Classifications

• • 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
  • B29C48/695—Flow dividers, e.g. breaker plates
  • B29C48/70—Flow dividers, e.g. breaker plates comprising means for dividing, distributing and recombining melt flows
  • B29C48/705—Flow dividers, e.g. breaker plates comprising means for dividing, distributing and recombining melt flows in the die zone, e.g. to create flow homogeneity
• • 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
  • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• • 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
  • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
  • B29C48/10—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels flexible, e.g. blown foils
• • 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
  • B29C48/16—Articles comprising two or more components, e.g. co-extruded layers
  • B29C48/18—Articles comprising two or more components, e.g. co-extruded layers the components being layers
  • B29C48/21—Articles comprising two or more components, e.g. co-extruded layers the components being layers the layers being joined at their surfaces
• • 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
  • B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
• • 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
  • B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
  • B29C48/33—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles with parts rotatable relative to each other
• • 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
  • B29C48/32—Extrusion nozzles or dies with annular openings, e.g. for forming tubular articles
  • B29C48/335—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles
  • B29C48/336—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles the components merging one by one down streams in the die
  • B29C48/3363—Multiple annular extrusion nozzles in coaxial arrangement, e.g. for making multi-layered tubular articles the components merging one by one down streams in the die using a layered die, e.g. stacked discs
• • 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
  • B29C48/362—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die using static mixing devices
• • 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
  • B29C48/36—Means for plasticising or homogenising the moulding material or forcing it through the nozzle or die
  • B29C48/50—Details of extruders
  • B29C48/695—Flow dividers, e.g. breaker plates
  • B29C48/70—Flow dividers, e.g. breaker plates comprising means for dividing, distributing and recombining melt flows
• • 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
  • B29C48/06—Rod-shaped

