JP5784744B2 - Method for the manufacture of an article comprising a recess - Google Patents

Description

  The present invention relates to a method for blow molding an article comprising at least one recess, the recess being located at the base of the open portion of the article for association with the article of sealing. In particular, the present invention relates to simplifying the demolding of an article with a recess that creates an undercut while preventing damage to the article during such operation.

  The formation of a recess in the blow molded article (which is located at the base of the open part of the article) is highly desirable because it allows the sealing design to be integrated with the article design. . This integration in turn allows the manufacturer to create a consumer-friendly design while making the sealing function intuitive to the user. It is even more desirable to integrate the seal with the article so that the seal can be miniaturized. This miniaturization of the seal is desirable because it reduces the weight of the seal and thus reduces the amount of raw materials and energy consumed. A further advantage is that the stability of the article can be achieved both on the top side and in the inverted position, thanks to the flat surface created by the article and the seal.

  The production of blown articles comprising at least one recess, which is located at the base of the open part of the article, is technically difficult. This is because the formation of a recessed neck requires the article to form a shoulder on the top of the neck portion. This is technically difficult because the material flow that forms such a shoulder would be contrary to the natural material flow in blow molding. The natural material flow in blow molding is guided by a pressure increase that expands the wall of the article being formed into the shape of a mold cavity, and from the neck of the parison or preform toward the bottom of the article. Materials that move against the natural flow direction require careful design of the parison or preform and careful definition of the blowing process.

  Another challenge is that such a shoulder on the neck creates an undercut during the blow molding process that prevents demolding of the finished article when using known demolding processes. This is especially true when such a shoulder presents multiple curvatures on its surface. It is impossible to demold an article with such an undercut without damaging the article.

  The art involves several attempts to solve the essential problems associated with forming recessed blow molded articles.

  One approach has been to form a container with a recess that does not create an undercut, such as that described in US Pat. No. D573469 (Procter & Gamble Company). Such a recess allows demolding with a simple “straight-pull” (or linear opening) action from a standard mold. However, the contour that is recessed so that it can be removed by straight drawing in the blow mold is very restrictive in terms of the design of the recess contour that will be obtained. This in turn limits the degree of integration of the sealing part with the blown article and thus fails to achieve the benefits described above.

  Another approach was to perform a second step of blow molding the article into a mold cavity followed by cutting (or deburring) excess plastic to finish the contour of the recess. An example of this approach is described in US Pat. No. 6,357,625 (OWENS-BROCKWAYS plastic product). However, the use of such a method creates several disadvantages that will be apparent to those skilled in the art. First, the operation of cutting excess material is inherently cost-effective and should therefore be avoided. Second, any incision operation requires full access to the part to be incised, thus limiting the recess profile that may be obtained. Thirdly, such a limitation of the recess profile limits the integration of the sealing part with the blown article and thus again fails to achieve the desired benefits described above.

U.S. Pat. No. D573469 US Pat. No. 6,357,625

  Generation of a blow molded article having a recess that is integral with at least a portion of the seal so that when the seal is connected to the blown article, it can substantially overlap the apex of the outermost surface of the article It is an object of the present invention to provide a method for

  The present invention provides a blow molding process that forms a recess in a blown article so that at least a portion of the article surrounds at least a portion of a hermetic seal when connected to the blown article. It is another object of the invention.

  It is a further object of the present invention to simplify the demolding of an article with an undercut at the base of its neck portion while preventing damage to the article during such operation.

  The present invention includes forming an article having an integral neck portion and at least one recess at a base of the neck portion, and a plurality of undercuts at the base of the neck portion; It is aimed at a method for the production of a blow molded article comprising the step of demolding the article at the end of the forming process so as to retain the final physical profile created.

A method according to an embodiment of the present invention comprises:
(A) blowing an intermediate product into the mold cavity to form at least one protruding region, preferably at the base of the neck portion;
(B) placing the intermediate product in a second mold cavity;
(C) closing the second mold cavity;
(D) using one or more moving plugs to form one or more recesses at the base of the neck portion while maintaining the pressure in the intermediate product above 0.1 MPa (1 bar) When,
(E) releasing excess pressure in the blown article, preferably before collecting at least one plug;
Discharging the blown article from the second mold cavity.

A method according to an embodiment of the present invention comprises:
(F) blowing the article into the mold cavity to form at least one recess at the base of the neck portion;
(G) displacing the lateral handle insert to provide a gap for the insert to rotate in subsequent phase motion;
(H) Displace the rotating insert in at least one second phase motion to finally provide a gap for the undercut feature to open the mold and eject the article. Enabling the process,
Opening the mold to discharge the finished article.

