METHOD OF MAKING A HOLLOW POLYETHYLENE TEREPHTHALATE BLOW MOLDED ARTICLE WITH AN INTEGRAL EXTERNAL PROJECTION SUCH AS A HANDLE

Abstract: The present invention is directed to a method of making a hollow polyethylene therephthalate (PET) blow molded article (18) with an integral external projection such as a handle (26) thereon. The method includes blow molding the hollow article (18) and then injection molding the integral projection (26) thereon.

Description: METHOD OF MAKING A HOLLOW POLYETHYLENE TEREPHTHALATE BLOW MOLDED ARTICLE WITH AN INTEGRAL EXTERNAL PROJECTION SUCH AS A HANDLE Background of the Invention The present invention is directed to a method of making a hollow article having an integral projection extending from a wall thereof, such as, a bottle with an integral handle thereon, in which both the hollow article and integral projection are fab¬ ricated of polyethylene terephthalate (PET) . There is a continuous demand for PET arti¬ cles such as bottles, buckets, pitchers, cylinders, funnels, etc., because they are relatively inexpen¬ sive, easy to use and generally non-breakable. It is oftentimes desirable that articles of large size have handles thereon to aid in their use. U.S. Patent No. 4,713,207 discloses a method of making a plastic container with an integral handle member thereon. The method disclosed includes the step of extruding a thermoplastic parison between sections of a mold and then blowing the container. Since it is generally understood that PET does not have sufficient hot melt thermoplastic materials, such as high density poly¬ ethylene and polyvinyl chloride, must be used to produce blow molded containers where the handle is integral with the container. When PET is used and handles are desired, it has been the practice to attach the handle to the PET article in a separate operation, such as by ultrasonic fusion, after the blow molded PET article has been formed in and removed from the blow mold. Another approach has been to injection mold a thermoplastic handle in an operation separate and apart from the blow molding of the container, and snap the separately molded handle over the neck or finish of the blown PET bottle. In accordance with a still further proposal, the separately molded handle is inserted in the blow mold and the bottle is blown over/into the handle. None of these practices, however, has been entirely satisfactory since they add steps to the fabrication process, may require ultrasonic bonding equipment, and are otherwise unduly time-consuming and expensive. Summary of the Invention The present invention is directed to a method of making articles of polyethylene terephthal¬ ate (PET) , .and more particularly to a method of making a blow molded PET article, for instance, a bottle, with an integral PET projection, such as a handle or foot, extending from a wall thereof. Since both the bottle and handle or foot are made of PET, they both possess the superior characteristics of this material and recycling is facilitated. In essence, in the method of this invention, a PET preform is inserted into a combination blow mold and injection mold wherein the blow mold cavity defines the article to be blown and the injection mold cavity defines the projection therefrom. The injec¬ tion mold cavity and the blow mold cavity are in communication with each other at at least one location defining the area where the handle or foot is to extend from the container. The "preform" may be a co-extruded, co-injected, or straight injection molded or fabricated PET preform. After insertion into the combination mold, the preform is injected with blow gas from a gas nozzle to conform the preform to the blow mold cavity, thereby forming the hollow blow molded article. Prior to blowing the preform in the blow mold cavity, the preform temperature is estab- lished at its stretch orientation temperature, which is well known for PET to be in the range of 195°F to 240 ° F . The preform may be one previously made on another machine which is heated to the stretch orient temperature range in a separate heating operation prior to insertion in the blow mold, or it may be a previously injection molded PET preform (as on a single-stage PET machine) that has cooled to the appropriate stretch orientation temperature immediate¬ ly prior to insertion in the blow mold cavity. While the pressure of the blow gas holds the preform in conformity with the blow mold cavity, and prior to exhausting the blow gas, molten PET is injected under pressure into the injection mold cavity to form the integral protrusion or handle and bond it to the blown preform article at the point where the injection mold cavity communicates with the blow mold cavity. The combination mold is then opened and the finished article is removed. Because the handle and container are both PET and the injected PET is molten when injected into the injection mold cavity, the injection molded projection, or handle, fuses to the hollow blown article without need for ultrasonic bonding, adhesive, snap-on fittings or the like. Brief Description of the Drawings Fig. 1 is a cross sectional view of the combination blow mold and injection mold with the preform (shown partially in phantom) being inserted therein. Fig. 2 shows the preform being expanded by blow gas to conform to the blow mold cavity. Fig. 3 shows the injection molding of the integral handle while pressure holds the article against the blow mold wall. Fig. 4 shows a finished blow molded bottle with an integral injection molded handle. Detailed Description of the Invention Fig. 1 shows a preform 10 (partially in phantom) being inserted into blow mold cavity 14 of combination blow mold and injection mold 12. Com¬ bination mold 12 consists of a blow mold cavity 14 having a configuration which corresponds to the desired shape of the hollow article body 31 (shown in Fig. 4) and an injection mold cavity 16 conforming to the desired shape of the projection or handle 32. Injection mold cavity 16 communicates at upper and lower ends 16a and 16b with the interior of the blow mold cavity 14 at the points where the projection extends from a wall of the hollow article. PET preform 10 may be formed by one of a number of known techniques such as are disclosed in U.S. Patent Numbers 4,151,250, 4,153,667, and 3,781,395. The preform is either heated to the appropriate stretch orientation temperature of between about 195°F and 240°F prior to insertion in the mold utilizing con¬ ventional techniques well known in the blow molding art, or