claims.Exemplary embodiments and further advantages of the invention are schematically illustrated and explained in more detail below in connection with the following figures. The following shows: FIG. 1 shows a schematic sectional illustration of a device according to the invention with a composite body according to a first exemplary embodiment. FIG. 2 shows a schematic sectional illustration of a device according to the invention with a composite body according to a second exemplary embodiment. FIG. 3 shows a schematic sectional illustration of a composite body according to the invention.The description of the above. Figures are made in Cartesian coordinates with a longitudinal direction X, a transverse direction Y oriented perpendicularly to the longitudinal direction X and a vertical direction Z oriented perpendicularly both to the longitudinal direction X and to the transverse direction Y. The longitudinal direction X can also be referred to as depth X, the transverse direction Y can also be referred to as width Y or axial direction Y and the vertical direction Z can also be referred to as height Z or radial direction Z. The longitudinal direction X and the transverse direction Y together form the horizontal, X, Y, which can also be referred to as the horizontal plane X, Y. The longitudinal direction X, the transverse direction Y and the vertical direction Z can also be collectively referred to as spatial directions X, Y, Z or as Cartesian spatial directions X, Y, Z.FIG. 1 shows an apparatus 1 according to the invention for producing a strip-shaped composite body 2 according to a first exemplary embodiment. The composite body 2 has a main body 4, wherein a left side strip 12 and right side strip 12 of elastomer material extending in the vertical direction Z respectively closes the cross section of the main body 4 on the left side and the right side. The apparatus 1 has a rotatably mounted and temperature-controllable cylindrical forming wheel 14 and a belt 16. The belt 16 rotates around the forming wheel 14 at a speed synchronized with the circumferential speed of the forming wheel 14.The composite body 2 has the main body 4 which, as shown in FIG. 3, has a first layer 6 and a second layer 8 of elastomeric material and a reinforcing layer 10 arranged between the first layer 6 and the second layer 8.The structure of the base body 4 arranged one above the other in layers and the side strips 12 run into the device 1 of FIG. 1 in a gap between the forming wheel 14 and the belt 16. The molding wheel 14 is tempered to a temperature above the vulcanization temperature of the elastomeric material of the composite body 2, so that the composite body 2 is vulcanized during the rotation of the molding wheel 14, wherein the elastomeric material crosslinks and the individual layers or components of the composite body 2 connect to one another in a materially bonded manner. The forming wheel 14 has a pressing device 18 for applying an axial force in the transverse direction Y to the left side strip 12 and the right side strip 12. The pressing device 18 is axially adjustable. The pressing device 18 has a plurality of individual segments 20, wherein the individual segments 20 are positioned over the angle of wrap of the composite body 2 around the forming wheel 14 in a first closed position 22 for exerting an axial force on the composite body 2. The individual segments 20 can be positioned spring-loaded into the first position 22 and or a second open position 24. In the region of the inlet into the gap between the forming wheel 14 and the belt 16 and or in the region of the outlet upon leaving the composite body 2 from the forming wheel 14, the individual segments 20 can be positioned in the second, force-free open position 22. The spring force on the individual segments 20 is designed such that the force exerted by the composite body 2 on the individual segments 20 brings about an axial displacement of the individual segments into the second position 22 when it leaves the forming wheel 14. The device 1 has two pressure rollers 26 for exerting an additional radial force in the vertical direction Z on the side strips 12. The pressure rollers 26 are arranged on the radially outer side of the belt 16 facing away from the composite body 2. The pressure rollers 26 are arranged in alignment with the side strips 12 in the radial direction or vertical direction Z. The radial force exerted by the pressure rollers 26 is transmitted to the side strips 12 via the belt 16. The pressure distribution in the radial or vertical direction Z on the side strips 12 is improved by the pressure rollers 26. As a result, the adhesion of the side strips 12 to the base body 4 and or the geometric dimensional stability of the composite body 2 is additionally improved.FIG. 2 shows an apparatus 1 according to the invention for producing a strip-shaped composite body 2 according to a second exemplary embodiment. In contrast to the device from FIG. 1, the pressing devices 18 are designed as toggle levers 18, wherein a first and a second lever are connected to one another by a joint 19. The first and second levers of the toggle lever 18 can be arranged at a variable angle to one another by the joint 19. A change in the angle between the first lever and the second lever has the effect that the toggle lever 18 is simultaneously adjusted in the radial direction Z and in the axial direction Y. This adjusting movement is effected by exerting a force in the radial direction Z on the pressing device 18 by the pressing rollers 26. To adjust the force exerted by the pressing rollers 26 on the pressing devices 18, the pressing rollers 26 can be adjusted in the radial direction Z.List of Reference Numerals (part of the description)1 Device 2 Composite body 4 Base body 6 First bearing 8 Second layer 10 Reinforcing member layer 12 Side strip 14 Forming wheel 16 Belt 18 Pressing device, toggle lever 19 Joint 20 Individual segment 22 First position 24 Second position 26 Pressing roller X Longitudinal direction; depth Y Transverse direction; axial direction; width Z Vertical direction; radial direction; height X, Y Horizontal; horizontal planeReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 32 35 740 A1