A method according to an embodiment of the present invention comprises:
(I) blowing the article into the mold cavity to form an integral neck portion and at least one recess at the base thereof;
(J) a first displacement of at least one first portion of the mold, preferably at the base of the neck portion, and a subsequent at least second displacement of at least two segments of the second portion of the mold. And opening the mold, wherein the first and second displacements are about the first and second planes, preferably the first and second planes are perpendicular to each other A process,
Discharging the completed article.

1 is an isometric view of a blown article formed by a method according to an embodiment of the invention. FIG. The side view of the blowing article of FIG. 1A. The enlarged view of A section of FIG. 1B. FIG. 1B is a plan view of the article of FIG. 1B. FIG. 3 is an isometric view of a blown article formed by a method according to an embodiment of the present invention connected to a seal. A method according to an embodiment of the invention. A method according to an embodiment of the invention. A method according to an embodiment of the invention. A method according to an embodiment of the invention. FIG. 2 is an isometric view of a half of a mold with an article therein for a method according to an embodiment of the present invention. The top view of FIG. 3A. Part of a method according to an embodiment of the invention. Part of a method according to an embodiment of the invention. Part of a method according to an embodiment of the invention. FIG. 3 is a cross-sectional view of a mold with a blowing container therein for a method according to an embodiment of the present invention. FIG. 5B is a cross-sectional view of the mold of FIG. 5A taken from BB. FIG. 5B is a cross-sectional view of the mold of FIG. 5A taken from BB. Figure 2 is a cross-sectional view of a mold for a method according to an embodiment of the invention. Figure 2 is a cross-sectional view of a mold for a method according to an embodiment of the invention. 1 is a cross-sectional view of an article formed by a method according to an embodiment of the invention.

  As used herein, the term “undercut” prevents the removal of an article from a mold (when the mold is opened in a linear direction intersecting at least a portion of the physical outline). means.

  As used herein, the term “multiple undercuts” means that the same profile prevents removal of the article from the mold (the mold opens in multiple linear directions that intersect at least a portion of the profile. (Typically the directions are perpendicular to each other).

  As used herein, the “z-axis” is the longitudinal axis Z (or article centerline).

  As used herein, an “xy” plane is a plane that is substantially perpendicular to the z-axis.

  As used herein, the term “preform” is a shaped element that is produced before being expanded to form a finished article. The preform is necessarily somewhat smaller than the finished blown article. Preforms are generally produced, for example, by injection molding at high temperatures above the melting temperature.

  As used herein, the term “stretch blow molding” means that preforms are heated to above their glass transition temperature and then blown into a mold using a high pressure medium, preferably air, A method of forming a hollow article such as a container. Usually, the preform is stretched using a stretching rod as part of the process.

  As used herein, “recycled” materials include post-consumer recycled (PCR) materials, post-industrial recycled (PIR) materials, and mixtures thereof.

  As used herein, “regrind” materials include sprue, runners, excess parison material, and thermoplastics such as defectives from injection molding, blow molding and extrusion operations, recovered by crushing or granulation. Waste material.

  As used herein, the prefix “bio-” is used to designate a material derived from a renewable resource.

  The present invention includes an integral neck portion (47, 305, 603) and at least one recess (50, 308, 604) at the base of the neck portion (47, 305, 603) forming a plurality of undercuts. Forming the article (42, 309, 601) having the article and at the end of the forming process such that the article (42, 309, 601) retains the final physical profile created in the forming process. And (42, 309, 601) demolding, and a method for producing a blow-molded article (42, 309, 601). This inevitably means that the article should be demolded without plastically deforming the blown article. By “integral neck portion” is intended herein that the neck portion is a single piece with the article.

  For purposes of the present invention, suitable recesses are those that allow a portion of the article to surround at least a portion of the seal when the seal is coupled to the article. Such a recess may allow the seal to remain substantially flush with the top surface apex of the article when coupled to the article. In this specification, “at least a part of the sealing part” means that when the sealing part is connected to the article, the part extends around the outer periphery of the sealing part, and from the center of the sealing part, and Taken in the xy plane, it is intended to form an angle of at least 45 °, preferably at least 60 °, more preferably 60 ° to 360 °.

  The novel method described above, which solves the overarching problem associated with demolding an article with an undercut at the base of the neck portion of the article, includes a plurality of optional detailed steps to achieve such a result. It has been found to contain.

  The following section illustrates an embodiment of the invention with reference to the drawings. First, articles made by the method of the present invention and suitable seals are considered, followed by a detailed description of a preferred embodiment of the method according to the present invention.

Article The article formed by the method of the present invention comprises a plurality of undercuts at the base of the neck portion, preferably at least two undercuts, more preferably at least three undercuts, and even more preferably at least four undercuts. May be provided. A particularly preferred contour for creating such an undercut is a contour with at least one curved surface, preferably a concave surface.

