DE202019103237U1 - Woven fabric with improved adhesive and release properties - Google Patents

Abstract

Conveyor belt with support side and machine side surfaces, comprising:
a fabric comprising at least one machine-side layer of MD yarns and a support side layer of MD yarns which are woven with at least one layer of CD yarns, at least some of the supporting layer side MD yarns are reinforced adhesive yarns, all supporting layer side MD yarns define one Surface support plane, at least some of the CD yarns are elastic, the elastic CD yarns are arranged in such a way that at least some of the MD yarns with improved adhesion in a region of the conveyor roller are adapted to a section of the fabric that is bent around a conveyor roller are that they move from the surface support plane to a release position by compressing the CD yarns of the elastic material with the support layer by a force of the MD yarns, so that at least some of the MD yarns with improved adhesion on the upper side of the elastic CD yarns are adapted so that they move below the surface bearing plane in order to ensure that the G To reduce ewebes to one material that is supported on the surface bearing plane, and when the portion of the curved fabric runs off the conveyor roller, the MD yarns with improved adhesion are adjusted to return to the surface bearing plane.

Description

The invention relates to technical textiles, in particular to conveyor belts used in various material handling applications. In particular, the invention relates to woven conveyor belts used in connection with the formation of spunbonded fabrics.

Nonwoven or nonwoven fabrics are typically made from fibers without the need for spinning, weaving, or knitting as in conventional textile production. Nonwovens are typically formed as a structure of fibers of limited length, created by cutting continuous filaments or yarns of any type or origin, blowing the fibers randomly onto a moving conveyor belt, and then joining the fibers together so that they are in any form Way are connected. The well-known production is sometimes referred to as "spunbond", "spunlaid" or "meltblown".

In the production of these nonwovens, the straight extruded and drawn fibers are placed on a conveyor belt to form a flat layer, namely the later nonwoven fabric, the nonwoven web of fibers then by heat activation of an adhesive integrated into the fibers or a separately added adhesive a hot and sticky state, whereby the fibers adhere to one another and form a continuous nonwoven web. The alternative production process also includes the well-known “airlaying” process, in which the nonwoven web is consolidated after fiber separation by means of a mechanical needling step or exposure to a water jet.

The conveyor belts used in the manufacturing process of the nonwovens play a crucial role in the quality of the nonwovens and the reliability of the production process. Typically, the conveyor belts consist of fabrics made from plastic monofilaments. Alternatively, metal meshes are used when the temperature conditions in nonwoven production are above the range that would allow the use of plastic-based conveyor belts. Most conveyor belts, whether made of plastic monofilaments or metal filaments, have a smooth surface based on the smooth surface of the filaments used. However, a smooth surface can lead to problems in the manufacture of nonwovens. In particular, problems arise from slippage or a relative movement between the fibers of the nonwoven fabric and the surface of the conveyor belt. A certain adhesion of the fleece layer on the conveyor belt is important, since it enables a uniform production by placing an even quantity of fibers on the running conveyor belt per unit area and time unit. However, this adhesion cannot be so great that it hampers the removal of the web from the conveyor belt, which can compromise constant production and a high quality product. These problems become more pronounced as the machine speed increases.

US Pat. No. 6,790,796,796 B2 discloses a conveyor belt which is used in the manufacture of nonwoven fabrics in which threads are used in the conveyor belt which have a rough surface in order to prevent the nonwoven fabric to be formed from slipping. For example, the raw threads can be in the form of structured, for example grooved, monofilaments or in the form of twisted threads. It can also be provided that the roughness and thus the slip resistance is direction-dependent, ie only in the running direction of the conveyor belt. In addition, an optional core-shell structure is provided for the roughness-relevant features.

Even if the well-known improved roughness of the thread or fabric surface US Pat. No. 6,790,796,796 B2 is used to reduce the risk of slipping against smoother threads, the behavior of the known conveyor belts in the production process is not yet satisfactory.

DE 20 53 624 A1 describes a fabric for belts or conveyor belts in which a load-absorbing reinforcement net is provided with a rubber matrix material forming the belt surface. In order to ensure the connection, in particular the cohesion, between the reinforcement fabric and the coating material, the filaments of the reinforcement fabric are coated with natural or synthetic rubber or polyurethane or mixtures of the above materials before coating with the matrix material.

