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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/4273—Auxiliary operations after the blow-moulding operation not otherwise provided for
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/0005—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor characterised by 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
  • B29C49/04—Extrusion blow-moulding
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/08—Biaxial stretching during blow-moulding
  • B29C49/10—Biaxial stretching during blow-moulding using mechanical means for prestretching
  • B29C49/12—Stretching rods
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C49/54—Moulds for undercut articles
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D1/00—Rigid or semi-rigid containers having bodies formed in one piece, e.g. by casting metallic material, by moulding plastics, by blowing vitreous material, by throwing ceramic material, by moulding pulped fibrous material or by deep-drawing operations performed on sheet material
  • B65D1/02—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents
  • B65D1/0223—Bottles or similar containers with necks or like restricted apertures, designed for pouring contents characterised by shape
  • B65D1/023—Neck construction
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
  • B29C2049/4807—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity by movable mould parts in the mould halves
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C49/54—Moulds for undercut articles
  • B29C2049/542—Moulds for undercut articles having means to facilitate the removal of the blow moulded articles
  • B29C2049/543—Moulds for undercut articles having means to facilitate the removal of the blow moulded articles at the neck portion
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C49/54—Moulds for undercut articles
  • B29C2049/542—Moulds for undercut articles having means to facilitate the removal of the blow moulded articles
  • B29C2049/545—Moulds for undercut articles having means to facilitate the removal of the blow moulded articles by rotationally actuating an auxiliary mould part while the mould is still in a closed position
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C49/54—Moulds for undercut articles
  • B29C2049/542—Moulds for undercut articles having means to facilitate the removal of the blow moulded articles
  • B29C2049/546—Moulds for undercut articles having means to facilitate the removal of the blow moulded articles by translatorilly actuating an auxiliary mould part while the mould is still in a closed position
• • 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
  • B29C2791/00—Shaping characteristics in general
  • B29C2791/001—Shaping in several steps
• • 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
  • B29C2791/00—Shaping characteristics in general
  • B29C2791/004—Shaping under special conditions
  • B29C2791/007—Using fluid under pressure
• • 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
  • B29C2949/00—Indexing scheme relating to blow-moulding
  • B29C2949/07—Preforms or parisons characterised by their configuration
  • B29C2949/0715—Preforms or parisons characterised by their configuration the preform having one end closed
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/02—Combined blow-moulding and manufacture of the preform or the parison
  • B29C49/06—Injection blow-moulding
• • 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
  • B29C49/00—Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
  • B29C49/42—Component parts, details or accessories; Auxiliary operations
  • B29C49/48—Moulds
  • B29C49/4802—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity
  • B29C49/4812—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity and welding opposite wall parts of the parisons or preforms to each other
  • B29C49/4815—Moulds with means for locally compressing part(s) of the parison in the main blowing cavity and welding opposite wall parts of the parisons or preforms to each other by means of movable mould parts
• • 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
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/04—Polymers of ethylene
  • B29K2023/06—PE, i.e. polyethylene
• • 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
  • B29K2023/00—Use of polyalkenes or derivatives thereof as moulding material
  • B29K2023/10—Polymers of propylene
  • B29K2023/12—PP, i.e. polypropylene
• • 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
  • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
  • B29K2067/003—PET, i.e. poylethylene terephthalate
• • 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
  • B29K2067/00—Use of polyesters or derivatives thereof, as moulding material
  • B29K2067/04—Polyesters derived from hydroxycarboxylic acids
  • B29K2067/046—PLA, i.e. polylactic acid or polylactide
• • 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
  • B29L2031/712—Containers; Packaging elements or accessories, Packages
  • B29L2031/7158—Bottles

Definitions

• the present invention relates to a process for blow-molding an article comprising at least one recess, and wherein said recess is located proximal to an opening portion of the article for association of a closure to said article.
• the present invention relates to simplifying the de-molding of articles comprising recesses generating undercuts, whilst preventing damage to the article during such operation.
