Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01F—CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
  • D01F1/00—General methods for the manufacture of artificial filaments or the like
  • D01F1/02—Addition of substances to the spinning solution or to the melt
  • D01F1/09—Addition of substances to the spinning solution or to the melt for making electroconductive or anti-static filaments
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H5/00—Drafting machines or arrangements ; Threading of roving into drafting machine
  • D01H5/18—Drafting machines or arrangements without fallers or like pinned bars
  • D01H5/70—Constructional features of drafting elements
  • D01H5/86—Aprons; Apron supports; Apron tensioning arrangements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G15/00—Conveyors having endless load-conveying surfaces, i.e. belts and like continuous members, to which tractive effort is transmitted by means other than endless driving elements of similar configuration
  • B65G15/30—Belts or like endless load-carriers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
  • B65G2207/00—Indexing codes relating to constructional details, configuration and additional features of a handling device, e.g. Conveyors
  • B65G2207/10—Antistatic features

Definitions

• the present invention relates to a conveyor belt for transporting a fibrous material to be compressed pneumatically, wherein the
• Conveyor belt at least in a fiber material-carrying region of an air-permeable sheet, in particular a fabric, consists of plastic filaments and wherein the plastic filaments are at least partially formed electrically conductive and a method for its preparation.
• the fiber material is first stretched in a arranged on the spinning frame drafting. Before the stretched fiber material is subsequently spun in the spinning unit of the spinning machine, the fiber material is passed through the
• Conducted compression device in which the stretched fiber structure is compressed and is reduced in width, so that the fibers lying in the edge region of the fiber strand are well integrated into the resulting thread. As a result, high-quality yarns with a low hairiness can be produced.
• the conveyor belt is driven and thereby transports the fiber structure through the compression zone arranged after the drafting equipment outlet.
• compression devices with an air-permeable
• Conveyor belt often encounters the problem that the conveyor belt, which is usually made of synthetic fibers, electrostatically charges, causing undesirable adhesion of fibers and contaminants to the Conveyor belt can come. As a result, the air permeability of the conveyor belt and thus the compaction effect of
• Compaction device reduced. To solve this problem has already been proposed to form the fabric of the conveyor belt electrically conductive so far that electrostatic charges can be avoided.
• DE 10 2004 005 953 A1 proposes to add to the fabric electrostatic charging-preventing materials.
• metal fibers or carbon fibers can be used as electrically conductive fibrils in a multifilament.
• the plastic filaments are monofilaments interspersed with cut carbon fibers.
• conveyor belts can be produced, which can reduce electrostatic charges.
• the properties of the conveyor belt are lost in terms of its flexibility and strength, so that it can come in operation to damage the conveyor belts.
• damage to the incorporated fibers may occur, which impair the conductivity of the filament or of the conveyor belt.
• Object of the present invention is therefore to propose a conveyor belt which can be produced in a simple manner and a
• a conveyor belt for transporting a fibrous material to be compacted pneumatically is made of plastic filaments at least in a fiber material-guiding region from an air-permeable fabric, in particular a fabric.
• the plastic filaments are at least partially electrically conductive.
• the electrically conductive plastic filaments are conductive in that they contain electrically conductive filling material objects, wherein the filling material objects have a nanostructure and consist of a ductile material.
• Transporting a fibrous material to be compressed pneumatically plastic filaments are extruded from a plastic mass, which are at least partially formed electrically conductive and further processed to the fabric of the conveyor belt.
• the plastic mass to be extruded is admixed with electrically conductive filler objects which have a nanostructure and consist of a ductile material.
• a ductile material is understood as meaning a material which has an elongation at break of at least 10%, the value of the elongation at break relating to a conventional solid-state sample.
• electrically conductive nanofillers are used, which are already buried before the extrusion of the plastic material, it is possible, the electrically conductive
• Plastic filaments in a conventional manner by melt spinning but still fine filaments can be produced.
• Plastic filaments containing such filler objects can therefore be produced without special measures in conventional spinning devices in any subtleties and processed easily.