DE 10 2016 107 811 of the applicant also discloses the use of thermoplastic elastomer in the MD yarns to reduce slippage and is incorporated herein as fully set forth.

It would be desirable to provide a conveyor belt that overcomes the problems of the prior art by providing a solution that allows better adhesion of the nonwoven fabric formed thereon to prevent slippage, while allowing clean peeling when the nonwoven fabric is used further processing is transferred to a downstream conveyor belt or roller for storage.

SUMMARY

The invention relates to a conveyor belt made of a fabric. The fabric includes at least one machine-side layer and a wear-side layer of MD yarns (machine-side direction) which are woven with at least one layer of CD yarns (cross direction). At least some of the MD yarns of the wear-side layer are better adhesive yarns, preferably made of a thermoplastic elastomer. All MD yarns of the wear-side layer define a surface wear level. At least some of the CD yarns are elastic. This elasticity of the elastic CD yarns can be due to an elasticity of the material used to form the elastic CD yarns, such as TPE, TPU, PLA or other elastomers, through a structure of the elastic CD yarns, such as braided yarns, warp knitting yarns, hollow monofilaments or by a combination of structural elasticity and material elasticity. The resilient CD yarns are arranged so that when a portion of the fabric is bent onto a conveyor roller, at least a portion of the MD yarns with improved adhesion are adapted to move from the surface support plane to a release position by the CD - Yarns with elastic material are compressed by a force of the MD yarns of the supporting layer, so that at least a part of the MD yarns move with improved grip on the upper side of the elastic CD yarns below the surface support plane of the fabric. This is tailored to reduce the adhesion of the fabric to the material to be worn on the surface bearing surface. As the portion of the curved fabric runs off the conveyor roller, the MD yarns with improved adhesion are cut to it to return to the surface bearing plane.

This conveyor belt solves the problem in spunbond machines where it is difficult to obtain adequate support on the web carried on the surface of the conveyor belt. However, as soon as liability by e.g. If the strength of the adhesive yarn is increased, the web sometimes adheres too strongly to the belt and does not come off when changing from one position to the next. Since the MD yarns with improved adhesion can compress the elastic CD yarns while the fabric is bent on a roll, a cleaner release or one with less force is achieved.

In a preferred embodiment, the thermoplastic elastomer is a block copolymer with alternating soft and hard segments, a mixture / alloy of a rubber-like polymer with a thermoplastic polymer or a composition of a rubber-like polymer and a thermoplastic polymer with a highly vulcanized / crosslinked similar polymer in a finely divided form thermoplastic polymer.

The thermoplastic elastomer, in particular a styrene block copolymer, in particular a styrene-butadiene-styrene or the like, a thermoplastic polyolefin, in particular a mixture / alloy of polypropylene and crosslinked EPDM rubber, a thermoplastic vulcanizate, in particular a mixture of polypropylene and ethylene-propylene Diene (EPDM) rubber, the latter two are vulcanized / cross-linked components during the compounding process, a thermoplastic polyurethane, in particular based on a polyester urethane or a polyether urethane, a thermoplastic copolyester, a melt-processable EPDM rubber, a thermoplastic polyether block amide, preferably with amide compounds between hard - and soft segments, or an ionomeric thermoplastic elastomer.

In a preferred embodiment, the more grippy MD yarns are arranged than at least every fourth MD yarn of the layer on the wearer side. Those skilled in the art will recognize that the MD yarns can be arranged with better adhesion than every third or any other MD yarn on the backing side, or at different intervals depending on how much adhesion is to be imparted.

Preferably at least every fourth of the CD yarns is the elastic CD yarn. In a preferred embodiment, the CD yarns are woven in pairs and one of the CD yarns in any other of these pairs is a CD elastic yarn.

Preferably all of the MD yarns with improved grip go over the elastic CD yarns on the support surface. Some of the conventional MD yarns can also run over the elastic CD yarns on the support surface.

