Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F27/00—Mixers with rotary stirring devices in fixed receptacles; Kneaders
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/395—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders
  • B29C48/397—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using screws surrounded by a cooperating barrel, e.g. single screw extruders using a single screw
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/53—Screws having a varying channel depth, e.g. varying the diameter of the longitudinal screw trunk
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/56—Screws having grooves or cavities other than the thread or the channel
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/59—Screws characterised by details of the thread, i.e. the shape of a single thread of the material-feeding screw
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/62—Screws characterised by the shape of the thread channel, e.g. U-shaped
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/64—Screws with two or more threads
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/68—Barrels or cylinders
  • B29C48/685—Barrels or cylinders characterised by their inner surfaces, e.g. having grooves, projections or threads
  • B29C48/686—Barrels or cylinders characterised by their inner surfaces, e.g. having grooves, projections or threads having grooves or cavities
• • 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
• • 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
  • B29C48/2513—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 plasticising 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/507—Screws characterised by the material or their manufacturing process
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/505—Screws
  • B29C48/64—Screws with two or more threads
  • B29C48/65—Screws with two or more threads neighbouring threads or channels having different configurations, e.g. one thread being lower than its neighbouring thread
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/68—Barrels or cylinders
  • B29C48/6801—Barrels or cylinders characterised by the material or their manufacturing process