• Due to the ductility of the filler objects, a conveyor belt produced in this way can also withstand high mechanical loads during operation without losing its conductivity and flexibility, as may occur, for example, when using conventional fillers and, in particular, carbonaceous fillers.
• the ductile fillers in the filament can be plastically deformed very well without breaking. Thus, if they themselves are conductive, they can produce a conductive filament by more or less touching each other in the filament.
• the plastic filaments contain nano-objects made of a ductile material, the plastic filaments advantageously still have a very high conductivity even after stretching, which is necessary to increase the strength, because the nano-objects, due to their ductility, either overstretch or overshoot
• Nano-objects often have in comparison to solids made of the same material again improved properties and can have a particularly high ductility.
• the electrically conductive plastic filaments are designed as monofilaments, since they can be produced and drawn in a particularly simple manner.
• Filler objects an aspect ratio, ie a ratio of the length of the filler objects to their smallest lateral extent (width or
• Diameter of at least 10, preferably of at least 100 and more preferably of at least 1000.
• the ductile material has an elongation at break of at least 10%, preferably of at least 30% and particularly preferably of at least 40%.
• the elongation at break figures again refer to conventionally determined values for tensile specimens from a solid. In particular come into question
• Filler objects containing or consisting of gold, silver, copper, nickel, aluminum, zinc, tin or even lead are particularly advantageous if the ductile material is silver and / or contains silver, since this can reach an elongation at break of about 60%. It can therefore be used for the filaments also materials that are higher factors, eg. B. 2 to 7 times their original length, are stretched, for example, polyamides. For fibers that are stretched only by a smaller factor, for example POY fibers (Partially Oriented Yarn) made of polybutylene terephthalate, but also filler objects made of a material with a lower elongation at break, for example steel and iron materials, can be used.
• POY fibers Partially Oriented Yarn
• Filler objects designed as silver nanorods These can be made with a particularly high aspect ratio of about 2000 and are also suitable for filaments drawn by a larger factor. On the other hand, with less ductile materials and / or with shorter structures there is a risk that the individual filler objects will tear as a result of stretching or that the contact bridges between the filler objects will be torn apart.
• the plastic filaments contain less than 10% filler objects, preferably less than 5% filler objects, since the mechanical properties of the filaments are then only slightly changed and the filaments are still a good one
• the filler objects are simply added to the plastic mass to be extruded, without aligning them in a certain way. A parallelization and longitudinal alignment of the filler objects then takes place in the production process through the spinneret and possibly the later
• the filler objects have a smallest distance to a surface of the plastic filaments of at most 10 ⁇ m in order to achieve a charge dissipation through the material of the plastic filament.
• a high-quality conveyor belt with high strength values can be achieved if the plastic filaments are made of a synthetic polymer, in particular a polyamide, wherein preferably the filaments have been drawn before being further processed into the fabric.
• plastic filaments are made of a synthetic polymer, in particular a polyamide, wherein preferably the filaments have been drawn before being further processed into the fabric.
• Polyetheretherketone or polyoxymethylene are conceivable.
• Conveyor belt are embedded in the ductile nano-objects in plastic filaments, it is further that even after prolonged operation of the conveyor belt with respect to the conductivity and thus the dissipation of electrostatic charges no deterioration can be expected. While, for example, in coated fibers due to abrasion over time to a deterioration of conductivity, can be ensured by the randomly distributed nano-objects, even with a wear of the conveyor belt, the conductivity.
• Figure 2 is a schematic plan view of the compression zone of
• Compression device with a conveyor belt.
• Figure 1 shows a schematic cross-sectional view of a
• the spinning machine 1 has a drafting system 2 with presently three pairs of rollers, between which a fiber structure 9 is drawn in a conventional manner and then a spinning unit 4, in this case a ring spindle, is supplied.
• a spinning unit 4 in this case a ring spindle
• a pneumatic compression device 3 is arranged after the defined by the pair of output rollers 6 drafting.
• Suction slot 10 is in the present representation directly in a
• Suction channel 12 is provided.
• the suction channel 12 is connected to a vacuum source and can also be several spinning units 4th
• the conveyor belt 8 is guided by means of a clamping device 13 tensioned around the suction channel 12 and is driven to the fiber structure in the direction of arrow P1 through the compression zone 7 to transport.
