Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/02—Making granules by dividing preformed material
  • B29B9/06—Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion
  • B29B9/065—Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion under-water, e.g. underwater pelletizers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D28/00—Shaping by press-cutting; Perforating
  • B21D28/24—Perforating, i.e. punching holes
  • B21D28/26—Perforating, i.e. punching holes in sheets or flat parts
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/02—Making granules by dividing preformed material
  • B29B9/06—Making granules by dividing preformed material in the form of filamentary material, e.g. combined with extrusion
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/12—Making granules characterised by structure or composition
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/05—Filamentary, e.g. strands
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/251—Design of extruder parts, e.g. by modelling based on mathematical theories or experiments
  • B29C48/2511—Design of extruder parts, e.g. by modelling based on mathematical theories or experiments by modelling material flow, e.g. melt interaction with screw and barrel
  • B29C48/2515—Design of extruder parts, e.g. by modelling based on mathematical theories or experiments by modelling material flow, e.g. melt interaction with screw and barrel in the die zone
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/30—Extrusion nozzles or dies
  • B29C48/345—Extrusion nozzles comprising two or more adjacently arranged ports, for simultaneously extruding multiple strands, e.g. for pelletising
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/78—Thermal treatment of the extrusion moulding material or of preformed parts or layers, e.g. by heating or cooling
  • B29C48/86—Thermal treatment of the extrusion moulding material or of preformed parts or layers, e.g. by heating or cooling at the nozzle zone
  • B29C48/87—Cooling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
  • B29C48/919—Thermal treatment of the stream of extruded material, e.g. cooling using a bath, e.g. extruding into an open bath to coagulate or cool the material
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F30/00—Computer-aided design [CAD]
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
  • B29B9/00—Making granules
  • B29B9/12—Making granules characterised by structure or composition
  • B29B2009/125—Micropellets, microgranules, microparticles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2793/00—Shaping techniques involving a cutting or machining operation
  • B29C2793/0027—Cutting off
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C2793/00—Shaping techniques involving a cutting or machining operation
  • B29C2793/009—Shaping techniques involving a cutting or machining operation after shaping
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
  • B29C48/04—Particle-shaped
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
  • B29K2101/12—Thermoplastic materials
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T29/00—Metal working
  • Y10T29/49—Method of mechanical manufacture
  • Y10T29/496—Multiperforated metal article making

Definitions

• the invention relates to a granule well plate, to a method for calculating well lengths of a granule well plate, and to a method for producing a granule well plate.
• thermoplastic material in particular polymers such.
• polymers such as polyethylene or polypropylene
• granulating devices in which extruded, molten plastic material is pressed through nozzle holes of a perforated plate in a cooling fluid, such as water, which in a
• Cutting chamber is located so that the emerging melt material is brought to solidification as quickly as possible by cooling. In the cutting chamber is still a
• Knife arrangement with knives which cover the openings of the perforated plate and separates the material strands, so that Granula tgromer be formed.
• Micro-injection molding, rotational molding, packaging or compounding / masterbatches increasingly microgranules use, indicative of granules with dimensions less than or equal to 1.0 mm.
• For microgranulation specially manufactured perforated plates are usually used, in which a large number of nozzle bores are formed. The nozzle holes are in
• Hole nest also referred to as cluster, grouped in which a variety of
• Nozzle holes are formed in close proximity.
• a plurality of bore nests is in turn arranged lying on one or more pitch circles of the perforated plate.
• Granulating devices of this type are known, for example, as underwater granulators of the SPHERO® series from Automatik Plastics Machinery GmbH.
• Hot zones of the perforated plate approximately in the immediate vicinity of a heat channel in which circulates a heat transfer oil, for example, 240 ° C for heating the perforated plate, or in the melt supply, in which the melt is supplied, for example, 230 ° C of the perforated plate, are colder zones opposite, as the opening side of the perforated plate, which is in contact with and is rinsed by the cooling fluid, which may for example have a temperature of 70 ° C.
