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
  • B29C48/88—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
• • 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
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/0022—Combinations of extrusion moulding with other shaping operations combined with cutting
• • 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
  • B29C48/11—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels comprising two or more partially or fully enclosed cavities, e.g. honeycomb-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
  • B29C48/03—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
  • B29C48/12—Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• • 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
  • B29C48/13—Articles with a cross-section varying in the longitudinal direction, e.g. corrugated pipes
• • 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
  • B29C48/355—Conveyors for extruded 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
  • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
  • B29C48/911—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
  • 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
  • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/0017—Combinations of extrusion moulding with other shaping operations combined with blow-moulding or thermoforming
• • 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
  • B29C48/001—Combinations of extrusion moulding with other shaping operations
  • B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/60—Multitubular or multicompartmented articles, e.g. honeycomb
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2031/00—Other particular articles
  • B29L2031/60—Multitubular or multicompartmented articles, e.g. honeycomb
  • B29L2031/608—Honeycomb structures

Definitions

• the present invention relates to a process for producing cellular structures in thermoplastic material, by extrusion, as well as the apparatus implementing this process and the structures thus obtained.
• thermoplastic material for example thermoforming from a sheet or molding in a closed mold.
• the extrusion is done vertically and the means used to avoid this deformation are twofold.
• traction is exerted on the extruded structure with traction members moving substantially at the extrusion speed.
• each cell undergoes on each side, as soon as it leaves the die, a constant pressure depending on the column of coolant which is the same in all the cells.
• the vertical arrangement of the extruder has the drawback of requiring a very complex installation in the case where elements of very long cellular structures are desired.
• each internal wall of the structure is maintained by the pressure of the liquid contained in the neighboring cells, and each external wall is maintained by the pressure of the coolant at the outside of the structure and by the pressure of the coolant inside the neighboring cell.
• the height of the cooling tank and if one limited this height compared to the length of the desired structure, the weight of the cooling liquid contained in the alveoli would deform the exterior walls of the structure.
• the present invention retains the advantages of this method, in particular with regard to the uselessness of a calibration subsequent to the output of the die, and makes it possible to avoid the disadvantages thereof.
• It relates to a method of extruding a cellular structure in thermoplastic material, through a die corresponding to the profile of the desired cellular structure, characterized in that said structure is subjected to a quenching operation on most of its different sides, as soon as it leaves the industry.
• the extruded structure is, as soon as it leaves the die, sufficiently rigid to stand by itself immediately, which not only makes posterior calibration unnecessary, it allows it to be handled without the need for special precautions.
• the structure being extruded is subjected, immediately before the quenching operation which it undergoes at the outlet of the die, to a traction which ensures its drawing, this drawing having the result is a molecular orientation which, fixed immediately by the quenching operation, will increase the mechanical properties of the extruded structure.
• the drawing of the structure in extrusion is preceded by a rolling, so as to cause the beginning of molecular orientation which will then be accentuated by the drawing.
• the die receives the thermoplastic material to be formed, from a supply chamber with at least two successive compartments, separated by a perforated plate intended to aid in homogenization and in a regular distribution of the thermoplastic material over the entire section of the die.
• each perforated plate is provided with heating means so as to participate in maintaining the temperature of the thermoplastic material.
• each perforated plate can advantageously constitute a spacer said bodies and thus allow the realization of a one-piece feed chamber.
• the coolant circuit is connected to a compressed air circuit intended to replace this liquid under certain conditions, so as to more economically ensure the seal between the extrusion circuit and the cooling system.