Definitions

• the present invention relates to a single-screw extruder having a grooved draw-in system, a cylinder and an extruder screw rotatably mounted in the cylinder, which has a softening zone, a Hauptplastifizierzone or Hauptschmelzzone and a Nachplastifizierzone or homogenizing or Restaufschmelzzone and is designed at leasttechnisch in the region of Hauptplastifizierzone ,
• a perennial requirement for single screw extruders is to increase their productivity. High throughputs at low discharge temperatures and high melt quality are to be achieved.
• the invention is based on the idea to operate a polygonal screw with a grooved feed system and in an at least partially grooved cylinder.
• Polygon screws are, for example, energy transfer screws (ET screws) and wave screws. These have a wave-shaped flight depth curve and stepped land areas, over which the melt in front of a wave crest, ie passage depth minimum, exceeds. While wave worms always have the same web discontinued, so that the melt flows over in different directions, the webs of ET worms alternate with each wave crest, so that the melt always flows in the same direction.
• the polygonal worm has at least two passages or channels with a channel depth which varies in each course in a wave-like manner and wave crests offset from one another to one another.
• the cylinder has, at least partially, at least one groove which runs essentially in the longitudinal direction, that is to say axially or spirally, but not exclusively radially.
• the minimum flight depth or channel height decreases in the direction of wave mountain from one gear to wave mountain of the other gear so that the relative compression, ie the ratio of the flight depths of two successive wave crests, remains approximately constant.
• Successive wave mountains are the wave mountain of a corridor and the following wave mountain of the neighboring Ganges.
• the flight depth increases in the valley areas, i. Gangtiefenmaxima, along the screw from valley to valley to increase the residence time of the plastic. Longer residence times favor temperature compensation processes in the raw melt between cold and warm material fractions.
• each screw land in front of each wave crest deposited to a gap, that is cut deeper than the remaining outer diameter of the screw, and the resulting gap height of the flight depth of each subsequent wave mountain corresponds.
• each screw flight on the active gear side in front of each wave crest is offset to a gap, wherein the gap height corresponds in each case to the flight depth of the following wave crest.
• the active gear side is the gear side from which the melt flows over the stepped land to the passive gear side.
• the stepped web can be stepped or continuously discontinued.
• the gap height corresponds in each case to the flight depth of the following wave crest
• the gap height on the subsequent wave crest corresponds in each case to the flight depth of this subsequent wave crest
• the length of the respectively offset web region along the screw increases in the process direction from wave mountain to wave mountain, so that the area of gap height and gap length in the process direction about 1 to 5%, but especially about 1 to 2% , increases. In this way, the decreasing flight depth in the area of the wave crests is compensated and the increase in the area of gap height and gap length does justice to the increase of the melt flow over the web.
• a further advantage is a pitch of the Hauptplastifizierzone of 1, 3 D (dimensionless slope), as this conveyor technology achieves the highest efficiency.
• the stepped land areas are advantageously provided on the active flank with a 45 ° bevel over about 30 to 70 percent, preferably about 50 percent, of the land width. This chamfer accelerates the material and increases the energetically more effective expansion flow component.
• the sections of increasing flight depth behind the wave crests are advantageously undercut, ie the flight depth behind the ridge quickly increases again, while the flight depth before the ridge slowly decreases.
• the sections of increasing flight depth behind a wave crest have a steeper flank than the sections of decreasing flight depth in front of a wave crest. In this way, unnecessary shearing is avoided and the material is better promoted.
• the screw is provided in sections of decreasing flight depth in front of a wave crest advantageously with additional groove-shaped recesses, so-called mixing pockets.
• the mixing pockets run parallel to the screw flights on the screw base.
• the mixing pockets promote the mixing of solids and melt. A multi-row arrangement of the mixing pockets enhances this positive effect.
• the depth profile and / or the width and / or the cross section of the groove are matched to the screw profile.
• the groove depth in the region of a wave crest on a local minimum In this way, the energy conversion or the melting capacity in the region of the wave crests can be controlled and a kind of drainage effect for the residual solids content can be generated.
• the single-screw extruder according to the invention has a significantly higher melting performance than known systems, the tendency for material overheating being greatly reduced.
• the comparatively small footprint of the single-screw extruder according to the invention is economically advantageous.
• the pressure level in the cylinder can be significantly lowered by the inventive design, whereby the energy efficiency is significantly improved and is expected to have a longer life of the extruder.
• FIG. 1 shows a development with Gangsiefenverlauf an extruder screw according to a first embodiment of the invention
• Fig. 2 shows a settlement with Gangsiefenverlauf an extruder screw with
• FIG. 3 shows an enlarged detail of the mixing pockets of Fig. 2 according to the second embodiment of the invention.
• the single-screw extruder according to the invention comprises a cylinder, not shown in the figures, and a polygon worm rotatably mounted in the cylinder.
• the polygon worm is designed as an energy transfer worm, as also shown in FIGS. 1 and 2.
• the polygon worm can also be designed as a wave worm.
• Fig. 1 shows a development with Gangsiefenverlauf an extruder screw according to a first embodiment of the invention.
• the extruder screw comprises in the process direction an intake zone 10, a softening zone 12, a Hauptplastifizierzone 14 and a Nachplastifizierzone not shown.
• the softening zone 12 comprises staggered, short web sections 16, which subdivide the still cold, hard solid bed several times. This results in a temperature increase in the solid. He is thereby plastically deformable.
• the main plasticizing zone 14 has two passages or channels 18, 20.
• the flight depth of the two gears 18, 20 independently of each other changes in a wave-like manner along the screw. In this way, deep gullies - wave troughs 22, shallow gullies - wave crests 24 and sections of decreasing gullet 32 and sections of increasing gullet 34 result. While troughs 22 and sections of decreasing 32 and increasing gullies 34 have a certain length, wave crests 24 ideally as can be seen in Fig. 1, a punctiform Gangsiefenminimum and do not extend over a longer range. Between the passages 18, 20, the screw webs 26, 28, which have the same, constant slope.
• the minimum channel depth at wave crests 24 from Wellenberg to Wellenberg is reduced in this way, that the relative compression, ie the ratio of the flight depths of two successive wave peaks 24, remains approximately constant.
• the maximum channel depth in the troughs 22, however, increases from valley to valley.
• the flight depth and aisle width depend on the delivery rate required for the desired throughput.
• the worm webs 26, 28 have on their active flank in front of the wave crests each offset areas - column 30 - on.
• the gap height corresponds to the flight depth of the following wave peak 24.
• the length of the gap 30 increases from gap to gap.
• the area of gap height and gap length increases in the process direction from gap to gap 1 to 2 percent.
• the gaps are provided on their active flank with a 45 ° bevel over 50 percent of the web width.
• the chamfer width corresponds to half the web width.
• the Hauptplastifizierzone has a pitch of 1, 3 D (dimensionless slope).
• the sections of increasing flight depth 34 behind the wave crests 24 are undercut, i. they have a steeper flank than the sections of decreasing flight depth 32 in front of the wave crests 24.
• the worm in sections of decreasing flight depth 34 groove-shaped recesses - mixing pockets 38 - on.
• a plurality of mixing pockets 38 run parallel to one another and parallel to the screw flights 26, 28 on the screw base.
• the mixing pockets are arranged offset to one another and each have a varying width and depth.
• the mixing pockets have a greater depth and width in a central region and taper towards their ends both in depth and width, so that they form a smooth transition to the cylinder inner wall and dead zones are avoided.
• the embodiment of the extruder screw according to the invention corresponds the second embodiment substantially that of the first embodiment; the same elements are therefore provided with the same reference numerals.
• a groove is arranged in the region of the Hauptplastifizierzone in the cylinder inner wall.
• the depth profile of the groove is matched to the profile of the polygon screw.
• the groove depth has a local minimum in the region of a wave crest of the polygon worm.
• the groove in the cylinder inner wall extends over the entire length of the Hauptplastifizierzone spiral and has a rectangular cross-section.
• the groove may have different cross-sections, for example. Semicircular, rectangular, triangular, in particular sawtooth, etc., and may extend completely or only partially axially or spirally along the cylinder inner wall. A combination of several configurations is also possible.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

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ID=48444326

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (4)

Citations (7)

Family Cites Families (26)

• 2012
  • 2012-04-21 DE DE102012008023.9A patent/DE102012008023B4/de not_active Expired - Fee Related
• 2013
  • 2013-04-18 IN IN8279DEN2014 patent/IN2014DN08279A/en unknown
  • 2013-04-18 WO PCT/EP2013/058059 patent/WO2013156555A1/de not_active Ceased
  • 2013-04-18 RU RU2014140754A patent/RU2623262C2/ru not_active IP Right Cessation
  • 2013-04-18 CN CN201380019627.5A patent/CN104245273B/zh active Active
  • 2013-04-18 US US14/394,407 patent/US20150085597A1/en not_active Abandoned
  • 2013-04-18 EP EP13722692.4A patent/EP2838704B1/de active Active

Patent Citations (7)

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