• the cooling effect of the cooling fluid is particularly pronounced in the area of the nozzle nests or nozzle bores, since there the contact surface of the perforated plate is in particularly intensive contact with the cooling fluid.
• Düsennestes may have different effects, wherein nozzle bores, which are arranged peripherally in the region of the nozzle nest, may be colder than centrally arranged
• melt material in the outer, cooler nozzle bores cools down to such an extent that it no longer flows and hardens.
• the affected holes "freeze” and it reduces accordingly, the number of nozzle holes of the perforated plate, which are in operation and emerging from the melt material that can be granulated.
• the freezing of nozzle bores thus leads to a reduction in granulation, or to a undesirable increase in the mean particle size distribution of the granules, since freezing of individual nozzle bores the throughput through the remaining free
• Nozzle holes increased. It is therefore an object of the invention to provide a perforated plate which overcomes the above disadvantages.
• thermoplastic material according to claim 14 solved.
• the present invention relates to a perforated plate for producing granules of thermoplastic material, having a plurality of nozzle bores, wherein the nozzle bores are each sized in length so that the nozzle bores have a substantially equal throughput of melt material.
• Nozzle holes are substantially compensated by the length of each
• the perforated plate may preferably be a perforated plate for producing ikrogranulat of thermoplastic material having a plurality of nozzle nests, which are arranged on at least one pitch circle of the perforated plate.
• Each nozzle nest may have a plurality of nozzle bores, which preferably each have the same
• the nozzle bores may have a diameter of less than 1.0 mm, preferably in the range of 0.2 to 0.8 mm.
• the bore length can be shortened by introducing a pilot hole of larger diameter, thus lowering the nozzle bore.
• a segment thickness may be altered or otherwise the topology of the nozzle nest may be changed to a shorter nozzle bore
• the topology may be described by a stepped surface, an aspherical surface, or a spherical surface that describes a side of the nozzle nest that faces away from a knife assembly and / or faces an inlet channel.
• the variation of the bore lengths may be a few 1/10 mm.
• the length of the nozzle bores can be determined in particular by means of a
• the present invention relates to a computer-implemented method for determining nozzle bore lengths for a die plate for producing granules of thermoplastic material, the die plate having a plurality of nozzle bores, comprising the steps of:
• the subset may describe a number of nozzle bores which are arranged adjacent in the perforated plate and / or formed in a delimitable region of the perforated plate are.
• the subset can represent a subset of all nozzle holes of the perforated plate. It is also possible in the process all the nozzle holes of the perforated plate to
• the subset corresponds to the entire plurality of nozzle bores.
• nozzle bore lengths are preferably determined for a perforated plate for producing microgranulate, wherein the perforated plate has a plurality of nozzle nests which are arranged on at least one pitch circle of the perforated plate.
• Nozzle holes can correspond to the nozzle bores of at least one of the nozzle nests.
• the computer-implemented simulation is performed as a three-dimensional simulation using Computational Fluid Dynamics CFD.
• the model can affect the geometry and the heat transfer
• the model may be a nozzle nest or may describe multiple nozzle nests as the subset. It is also possible to use a model for the entire perforated plate.
• the operating parameters may in particular viscosity parameters for the melt material, a
• Lochpia ttenMapungstemperatur and / or a cooling fluid temperature include.
• the flow rate of melt material through a nozzle bore can be determined by determining the rate at which the melt material flows through the nozzle bore.
• a velocity profile can be determined via the diameter of the at least one nozzle nest and / or the average velocity over the diameter.
• the reference value may preferably be a predetermined setpoint for the throughput of
• Melt material a value of the flow rate of melt material determined for a nozzle bore selected as a reference, or an average of the flow rate of melt material of all nozzle bores of the subset of nozzle bores.
• a reference nozzle bore may preferably be a centrally located in the nozzle nest nozzle bore can be selected.