As an alternative to weaving the fabric with at least a portion of the MD yarns with improved adhesion, the MD yarns with improved adhesion could be provided by fabricating the conveyor belt with a backing layer of conventional MD yarns and at least a portion of the elastic CD yarns woven and then the carrying side of the fabric is coated as a whole with an adhesive coating.

Figure list

• 1 ist eine Ansicht eines Teils eines Förderbandes, das aus einem Gewebe gemäß einer Ausführungsform gebildet ist.
• 2 ist eine Seitenansicht des in 1 dargestellten Gewebes.
• 3 ist eine schematische Darstellung eines Förderbandes nach der Erfindung in einer Anlage zur Herstellung eines Vliesstoffes.
• 4 ist ein vergrößerter Ausschnitt des Gewebes des in 3 dargestellten Förderbandes, das an einem Abwurfende eines Förderer-Umlaufs um eine Rolle gebogen wird.
• 5 ist eine schematische Darstellung, die den Aufbau einer weiteren Ausführungsform eines Gewebes für den Einsatz als Förderband zeigt.

The foregoing summary and the following detailed description will be better understood when read in conjunction with the accompanying drawings, which illustrate a preferred embodiment of the invention. In the drawings:

• 1 Figure 13 is a view of a portion of a conveyor belt formed from a fabric according to one embodiment.
• 2 is a side view of the in 1 illustrated tissue.
• 3 is a schematic representation of a conveyor belt according to the invention in a plant for the production of a nonwoven fabric.
• 4th is an enlarged section of the tissue of the in 3 conveyor belt shown, which is bent at a discharge end of a conveyor circuit around a roller.
• 5 Figure 3 is a schematic diagram showing the construction of another embodiment of a fabric for use as a conveyor belt.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Certain terminology is used in the following description for the sake of clarity and is not restrictive. The fabric according to the invention is an industrial textile which can have many industrial uses, e.g. Conveyor Belts, etc. The words "carrier side" and "machine side" denote surfaces of the fabric in relation to their use in a preferred application in a conveyor application; however, these terms represent only first and second or top and bottom surfaces of the planar fabric. "Yarn" is used to generally identify a monofilament or multifilament fiber. "Warp" and "weft" are used to refer to yarns or monofilaments based on their position in the loom that extend in perpendicular directions in the fabric and can be either a machine direction (MD) or a cross machine direction (CMD) yarn in the fabric once it is installed on a facility, depending on whether the fabric is flat or continuously woven. In the preferred arrangement, the fabric is woven flat and connected to the warp threads to form an endless belt, so that the warp threads are MD threads and the weft threads are CMD threads.

A preferred application of the fabrics according to the invention is as a conveyor belt 10 with a support side surface 16 and a machine side surface 18th located between two conveyor rollers 12 , 14th extends, as in 3 shown. A preferred application of such a conveyor belt 10 is the formation of a spunbonded nonwoven 11 for example, through an extruder with an air duct 15th is spun and then activated by heat to bind the fibers together. At least a portion of the spunbond fibers can include a heat activated component or a separate binder resin can be used and deposited with the fibers of the nonwoven web.

With reference to the 1 and 2 is a detail of the conveyor belt 10 shown. The conveyor belt 10 consists of a fabric 20th , the at least one machine-side layer 36 made of MD yarns 38 and a wear-side layer 30th made of MD yarns 32 includes that with at least one layer 50 made of CD yarn 52 are interwoven. All MD yarns 32 of the support-side layer define a surface support plane 40 which generally runs flat over a run of the conveyor system and in the area around the rollers 12 , 14th is bent. In the context of the invention, “generally flat” refers to the support surface 40 between the conveyor rollers 12 , 14th and allows typical waste from slack in the conveyor belt 10 and does not exclude the tissue 20th Has peaks and valleys caused by the fabric pattern or the profile yarns used.