  Articles made by the methods of the present invention may be selected from the group consisting of containers, devices, handles, instruments, and combinations thereof. A preferred article is a container for use in a variety of fields. Non-limiting examples of such areas include beauty products such as body soaps, shampoos, and containers for conditioners; detergents or other cleans to clean and / or condition fabrics and / or hard surfaces There are domestic and / or household products, such as preparation containers, oral care products such as mouthwash containers, and the like.

  Articles made by the method of the present invention may be made of any suitable plastic resin material. Preferred plastic resin materials for use in the present invention may be polyolefins (such as PP and PE), polystyrene (PS), polyvinyl chloride (PVC), polylactic acid (PLA) or polyethylene terephthalate (PET). In one embodiment, the plastic resin material is polyethylene terephthalate (PET). Alternatively, the article made by the method of the present invention may be made of a sustainable material selected from the group consisting of renewable materials, recyclable materials, regrind materials, and mixtures thereof.

  Examples of “renewable materials” include biopolyethylene, biopolyethylene terephthalate, and biopolypropylene. As used herein, unless otherwise specified, “polyethylene” means high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and ultra low density polyethylene (ULDPE). ). As used herein, unless otherwise specified, “polypropylene” includes homopolymer polypropylene, random copolymer polypropylene, and block copolymer polypropylene.

  Referring to FIGS. 1A-E, the article (101) may be a container with an opening (102) defined by a neck portion (103), the neck portion (103) being a top surface (104). May be provided. At least a portion of the top surface (104) of the neck portion (103) is taken along an axis extending parallel to the centerline (or z-axis) of the article (101) to provide a top surface of the article May be under at least a portion of The top portion of the article may be in the form of at least one shoulder (105), preferably the shoulder portion (103) so as to define a recess in the base of the neck portion (103). 103) extends in parallel to at least a part of the outer side. A recess may be located between the shoulder (105) and the neck portion (103). An advantage of such a configuration is that it allows the fit of the seal (106) to sink substantially into the blown article. “Settling into” as used herein means that at least one surface of the seal (106) remains substantially flush with at least one surface of the article, preferably of the article. It is contemplated that the at least one surface is on the outer surface of the shoulder (105). Preferably said at least one surface is an uppermost surface taken along a plane substantially parallel to the centerline of said article.

  In one embodiment, at least a portion of the recess has a substantially concave shape. This configuration has the advantage of reducing the gap between the two when the seal (106) and the article are connected together. However, this external complexity results in a cumbersome demolding using current methods. In fact, such a recess does not allow demolding of the article due to traditional straight pulling during opening of the moving mold.

  In one embodiment, at least a part of an interface between a part (101) of the article into which the sealing part (106) is fitted and a part of the sealing part (106) in an opposing relationship with the part (101) is concave, An outline selected from the group consisting of convex, linear, non-linear, and combinations thereof is presented. Preferably, the interface is along at least one surface of the shoulder (105).

  In another embodiment, an article made by the method of the present invention may have a non-linear profile at the base of the neck portion (103). The curvature of the non-linear outer shape may allow a portion of the article to surround at least a portion of the seal (106) once the seal is fitted over the article. Preferably, a portion of the article surrounding at least a portion of the seal (106) is within at least one surface of the shoulder (105), more preferably within the shoulder (105) facing the neck portion of the article. Surface (107).

  In one embodiment, the inner surface (107) of the shoulder (105) may comprise a positive draft of less than 10 °, preferably less than 8 °, more preferably less than 5 °. Such draft is defined as the angle of the surface taken from a plane perpendicular to the mold parting line formed on the surface. Having a positive draft of less than 10 ° can be important for a number of reasons, including consumer acceptance and the possibility of reuse of the same seal across various article dimensions. Without being bound by theory, it is believed that the smaller the draft, the smaller the space or gap between the article and the seal that will exist after the seal is assembled thereon. Thus, achieving a more aesthetically pleasing design and gaining consumer acceptance. Furthermore, having a low positive draft on the inner surface (107) of the shoulder (105) allows the use of a seal with zero or low positive draft. A seal with a low positive draft may then be used with a variety of different shoulder designs and / or with articles that have no shoulder at all. This results in greater flexibility because the same seal can be used across a wide variety of articles, thus creating scale, which in turn typically reduces cost and logistics complexity.

  In a preferred embodiment, an article made by the method of the present invention may include a seal retaining mechanism (108) that can be selected from the group consisting of snap beads, threads, and combinations thereof. The sealing portion holding mechanism (108) may protrude from at least one section of the outer side portion of the neck portion (103), and preferably the sealing portion holding mechanism (108) is provided on the neck portion (103). Located at the base of the top surface (104). It will be apparent to those skilled in the art that such protrusions further complicate the demolding of the article. Indeed, such a seal retention mechanism (108) will prevent removal of the article from the mold in a direction substantially perpendicular to the horizontal "xy" plane.