• a blown article comprising at least one recess, wherein said recess is located proximal to an opening portion of the article, is technically challenging. This is because the formation of a recessed neck requires the article to form a shoulder(s) above the top portion of the neck portion. This is technically challenging because the material flow to form such shoulders would be against the natural material flow in blow molding.
• the natural material flow in blow molding is from the neck of the parison or preform towards the base of the article guided by a pressure build up that expands the walls of said article being formed to the shape of the mold cavity. Moving material against that natural flow direction requires careful design of the parison or preform, and careful definition of the blowing process.
• the art contains a number of attempts to solve the inherent problems of forming recessed blow molded articles.
• the invention is directed to a process for the manufacture of a blow molded article comprising the steps of: forming an article having an integral neck portion and at least one recess, proximal to said neck portion, and more than one undercut proximal to said neck portion; and de-molding said article at the end of the forming process such that said article retains the end physical geometry generated in the forming step.
• Fig. 1A illustrates an isometric view of a blown article formed by a process according to an embodiment of the present invention.
• Fig. IB illustrates a side view of the blown article of Fig. 1 A.
• Fig. 1C illustrates an enlargement of section A of Fig. IB.
• Fig. ID illustrates a top view of the article of Fig. IB.
• Fig. IE is an isometric view of a blown article formed by a process according to an embodiment of the present invention coupled to a closure.
• Fig. 2A-D illustrate a process according to an embodiment of the present invention.
• Fig. 3A illustrates an isometric view of one half of a mold, with an article therein, for the process according to an embodiment of the present invention.
• Fig. 3B illustrates a top view of Fig.3A.
• Fig. 4A-C illustrate part of the process according to an embodiment of the present invention.
• Fig. 5A illustrates a cross-section of a mold with a blown container therein for a process according to an embodiment of the present invention.
• Fig. 5B and Fig. 5C illustrate a cross-section of a mold of Fig. 5 A taken from BB.
• Fig. 5D and 5E illustrate a cross-section of a mold for a process according to an embodiment of the present invention.
• Fig. 5F illustrates a cross-section of an article formed by a process according to an embodiment of the present invention.
• undercut means a physical geometry that hinders article removal from a mold when said mold is opened in a linear direction which intersects at least a portion of said geometry.
• more than one undercut means that the same geometry hinders article removal from a mold when opened in more than one linear directions intersecting at least a portion of said geometry, typically said directions being at right angles with respect to each other.
• the "z-axis” as used herein is the longitudinal axis Z (or centerline of the article).
• the "x-y” plane as used herein is the plane substantially perpendicular to the z-axis.
• the term "preform” as used herein is a molded element which is produced prior to expansion to form the finished article. A preform is necessarily somewhat smaller than the finished blown article. A preform is generally produced by, for example injection molding, at an elevated temperature in excess of the melt temperature.
• stretch-blow molding is the process in which preforms are heated above their glass transition temperature, and then blown in molds using a high pressure medium, preferably air, to form hollow articles, such as containers. Usually the preform is stretched with a stretch rod as part of the process.
• recycled materials encompass post-consumer recycled (PCR) materials, post-industrial recycled (PIR) materials, and mixtures thereof.
• regrind material is thermoplastic waste material, such as sprues, runners, excess parison material, and reject parts from injection and blow molding and extrusion operations, which has been reclaimed by shredding or granulating.
• bio- is used to designate a material that has been derived from a renewable resource.
• the invention is directed to a process for the manufacture of a blow molded article (42, 309, 601) comprising the steps of: forming an article (42, 309, 601) having an integral neck portion (47, 305, 603) and at least one recess (50, 308, 604) proximal to said neck portion (47, 305, 603) forming more than one undercut; and de-molding said article (42, 309, 601) at the end of the forming process such that said article (42, 309, 601) retains the end physical geometry generated in the forming step.
• integral neck portion it is herein intended that said neck portion is one part with said article.
• suitable recesses are those that permit a portion of the article to wrap around at least part of a closure, when said closure is coupled with said article. Such recess may allow the closure, when coupled to said article, to remain substantially flush to the apex of the outermost surface of said article.