At least some of the MD yarns 32A of the carrying side layer are yarns with increased adhesion. The yarns with improved adhesion can be structured or formed from a material with improved adhesion, such as, for example, a thermoplastic elastomer, or coated with a material with improved adhesion. In a preferred embodiment, the MD yarns with improved adhesion are made from a thermoplastic elastomer, which is a block copolymer with alternating soft and hard segments, a mixture / alloy of a rubber-like polymer with a thermoplastic polymer or a composition of a rubber-like polymer and a thermoplastic Polymer with a highly vulcanized / crosslinked similar polymer in a finely divided thermoplastic polymer. Preferably, the thermoplastic elastomer comprises a styrene block copolymer, a thermoplastic polyolefin, a mixture of alloyed polypropylene and crosslinked EPDM rubber, a thermoplastic vulcanizate, a mixture of polypropylene and ethylene-propylene-diene (EPDM) rubber, a thermoplastic polyurethane, a thermoplastic copolyester, a melt-processable EPDM rubber, a thermoplastic polyether block amide or an ionomeric thermoplastic elastomer. Those skilled in the art will recognize that other materials can be used.

As in the and shown are the MD yarns 32A with better adhesion than every fourth MD yarn of the wear-side layer 32 arranged. However, this distance can vary depending on the application and the desired adhesion. For example, the MD yarns 32A with improved adhesion all 8th . or 16 . MD yarns or any different distance to ensure the desired grip for the material to be transported. The remaining top layer MD yarns 32B are conventional yarns and can be made from polyamide, polyester, or any other known suitable material. In one embodiment the are MD yarns 32A with improved adhesion like all other side layers on the wearer 30th MD yarn 32 arranged. Those skilled in the art will recognize from the present disclosure that different spacings can be used or that all 30 MD yarns 32 the load-side layer 30th the MD yarns 32A with increased liability.

In the preferred embodiment of the fabric 20th the MD yarns of the supporting layer are placed directly over the MD yarns 38 the machine-side layer 36 stacked, and all MD yarns are generally rectangular in cross-section for better stackability with about 200% warp fill (for a flat weave 20th ) to enable. The MD warp yarns can have various sizes and cross-sectional shapes, such as round or rectangular. Preferably the size is in the range from 100 tex to 1000 tex. The specific sizes and cross-sectional shapes for the MD yarns 32 , 38 can be selected depending on the application.

Still referring to the 1 and 2 are at least some of the CD yarns 52 elastic CD yarn 52A . The elasticity of the elastic CD yarns 52A can be based on an elasticity of the material used to form the elastic CD yarns such as TPE (thermoplastic elastomer), TPU (thermoplastic urethane), PLA (poly (lactic acid) or polylactic acid or polylactide) or other elastomers, through a structure of the elastic CD Yarns formed from conventional materials such as polyamide or polyester, such as braided yarns, knitted yarns, hollow monofilament yarns, or by a combination of structural elasticity and material elasticity. Depending on the weave pattern of the fabric 20th can for example be every fourth, eighth or sixteenth CD thread 52 an elastic CD thread 52A be. The position and spacing of the CD elastic yarns 52A however, it can be varied. The CD yarns 52 may be circular in cross-section, but may have other shapes, and the size may vary depending on the application. In a preferred embodiment, the CD yarns 52 woven in pairs and every other pair contains the elastic CD yarns 52A . Also the diameter of the CD threads 52 in each pair can vary.

With reference to the are the elastic CD yarns 52A so arranged that if a section of tissue 20th around a conveyor roller 14th is bent around at least some of the MD yarns 32A with improved adhesion in one area of the conveyor roller 14th from the surface bearing plane 40 that at a distance T1 from the surface of the conveyor roller 14th adjacent to conventional CD yarns 52B is indicated, can be moved into a release position, indicated by the distance T2 from the surface of the conveyor roller 14th adjacent to the elastic CD yarns 52A , the CD yarn 52A be compressed by a force generated by the fabric tension (radial force towards the axis of the roller). It must be the outer part of the fabric 20th travel a longer path (roll diameter plus fabric thickness) than the machine side of the fabric 20th so that the force is increased so that at least part of the MD yarns 32A with improved adhesion on the upper side of the elastic CD yarns 52A is adapted to move below the surface bearing plane, ie T2 <T1, around a handle of the fabric 20th on the one on the surface bearing plane 40 worn material 11 to reduce. In the configuration of the conveyor belt 10 with that in the 1 , 2 and 4th the tissue shown, the difference ranged from 60 to 100 µm for the tissue 20th with a thickness of about 1.5 mm. However, this can vary depending on a number of factors including one or more factors such as belt tension and roll diameter, softness / hardness (elasticity) of the material, weave pattern, and fabric thickness.