  In one embodiment, the seal retention mechanism (108) may protrude from a proximal end to a distal end over a distance “a”. Typically, the proximal end is closer to the z-axis than the distal end. Preferably the distance “a” is taken along a plane substantially perpendicular to the z-axis. In one embodiment, the distance “a” is less than 3 mm, preferably less than 2 mm, more preferably 0.5 mm to 2 mm, and most preferably 0.5 mm to 1.5 mm.

Seals Seals that can be used with articles made by the method of the present invention are also any seals that are suitable for compliance with the article.

  In one embodiment, the seal (106) may be capable of being coupled to the article (101), preferably the seal (106) interacts with the seal retainer mechanism (108). And the connection means (not shown) which fixes this sealing part (106) on the said article | item (101) is provided.

  In one embodiment, when the sealing portion (106) is coupled to the article, the fluid between the inner surface and the outer surface of the article via a passage when the sealing portion (106) is in the first position. Communication may be provided. When the sealing portion (106) moves to the second position, the passage is closed and fluid communication is blocked. As a result, the sealing portion (106) may move from the first position to the second position, and vice versa. Preferably, the movement from the first position to the second position is selected from the group consisting of translation, rotation and combinations thereof.

Method Blow molding is a well-known manufacturing method for the production of plastic articles such as containers, fuel tanks, handles and the like. The blow molding process begins with melting the plastic and forming it into a parison or preform. The parison is then clamped into the mold and a pressurized medium, usually air, is blown or pumped into it. The air pressure forces the plastic to match the contour around the mold. Once the plastic cools and hardens, the mold opens and the parts are ejected.

  There are three main types of blow molding platforms: extrusion blow molding (EBM), injection blow molding (IBM) and stretch blow molding (SBM). For some applications, depending on the properties and complexity of the article to be formed, a combination of the above-described blow molding platforms, such as injection stretch blow molding (ISBM), may be more appropriate.

  The next page illustrates a preferred embodiment of the method according to the invention for forming and demolding an article with a plurality of undercuts at the base of its neck portion.

In one embodiment, such an article comprises a method comprising forming at least one recess in the base of the neck portion by translation of at least one moving plug relative to a first portion of the article, May be blown. The advantage of such a method is that the recess is formed by essentially shifting the neck portion of the article in a downward direction relative to the bottom of the article so that no part of the mold is captured and stays. That is. Thus, simple demolding can be achieved through linear displacement of the mold, even for articles that present multiple undercuts at the neck portion. Another advantage is that the need for more complex mold profiles is avoided. This method can be better understood with reference to FIGS. Such a method is
a) FIG. 2A, preferably blowing an intermediate article (301) having a region (303) protruding in the vicinity of the opening (304) defined by the neck portion (305) of the article into the mold cavity (302). And the process of
b) optionally placing the intermediate product (301) in the second mold cavity (306);
c) FIG. 2B-C, preferably using the inwardly moving plug (307) while the protruding area maintains the pressure inside the intermediate blown article (301) of at least 0.1 MPa (1 bar). Forming one or more recesses (308) utilizing one or more moving plugs (307) to indent;
d) releasing excess pressure in the blown article (309), preferably before collecting the plug (307);
e) FIG. 2D, including discharging the completed blown article (309) from the second mold cavity (306).

  The process shown in FIG. 2A can be performed with any of the primary molds of a blow molding platform, or a combination thereof. In one embodiment, the molding platform comprises an injection stretch blow molding in which an injected preform is placed in a mold cavity and stretch blow molded into an intermediate article (301) having a protruding neck portion (305). ISBM). In another embodiment, the molded platform is extruded with an extruded parison that may be blown to form a blown article comprising a protruding neck portion (305), preferably further comprising at least one seal retention mechanism. It can be blow molding (EBM).

  The steps shown in FIGS. 2A-C may be performed in the same mold cavity immediately after the blow molding of the intermediate product (ie, without the need for a second mold cavity). When performed in the same cavity, this has the advantage that the time between blow molding and recess formation of the protruding area (303) is minimized. Another advantage is that there is no relative movement of the blown article versus the plug (307), so that the tolerances to the final product, particularly around the neck portion, are very tight.

  In a variant, the intermediate product (301) may be moved to a second mold cavity (306) that differs from the mold cavity (302) into which the intermediate product (301) is blown. If the plug (307) is utilized in a separate mold cavity, the blown intermediate article (301) may be reheated just prior to placement in the second mold cavity (306). The reheating step may be performed when the region at the base of the neck portion (305) is overcooled during the blowing step, transfer and / or storage time of the intermediate product (301). In a preferred embodiment, the intermediate blow article may be transferred into the second mold cavity (306) immediately after blow molding.

