1. Field of the Invention
The present invention relates to a belt, especially a belt or process belt for web converting and/or web producing machines, especially paper, cardboard or tissue machines.
2. Description of the Related Art
Belts are utilized in paper machines, for example, to transport a paper web in the paper machine from a first transfer location where the material web is transferred from one clothing onto the belt to a second transfer location where the material web is transferred from the belt to an additional clothing. On such belts the paper web is frequently run through a press nip between the two transfer locations. In this case, a smoothing of the web, for example caused by the belt, would occur. The belts in question normally have a weight-carrying structure, for example in the form of a woven structure, on which a polymer layer representing the paper side and which is often impermeable is disposed. A disadvantage of belts known from the current state of the art is that the belt edges extending in a longitudinal direction of the belt often become “frayed” or abraded, resulting in a weakening of the belt edges.
What is needed in the art is an improved belt which provides greater wear resistance at the belt edges.
If the belt has only one paper side polymer layer, the present invention provides a belt which transports a material web in a web producing and/or web converting machine, especially a paper, cardboard or tissue machine, which is bordered in a cross direction on each side by a respective longitudinal edge. The belt includes a weight-carrying base structure and a polymer layer disposed on the base structure providing the paper side of the belt. In the region of at least one longitudinal edge, an edge reinforcement providing at least a section of the longitudinal edge is formed. The paper side polymer layer protrudes in the area of the longitudinal edge in the cross direction beyond the base structure and a hereby created step extending in the longitudinal direction of the belt is filled at least in sections with a polymer material as a result of which the edge reinforcement forms at last part of the longitudinal edge.
If the belt has a paper side and a machine side polymer layer, the present invention provides a belt which transports the material web in a web producing and/or web converting machine, especially a paper, cardboard or tissue machine and which is bordered in cross direction on both sides by a respective longitudinal edge. The belt includes a weight-carrying base structure which is disposed between a paper side polymer layer and a machine side polymer layer. In the region of at least one longitudinal edge, an edge reinforcement providing at least a section of the longitudinal edge is formed, whereby the two polymer layers protrude in the region of the longitudinal edge in cross direction beyond the base structure, forming a groove extending in longitudinal direction of the belt, which is filled at least in sections with a polymer material.
In other words, the edge reinforcement includes a polymer material and, viewed in cross direction of the belt, the paper side polymer layer (and the machine side polymer layer) protrudes toward the longitudinal edge of the belt beyond one end of the base structure, whereby at least one part of the longitudinal edge of the belt is formed in that the polymer material at least partially covers the section of the polymer layer protruding beyond the edge of the base structure and in that the polymer material completely covers the end of the base structure.
The present invention is based on the concept of protecting the base structure which is often susceptible to wear in the area of the belt edge with a polymer material. According to the present invention, in the region of the belt edge, the paper side polymer layer protrudes toward the outside beyond the end of the base structure and the space which is created by the section of the polymer layer protruding over the end of the base structure and the end of the base structure is filled at least in sections with a polymer material.
The polymer material forming the edge reinforcement is, for example, in the embodiment of one piece. One embodiment of the present invention, for example, provides that the polymer material filling the step or groove respectively is formed complementary to the form of the step or groove respectively. This may be achieved, for example, in that the polymer material is filled into the step or groove respectively in a formless form, for example in a liquid form, and is subsequently solidified. The polymer material may, for example, be solidified or hardened through heat effect. In addition, it is conceivable that the polymer material cross-links with itself and/or with the polymer material of the paper side and/or the machine side polymer layer. Due to the fact that the polymer material is added in a formless state, it is able to completely fill all hollow spaces in the step or groove respectively. After its solidification, the polymer material of the edge reinforcement assumes a complementary form in the contact area with the polymer layer(s) and the base structure with these and is, therefore, firmly joined with them. It is, therefore, conceivable that the edge reinforcement is linked through a material fit and/or friction and/or form fit with the at least one polymer layer and with the base structure. Connections where all connecting partners are held together by atomic or molecular forces are termed a material fit connection. For example, this is to be understood to be connection through gluing, chemical cross-linking or vulcanizing. A friction connection in this context is to be understood to be a connection which is established by the use of force whereby the cohesiveness of the bonding partners is assured through static friction.