• at least part of a closure it is herein intended that said portion extends around the perimeter of the closure to form an angle of at least 45°, preferably at least 60°, more preferable between 60° and 360°, taken from the centre of the closure and in the x-y plane, when said closure is coupled to said article.
• Articles formed by the process of the present invention may comprise more than one undercut, preferably at least two undercuts, more preferably at least three undercuts, and even more preferably at least four undercuts, proximal to the neck portion thereof.
• Particularly preferred geometries generating such undercuts are those that comprise at least one curved surface, preferably a concave surface.
• Articles made by the process of the present invention may be selected from the group consisting of containers, devices, handles, implements and combinations thereof.
• Preferred articles are containers for use in a variety of fields. Non-limiting examples of such fields are; beauty care products, such as containers for body wash, shampoos and conditioners; domestic and/or household products, such as containers for detergents or other cleaning preparations for cleaning and/or conditioning fabric and/or hard surfaces; oral care products, such as containers for mouth wash; and so on.
• Articles made by the process of the present invention can be made of any suitable plastic resin material.
• Preferred plastic resin materials for use in the present invention can be polyolefins (such as PP and PE), polystyrene (PS), polyvinyl chloride (PVC), polylactic acid (PLA) or polyethylene terephthalate (PET).
• the plastic resin material is polyethylene terephthalate (PET).
• articles made by the process of the present invention may be made of sustainable materials selected from the group consisting of renewable materials, recycled materials, regrind materials, and mixtures thereof. Examples of “renewable materials” include bio-polyethylene, bio-polyethylene terephthalate, and bio-polypropylene.
• polyethylene encompasses high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and ultra low density polyethylene (ULDPE).
• polypropylene encompasses homopolymer polypropylene, random copolymer polypropylene, and block copolymer polypropylene.
• said article (101) may be a container comprising an opening
• said neck portion (103) may comprise a top surface (104). At least one portion of the top surface (104) of said neck portion (103) may be below at least one portion of the uppermost surface of said article taken along an axis extending parallel to the centerline (or z-axis) of said article (101).
• the uppermost portion of said article may be in the form of at least one shoulder (105), preferably said shoulder extends parallel to at least a portion of the perimeter of said neck portion (103) so as to define a recess proximal to said neck portion
• the recess may be located between said shoulder (105) and said neck portion (103).
• the advantage of such configuration is that it allows fitting of a closure (106) to be substantially sunk into the blown article.
• sunk into it is herein intended that at least one surface of said closure (106) remains substantially flush with at least one surface of said article, preferably said at least one surface of said article is on the outer surface of said shoulder (105).
• said at least one surface is the uppermost surface taken along a plane substantially parallel to the centerline of said article.
• At least one portion of said recess is substantially concave in shape.
• This configuration has the advantage of reducing the gap between the closure (106) and the article when the two are coupled together.
• this geometrical complexity results in problematic unmolding using current processes. Indeed, such recesses do not allow unmolding of the article with traditional straight-pull movement during mold opening.
• at least part of the interface between the portion of the article (101) wherein said closure (106) is fitted and the portion of the closure (106) in facing relationship thereto presents a geometry that is selected from the group consisting of concave, convex, linear, non-linear and combinations thereof.
• said interface is along at least one surface of said shoulder (105).
• articles made by the process of the present invention may comprise a non-linear geometry proximal to said neck portion (103).
• the curvature of said nonlinear geometry may allow a portion of the article to wrap around at least part of the closure (106), once said closure is fitted onto said article.
• said portion of the article wrapping around at least part of the closure (106) is at least one surface of said shoulder (105), more preferably the inner surface (107) of said shoulder (105) facing the neck portion of said article.
• the inner surface (107) of said shoulder (105) may comprise a positive draft angle of less than 10°, preferably less than 8°, more preferably less than 5°.