Definitions

• the present invention relates to the method according to the introductory part of claim 1 and the extrusion head according to the introductory part of claim 7 for the manufacture of multilayer extrusion products.
• Another disadvantage is caused by the fact, that the mixture agents tend because of insufficient mixing as well as differences in temperature, velocity and pressure to separate from the plastic material and deposit on the walls of the flow passages and build bandlike or stripelike formations in the material flow, which easily make weaker or stronger layers in the material flow.
• the primary object of the present invention is to eliminate the disadvantages and weaknesses associated with the traditional extrusion as well as to provide a novel method and an extrusion head with a simple structure and realiable in operation to enable the production of multilayer and homogeneous extrusion products by exactly proper amounts of partial mass flows corresponding the yield.
• Another object of the invention is to enable the accurate measurement and follow-up of the partial mass flows and thus for example by feedback to arrange the partial mass flows synchronously in relation to each other and to the production.
• the invention is based on the ingenious realization to utilize advantageously the functional principle of the hydraulic motor, whereby rotor means is rotated hyd,raulically by the material flow to be extruded, so that certain angle variation of the rotor means corresponds the particular volume flow of the material to be extruded.
• the rotor means is rotated hydraulically by a pressurized extrudable material divided into partial flows, whereby the material to be extruded is fed through infeed channels to subsequent intermediate spaces which have been separated from each other by separator means and contain the same volumes, as recessions, grooves, compartments or the like, which during the movement of the rotor means operate synchronously with each other opening in sequence to the pressure side of the separator means of the extrudable material.
• the rotor means rotates with a velocity accurately corresponding the feed of the extrudable material and the material is guided smoothly into the extrusion head, which enables the_manufacture of a product with layers comprising equal wall thicknesses with exactly proper volume.
• Figure 1 shows a longitudinal cross-section of the extrusion head according to a first advantageous embodiment of the invention
• Figure 2 shows a cross-sectional view of the extrusion head similar to figure 1 seen from the front and partly opened;
• Figure 3 shows an advantageous solution for the connection of the infeed pipe for the additive to the extrusion head according to the invention
• Figure 4 shows an advantageous solution for the connection of a pressure measurement sensor to the extrusion head according to the invention
• Figure 5 shows a cross-sectional view of the extrusion head according to another advantageous embodiment of the invention
• Figure 6 shows a cross-sectional view of the extrusion head according to the third advantageous embodiment of the invention.
• Figure 7 shows a cross-sectional view of the extrusion head according to the fourth advantageous embodiment of the invention.
• Figure 8 show in more detail the adaptment of the rotor means between the stator means in the fourth embodiment of the invention.
• Figure 9 shows a cross-sectional view of the extrusion head of the fifth advantageous embodiment of the invention.
• Figure 10 shows in more detail the adaptment of the rotor means between the stator means in the fifth embodiment of the invention
• Figure 11 illustrates the separator means moving- guidingly by the guide grooves and the flow of the extrudable material.
• the extrudable material is introduced between the base side surfaces of the stator means l r 2 and the rotor means 3 inwards past the peripheral inner edge 5 of the rotor means 3 to the central extrusion channel 4 and further to the extrusion nozzle 6 of the extrusion head.
• the flow of the extrudable material is provided by rotating the rotor means.
• the operational principle of the hydraulic motor is used for the rotation of the rotor means 3, whereby the substance to be used is the pressurized extrudable material, whereby an angle variation of the rotor means 3 corresponds particular volume flow of the extrudable mate,rial, so that no by-pass flow takes place in the rotation of the rotor means 3, which enables to speed up the mutual arrangement of infeed and yield of the extrusion head.
• the extrusion head includes in the flow direction of the extrudable material:
• the purpose of the infeed channels 9 is in order to provide a homogeneous product to divide the extrudable material into several partial flows and to guide these partial flows peripherically and symmetrically oriented in relation to each other to the the extrusion head.
• the infeed channels 9 can naturally be constructed by several different ways.
• a branch pipe system or mechanized channels can be used as infeed channels 9, whereby the ends of the branch pipes or channels extend straightly through the stator means 1, 2 according to figures 1, 5 and 6.
• Infeed channels can advantageously be constructed also in such a way, that the last division of the extrudable material takes place according to figures 7 or 9 in the branch channel made in the wall of the stator means 1, 2, whereby the end of each branch channel extends inside the peripheral wall 12, 13 of the stator means 1, 2.
• the infeed channels 9 are constructed so, that the flow passages of separate partial mass flows become as long and with same configuration, and that the ends of the branch pipes are located symmetrically and at equal distances from each other, whereby it is possible to elimi,nate variations in the feed pressure in different parts of the extrusion head and also the pressure differences caused by flow losses.
• the infeed chan-nels are provided with premixing means for the extrudable material, comprising tooth spaces in the peripherical gearing of the rotor means and elongated recessions matching with these tooth spaces machined in the -side surfaces of the stator means.
• the extrudable material When the rotor means 3 rotates, the extrudable material is forced in the recessions to a turbulent movement making the mixing and homogeniza ion of the material more effective. After the above-mentioned premixing means the extrudable material flows to the outlet of the infeed channels 9, comprising in this embodiment four arcuate elongate side channels of the stator means separate from each other.
• discharge and/or mixing channels 10 The purpose of the discharge and/or mixing channels 10 is to provide a forced material flow and to unite through individual infeed channels 9 separately but symmetrically ififed partial flows before the peripherical inlet gap of the central extrusion channel as one material flow proceeding toward the central extrusion channel 4 and to advantageously mix and homogenize further the radial flow in question.