• the length of a nozzle bore can be shortened if the melt flow rate determined for the nozzle bore is less than the reference value.
• the length of a nozzle bore can be changed with a fixed predetermined increment.
• the length of a nozzle bore is varied with a varying value.
• a step size decreasing for each iteration may be used.
• a quality measure is determined that is representative of a deviation of
• the quality measure may in particular be based on a minimum value and / or a maximum value of the determined throughputs of melt material through the nozzle bores; a difference between the maximum value and the minimum value of the determined throughputs of melt material through the nozzle bores; or a sum of the squares of the differences in the determined throughputs of melt material through the nozzle bores to an average of the determined throughputs of the melt material.
• the quality measure can in particular be used to be compared with a predetermined criterion in an iterative determination of nozzle bore lengths, wherein the iteration is aborted if the quality measure satisfies the criterion.
• the method can be used to appropriate, especially optimal
• the method may be part of a method for producing a perforated plate for producing micro-granules of thermoplastic material, wherein the perforated plate is manufactured according to the determined nozzle bore lengths.
• the perforated plate may be part of a hot roll pelletizer.
• microgranules of LDPE with 5% Masterbatch white were prepared by means of an underwater pelletizer SPHERO 50 with a material throughput of 16 kg / h through a perforated plate with 20 holes, the associated knife carrier with 6 knives had a speed of 3500 rev / min.
• the particle size distribution thus obtained was determined by means of a Camsizer from Retsch Technology GmbH.
• the nozzle length compensation according to the invention causes a significant reduction of the standard deviation, i. With almost constant granule diameter, the size distribution of the Granulatkömer is much narrower and thus the throughput per nozzle bore much more uniform.
• Fig. 1 shows a Mikrogranulatlochplatte according to an embodiment
• Fig. 2 shows schematically a section of a perforated plate in the region of a nozzle nest
• FIG. 3 shows an exemplary temperature profile in a section of a perforated plate in the area of a nozzle test in the case of identical nozzle bore lengths
• Fig. 4 schematically illustrates a first distribution of melt flow velocities through nozzle bores of a nozzle nest in the case of equal nozzle bore lengths
• Fig. 5 schematically illustrates a second distribution of melt flow velocities through nozzle bores of a nozzle nest in the case of equal nozzle bore lengths
• Fig. 6 shows schematically a nozzle bore with adapted bore lengths of
• Nozzle holes according to one embodiment
• Fig. 7 schematically illustrates a distribution of velocities of melt flows
• FIG. 8 shows an exemplary temperature profile in a section of a perforated plate in the area of a nozzle nest for the case of adapted nozzle bore lengths according to an embodiment
• FIG. 9 shows a method for determining nozzle bore lengths for a die plate according to an embodiment
• FIG. 10 schematically shows a section of a perforated plate in the region of a nozzle nest according to a further embodiment.
• FIG. 1 A perforated plate 10 for producing micro-granules of thermoplastic material according to an embodiment is shown in FIG. 1 in a plan view of a melt outlet side of the perforated plate 10.
• a plurality of nozzle bores 30 are formed, which are in Bohrungsnestem 20, also referred to as clusters, grouped.
• the Bore nests 20 are arranged lying on one or more pitch circles of the perforated plate 10.
• FIG. 2 shows a section in the region of a nozzle nest 20 of a perforated plate 10 for producing ikrogranulat from thermoplastic material according to another
• a plurality of nozzle bores 30 are formed in the nozzle nest 20.
• the nozzle bores 30 each have a same bore diameter, which may be in the range between 0.1 mm and 1.0 mm.
• the nozzle bores 30 are formed in the nozzle nest 20 in close proximity.
• the distance between two adjacent nozzle bores may be less than 7 times, preferably less than 5 times, more preferably less than 3 times the bore diameter of the nozzle bores 30. In this way, a compact package is achieved and it can be formed in the perforated plate 10 a very large number of nozzle nest 20 with a large number of nozzle bores 30.