  In the steps shown in FIGS. 2B-C, the intermediate article may be pressurized to allow a positive location for the article in the second mold cavity (306), preferably the plug (307) is Pushed into the protruding region (303) at the base of the neck portion (305) of the blown article, more preferably the plug (307) is in the form of at least one plug auxiliary piston, and even more preferably The plug (307) is at least one segment of the blowing nozzle (311) and may be located in the blowing nozzle (311) and / or on the outer side of the outer side of the blowing nozzle (311). As a result, the protruding region (303) may be recessed relative to the shoulder (312) of the blown article (309). When the male part of the plug is fully engaged with the article, an overpressure of 0.1-2 MPa (1-20 bar), preferably 0.1-0.5 MPa (1-5 bar) is utilized. Thus, the outer shape of the final blown article may be calibrated with respect to the female part of the second mold cavity (306). This pressure inside the blown article can fulfill different functions. First, it presses the article against the cold second mold cavity (306) wall, which essentially functions as a secondary cooling cycle after blowing. This can prevent panel and bottom deformation in the final product, especially when a hot secondary mold (313) is used. In order to avoid unnecessary deformation in the final product, a pressure in excess of 0.5 MPa (5 bar) may be required. Higher pressures have been found to be beneficial because they help avoid local deformation near the recessed area during movement of the plug (307). These deformations are usually caused by radial tension and tangential compressive stress in the area. Finally, the inner pressure article also forms a plastic against the metal skin (or outer surface) of the plug (307) as it moves progressively toward the inside of the second mold cavity (306). It also operates as a hydrostatic die. Once the male plug (307) is fully engaged, the plastic can be fitted to the plug and the final recess profile is achieved. In a preferred embodiment, the outer contour of the moving plug (307) may correspond to the inner contour of the at least one recess (308), preferably the at least one recess (308) is at least one. With one concave part.

  In the steps shown in FIGS. 2C-D, the excess inner pressure blown article is preferably vented and the plug (307) is removed before the final blown article (309) is discharged. Good.

In a preferred embodiment, the process shown in FIG 2B~C, the temperature of the material in the area at the base of the neck portion (305) of the intermediate product (301) is maintained at a temperature below the glass transition temperature T _g While done. It is particularly preferred that such a temperature regime is maintained for articles made of polyethylene terephthalate (PET). In another embodiment, the temperature is maintained between a glass transition temperature Tg and a melting temperature Tm. Preferably, such a temperature regime is maintained for articles made of polyolefins (such as PP and PE).

  In another embodiment, demolding such a hollow article may be accomplished by a method that utilizes a moving mold insert. The advantage of such a method is that the complex profile that creates the undercut can be formed directly by blowing. The portion of the mold that would normally be captured by the undercut during mold opening is divided into a plurality of mold inserts following the forming process, providing gaps, and the formed article is the mold. Are shifted in one or more phases until they can be removed by simply opening them.

With reference to FIGS. 3A-B and FIGS. 4A-C, the method according to the above embodiment comprises:
(I) blowing the article (42) into the mold cavity (45) to form a recess (50), preferably in the base of the neck portion (47);
(Ii) displacing the lateral handle insert (43) in a first phase actuation to provide clearance for the insert (44) rotating in subsequent phase motion;
(Iii) Displace the insert (44) that rotates in at least one second phase motion to finally provide a gap for the undercut feature to open the mold and complete the finished article A process that allows it to be discharged; and
(Iv) opening the mold (46) to discharge the completed article.
(V) Preferably, the rotating inserts (44) move back to their starting position, after which the lateral handle insert (43) also returns to their starting position, optionally The process cycle is repeated.

  In step (ii), the lateral handle insert (43) may be operated in a linear motion to create space for the next movement of the rotating insert (44). The lateral handle insert (43) may move in a direction different from the direction in which the mold is opened. The first phase actuation may be a linear motion and may store a lateral handle insert (43). In one embodiment, the mold may be divided into at least two parts to allow for opening along the mold parting line, preferably the at least two parts are symmetrical, each being a mold. Form half of the mold. Preferably a lateral handle insert (43) is stored on each half of the mold. Each of the lateral handle inserts (43) may serve to form one quadrant of the neck portion (47) of the article and the seal retaining mechanism (48). By the first movement, the space created in the mold adjacent to the article may allow the gap for the rotating insert (44) to move.

Without being bound by theory, it would be undesirable to have a single set of two moving inserts (41) to remove the undercut region. In fact, using a single set of moving inserts (41) makes each moving insert (41) create a semicircle or 180 degree arc around the neck portion (47) and at its base. ) Will bring. Any rotation of the moving insert (41) creating a 180 degree arc will cause a collision at the mold parting line while the mold is in its closed position. On the other hand, to avoid such a collision, it has more than two moving inserts (41), at least two of which are rotating inserts (44), each less than 180 degrees, preferably 90 It is preferable to create an arc of less than or equal to degrees. In one embodiment, the rotating insert (44) comprises a concave shape on at least one of the surfaces of the rotating insert (44). Preferably, the angle of rotation (A _r ) does not exceed the difference between 180 degrees and the angle (A _s ) formed by at least one surface of the rotating insert facing the neck portion. More preferably, the angle of rotation (A _r ) is greater than or equal to the angle (A _s ) formed by at least one surface of the rotating insert facing the neck portion. Most preferably, the angle of rotation (A _r ) satisfies the following formula (I):
A _s ≦ A _r ≦ (180 ° −A _s ) (I)