When the section of tissue 20th that was bent from the conveyor roller 14th expires are the MD yarns 32A with improved adhesion tailored to the surface bearing plane 40 to return. As in the 1 , 2 and 4th preferably all MD yarns go 32A with improved adhesion over the elastic CD yarns 52A on the carrying side. But it is also possible to use at least some of the conventional MD yarns 32B on a support surface via the elastic CD yarns 52A run or only part of the reinforced MD yarns 32A about the elastic CD yarns 52A to run on the carrying side.

The preferred embodiment of the fabric 20th is a double chain fabric. The invention can be applied to single or other multilayer fabrics.

In a further aspect of the invention, the conveyor belt 10 ' without the MD yarns 32A can be shaped with improved adhesion so that each thread is in the position on the wearer 30th a conventional MD yarn 32B is. The same weave pattern as in the 1 and 2 or another suitable weave pattern can be used. At least some of the CD yarns 52 are elastic CD yarns 52A , and CD elastic yarns 52A are arranged so that on a section of fabric 20 ' , of the on a conveyor roller 14th is bent, at least part of the MD yarns 32B is moved from the surface support plane to a release position by the elastic CD yarns 52A by a force of the MD yarns on the wearer side 32 be compressed so that at least part of the MD yarns 32b on top of the elastic CD yarns 52a under the through the tissue 20 ' defined surface bearing plane 40 is moved in order to adhere the fabric to a surface bearing plane 40 worn material 11 to reduce. This alternative can be for materials 11 be useful that have good adhesion or adhesion to the conventional MD yarns 32B have, which are necessary for the transport without slippage, in order to facilitate the release of the material 11 when unloading or transferring to another conveyor belt or another roller. As in the previous embodiment, the MD yarns are reversing 32B to the surface bearing plane 40 back when the bent section of the fabric 20 ' from the conveyor roller 14th going off.

In this context it would be if increased liability is required, as in shown, also possible after completion of the fabric 20 ' an adhesive coating 33 ' at least on the MD yarns on the wearer side 32B such as a water-based polyurethane coating.

In a further aspect of the invention, a method of transferring a material 11 from a surface of a conveyor belt 10 , 10 ' that is between two roles 12 , 14th running. The method includes providing the conveyor belt 10 , 10 ' as tissue 20th , 20 ' , as detailed above, wherein at least a portion of the CD yarns 52 elastic CD yarn 52A are. These elastic CD yarns 52A are arranged so that on a section of fabric 20th , 20 ' that deals with the role 14th bends at least some of the MD yarns 32 is moved from the surface support plane to a release position by the elastic CD yarns 52A by a force of the base layer MD yarns 32 be compressed so that at least part of the MD yarns 32 on top of the elastic CD yarns 52A below the surface bearing plane 40 is moved in order to adhere the tissue 20th , 20 ' on the one on the surface bearing plane 40 worn material 11 to reduce. When the section of curved fabric 20th , 20 ' from the conveyor roller 14th runs out, the MD threads sweep 32 to the surface bearing plane 40 back. When performing the procedure, part of the woven fabric 20th , 20 ' about the role 14th bent around at least part of the elastic CD yarns 52A compressed and at least part of the MD yarns 32 , 32A is moved to the release position, reducing the adhesion of the tissue 20th , 20 ' on the material to be transferred 11 is reduced. The material 11 is then off the conveyor belt 10 , 10 ' to hand over.

As explained above, at least some of the base layer-side MD yarns 32 than MD yarns 32A provided with improved adhesion. Alternatively, at least on the carrying side of the MD yarns 32 an adhesive coating can be provided.

Having thus described the present invention in such detail, it will be appreciated, and will be apparent to those skilled in the art, that many physical changes, few of which are exemplary in the detailed description of the invention, could be made without the inventive concepts and concepts contained therein To change principles. It should also be noted that numerous embodiments are possible including only a portion of the preferred embodiment that do not change the inventive concepts and principles contained therein with respect to those portions. The present embodiment and the optional configurations are therefore to be considered in all respects as exemplary and / or illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and therefore all alternative embodiments and changes thereto Embodiments that come within the meaning and scope of equivalency of these claims are to be included therein.