• FIG. 1 As further illustrated in FIG.
• the nozzle nest 20 may be formed as an insert 22 which is inserted into a perforated plate body to form the perforated plate 10. It is ebeno possible to form the perforated plate 10 in one piece and form the nozzle nest in the one-piece body of the perforated plate 10.
• the nozzle bores 30 may be arranged in the nozzle nest 20 irregularly or regularly distributed, for example, regularly distributed on concentric circles, or in a triangular, quadrangular or hexagonal arrangement.
• a feed channel 40 can be provided in the perforated plate 10, by means of which hot melt material is supplied to the nozzle nest 20.
• Fig. 2 further channels 50 are shown, which are formed in the perforated plate 10 and which serve to guide a heat transfer fluid to temper the perforated plate 10.
• the hot melt material supplied via the supply passage 40 to the nozzle nest 20 is forced through the plurality of nozzle bores 30 of the nozzle nest 20 to be forced through the outlet side openings of the nozzle bores 30 into a cooling fluid, such as water to become.
• the outlet-side surface of the perforated plate 10 is therefore in particular in the area of
• Nozzle nests 20 in intimate contact with the cooling fluid, which may for example have a temperature of 70 ° C. This causes a flow of heat energy from the hot perforated plate 10 into the cold cooling fluid, which locally cools the perforated plate 10, in particular in the area of the nozzle nests 20, which has an effect on the temperature of the nozzle bores 30 in particular.
• the nozzle bores 30 of the nozzle nests 20 are at the same time in intimate contact on their inner walls with the hot melt material flowing through the nozzle bores 30, which emits a portion of the heat energy contained via the inner wall to the respective nozzle bores 30.
• a nozzle bore 30 arranged in the center of the nozzle nest 20 is completely surrounded by further nozzle bores 30, while no further adjacent nozzle bores exist to the outside for a nozzle bore 30 arranged at the edge of the nozzle nest 20.
• the nozzle bores 30 all have a same geometry, in particular a same diameter and a same length.
• the heat given off by a nozzle bore 30 arranged in the center of the nozzle nest 20 therefore feeds a smaller volume of the nozzle nest 20, and therefore heats it more strongly than does a nozzle bore 30 arranged at the edge of the nozzle nest 20.
• the proportion of the surface in contact with the cold cooling fluid, which is dispensed with a nozzle bore 30 arranged at the edge of the nozzle nest 20 is smaller because of the smaller number of neighboring holes
• the nozzle bores 30 at the edges of the nozzle nest more strongly cool and have a lower temperature than nozzle bores 30 in the center of the nozzle nest 20.
• FIG. 3 is the result of a simulation of the
• the different temperatures of the nozzle bores 30 cause melt material, which flows through a nozzle bore 30 arranged at the edge of the nozzle bore 20, to be cooled more strongly than is the case for melt material which is arranged in the center of the nozzle nest due to the relatively colder inner wall Nozzle bore 30 flows, due to the relatively warmer nozzle bore there.
• FIG. 4 shows the result of a simulation of the flow of melt material through the nozzle nest 20, in the representation of FIG. 4 for each nozzle bore 30 the vectors of the velocity are shown, with the Melt material flows through the respective nozzle bores 30 and exits therefrom.
• Fig. 4 it can be seen that the speed at which the melt material by a
• Nozzle bore 30 flows, highest for centrally located in the nozzle nest 20
• Nozzle holes and the speed decreases towards the edge of the nozzle nest 20, as can be seen by the different length and width velocity vectors.
• FIG. 5 shows a further result of a further simulation of the flow of melt material through the nozzle nest 20, in which case those lying on the edge of the nozzle nest 20
• Nozzle holes 30 have cooled down to such an extent that the melt material no longer flows and the peripheral nozzle bores 30 are "frozen";
• the nozzle bores 30 can be countersunk with pilot bores, such that the pilot bores extend the nozzle bores 30 to such an extent that different nozzle bore lengths result for different nozzle bores 30.