• the discharge and/or mixing channels comprise in the direction of propagation of the material four spiral channels machined in the side surfaces of the stator means 1 and 2, the beginning part of which is in flow connection to the intermediate space 8 at the discharge side of the stator means, as well as recessions in cup form machined and peri-pherically arranged in the side surfaces of the rotor means 3 and the stator means 1, 2.
• the recession circles have been placed partly matching, whereby the material flow may progress in the radial direction from one recession circle to another between the base side surfaces of the rotor and stator means 1, 2, 3.
• the base surfaces of the rotor means 3 and the stator means 1, 2 can be provided with protuberances arranged by the radial turbine principle, and also in this case the extrudable material can be effectively mixed, when it progresses between the rotor means 3 and the stator means 1, 2.
• each discharge and/or mixing channel assembly 10 between the stator means 1 or 2 and the rotor means 3 comprises eight inflow openings in flow connection with the intermediate space 8 at the discharge side of the separator means 7, whereby these openings have been machined at equal distances from each other in the stator means 1 in radial direction from the inner ring channel machined in the stator means, as well as sixteen spiral channels machined at equal distances from each other in the rotor means 3.
• Beginning parts of the spiral channels are adapted so that they match with the ring channel, whereby the material flow may progress from the * ring channel to the spiral channels turning ' in spiral form inwards. Union of the partial mass flows is facilitated by the fact, that one part of the extrudable material coming to the spiral channels goes over the neck part separating the spiral channels, when the rotor means 3 is rotating .
• each discharge and/or mixing channel assembly 10 between the base side surfaces of the stator means 1 or 2 and the rotor means 3 comprises the outer spiral channel circle formed by four spiral channels machined in the side surface of the stator means 1 and the inner spiral channel circle formed by eight spiral channels machined in the side surface of the rotor means 3.
• the beginning part of each spiral channel of the stator means 1 is in flow connection to the intermediate space 8 at the discharge side of the separator means 7, whereby the material flow progresses between each side surface of the stator and rotor means from the spiral channel circle of the stator means to the spiral channel circle of the rotor means and further on past the inner periphery 5 of the rotor means to the inflow gap of the extrusion channel 4.
• the separator means 7 adapted to the stator means l r 2 comprise the teeth of the peripherical rotor means 21 affecting to the outer periphery of the rotor means 3 r and the intermediate spaces for their part comprise compart,ments defined by the tooth spaces of the rotor means and by the inner base surfaces of the stator means 1, 2, whereby the feed pressure of the extrudable material affect,ing to the separator means 7 has its effects on the outer periphery of the peripherical rotor 21 in the side opening in relation to the rotor means, whereby the discharge pres,sure affects correspondigly in the side closing in relation to the rotor means 3.
• the side surfaces of the stator means 1 and 2 toward the rotor means 3 are provided with channel-formed recessions, one end of which matches the central bore of the peripherical rotor 21 and the other end with the opening point of the tooth rings of the rotor means 3 and the peripherical rotor 21.
• recessions the partial mass flows are fed from both sides of the peripherical rotor 21 simultaneously to the subsequent tooth spaces of both the peripherical rotor 21 and the central rotor means 3 in the opening side of the rotor means 3 and the peripherical rotor 21 rotating in relation to each other.
• the material fed to the tooth spaces of the rotor means 3 and 21 rotates thus hydraulically the peripherical rotors 21 and the central rotor means 3 at the same time when the tooth connection between them prevents the rotation by other than the transmission ratio determined by the tooth rings. Due to the rotational drive according to the invention the rotational movement of the central rotor 3 can be regulated accurately to correspond the desired yield and to stabilize the partial mass flows needed for the generation of each separate material layer to be formed as identical regarding each other.
• FIG. 5 and 6 has been presented the cross- sections of one stator/rotor unit of the extrusion heads according to the second and third advantageous embodiments of the invention.
• the rotor means is rotated hydraulically as before by partial material flows divided into identical parts in relation to each other.
• the hollow space between the outer periphery surface 11 of the rotor means 3 and the inner periphery surfaces 12, 13 of the stator means 1, 2 has been divided by several projection parts adapted to the rotor means 3 and extending from the outer peripehry thereof and forming the separator means 7 into intermediate spaces 8 for receiving the extrudable material and to form the work space causing the torque.
• the rotor means 3 to be rotated by the extrudable material has been adapted centrally to the hollow space defined by the stator means 1, 2, the outer periphery of the rotor means 3 being equipped with lamellae 7 transversal and radially moving in relation to its rotational direction, whereby the lamellae 7 are always against the shaped peripherical surface of the hollow space and define closed intermediate spaces 8 or compartments, from which no by-pass flow of the plastic material takes place, inside the interfaces of the hollow space.
• the intermediate spaces 8 are at one side of the separator means 7, i.e.
• the distance between two subsequent separator means has been selected as smaller than the distance between two subsequent inlet openings of the discharge and mixing channels 10.
• the third embodiment of the invention shown in figure 6 differs from the second embodiment of the invention described above only in that flexible lamellae attached to the outer periphery of the peripherical rotor 3 are used as separator means 7 instead of the radially moving lamellae, whereby these flexible lamellae function as separator means and are supported like leaf springs against the inner periphery surfaces 12 and 13 of the stator means 1 and 2.