  In the preferred embodiment, the total number of moving inserts (41) is four, presenting a 180 degree concave part divided into two 90 degree parts evenly divided between the mold halves. Preferably, two sets of two symmetrically opposite or mirror image moving inserts (41) on each mold half. The concave feature of the moving insert (41) may partially surround the neck portion (47) and the at least one seal retaining mechanism (48). In a more preferred embodiment, the two sets of moving inserts (41) include one set of lateral handle inserts (43) and one set of rotating inserts (44).

  Step (iii) comprises displacing the rotating insert (44) with respect to an opening formed proximal to the neck portion (47) by eccentric rotation to provide a shoulder (49) design and seal. Removing undercut caused by the retaining mechanism (48). The axis of rotation of the rotating insert (44) may be positioned to allow eccentric movement with respect to the diameter of the neck portion (47) of the article. If the shaft is collinear with the centerline of the neck portion (47), the rotating insert (44) can remain in contact with the surface of the neck portion (47) throughout the rotation and the formed article ( 42) may cause shearing or abrasion. Offsetting the axis of rotation from the diameter axis of the neck portion (47) may allow stepped discharge and a gap between the neck portion (47) and the associated rotating insert (44) profile, and thus It eliminates any risk of scratching or shearing the molded surface. Once the rotating insert (44) has removed the undercut area, removal of the molded article may then be accomplished by utilizing a conventional mold opening operation.

  Step (v) allows the rotating inserts (44) to return to their original molding position and frees space for the lateral puller inserts to return to their initial location. This operation may allow completion of the outline of the article to be molded. Following these steps, the mold is ready to blow the next article and restarts the process cycle.

  In another embodiment, demolding such a hollow article may be accomplished by a method utilizing a particular mold design that includes several parting lines that define several mold parts. Often, the method includes the act of shifting the mold part in a predetermined manner. The advantage of such a method is that the complex profile that creates the undercut can be formed directly by blowing. The part of the mold that would normally be captured by the undercut is divided into a plurality of mold parts and shifted in a further phase to allow the finished article to be discharged without damage.

  In certain examples of the above embodiments, the mold and mold cavity may be designed to have an upper portion at the base of the neck portion that is separated from the body portion of the mold cavity. The upper portion of the mold cavity may include a female shaped recess to be formed on the surface of the article, while the body portion includes the remainder. Without intending to limit the scope of the invention, the body portion may generally be divided into two body portion halves (or segments) that together form the entire body portion, during ejection of the blown article. It may be opened. Typically, the body portion of the mold cavity may be further subdivided, preferably using a bottom of the blow cavity that is dedicated to form the bottom of the article. Translation of the bottom typically occurs before opening the remaining body part.

5A-F, the method according to the above embodiment comprises
(I) blowing the article (601) into the mold cavity (602) to form preferably an integral neck portion (603) and at least one recess (604) at the base thereof;
(Ii) a first displacement of at least one first part (606) of the mold (605), preferably at the base of the neck part (603), and a subsequent part (607) of the mold (605); And at least a second displacement of at least two segments (616, 617) to open the mold (605) (where the first and second displacements are about the first and second planes). And preferably the first and second planes are perpendicular to each other)
(Iii) discharging the completed article.

  In one embodiment, the displacement (both first and second displacement) in step (ii) may be selected from the group consisting of translation, rotation, and combinations thereof. The actual translation to be used may depend on the design of the recess. In one embodiment, the second displacement may be linear translation.

  In a preferred embodiment, the mold (605) is opened through a plurality of phase changes that occur in step (ii). The first phase may include displacement of the first portion (606) away from the second portion (607), ie, the body portion, in a direction substantially parallel to the z-axis. The second phase reduces the displacement of the at least two segments (616, 617) of the second part (607) in a substantially opposite direction, preferably in a direction perpendicular to the z-axis, respectively. May be included. If the mold (605) comprises a bottom (608), the bottom (608) is preferably in the direction substantially parallel to the z-axis, the second part (before the second phase) 607).

  In another preferred embodiment, said first part (606) is itself divided into at least two segments: a right first part (609) and a left first part (610). The first phase then includes further displacement before the first portion (606) is moved away from the second portion (607). Said further displacement being a right first part (609) moving away from the left first part (610) in a substantially opposite and mirror image direction as measured from the z-axis.