[0003] DE 10 2013 102 148 A1

[0003]

Claims

Device (1) for producing a strip-shaped composite body (2), wherein the composite body (2) has a base body (4) with at least a first layer (6) and a second layer (8) of polymeric material and at least one reinforcing layer (10) arranged between the first layer (6) and the second layer (8), wherein a left side strip (12) and / or right side strip (12) of polymeric material at least partially closes the cross section of the base body (4) on the left side and / or the right side, wherein the device (1) has a rotatably mounted and temperature-controllable cylindrical forming wheel (14) and a strip (16), wherein the first layer (6), the reinforcing layer (10) and the second layer (8) are arranged one above the other in layers, and the side strip (12) wraps around the forming wheel (14) in a gap between the forming wheel (14) and the belt (16) and can be formed into the composite body (2), characterized in that the forming wheel (14) has a pressing device (18) for applying an axial force in a transverse direction (Y) to the left side strip (12) and / or the right side strip (12).Device (1) according to claim 1, characterised in that the pressing device (18) is axially or radially and axially adjustable.Device (1) according to claim 2, characterised in that the device (1) has at least one pressure roller (26) for exerting a radial force on the pressure device (18), whereby the pressure device (18) is radially and axially adjustable.Apparatus (1) according to either of Claims 2 and 3, characterized in that the pressing device (18) has individual segments (20), it being possible for the individual segments (20) to be positioned in a first closed position (22) over the angle of wrap of the composite body (2) around the forming wheel (14).Device (1) according to claim 4, characterised in that the individual segments (20) can be positioned spring-loaded or pneumatically or hydraulically into the first position (22) and / or a second open position (24).Use of the device (1) according to one of claims 1 to 5 for producing a strip-shaped composite body (2), having a base body (4) with at least a first layer (6) and a second layer (8) of polymeric material and at least one reinforcing layer (10) arranged between the first layer (6) and the second layer (8), wherein a left side strip (12) and / or right side strip (12) of polymeric material at least partially closes the cross section of the base body (4) on the left side and / or the right side.Method for producing a strip-shaped composite body (2), having a base body (4) with at least a first layer (6) and a second layer (8) of polymeric material and at least one reinforcing layer (10) arranged between the first layer (6) and the second layer (8), wherein a left side strip (12) and / or right side strip (12) of polymeric material at least partially closes the cross section of the base body (4) on the left side and / or the right side, using a device (1) according to one of Claims 1 to 5, characterized bythe following method steps: a) arranging the first layer (6), the reinforcing layer (10) and the second layer (8) one above the other in layers, b) applying the left side strip (12) and / or the right side strip (12) in layers, c) introducing the layer-by-layer arrangement from method step a) and the side strips (12) from method step b) into a gap between a forming wheel (14) and a belt (16), d) applying an axial force in a transverse direction (Y) to the left side strip (12) and / or the right side strip (12) by a pressing device (18), wherein the pressing device (18) is adjusted axially or radially and axially, e) forming the composite body (2) under a pressure of 2 to 12 bar at a temperature between 100° C. to 250° CA band-shaped composite body (2), preferably a transport belt or drive belt, produced in a method according to claim 7.

Images