As a rule the polymer material of the edge reinforcement fills the groove or respectively the step at least partially from the end of the base structure. Viewed as a cross section of the belt, the groove can, for example, be configured so that the distance between the surfaces of the paper side and the machine side polymer layer facing each other remains constant from the inside of the belt, that is from the end of the base structure toward the longitudinal edge of the belt. In this case the groove is, for example, U-shaped. Alternatively, it is conceivable that the groove is designed so that the distance between the surfaces of the paper side and the machine side polymer layer facing each other increases or decreases from the inside of the belt toward the longitudinal edge of the belt. In this case, the groove can be designed to be V-shaped. If the groove enlarges toward the longitudinal edge, then the wear volume provided by the polymer material of the edge reinforcement increases in the cross direction, from the end of the base structure toward the end of the paper side and/or machine side polymer layer. The belt may, for example, have a constant thickness across its entire width. This means that on the paper side and the machine side of the belt the area around the belt edge is no thicker compared to the belt center.
In order to further improve the wear resistance of the belt, a second embodiment of the present invention provides that the polymer material of the edge reinforcement, viewed in the cross direction of the belt, protrudes at least in sections beyond the paper side polymer layer and/or beyond the machine side polymer layer. This results in the fact that the longitudinal edge of the belt, according to the present invention has a section protruding in the cross direction of the belt beyond the paper side and machine side (if this is provided) polymer layer which is formed by the edge reinforcement and which represents a wear volume of the longitudinal edge of the belt edge.
The polymer material of the edge reinforcement may be a different polymer material than the polymer material of the paper side polymer layer and/or the polymer material of the machine side polymer layer. In this context, the polymer material of the edge reinforcement may have a greater hardness and/or a greater abrasion resistance than the polymer material of the paper side polymer layer and/or the polymer material of the machine side polymer layer. This allows for a further improvement in the wear resistance of the belt edge. It is conceivable, in this context that the polymer material of the paper side and/or the machine side polymer layer has a hardness in the range of between approximately 20 and 95 Shore A, whereas the polymer material of the edge reinforcement has a greater hardness than the paper side and/or the machine side polymer layer, which can be in the range of between approximately 50 Shore A to 90 Shore D, for example between approximately 50 Shore A to 95 Shore A. It is conceivable in this context that the two polymer layers as well as the polymer material of the edge reinforcement are formed of polyurethane, whereby the polyurethane of the edge reinforcement is harder than the polyurethane of the two polymer layers. The polymer material of the one or of both polymer layers may, for example, include polyurethane. The polymer material of the edge reinforcement can include, for example, polyurethane, silicone, polyamide, epoxy resins, polyolefin, polyester or amide, alone or in combination.
A third embodiment of the present invention provides that the polymer material of the edge reinforcement is thixotropic and, for example, has a viscosity in the range of between approximately 400000 cps to 1000000 cps.
In order to further increase the abrasion resistance of the edge reinforcement, a fourth embodiment of the present invention provides that a filler, for example, a particulate filler, i.e. SiC (silicone carbide) and/or CaCO3 (calcium carbonate) which has a higher abrasion resistance than the polymer material of the edge reinforcement is embedded into the polymer material of the edge reinforcement.
The polymer material of the edge reinforcement extends, for example, in the cross machine direction from the longitudinal edge in an area of between approximately 1 mm to 15 mm, for example between approximately 2 mm to 7 mm, toward the inside. If the base structure includes, for example, longitudinal yarns which extend parallel to the longitudinal edge, then the step or groove can be formed, for example, by removing the longitudinal yarn or yarns which are located at the outermost region of the longitudinal edge—viewed in the cross direction of the belt—from the base structure.