  In one embodiment, the mold (605) may comprise at least two parting lines (613) that form an angle greater than 10 ° at the intersection. Preferably the angle above 10 ° is taken starting from a point on a plane perpendicular to the z-axis. At least two parting lines (613) may extend along the z-axis, and at least one first parting line (611) that may extend along the cross-sectional diameter of the mold (605) in the xy plane. At least one second parting line (612) may be provided. However, it is understood that the first and second dividing lines (611, 612) can extend at any angle with respect to the respective xy plane and the z-axis. In one embodiment, the at least one first parting line (611) is taken on the article from a position furthest from the neck portion (603) and along the z-axis of the mold (605). It may be located at least 1/2 of the total height, preferably at least 3/4. In a preferred embodiment, the at least two parting lines (613) are perpendicular to each other. The dividing line (613) may have several forms and / or outlines. For example, the dividing line (613) may be substantially linear, curved and / or angular in a two-dimensional and / or three-dimensional space. “Two-dimensional” as used herein is intended to mean that such an outline exists across a single plane of a solid object, typically one of the Cartesian planes. “Three-dimensional” as used herein is intended to mean that such outlines and / or forms exist across multiple planes of a solid object. Preferably, at least one of the dividing lines (613) is substantially linear, curved and / or angular in a three-dimensional space. This configuration may introduce several advantages, such as allowing the formation of articles that present multiple curvatures on the outer surface while ensuring that subsequent labeling is not affected. In fact, forming an article with a mold with a parting line is very much corresponding to the contour of the parting line due to the high pressure of making it in combination with a small gap formed between the mold parts. This results in the creation of small protrusions (or flanges). Without being bound by theory, the three-dimensional dividing line allows these protrusions to be carefully positioned in an area that is less likely to be noticed by the human eye when the label is used, and the finished blown article It is considered preferred for proper labeling.

  In one embodiment, the first portion (606) of the mold (605) may be integral with the blow nozzle, preferably the first portion is formed with a neck portion (603). Proximal to. In this embodiment, the first part (606) may be displaced together with the blowing nozzle.

  In a further embodiment, said first portion (606) may itself comprise at least one third parting line (614) at the base of 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 as to allow demolding of the seal retention mechanism (615) without damage. Preferably, said third parting line (614) comprises said at least one first part (606) of mold (605), at least one right first part (609) and at least one left Into the first part (610). In one embodiment, the third parting line (614) extends along the same plane as the second parting line (612).

  In one embodiment, step (i) includes forming at least one seal retaining mechanism (615) that forms a second undercut. Preferably, the sealing part holding mechanism (615) is formed together with the entire shape of the article. More preferably, the sealing part holding mechanism (615) is formed by at least one surface of the inner wall of the first part (606) of the mold. Even more preferably, the seal retaining mechanism (615) is formed by at least one surface of either the right first portion (609) and / or the left first portion (610).

In one embodiment, the mold (605) is
(A) a first displacement of the at least one right first portion (609) and a displacement of the at least one left first portion (610) substantially simultaneously;
(B) at least a second displacement of the at least two segments (616, 617) of the second portion (607) of the mold (605) that follows (preferably step (b)) If present, may be opened via the bottom (608) after displacement)
The first displacement is an angle “g” of less than −10 °, preferably −10 ° to −45 °, measured from the z-axis, and the simultaneous displacement of the at least left first portion (610). The displacement is an angle “g ¹ ” of more than 10 °, preferably 10 ° to 45 °, measured from the z-axis. This allows the mold (605) to be opened without plastically deforming and / or damaging the portion of the article that forms one or more undercuts. In this embodiment, the angle and force utilized will depend on the material properties and material thickness of the article being formed. Preferably, the maximum point of elasticity of the material is not exceeded, especially during step (a). More preferably, the portion of the part at the base of the undercut is subjected to a stress below the yield stress of the material being formed.

  In another embodiment, the at least one seal retaining mechanism (615) has a distance “a” of less than 3 mm, preferably less than 2 mm, more preferably 0.5 mm to 2 mm, and most preferably 0.5 mm to 1.5 mm. It may protrude from the proximal end to the distal end. Without being bound by theory, the retention mechanism (615) protruding beyond 3 mm is believed to cause high stress concentrations being generated proximal to the undercut region. This in turn may lead to plastic deformation of the part, which should preferably be avoided.

Example 1
A standard PET resin (Equipolymer C93, IV = 0.80 dl / g) preform is stretch blow molded at a mold temperature of 65 ° C. The intermediate product is blown with a 360 degree protruding neck. The intermediate product is discharged from the blow mold hole and presented in the secondary cavity. Use a male plug to recess the neck. The final product has a neck with a shoulder profile of 360 degrees, measured from the “xy” plane at the top of the protruding shoulder to the “xy” plane at the bottom of the neck, Hollow 15mm. A round seal is placed over the final article, which has the effect of the seal substantially sinking into the blown article shape.