• Such draft angle is defined as the angle of a surface taken from a plane perpendicular to the mold parting line formed on said surface. Having a positive draft angle of less than 10° may be important for several reasons including, consumer acceptance and potential re-application of the same closure across a range of article sizes. Without being bound by theory it is believed that the smaller the draft angle, the smaller the space or gap that will exist between the article and the closure after said closure is assembled thereon. Thus achieving a more aesthetically pleasing design and a winning consumer acceptance.
• having a low positive draft angle on the inner surface (107) of said shoulder (105) enables the utilization of closures with no or low positive draft angles. Closures having a low positive draft angle may then be used with a variety of different shoulder designs and/or with articles not having a shoulder at all. This results in greater flexibility as the same closure may be used across a wide variety of articles thus creating scale, which in turn typically reduces costs and logistic complexity.
• articles made by the process of the present invention may include a closure retention mechanism (108) that can be selected from the group consisting of snap bead, thread, and combinations thereof.
• Said closure retention mechanism (108) may protrude from at least one section of the perimeter of said neck portion (103), preferably said closure retention mechanism (108) is located proximal to the top surface (104) of said neck portion (103). It will be apparent to the person skilled in the art that such protrusions will further complicate the un-molding of the article. Indeed, such closure retention mechanism (108) will hinder the removal of said article from the mold in a direction substantially perpendicular to the horizontal "x-y" plane.
• said closure retention mechanism (108) may protrude for a distance "a" from a proximal end to a distal end.
• said proximal end is closer to the z axis than said distal end.
• said distance "a” is taken along a plane substantially perpendicular to said z axis.
• the distance "a” is less than 3mm, preferably less than 2mm, more preferably between 0.5mm and 2mm, most preferably between 0.5mm and 1.5mm.
• Closures that may be used with articles made by the process of the present invention are any that are suitable for compliance with said articles.
• the closure (106) may be capable of coupling with said article (101), preferably said closure (106) comprises a coupling means (not shown) that interacts with said closure retention mechanism (108) to secure said closure (106) onto said article (101).
• said closure (106), when coupled to said article, may provide for fluid communication between the interior and exterior of said article via a passage when said closure (106) is in a first position.
• said closure (106) When said closure (106) is moved to a second position, said passage is blocked and fluid communication is interrupted. Accordingly said closure (106) may be moved from said first position to said second position and vice versa.
• the movement from said first position to said second position is selected from the group consisting of translational, rotational and combinations thereof.
• Blow molding is a well known manufacturing process for the fabrication of plastic articles such as containers, fuel tanks, handles etc.
• the blow molding process begins with melting down plastic and forming it into a parison or preform.
• the parison is then clamped into a mold and a pressurized medium, usually air, is blown or pumped into it.
• the air pressure forces the plastic to match the peripheral geometry of the mold. Once the plastic has cooled and hardened the mold opens up and the part is ejected.
• blow molding platforms There are three main types of blow molding platforms: extrusion blow molding (EBM), injection blow molding (IBM) and stretch blow molding (SBM). In some applications the combination of the abovementioned blow molding platforms may be more appropriate depending on the properties and complexity of the articles to be formed, such as injection stretch blow molding (ISBM).
• EBM extrusion blow molding
• IBM injection blow molding
• SBM stretch blow molding
• such articles may be blown by a process that comprises the step of forming at least one recess proximal to said neck portion by translation of at least one moving plug relative to a first portion of said article.
• the advantage of such process is that the recess is formed by essentially displacing the neck portion of the article in a downwardly direction relative to the base of the article such that no portion of the mold remains trapped.
• simple de-molding via linear displacement of the mold may be achieved even for articles presenting multiple undercuts at the neck portion.
• Another advantage is that the need for more complex mold geometries is avoided.
• This process may be well understood with reference to Fig. 2A-D. Such process may comprise the steps of:
• Fig. 2A Ejecting the finished blown article (309) from said secondary mold cavity (306) Fig. 2D.
• the step shown in Fig. 2A can be done with any of the main types of blow molding platforms, or combination thereof.
• said molding platform is injection stretch blow molding (ISBM) where an injected preform is placed into a mold cavity and stretch-blow molded into an intermediate article (301) with a protruding neck portion (305).