• Nozzle holes 20 may be made with a deeper pilot hole, so that there is a shorter nozzle bore length for the located at the edge of the nozzle nest 20 nozzle bores 30 than for centrally located in the nozzle nest 20 nozzle bores.
• the hydraulic resistance of the affected nozzle bore 30 is reduced, so that it presents a smaller flow resistance to the melt flow.
• the melt flow can therefore flow faster through the shortened nozzle bore 30.
• the nozzle bore length is dimensioned such that the resulting, adjusted hydraulic resistance compensates for the influence resulting from the temperature differences as optimally as possible.
• melt material through the nozzle bores 30 results. This is shown by way of example in FIG. 7, which adjusts a distribution of melt flow velocities through nozzle bores of a nozzle nest in the case
• nozzle bore lengths Represents nozzle bore lengths.
• the velocity vectors of the melt material are essentially the same for all nozzle bores 30 of the nozzle nest 20. This was achieved in that, as can also be seen in FIG. 7, the nozzle bore lengths, in particular those at the edge of the nozzle nest 20 lying nozzle bores 30 have been lowered accordingly far, so that the nozzle bore lengths of the peripheral nozzle bores 30 are adjusted and shortened so that the best possible compensation results.
• Nozzle bore lengths are used for a perforated plate shown in FIG.
• a model is first provided in a step 110.
• the model used as a computational and / or
• Simulation model describes the geometry and properties of the perforated plate.
• the model describes the number and spatial arrangement of the nozzle bores 30 in the nozzle nest 20, as well as the geometry of the nozzle bores 30 themselves, such as diameter and length of the nozzle bores.
• the model can further describe the thermal behavior of the materials of the perforated plate. It is possible that the model describes only the area of a nozzle nest. This may be possible in particular if all the nozzle nests 20 of the perforated plate 10 are subject to the same conditions, for example if all the nozzle nests 20 are arranged on the same pitch circle of a rotationally symmetrical perforated plate 10. Alternatively, it is also possible that the model describes the entire perforated plate 10, or that the model describes a region of the perforated plate 10 with a plurality of nozzle nest 20.
• the parameters necessary for the calculation and / or simulation are provided.
• this can be parameters of a desired
• Predeterminable parameters can be, in particular, viscosity parameters for the melt material, a temperature of Melting material in a supply area, a perforated plate heating temperature or a ühlfluidtemperatur include.
• step 130 computer-aided calculation and / or simulation is performed in step 130 to determine how the melt material flows through the nozzle nest 30. Preference is given to a three-dimensional simulation using
• Computational Fluid Dynamics executed. In this way, it is determined for each nozzle bore, which throughput of melt material results through the individual nozzle holes.
• the throughput can be determined directly as a calculated value or derived from the flow rate of the melt material.
• a step 160 the lengths of the nozzle bores are adjusted.
• the nozzle bore lengths can be shortened.
• the nozzle bore lengths can be extended. The calculation process would then be with a corresponding new (e.g., longer) bore
• a reference value can be used. If the flow rate of melted material determined for a nozzle bore deviates from the reference value by more than a predetermined amount, it is determined that the length of the nozzle bore is to be changed.
• a reference for example, a predetermined setpoint for the flow rate of melt material, a value of the throughput of
• Nozzle nesting be used.
• the nozzle bore lengths may be changed at a predetermined pitch.
• the step size can preferably be reduced with each iteration.
• the method may return to step 130 to re-calculate and / or simulate the changed nozzle bore lengths. In this way it is possible in an iterative manner, by means of repeated simulations and changes, to determine step by step the most optimal determination of the nozzle bore lengths.
• a quality measure can be determined that is representative of a deviation of the throughputs of melt material by the
• the quality measure may be based on a minimum value and / or a maximum value of the determined throughputs of melt material through the nozzle bores, a difference between the maximum value and the minimum value of the determined throughputs of melt material through the nozzle bores, or a sum of the squares of the differences determined throughputs of melt material by the
• the quality measure can thus be a measure of how good the compensation made by the change in length.