• FIG. 1 schematically shows an installation for implementing the invention.
• FIG. 2 shows a detail of the supply chamber of the die of the installation of FIG. 1.
• FIG. 3 is a view, partially in section, along the line III-III, of FIG. 2.
• FIG. 1 there is an extruder 1 with a feed hopper 2 and a thermally insulated outlet pipe 3, which feeds a die 4 via a feed chamber 6.
• This die 4 comprises (see FIGS. 2 and 3) a certain number of hexagonal elements 36, the mounting of which will be explained below.
• the supply chamber 6 is separated by a bottom 13 and a partition 15 of a compartment 7 which is adjacent to it and on which is fixed a pipe 8, connected to a water pipe 9 carrying a temperature regulating device 5 and a stop valve 11 and to a compressed air pipe 10 carrying a stop valve 12.
• Tubes 14 are poked on the bottom 15 and pass through the internal partition 13 on which cylinders 16 are welded.
• Each cylinder 16 is concentric with one of the pipes 14 and carries at its free end a part 17 whose function is twofold: serve as a spacer between the cylinder 16 which carries it and the pipe 14 concentric with said cylinder, and constitute a seat for elements 36.
• These elements 36 which have a hexagonal shape because the desired profile for the product to be extruded is a honeycomb profile, are made of insulating material such as polytetrafluoroethylene and are held on the parts 17 by nuts 19 which are screwed onto the pipes 14 thanks to the slots 20 which they comprise. They are separated so that their lips 18 achieve a narrowing of the passage section of the thermoplastic material.
• the supply chamber 6 is divided into three compartments 28, 29 and 30 by two perforated plates 21 and 22 held in place by spacers 23, 24 and 25 arranged around the cylinders 16.
• the spacers 23 maintain the spacing of the perforated plate 21 relative to the bottom 13.
• the spacers 24 maintain the spacing of the two perforated plates 21 and 22 between them.
• the spacers 25 maintain the spacing of the perforated plate 22 relative to the parts i7 and therefore also relative to the elements 36 constituting the die.
• the perforated plate 22 has smaller perforations than the perforated plate 21 as it appears in FIG. 3.
• the two perforated plates 21 and 22 are made of material allowing them to be heated by the Joule effect and are integrated into an electric heating system, not shown.
• a tray 26 follows the ridge. It is equipped with a traction bench for extruded structures constituted by two endless belts 27 and 34, the control device of which, not shown, includes a speed variator.
• the tank 26 ends with an inclined plane 31 and comprises, between this inclined plane and the belts 27 and 34 of the traction bench, a conventional cutting device 32, movable on rails f.3 to allow the cutting of the extruded structures 37 , 38, without having to stop their translational movement towards the inclined plane 31.
• thermoplastic material heated and fluidized in the extruder 1 passes, through the piping 3, into the supply chamber 6, where it arrives in the compartment 28, before being pushed back through the perforated plate 21 into the compartment 29, then, through the perforated plate 22, into the compartment 30 which immediately precedes the die 4 through which it will receive its honeycomb profile.
• the thermoplastic material is at a temperature sufficient to be fluent. But when passing through the die, this temperature must be rigorously constant over time and in all points of the die to obtain a regular structure.
• the passage of the thermoplastic material through the perforated plate 21 carries out a first stage of the homogenization of the heating since each stream of material passing through the perforations is heated in contact with the perforated plate.
• the temperature of the coolant which arrives in the cells at the outlet of the die has no effect on the temperature of the material upstream of said die and, therefore, the extrusion can be carried out normally.
• the pipes 14 which supply the coolant they are thermally insulated from the perforated heating plates 21 and 22. This insulation is obtained by the stationary air present between the pipes 14 and the cylinders 16.
• the spacers 23, 24 and 25 can optionally be provided with heating means to help maintain the thermoplastic material contained in the supply chamber at a constant temperature.
• the hexagonal slots made by the lips 18 of the elements 36 are narrower than the spacing between two neighboring sets of cylinder 16 and spacers 23, 24, 25.
• the profile of the parts 17 and the traction operated on the structure in extrusion by the belts 27 and 34 cause a double action on this structure, namely a stretching preceded and / or accompanied by a rolling, these two actions having the result of achieving molecular orientation.
• the thermoplastic material is laminated in the passage between two neighboring pieces 17 and between two neighboring lips 18, thanks to the reduction in section that it undergoes.
• This cooling is obtained by the distribution, through the pipes 14, of a cooling liquid brought to an ad hoc temperature by the temperature regulating device 5.