• the molding platform may be extrusion blow molding (EBM) wherein an extruded parison may be blown to form a blown article comprising a protruding neck portion (305), and preferably additionally comprising at least one closure retention mechanism.
• ISBM injection stretch blow molding
• EBM extrusion blow molding
• 2A-C may be done in the same mold cavity straight after the blow molding of the intermediate article (i.e. with no need of a secondary mold cavity). If done in the same cavity, this has the advantage that the time between blow molding and recessing the protruding region (303) is minimized. Another advantage is that the tolerances on the final article specifically around the neck portion are very tight as there is no relative movement of the blown article versus said plug(s) (307).
• the intermediate article (301) may be moved to a secondary mold cavity (306) that is different to the mold cavity (302) where the intermediate article (301) is blown. If the plug(s) (307) is applied in a separate mold cavity, the blown intermediate article (301) may be re-heated just before placing in the secondary mold cavity (306).
• a reheating step may be done in case the region proximal to the neck portion (305) has cooled down too much during the blowing step, the transfer and/or the storage time of the intermediate article (301).
• the intermediate blown article may be transferred into a secondary mold cavity (306) right after blow molding.
• the intermediate article may be pressurized to enable a positive location of the article in the secondary mold cavity (306), preferably said plug(s) (307) is/are forced into the protruding region (303) proximal to said neck portion (305) of the blown article, more preferably said plug(s) (307) is/are in the form of at least one plug-assist piston, even more preferably said plug(s) (307) is/are at least one segment of the blow nozzle (311) and may be located within said blow nozzle (311) and/or on the outside of the perimeter of said blow nozzle (311).
• the protruding region (303) may be recessed against the shoulder(s) (312) of the blown article (309).
• an over pressure from 1 to 20 bar may be applied to calibrate the geometry of the final blown article against the female part of the secondary mold cavity (306).
• This pressure inside the blown article may fulfill different functions. Firstly, it may press the article to the cool secondary mold cavity (306) walls, which essentially functions as a secondary cooling cycle after the blowing. This may prevent panel and base deformation in the final article specifically if a hot secondary mold (313) is being employed. Pressures above 5 bar may be needed to avoid unwanted deformation in the final article. Higher pressures have been found to be beneficial as they aid the avoidance of local deformations near the region which is recessed during movement of the plug(s) (307).
• the pressure inside the article also acts as a female hydrostatic die that shapes the plastic to the metal skin (or outer surface) of the plug(s) (307) as it progressively moves towards the inside of said secondary mold cavity (306).
• plastic may be conformed to the plug(s) and the final recess geometry is achieved.
• the outer profile of said moving plug(s) (307) may correspond to the interior profile of said at least one recess (308), preferably said at least one recess (308) comprises at least one concave portion.
• the excess pressure inside the blown article may be vented and the plug(s) (307) removed, preferably before the final blown article (309) is ejected.
• the step shown in Fig. 2B-C is carried out whilst the temperature of the material in the region proximal to said neck portion (305) of said intermediate article (301) is maintained at a temperature below the glass transition temperature, T g .
• T g glass transition temperature
• said temperature is maintained between the glass transition temperature, Tg, and the melt temperature, Tm.
• such temperature regime is maintained for articles made of poly olefins (such as PP and PE).
• de-molding such recessed articles may be achieved by a process utilizing moving mold inserts.
• the advantage of such a process is that complex geometries generating the undercuts may be formed directly by blowing. The portions of the mold that would normally be trapped by said undercut during mold opening, are divided into a plurality of mold inserts and displaced in one or more phases, following the forming step, until clearance is provided and the formed article can be removed by simple opening of the mold.
• the process according to the abovementioned embodiment may comprise the steps of:
• said rotating inserts (44) are moved to return their starting position and subsequently said lateral pull section inserts (43) also return to their starting position, and optionally, the process cycle is repeated.
• the lateral pull section inserts (43) may actuate in a linear motion to make space for the rotating inserts' (44) next movement.
