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
  • B29C48/30—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
  • B29C48/03—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
  • B29C48/001—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
  • 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
  • B29C48/25—Component parts, details or accessories; Auxiliary operations
  • B29C48/256—Exchangeable extruder parts
  • B29C48/2566—Die parts
• • 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
  • B29C48/256—Exchangeable extruder parts
  • B29C48/2568—Inserts
  • B29C48/25686—Inserts for dies
• • 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
  • B29C48/3001—Extrusion nozzles or dies 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
  • B29L—INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
  • B29L2023/00—Tubular articles
  • B29L2023/001—Tubular films, sleeves

Definitions

• the present invention relates to an extruder for making tubular articles with highly specific geometric / dimensional characteristics, such as for example a "multi-lumen" cross-section (i.e., defining multiple passage sections within a maximum perimeter), wherein the passing openings are arranged on multiple concentric crowns, and which may also have different macro- or microscopic dimensions both in terms of maximum external diameter and of overall number of internal passage openings (and also of angular distance between adjacent openings or again in terms of internal diameters of the individual passage openings themselves).
• a multi-lumen cross-section i.e., defining multiple passage sections within a maximum perimeter
• the passing openings are arranged on multiple concentric crowns, and which may also have different macro- or microscopic dimensions both in terms of maximum external diameter and of overall number of internal passage openings (and also of angular distance between adjacent openings or again in terms of internal diameters of the individual passage openings themselves).
• tubular products and micro-products with multi-lumen sections can be used in various fields, from medical applications to other engineering fields where considerable dimensional precision is required and where extremely strong structure and passage characteristics are required.
• the present invention therefore intends to devise an extruder device which allows to overcome the aforementioned drawbacks, and in particular which allows to obtain multi-lumen tubular products with particularly small dimensions and / or with multi-coronal arrangement of the various passage openings, all with very high geometric / dimensional precision characteristics, with sufficiently high production rates and with high reliability and durability of the extrusion / forming plant.
• multi- coronal arrangement of the passage openings inside a section of an extruded product means an arrangement of passage openings along two or more concentric circumferences with differentiated radii: these circumferences are obviously inscribed within a circumference of maximum radius defined by the outer surface of the extruded product itself.
• a further object of the present invention is to provide a forming / extrusion device which can be advantageously integrated with other functional modules, for example a precision module and / or a localized temperature module, in order to guarantee further operating margins in terms of accuracy and reliability.
• FIG. 1 shows a partial cut through of the forming head according to the invention
• - figures 2 and 3 show respectively two enlargements of the partial section illustrated in figure 1 from different angles.
• the device according to the present invention basically comprises a main body 2 defining a passage cavity 2a and thus defining also an average outflow direction 2b: said main body 2 can be positioned at the end of an extrusion line, such that the passage cavity 2a is penetrable by an extrusion material.
• the main body 2 defines in turn an input surface 3 (obtained on a first face of the main body 2), on which there is a plurality of entry areas afferent to the passage cavity 2a as well as an exit surface 4 (obtained on a second face of the main body, opposite to the first face) and defining a plurality of exit portions efferent from the passage cavity 2a and advantageously further comprising an expansion portion (4a) operatively associated with the exit surface (4) and adapted to mutually orient spontaneous expansive flows (or in currently used words in this technical field, the so-called expansive flows related to the "die swell' phenomenon) of the extrusion material through the exit surface (4) in reciprocal directions of mutual intersection.
• the invention envisages making an extruder whose head has, along its axis of development, a portion of dimensions carefully shaped and calibrated so as to allow spontaneous reunion of the partial flows of material through the different passage openings: this reunion (or more accurately, the different local reunions radially distributed in the overall passage section) allows the creation of separation walls - by complementarity defining the passage openings of a multi-lumen extruded product - having thinnesses and mutual closeness ratios that would otherwise be impossible to define by directly imparting a forming through traditional passage openings (i.e. with such sizing that their cavities correspond identically to the "definitive" shape / section of the extruded product).