• the separator means 7 maintaining the pressure difference comprise.rollers 20 placed ih the stator means 1, 2 and adapted to the recessions machined to partly match with the outlet openings of the infeed channels 9. A part ofthe side surface of the roller 20 is thus in connection with the infeed channels 9 of the extrudable material, whereby the inflow of the extrudable material to the pressure side of the separator means 7 presses the roller 20 continuously against the outer periphery 11 of the rotor means 3.
• the outer periphery 11 serves as the running surface for the roller 20, whereby the roller during the rotation of the rotor means moves radially back and forth in the recession machined in the stator means.
• Wavelike ridges of the rotor means 3 separate the intermediate spaces between the inner periphery surfaces 12,13 of the stator means 1, 2 and the outer periphery surface ⁇ l of the rotor means 3 for receiving the extrudable material.
• the pres,sure difference influences over the roller serving as the separator means 7 in such a way, that feed pressure affects at one side of the roller 20 and discharge pressure at the other side thereof, whereby the work space generating the torque is at the pressure side corresponding the feed pressure in relation to the roller 20 between the outlet opening of the infeed channels 9 and the ridge of the rotor means 3.
• the outlet opening of the infeed channels 9 and the inlet opening of the discharge and/or mixing channels have been ⁇ advantageously adapted at the both sides of the roller 20 at the distance corresponding about the diameter of the roller 20 from each other, so that the inlet opening of the discharge and/or mixing channels is first in the rotational direction of the rotor means and thereafter the outlet opening of the infeed channels 9.
• the separator means maintaining the pressure difference and adapted to the rotor means 3 comprise pin means 15 moving back and forth in the essentially in axial direction extending openings 14 machined to the rotor means 3, as bores, each of which comprising the first head 16 and the second head 17.
• guide grooves 18, 19 have been machined in the base side surfaces of the stator means 1, 2 turned toward the rotor means 3, which grooves correspond in their shape the ends 16, 17 of the pin means and are matched to each other.
• Each guide groove 18, 19 has been formed as variable in waveform in its depth, so that the distance of the bottoms of the guide grooves 18, 19 from each other corresponds the length of the pin means 15.
• the length of the pin means 15 is essentially greater than the base width of the rotor means 13, whereby the other side surface of the first head 16 of the pin means is, when the pin means 15 is extended out of the side level of the rotor means 3, in connection with the infeed channels 9 of the extrudable material, so that the- feed pressure of the extrudable material affects to the part of the pin means 15 projecting from the rotor means 3.
• the intermediate space 8 is thus first open to the infeed channels 9, whereby the extrudable material is fed to the pressure side of the separator means 7 adapted to the rotor means 3, closing temporarily during the rotation as a closed work space with constant volume defined by two pin means 15, opening thereafter to the discharge and/or mixing channels 10 of the extrudable material.
• at the one side of the pin means 15 prevails thus a higher feed pressure and at the other side lower discharge pressure, and in order to maintain such continuous pressure difference the distance of the pin means from each other is smaller than the distance between the outlet opening of the infeed channels 9 and the inlet opening of the discharge and/or mixing channels 10.
• FIG 3 is shown an advantageous embodiment for feeding an additive to the extrudable material.
• the feed pipe 22 of the additive extends through the wall of the stator means 1 to the intermediate space 8 of the extrudable material. It is advantageous, that the place of the feed pipe is selected so, that the inflow of the additive takes place either at the same time time with the inflow of the extrudable material or immediately thereafter, whereby the mixing time of the additive in the intermediate space becomes as long as possible.
• the tooth space of the rotor means 3 or 6 serves as the intermediate space, the material in this tooth space becomes under a continuous rotating movement, so that the additive, which is radially fed to the tooth space, is effectively mixed there.
• FIG 4 is shown an advantageous embodiment for follow-up and measuring of the flow of the extrudable material. Due to the reliable flow measurement it is possible to realize almost non)delayed feedback, whereby • the feed of the extru,dable material can be arranged to accurately correspond the yield velocity desired at each moment.
• the flow measurement has been realized by a pressure sensor 23, the measuring end of which is extended to the intermediate space 8 of the extrudable material defined by the separator means 7 to measure the pressure variations generated by the feed pressure and the discharge pressure in the intermediate space. It is easy to find out by the pressure sensor 23 the analogy curve indicating the pressure variation of the intermediate space, especially the work space, in relation to time, from which curve can be read also the pressure impulses caused by the separator means 7 themselves.
• FIG 11 it is illustrated the location of the above ⁇ mentioned pressure measurement in the extrusion head according to the fifth advantageous embodiment, whereby the measurement by the pressure sensor is effected from the intermediate space.8 in such a way, that the work pressure is attained also in the case, when the separator means 7 temporarily close the intermediate space 8 at its both ends.
• a simple A/D-converter a pulse signal is generated, by which the material feed to the extrusion head can easily be guided using feedback and thus to arrange the material yield accurately to the desired value by adjusting the yield of the extruder feeding the material.
• the invention has,.b ⁇ a*3n described above only by some of its advantageous embodiments. This does not, naturally, restrict the invention and as is apparent for the person well-versed in the field, the invention can be varied within very broad limits in the scope of the principle of the invention defined in the accompanying claims. It must especially be emphasized, that almost all principal solutions in hydraulic motors can be adapted to provide the forced rotational movement of the central rotor means.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26158204

Family Applications (1)

Country Status (2)

Cited By (4)

Citations (5)

• 1988
  • 1988-01-28 FI FI880402A patent/FI880402A/fi not_active IP Right Cessation
  • 1988-07-08 WO PCT/FI1988/000116 patent/WO1989000910A1/en unknown

Patent Citations (5)

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