• the lateral pull section inserts (43) may move in a direction which is different from the direction in which the mold is opened.
• the first phase actuation may be linear in motion and may retract the lateral pull section inserts (43).
• the mold may be divided in at least two parts to enable opening along a mold parting line, preferably said at least two parts are symmetric and each form one half of the mold.
• a lateral pull section insert (43) is retracted on each half of the mold.
• Said lateral pull section inserts (43) may each serve the function of forming one quadrant of the neck portion (47) and closure retention mechanism (48) of the article.
• the space created in the mold adjacent to the article by said first movement may allow clearance for the rotating inserts (44) to be moved.
• the rotating insert (44) comprises a concave shape on at least one of the rotating insert' s (44) surface.
• the angle of rotation (A r ) does not exceed the difference of 180 degrees and the angle formed by the at least one surface of the rotating insert (A s ) facing the neck portion. More preferably, the angle of rotation (A r ) is greater or equal to the angle formed by the at least one surface of the rotating insert (A s ) facing the neck portion. Most preferably the angle of rotation (A r ) satisfies the following formula (I):
• the total number of moving inserts (41) is four and present a 180 degree concave portion bisected into two 90 degree portions equally split between the mold halves.
• the concave feature of the moving inserts (41) may partially surround the neck portion (47) and the at least one closure retention mechanism (48).
• said two sets of moving inserts (41) comprise one set of lateral pull section inserts (43) and one set of rotating inserts (44).
• Step (iii) may comprise the step of displacing said rotating inserts (44) by eccentric rotation versus the opening formed proximal to said neck portion (47) to clear the undercuts caused by the shoulder(s) (49) design and the closure retention mechanism (48).
• the rotating inserts' (44) axes of rotation may be positioned to enable an eccentric movement relative to the article's neck portion (47) diameter. If the axes were collinear with the centerline of the neck portion (47), the rotating inserts (44) may remain in contact with a surface of the neck portion (47) throughout the rotation, possibly causing a shearing or scraping of the formed article (42).
• Step (v) allows the rotating inserts (44) to return to their original molding position, clearing the space for the lateral pull inserts to return to their original location. This operation may allow the completion of the outline of the article to be molded. Following these steps, the mold is ready to blow the next article, re-starting the process cycle.
• de-molding such recessed articles may be achieved by a process utilizing a particular mold design comprising a number of parting lines, defining a number of mold portions, the process comprising the action of displacing said mold portions in a predetermined manner.
• the advantage of such process is that complex geometries generating the undercuts may be formed directly by blowing. The sections of the mold that would normally be trapped by said undercut are divided into a plurality of mold portions and displaced in more phases to enable ejecting the finished article without damage.
• a mold and mold cavity may be designed to have an upper part, proximal to the neck portion, divided from the body part of the mold cavity.
• the upper part of the mold cavity may include the female shape of the recess to be formed on a surface of the article, while the body part includes the remainder.
• the body part may generally be divided into two body part halves (or segments) that together form the entire body part and may be opened during the ejection of the blown article.
• the body part of the mold cavity may further be divided, preferably by means of a base part of the blow cavity that is dedicated to forming the base of the article. Translation of the base part typically occurs before the opening of the remaining body part.
• the process according to the abovementioned embodiment may comprise the steps of:
• step (iii) Ejecting the finished article.
• the displacements (both first and second displacements) in step (ii) may be selected from the group consisting of translational, rotational, and combinations thereof.
• the actual translation to be used may depend on the design of the recess.
• said second displacement may be a linear translation.
• the mold (605) is opened via several displacement phases occurring in step (ii).
• the first phase may comprise the displacement of the first portion (606) away from the second portion (607), namely the body part, in a direction substantially parallel to the z-axis.
• the second phase may comprise the displacement of at least two segments (616, 617) of the second portion (607) each in a substantially opposite direction, preferably in a direction perpendicular to the z-axis . If the mold (605) comprises a base part (608), then said base part (608) is displaced away from said second portion (607) prior to said second phase, preferably in a direction substantially parallel to the z-axis.