• a comparison of the quality measure with a predeterminable criterion can be made to determine whether the compensation provided
• steps 160, 130, 140 and 50 are iteratively repeated until the criterion is met or the method is aborted by a user.
• step 150 If it is determined in step 150 that the quality measure satisfies the predetermined criterion, the method goes to step 170 and ends.
• the determined nozzle bore lengths can now be output, for example to produce a perforated plate on the basis of the data obtained.
• the nozzle bores 20 can be adjusted in length by mounting pilot holes which are the
• Countersink nozzle bores 30 so far that the nozzle bores 30 provided for the respective nozzle bores result.
• the nozzle nest 20 may be formed by an insert 22 which may be inserted into a perforated plate main body to form the perforated plate 10.
• the plurality of nozzle bores 30 of the nozzle nest 20 are formed.
• the insert 22 is formed in the example of FIG. 10 so that the insert 22 on the side facing the blade assembly plan and on the inlet channel 40 side facing is convex. This results in a topology of the insert 22, on the basis of which nozzle bores 30 in the center have a length which is greater than the length of
• the insert 22 can be processed, for example, on the side facing the inlet channel 40 by a processing center which processes the affected area as a free-form surface in order to obtain the corresponding determined nozzle lengths.
• the surface may have a stepped profile, or as shown in Fig. 10, a substantially lenticular profile.
• the profile can be described by an aspherical surface.
• the profile may also be described by a spherical surface, wherein the parameters of the spherical surface may be chosen so that the determined adapted lengths of the nozzle bores to be achieved are approximated as well as possible.
• a spherical surface machining can also be done by grinding.
• the nozzle bores 30 can be adapted in the nozzle nest 20
• Nozzle bore length can be formed without interfering with the affected nozzle bores
• Nozzle holes can be improved.
• a respective adapted bore diameter can be determined for all nozzle bores of a nozzle nest by a corresponding simulation analogous to the method described with reference to FIG. 9, such that an optimally uniform or at least sufficiently uniform throughput of melt material is established through the nozzle bores. Since already a change of the
• Hydraulic resistance of the affected nozzle bore can cause the parameter of the nozzle diameter is very sensitive in terms of adjustability.
• Nozzle hole to determine an adapted length of the nozzle bore. If the determined length assumes a value that is greater than a desired maximum length of a nozzle bore, or a value that is smaller than a minimum length of a nozzle bore, the
• Output diameter can be increased or decreased and based on it emeut an adjusted length of the nozzle bore can be determined. In this way it can be achieved that the nozzle bores do not differ in their length in a possibly undesirably large extent. If only a limited number of differing diameters are provided for the possible diameters of the nozzle bores, for example 2, 3, 4 or 5 different diameters, it is possible to provide corresponding tools such as drills for this limited number of diameters, which allow precise production of these allow limited number of different diameters. That's the way it is without too much
• the nozzle bores are adjusted accordingly both in their diameter and in their length in order to achieve the most uniform throughput of melt material through the nozzle bores.
• Microgranulate was described, the present invention is not limited in this way. Rather, the invention can also be applied to other types of perforated plates having a plurality of nozzle bores, which need not be arranged in the nozzle nest.

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• 2012
  • 2012-08-01 DE DE102012015257.4A patent/DE102012015257A1/de not_active Withdrawn
• 2013
  • 2013-07-29 EP EP13752819.6A patent/EP2879850A1/de not_active Withdrawn
  • 2013-07-29 WO PCT/EP2013/002233 patent/WO2014019668A1/de active Application Filing
  • 2013-07-29 JP JP2015524664A patent/JP2015524758A/ja active Pending
• 2015
  • 2015-01-28 US US14/608,090 patent/US20150149125A1/en not_active Abandoned

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