• the expansion portion 4a is geometrically shaped according to a plurality of slots (4b) segmented and mutually arranged according to a matrix scheme: for example, such slots 4b can be shaped like an arc of circle or having a curved line, or still may be shaped according to substantially straight segments.
• the expansion portion 4a can define, typically through a closed polygonal succession of slots (4b) shaped like an arc of circle or having a curved line, at least one coronal circumference having an average diameter smaller than a maximum diameter of a product achievable through the device 1 : as a matter of facts, this section topology of the extruded product exploiting the present invention is rather critical to obtain with forming heads having a direct and two-way geometric correspondence between the surfaces of the extrusion openings and the shapes / sections of the extruded structures coming out of them.
• the expansion portion 4a defines (for example, through a radial arrangement of slots 4b having substantially straight segments) at least one cross member radially arranged respect to at least a coronal circumference having an average diameter less than or equal to a maximum diameter of a product manufacturable through the device 1 .
• the passage cavity 2a is defined by a plurality of substantially parallel axial conduits, these axial conduits emerge at the central portions of the slots 4b defining the expansion portion 4a.
• the segmented slots 4b defining the expansion portion 4a can be geometrically interconnected at least in pairs in correspondence of the respective ends or can be geometrically separated, but placed in a mutual proximity relation, at least in pairs in correspondence of respective ends (so as to effectively exploit the die swell phenomena only where they are "locally" necessary in the overall section of the extruded product).
• an guiding portion 3a may be present, which is geometrically shaped according to a matrix scheme and is adapted to guide the extrusion material flows through the plurality of axial conduits defining the passage cavity 2a: in addition, where it is necessary the addition of "volumizing" material to define and keep stable the empty configuration of one or more passage openings in the extruded product, there may be appropriate insufflation means operatively active in the main body 2 and interposed between the axial conduits of the latter to enter a filler flow between the walls of the product manufacturable through the device 1 at least at the exit surface 4 (according to the technical implementation requirements, this filler flow can be of inert gas or air, or of an incompressible fluid or still of inert solid / granular fillers such as sand or sacrificial materials such as, for example, suitable polymers or aggregates which are then subjected to pyrolysis with relative elimination of the ashes... or more generally substances that can be chemically de
• the invention achieves several advantages.
• the peculiar mode of cooperation of the various ducts of the device ensures optimal post-extrusion control of the product, which is maintained in a sufficiently stable form at least for the time during which the polymeric material is subjected to chemical-physical stabilization: in other words, the optimal mutual arrangement of the passages of the extrusion material and of those dedicated to the "filler flow" allow to maintain accuracy of processing and, with the appropriate modifications, a wide variety of conformations.
• the versatility of the present invention must be seen in two equally advantageous and possibly combinable aspects: one aspect is linked to the possibility of obtaining very complex multi-lumen internal architectures (and with passage openings of different shapes, not necessarily polygonal but also, for example, perfectly circular or in any case curvilinear) and the another aspect is that of obtaining multi-lumen tubes with "single-crown" arrangement but with extremely small dimensions.
• the present invention allows to maintain low production costs of the device and also allows to obtain a high operating life: this makes possible an industrial process being highly efficient and having very rapid amortization, thus generating a further reduction of costs and a consequent increase in profitability.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)
• Media Introduction/Drainage Providing Device (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

Family

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Family Applications (1)

Country Status (9)

Cited By (1)

Families Citing this family (4)

Citations (9)

Family Cites Families (21)

• 2016
  • 2016-11-29 IT IT102016000120563A patent/IT201600120563A1/it unknown
• 2017
  • 2017-11-27 WO PCT/IB2017/057420 patent/WO2018100480A1/en not_active Ceased
  • 2017-11-27 EP EP17817146.8A patent/EP3548251B1/en active Active
  • 2017-11-27 JP JP2019528713A patent/JP7085547B2/ja active Active
  • 2017-11-27 PL PL17817146T patent/PL3548251T3/pl unknown
  • 2017-11-27 CN CN201780073410.0A patent/CN110087855B/zh active Active
  • 2017-11-27 ES ES17817146T patent/ES2910111T3/es active Active
  • 2017-11-27 DK DK17817146.8T patent/DK3548251T3/da active
  • 2017-11-27 US US16/464,886 patent/US11660797B2/en active Active

Patent Citations (9)

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