Different possibilities are conceivable with regard to the design of the weight carrying base structure. It is conceivable that the weight carrying base structure is formed by a textile surface structure, for example, by a woven structure, a group of yarns extending in a machine direction and/or a cross machine direction and/or by a non-textile surface structure, for example, by one or more film(s). The belt according to the present invention may be a belt whereby the paper side and/or machine side polymer layer is fluid impermeable.
An additional aspect of the present invention provides a method for the manufacture of a belt to transport a material web in a web converting and/or web producing machine including:
a) provision of a weight-carrying base structure;
b) coating of one side of the base structure with a first polymer material to provide a paper side of the belt;
c) removal of part of the base structure in at least one edge area of the semi-completed belt in a way that the paper side polymer layer viewed in cross direction of the belt protrudes beyond the base structure;
d) at least sectional filling of the space which is created between the paper side polymer layer and the base structure with a formless second polymer material in order to form at least one section of the longitudinal edge of the belt; and
e) solidifying of the formless second polymer material.
One embodiment of the method according to the present invention provides that in step b) the one side of the base structure is coated with the first polymer material to provide the paper side and simultaneously or subsequently the other side of the base structure, opposite the one side is coated with a third polymer material. It is conceivable in this context that the first and the third polymer material are the same polymer material.
A second embodiment of the method according to the present invention provides that in step c) a part of the base structure in an edge area of the semi-completed belt is removed in a way that the paper side and the machine side polymer layer viewed in the cross direction of the belt protrude beyond the base structure. If the belt includes a paper side and a machine side polymer layer, then step d) provides that the groove (this extends in a longitudinal direction of the belt) formed between the paper side polymer layer, the machine side polymer layer and the base structure is filled at least in sections with the second polymer material in order to form at least one section of the longitudinal edge of the belt. The second formless polymer material, for example liquid polymer material, is filled into the space, for example by a casting process.
A third embodiment of the method according to the present invention further provides that the base structure includes longitudinal yarns extending in a longitudinal direction of the belt and that in step c) the two outermost longitudinal yarns are removed from the base structure in the at least one edge region.
In order to clearly increase the durability of the belt produced with the method according to the present invention in step e) a solid bond is formed between the second polymer material and the base structure and the paper side and/or machine side polymer layer.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
It is to be noted that that the longitudinal direction of belt 1 in the illustration in
Polymer material 10 which fills groove 9 is complementary in form to groove 9. This is achieved predominantly in that polymer material 10 is filled into groove 9 in a liquid state and is subsequently solidified through heat effect. During solidification polymer material 10 is interlinked with itself, as well as with the polymer material of aper side polymer layer 5 and machine side polymer layer 6. Belt 1 has a constant thickness across its entire width. It is further to be recognized that polymer material 10 of edge reinforcement 11, viewed in the cross machine direction CMD of belt 1, extends beyond paper side polymer layer 5 and beyond machine side polymer layer 6, thereby providing an increased wear volume.
The polymer material in two polymer layers 5, 6 in the current example is polyurethane (PU) with a hardness of approximately 85 Shore A, whereas polymer material 10 of edge reinforcement 11 is PU with a hardness of approximately 60 Shore D. In addition, a particulate filler, for example SiC (silicone carbide), is embedded into polymer material 10 of edge reinforcement 11. SiC has a greater abrasion resistance than the PU of edge reinforcement 11.
Referring now to
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While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
Number | Date | Country | Kind |
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10 2007 044 552.2 | Sep 2007 | DE | national |
This is a continuation of PCT application No. PCT/EP2008/055221, entitled “TRANSPORTING BELT WITH PERIPHERAL REINFORCEMENT”, filed Apr. 29, 2008, which is incorporated herein by reference.
Number | Date | Country | |
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Parent | PCT/EP2008/055221 | Apr 2008 | US |
Child | 12723811 | US |