• said first portion (606) is itself divided into at least two sections: namely a right first portion (609) and a left first portion (610).
• the first phase may now comprise an additional displacement prior to displacing the first portion (606) away from said second portion (607). Said additional displacement being the right first portion (609) moving away from the left first portion (610) in a substantially opposite and mirrored direction taken from the z-axis.
• said mold (605) may comprise at least two parting lines (613) forming an angle of greater than 10° at the point of intersection. Preferably said angle of greater than 10° is taken starting from point on a plane perpendicular to the z axis.
• the at least two parting lines (613) may comprise at least one first parting line (611) which may extend along the cross-sectional diameter of the mold (605) in the x-y plane and at least one second parting line (612) which may extend along the z axis. It is however understood that said first and second parting lines (611, 612) may extend at any angle relative to said respective x-y plane and said z- axis.
• said at least one first parting line (611) may be located at least 1 ⁇ 2, preferably at least 3 ⁇ 4, of the total height of said mold (605) taken from the furthest position on the article from the neck portion (603) and along the z axis.
• said at least two parting lines (613) are perpendicular relative to each other.
• the parting lines (613) may have a number of forms and/or geometries.
• said parting lines (613) may be substantially linear, curvilinear and/or angular in a two-dimensional and/or three-dimensional space.
• two- dimensional it is herein intended that such geometry is present over a single plane of a solid object, typically one of the Cartesian planes.
• At least one of said parting lines (613) is substantially linear, curvilinear and/or angular in a three- dimensional space.
• This configuration may introduce several advantages, such as allowing the forming of articles presenting multiple curves on the outer surface whilst making sure that quality of subsequent labeling is not affected.
• forming articles with molds comprising parting lines results in the generation of very small protrusions (or flanges) corresponding to the profile of the parting line due to the high pressure of forming in combination with the small gap formed between mold portions.
• a three- dimensional parting line allows to carefully locate these protrusions in areas which are less likely to be noticed by human eye upon the application of a label and are preferred for proper labeling of the finished blown article.
• said first portion (606) of the mold (605) may be integral with a blow nozzle, preferably said first portion is proximal to the neck portion (603) being formed. In this embodiment said first portion (606) may displace together with said blow nozzle.
• said first portion (606) may itself comprise at least one third parting line (614) proximal to the neck portion (603) of the article being formed. This may allow displacement of the first portion (606) away from the z-axis in such a way to permit the unmolding of a closure retention mechanism (615) without damage.
• said third parting line(s) (614) divides said at least one first portion (606) of the mold (605) into at least one right first portion (609) and at least one left first portion (610).
• said third parting line (614) extends along the same plane as said second parting line (612).
• step (i) may comprise the step of forming at least one closure retention mechanism (615) forming a second undercut.
• said closure retention mechanism (615) is formed together with the entire shape of the article. More preferably said closure retention mechanism (615) is formed by at least one surface of the inner wall of the first portion (606) of the mold. Even more preferably, said closure retention mechanism (615) is formed by at least one surface of either right first portion (609) and/or left first portion (610).
• said mold (605) may be opened via the steps of:
• step (b) A subsequent at least second displacement of said at least two segments (616, 617) of a second portion (607) of the mold (605), preferably step (b) is performed after the displacement of a base part (608), if present;
• said first displacement is at an angle "g" of less than -10°, preferably between -10° and -45°, taken from the z-axis, and wherein said simultaneous displacement of said at least left first portion (610) is at an angle "g ⁇ 'of greater than 10°, preferably between 10° and 45°, taken from the z-axis.
• said angles and forces applied will depend on the material properties of the article being formed and the material thickness. Preferably the maximum point of elasticity of the material is not exceeded, particularly during step (a).
• the at least one closure retention mechanism (615) may protrude for a distance "a" of less than 3mm, preferably less than 2mm, more preferably between 0.5mm and 2mm, most preferably between 0.5mm and 1.5mm, from a proximal end to a distal end.