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• US 6790796796 B2 [0005, 0006]
• DE 2053624 A1 [0007]
• DE 102016107811 [0008]

Claims (14)

Conveyor belt with support side and machine side surfaces, comprising: a fabric comprising at least one machine-side layer of MD yarns and a support side layer of MD yarns which are woven with at least one layer of CD yarns, at least some of the supporting layer side MD yarns are reinforced adhesive yarns, all supporting layer side MD yarns define one Surface support plane, at least some of the CD yarns are elastic, the elastic CD yarns are arranged in such a way that at least some of the MD yarns with improved adhesion in a region of the conveyor roller are adapted to a section of the fabric that is bent around a conveyor roller are that they move from the surface support plane to a release position by compressing the CD yarns of the elastic material with the support layer by a force of the MD yarns, so that at least some of the MD yarns with improved adhesion on the upper side of the elastic CD yarns are adapted so that they move below the surface bearing plane in order to ensure that the G To reduce ewebes to one material that is supported on the surface bearing plane, and when the portion of the curved fabric runs off the conveyor roller, the MD yarns with improved adhesion are adjusted to return to the surface bearing plane. Conveyor belt after Claim 1 wherein the MD yarns with improved adhesion are formed from a thermoplastic elastomer. Conveyor belt after Claim 1 wherein the thermoplastic elastomer is a block copolymer with alternating soft and hard segments, a mixture / alloy of a rubber-like polymer with a thermoplastic polymer or a composition of a rubber-like polymer and a thermoplastic polymer with a highly vulcanized / crosslinked similar polymer in a finely divided thermoplastic polymer includes. Conveyor belt after Claim 1 wherein the thermoplastic elastomer is a styrene block copolymer, a thermoplastic polyolefin, a mixture of alloyed polypropylene and crosslinked EPDM rubber, a thermoplastic vulcanizate, a mixture of polypropylene and ethylene-propylene-diene (EPDM) rubber, a thermoplastic polyurethane, a thermoplastic copolyester , a melt processable EPDM rubber, a thermoplastic polyether block amide, or an ionomeric thermoplastic elastomer. Conveyor belt after Claim 1 wherein the MD yarns are arranged with improved adhesion than at least every 16th load-bearing side MD yarn. Conveyor belt after Claim 1 wherein the MD yarns with improved adhesion, arranged like any other load-bearing side MD yarn. Conveyor belt after Claim 1 wherein an elasticity of the CD elastic yarns is generated by at least one elasticity of the material used to form the CD elastic yarns or a structure of the CD elastic yarns. Conveyor belt after Claim 1 wherein at least every fourth of the CD yarns are the elastic CD yarns. Conveyor belt after Claim 1 wherein the CD yarns are woven in pairs and one of the CD yarns in each other of the pairs is one of the elastic CD yarns. Conveyor belt after Claim 1 wherein all MD yarns with improved adhesion run over the elastic CD yarns on the carrying side. Conveyor belt after Claim 1 wherein the backing side layer includes at least some conventional yarns. Conveyor belt after Claim 11 wherein at least a portion of the conventional MD yarns pass over the elastic CD yarns on a support surface. Conveyor belt with support side and machine side surfaces, comprising: a fabric comprising at least one machine-side layer and one support-side layer made of MD yarns which are interwoven with at least one layer of CD yarns, all of the base layer side MD yarns defining a surface bearing plane, at least some of the CD yarns being elastic, the elastic ones being elastic CD yarns are arranged so that on a portion of the fabric that is bent onto a conveyor roller, at least a part of the MD yarns is moved from the surface support plane into a release position by the CD yarns of the elastic material by a force of the support side layer MD yarns are compressed so that at least a portion of the MD yarns on top of the elastic CD yarns are moved below the surface bearing plane to reduce adhesion of the fabric to a material supported on the surface bearing plane, and if the portion of the fabric that has been bent runs off the feed roller, the MD yarns return to the surface bearing plane n. Conveyor belt after Claim 13 , further comprising an adhesive coating at least on the MD yarns on the wearer side.

Images