• a pinch roller 1 1 which is connected to the output roller pair 6 of the drafting system 2 transmission technology, for example by means of a belt drive or a gear transmission.
• the fiber structure 9 is finally exposed to the compression effect of the suction flow.
• the pinch roller 1 1 also forms a nip 14, which limits the compression zone 7 and after which the
• Fiber assembly 9 of the spinning unit 4 is supplied where it receives its spin twist.
• the compression device shown here is to be understood merely as an example.
• the conveyor belt 8 instead of the drive by the pinch roller 1 1 may also be driven in another way or be guided over a self-driven drum.
• the conveyor belt 8 according to the invention can be used in all compaction devices 3, in which an air-permeable conveyor belt 8 is required.
• FIG. 2 now shows a schematic plan view of the compression zone 7 of a compression device 3 with a device according to the invention
• the conveyor belt 8 consists in the present case of a fabric 5, which is woven from individual plastic filaments 15 and thereby has a high strength.
• the execution of the conveyor belt 8 is also meant to be exemplary only.
• the conveyor belt 8 can also be embodied as air-permeable fabric only in its central region, which is guided over the suction slot 10 and be woven more firmly in the edge regions or consist of a different material.
• the conveyor belt 8 can also be made of a multiply perforated
• Sheet of plastic filaments 15 exist, for example, a knitted fabric.
• the plastic filaments 15 is electrically conductive, in which the plastic filaments are added electrically conductive filler objects, which have a nanostructure and consist of a ductile material.
• the corresponding plastic filaments can be produced particularly easily, since these are only the one to be extruded
• Plastic mass must be buried and because of their ductility in the processing process, for example, when peeling off the
• Filler objects is the flexibility and strength of such
• Plastic filament produced conveyor belt is not affected, so that it is not due to stress during operation to a tearing of contact bridges between the plastic filaments and thus a
• Plastic filaments 15 can also be easily after the
• Particularly advantageous in the conveyor according to the invention is further that this retains its electrical conductivity even after many hours of operation and even with heavy wear of the conveyor belt 8.
• this especially in the region of the nip 14, at which the pinch roller 1 1 limits the compression zone 7, causes a particularly high wear of the conveyor belt 8, which can lead to a strong reduction in conductivity in conveyor belts 8 of coated filaments 15 over time.
• objects having a nanostructure are added to a plastic melt, in particular a polyamide melt, a filler or filling material.
• a plastic melt in particular a polyamide melt
• a filler or filling material for example, silver nanorods which have a particularly high aspect ratio of 2000 have proved to be particularly advantageous.
• silver nanorods with a diameter of 50 nm and a length of 100 ⁇ m may be added. Due to the length of such silver nanorods sufficient electrical conductivity can be achieved even with the addition of a comparatively small amount of filler objects.
• Silver nanorods have a particularly high ductility. For example, fine silver as a solid already has an elongation at break of up to 60%. Due to the particularly high ductility of the buried
• Silver nanorod is therefore also a stretching of the produced
• Filaments 15 by a larger factor possible, without there being a cracking or breakage of contact bridges between individual, adjacent silver nanorods. But it can also be used nanorods made of gold, which usually have a lower aspect ratio. Also gold as well
• Gold alloys have a high elongation at break. Unless the
• Plastic filaments are stretched after their preparation only by a very small factor, in principle, nanofibers of an iron or steel material in question, by means of which still
• the distances between the individual filler objects can be so small even after a breakage of individual objects or a rupture of individual contact bridges that still a conductivity can be ensured.
• a conditioned polyamide may, for example, a
• a discharge can be achieved even at a voltage of 200 volts.
• these values can be easily achieved even with simple random arrangement in the plastic filaments, so with a simple addition to the plastic melt due to the length of the individual filler.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Belt Conveyors (AREA)
• Woven Fabrics (AREA)

Priority Applications (2)

Applications Claiming Priority (2)

Publications (1)

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Citations (4)

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• 2013
  • 2013-07-11 DE DE102013107353.0A patent/DE102013107353A1/de not_active Withdrawn
• 2014
  • 2014-07-07 WO PCT/EP2014/064479 patent/WO2015004072A1/de active Application Filing
  • 2014-07-07 EP EP14736788.2A patent/EP3019649A1/de not_active Withdrawn
  • 2014-07-07 CN CN201480039230.7A patent/CN105358747A/zh active Pending

Patent Citations (4)

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