• a retention mechanism (615) protruding in excess of 3mm would cause high stress concentrations being generated proximal to the undercut regions. This in turn may lead to plastic deformation of the part, which preferably is to be avoided.
• An intermediate article is blown with a 360 degree protruding neck.
• the intermediate article is ejected from the blow mold cavity and presented to a secondary cavity.
• a male plug is used to recess the neck.
• the final article has a neck with a 360 degree shoulder profile and the neck is recessed by 15 mm - measured from "x-y" plane of the uppermost portion of the protruding shoulders to the "x-y" plane of the base of the neck.
• a round closure is capped onto the final article with the effect that the closure is substantially sunk into the blown article shape.
• the most favorable geometry is the geometry that eliminates any unwanted distortion during the operation of recessing the neck in the region nearby the recessed neck. It has been found that geometries with a small radius at the base of the neck help to initiate the deformation and specifically straight wall sections in the intermediate protruding neck are best to control the deformation during the movement of the plug.
• the shape deformation needed to recess the neck is a combination of material bending, reverting and stretching, the forces encountered during the deformation are critically dependent on the material distribution in the protruding region and the final intended shape geometry.
• a specific preform has been developed to obtain the desired homogeneous material distribution in the protruding neck region. It has been found that non-cylindrical recess shapes can be equally obtained to cylindrical recess shapes, yet deformations in the regions nearby the recess area are more difficult to avoid.
• a bottle is made by extrusion blow molding using a High Density Polyethylene resin (FORMOSA 5502F, 0.35 g/lOmin @ 190dC/2.16kg).
• the bottle has a recess that is recessed by 11.5mm against the snap-on neck of said bottle.
• a closure is made by injection molding using a Polypropylene resin (BOREALIS RF365MO, 20g/10min @ 230dC/2.16kg).
• the closure when snapped onto the bottle, remains substantially flush with the top surface of the bottle (bottle shoulder).
• Said bottle shoulder wraps around the closure over a 120 degree arch.
• the shoulder is formed during blow molding with a mold that has four moving inserts.
• a bottle is made by extrusion blow molding using a High Density Polyethylene resin (DOW 35060, 0.29 g/lOmin @ 190dC/2.16kg).
• the bottle has a recess that is recessed by 8mm against the snap-on neck of said bottle.
• a closure is made by injection molding using a Polypropylene resin (BOREALIS RF365MO, 20g/10min @ 230dC/2.16kg).
• the closure when snapped onto the bottle, remains substantially flush with the top surface of the bottle (bottle shoulder). Said bottle shoulder wraps around the closure over a 180 degree arch.
• the snap bead depth is 1mm and is formed during blow molding.
• the bottle is blown in a blow mold that has two upper mold halves that enable proper formation of the recess but are actuated before the remaining blow cavity is opened and the blown bottle ejected.
• the actuation of the upper mold halves is controlled by the blowing machine and the trajectory of the movement is in a 30 degree angle against the z-axis of the bottle - this trajectory enables to unmold the bottle including the snap- on bead without damage.
• the bottle cannot be ejected without the movement of the upper mold halves.
• the mold uses a 3D parting line between the upper part of the mold and the body part. This is required as bottle features a smooth transition from the neck portion into the body of the bottle and without such a 3D parting line the witness line of the mold would be visible to the consumer.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Manufacturing & Machinery (AREA)
• Ceramic Engineering (AREA)
• Containers Having Bodies Formed In One Piece (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)
• Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
• Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)

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• 2012
  • 2012-01-13 CN CN201280003624.8A patent/CN103201187B/zh not_active Expired - Fee Related
  • 2012-01-13 WO PCT/US2012/021203 patent/WO2012097224A2/fr not_active Ceased
  • 2012-01-13 MX MX2013005287A patent/MX352554B/es active IP Right Grant
  • 2012-01-13 EP EP12705514.3A patent/EP2663509A2/fr not_active Withdrawn
  • 2012-01-13 JP JP2013539010A patent/JP5784744B2/ja active Active

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