  A study of different projecting shape profiles was conducted to identify the most preferred profile. The most preferred profile is one that eliminates any unnecessary distortion during the operation of denting the neck in the area near the recessed neck. A profile with a small radius at the bottom of the neck helps to initiate the deformation, and in particular, a straight wall section at the middle protruding neck is optimal for controlling the deformation during plug movement. It has been found.

  The shape deformation required to recess the neck is a combination of bending, returning and stretching of the material, and the forces encountered during deformation depend on the material distribution in the protruding area and the final intended shape profile. Depends decisively. Certain preforms have been developed to obtain the desired uniform material distribution in the protruding neck region. A non-cylindrical recess shape can be obtained equally with a cylindrical recess shape, but nonetheless, deformation in the region near the recess area has been found to be more difficult to avoid. Has been.

(Example 2)
Bottles are made by extrusion blow molding using high density polyethylene resin (FORMOSA 5502F, 190 dC / 2.16 kg, 0.35 g / 10 min). The bottle has a recess recessed 11.5 mm with respect to the snap-on neck of the bottle. The sealed part is made by injection molding using polypropylene resin (BOREALIS RF365MO, 230 dC / 2.16 kg, 20 g / 10 min). The closure remains substantially flush with the top surface of the bottle (bottle shoulder) when snapped on the bottle. The bottle shoulder surrounds the seal over a 120 degree arch. The shoulder is formed with a mold having four moving inserts during blow molding. At rest, the insert allows proper formation of the shoulder, but activates the insert before the mold opens and the bottle is discharged. This operation is driven by two separate electric motors controlled by the molding machine. If the insert stays idle and is not activated, the bottle will not drain without damage.

(Example 3)
Bottles are made by extrusion blow molding using high density polyethylene resin (DOW35060, 0.29 g / 10 min at 190 dC / 2.16 kg). The bottle has a recess recessed 8 mm to the snap-on neck of the bottle. The sealed part is made by injection molding using polypropylene resin (BOREALIS RF365MO, 230 dC / 2.16 kg, 20 g / 10 min). The closure remains substantially flush with the top surface of the bottle (bottle shoulder) when snapped on the bottle. The bottle shoulder surrounds the seal over a 180 degree arch. The snap bead is 1 mm deep and is formed during blow molding. The bottle is blown into a blow mold with two upper mold halves that allows proper formation of the recess but is activated before the remaining blow cavity is opened and the blow bottle is discharged . The operation of the upper mold half is controlled by a blower and the trajectory of movement is at a 30 degree angle with respect to the bottle's z-axis, but this trajectory unmolds the bottle containing the snap-on bead without damage. Make it possible to do. The bottle cannot be discharged without moving the upper mold half. The mold uses a 3D parting line between the upper part of the mold and the body part. This is required when the bottle is characterized by a smooth transition from the neck portion into the body of the bottle, and without such a 3D dividing line, the mold hit line is visible to the consumer. Will.

  The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Rather, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” shall mean “about 40 mm”.

  All documents cited in this application, including all patents or patent applications that are cross-referenced or related, are hereby incorporated by reference in their entirety unless specifically stated to be excluded or limited. Citation of any document does not admit that such document is prior art to all inventions disclosed or claimed in this application, or such document alone or in all other references. And no reference to, teaching, suggestion, or disclosure of any such invention in any combination thereof. Further, in this document, if the scope of any meaning or definition of a term conflicts with any meaning or definition of the same term in the incorporated literature, the meaning or definition given to that term in this document Priority shall be given.

  While specific embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims (5)

A method for manufacturing a blow molded article (42), comprising:
(I) an integral neck portion (47), at least one recess (50) at the base of the neck portion (47), and at the base of the neck portion (47) and made by the recess (50) Forming an article (42) having a plurality of undercuts,
(Ii) demolding the article at the end of the forming step so that the article (42) retains the final physical profile created during step (i);
Step (i)
(A) blowing the article (42) into the mold cavity (45) to form at least one of the recesses (50) at the base of the neck portion (47);
(B) displacing the lateral handle insert (43) to provide clearance for the insert (44) rotating in subsequent phase motion;
(C) displacing the insert (44) rotating around the neck portion (47) in at least one second phase motion to provide the gap for the undercut feature last, Allowing the mold to be opened and the article (42) to be discharged;
The method wherein step (ii) includes opening the mold (46) to discharge the finished article (42).   The displacement of the rotating insert (44) according to claim 1, wherein the rotating insert (44) is displaced by an eccentric rotation relative to an opening formed proximal to the neck portion (47). The method described.   The method of claim 1 or 2, wherein the article (42) is a container.   The method according to any one of claims 1 to 3, wherein the method is selected from the group consisting of extrusion blow molding, injection blow molding, injection stretch blow molding, and combinations thereof.   Subsequent to step (ii), the rotating inserts (44) move back to their starting position, after which the lateral handle insert (43) also returns to their starting position, optionally The method according to claim 1, wherein the process cycle is repeated.

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