• the final product obtained is mechanically more resistant than if it had been extruded by the usual methods, thanks, on the one hand, to the quenching effect, but also thanks to the fact that this quenching took place on a thermoplastic material. in which rolling and drawing had achieved molecular orientation.
• the structure obtained 37 advances in the tank 26 thanks to the tractir ⁇ operated by the belts 27 and 34, and also, but to a lesser extent, to the thrust coming from the extruder.
• the belts 27 and 34 are equipped with a speed variator which makes it possible to adapt it to the desired extrusion conditions. Indeed, for a constant thrust of the extruder, a slowing down of the traction bench would cause a thickening of the walls, or even blistering, while an acceleration would cause them to lose weight, or even a lack of material in places.
• the extruded structure is cut, on demand and according to the desired length, using the cutting device 32, and the cut section 38 continues to advance, pushed by the next section 37 driven by the belts 27 and 34, up to that said cut section reaches the plane inclined 31 which makes it leave the tank while simultaneously emptying into the tank, the coolant contained in the cells.
• the extruder 1 and the belts 27 and 34 which eliminates the thrust upstream of the die and the traction downstream on the structure in extrusion, the extruded structure is cut by any means at a very short distance from the die, for example at 20 centimeters, in order to facilitate re-starting and the heating system is then placed on the minimum desired position both for the extruder 1 and for the supply chamber 6.
• thermoplastic material could then no longer normally supply the liquid of cooling required in extrusion operation.
• the invention proposes to replace the cooling liqui ⁇ e with compressed air.
• the tap 11 of the coolant is gradually closed, by gradually opening the tap 12 located on the compressed air pipe 10.
• the latter passes, by emptying their coolant, into the piping 8 and into the compartment 7, and exits through the pipes 14 which it keeps open by opposing an untimely entry of the thermoplastic material which would flow from the supply chamber 6, along the die.
• thermoplastic material is no longer fluent in the supply chamber 6 and the shut-off valve 11 of the coolant is closed. As in the previous case, it is recommended to cut it at a small distance from die 4, in order to facilitate re-starting.
• the heating systems of the extruder 1 and of the supply chamber 6 are first started and the compressed air valve 12 is opened to prevent the thermoplastic material becoming fluent from plugging. the pipes 14.
• the compressed air is replaced by the coolant by gradually opening the valve 11 and gradually closing the valve 12 and the extruder 1 and the traction bench 27-34.
• the perforated plates 21 and 22 which are arranged in the supply chamber 6, could, instead of being heated directly, be heated indirectly, for example, by means of resistance cords which could be wound around cylinders 16.
• the hexagonal profile of the cells could be replaced by any other cylindrical profile, in particular triangular, allowing the production of beams resistant to bending.
• the tank 26 can be equipped with a valve arranged, for example, 50 centimeters from the die.
• This valve drawn in dotted line rep.35 in fig.1, is open in extrusion operation and closed when the die stops. Vlle allows instant filling of the part of the tank between valve and die, at the time of restarting, which represents a saving of time for carrying out this restarting.
• the compressed air could be replaced by a closed circuit of coolant which would be supplied in the part of the tank closed by the valve 35 and would return to the top of the supply chamber 6, upstream or downstream of the temperature regulating device 5.
• thermoplastic material could also, in order to limit the exit of the thermoplastic material through the die when the extruder is stopped but with a certain heating in the supply chamber 6, equip this with an adjustable valve so as to ensure the evacuation of any surplus volume of material due to gasification due to the heat, and to evote as this surplus does not pass through the die.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Thermal Sciences (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9320580

Family Applications (1)

Country Status (10)

Families Citing this family (9)

Family Cites Families (8)

• 1985
  • 1985-06-24 FR FR8509554A patent/FR2583676B1/fr not_active Expired
• 1986
  • 1986-06-20 GR GR861614A patent/GR861614B/el unknown
  • 1986-06-23 EP EP86903441A patent/EP0267900A1/fr not_active Withdrawn
  • 1986-06-23 WO PCT/FR1986/000219 patent/WO1987000119A1/fr not_active Application Discontinuation
  • 1986-06-23 JP JP61503492A patent/JPS63501491A/ja active Pending
  • 1986-06-23 AU AU59953/86A patent/AU5995386A/en not_active Abandoned
  • 1986-06-23 CA CA000512205A patent/CA1294404C/fr not_active Expired - Lifetime
  • 1986-06-24 ES ES556536A patent/ES8707445A1/es not_active Expired
  • 1986-06-24 ZA ZA864708A patent/ZA864708B/xx unknown
• 1987
  • 1987-02-23 DK DK091287A patent/DK91287D0/da not_active Application Discontinuation

Non-Patent Citations (1)

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