it may reach the appropriate stretch orien¬ tation temperature by cooling after being injection molded on a single stage PET machine. It will be appreciated that preform 10 need not be of the shape shown in Fig. 1. Once preform 10 has been inserted into blow mold cavity 14 and combination mold 12 has been closed therearound, by any suitable means, blow gas injection means (shown generally as 20 in Fig. 2) is inserted into and injects blow gas into preform 10 such that preform 10 conforms to the shape of blow mold cavity 14 (also shown in Fig. 2) . The blow gas is injected at a pressure of between about 100 psi and about 750 psi and at a temperature of between about 40°F and about 120°F. At this point the exterior wall of article 31 communicates with the ends 16a and 16b of the injection mold cavity 16 at points 31a and 31b. In Fig. 3 there is shown a PET injection melt stream 22 which carries molten PET flowing in the direction of the arrow. The molten PET, which is at a temperature above 485°F, is injected through injection nozzle means (shown generally as 24) into injection mold cavity 16 while blown preform 18 is conformed to blow mold cavity 14 by the blow gas. In this way, the injection molded handle 26 directly fuses or bonds to blown PET article 18 at points 31a and 31b proximate injection mold cavity ends 16a and 16b. Standard injection molding apparatus and procedures, which are well known in the art for producing PET preforms, are used in the injection molding step of this invention. Fig. 4 shows a finished blow molded bottle with an integral injection molded handle 30. As will be appreciated, since the handle or projection is injection molded, it may have any suitable cross- section, including cored, and may be of any suitable size. In addition, if desired, a name or identifica- tion symbol can be molded into the injection molded handle as indicated at 32 by including such name or symbol in the injection mold cavity 16. Furthermore, since the handle is injection molded it may be made from recycled or regrind PET. Finally, the handle may be clear or colored or crystallized. It will be appreciated by those skilled in the art that the method of the present invention is adaptable to produce a wide variety of PET articles with integral PET projections thereon, one example of which is a blow molded bottle with an integral handle connected to that bottle at two points as is shown in Figs. 1-4. Other products include, but are not limited to, funnels, buckets, pitchers, cylinders, etc. Any of the above articles may have a handle attached at two points (as shown in the Figs.) or at one point so that it functions as a hook, or they may have a base structure or feet injection molded there¬ on. An example of a blow molded container having an injection molded foot is shown in Figure 5 and an example of a blow molded container having an injection molded base structure is shown in Figure 6. The projection can be attached to the article in a variety of positions, such as the bottom, side, or upper end. For example, a handle on the bottom of a bottle can be provided to facilitate hanging the bottle upside down for drainage or other purposes. In addition, multiple feet can be injection molded onto the lower end of the blow molded article using the method of this invention to provide a stable base or support. It will be further understood that the method disclosed herein is adaptable to injection mold an integral external projection on a previously blow molded hollow article. In accordance with this approach, the previously blow molded PET article is inserted in mold 14, gas pressure is applied to hold the external wall of the article against the mold, and the handle 16 injected and bonded to the container in the manner previously disclosed. The preferred embodiment of the method and apparatus of this invention has been described in connection with bonding a PET handle to the outside wall of a blow molded PET container by injecting the handle onto and/or against the outside wall of the blow molded container while the blow molded container is still in the mold and the blow gas pressure is still applied. It is also contemplated that the PET handle can be bonded to the outside of a blow molded PET container which has been previously blown and removed from the blow mold cavity. More particularly, it is contemplated that a previously blown PET con¬ tainer can be placed on a fixture which internally supports, with an anvil or mandrel, that portion of the wall of the PET container to which the handle is to be attached. With the container so supported and the injection mold cavity located to position the ends thereof, 31a and 31b, adjacent the outside surface of the container behind which the anvil or mandrel is located, the molten PET material is injected into the injection mold handle cavity to bond to the supported wall portions of the container. With this approach, the blow molded container need not be located in the blow mold cavity and/or under internal gas pressure at the time the injection molded handle is bonded to the external wall of the container. Additionally, the blow molded container can be at room temperature, that is "cold", at the time the injection molded handle is bonded to the exterior wall of the container. While the invention has been described in detail with respect to a preferred embodiment thereof, it will be understood by those skilled in the art to which the invention pertains that numerous changes may be made in the invention without departing from the spirit and scope thereof.

Claims: AMENDED CLAIMS [received by the International Bureau on 21 November 1989 ( 1.11.89) original claims 1 - 9 replaced by amended claims 1 - 11 (21 pages)] 1. A method of making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling grooves, comprising the steps of: (a) inserting a preform of polyethylene terephthalate into the blow mold cavity of a com¬ bination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein the blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, the blow mold cavity interior wall surface being free of relatively movable parts when the mold is closed, the blow mold cavity interior wall surface being free of inwardly extending circumferential ridges communi¬ cating with the injection mold cavity at the inter¬ face, the injection mold cavity defines the projection extending from the exterior wall section of the ' article, and the blow mold and injection mold cavities being in communication with each other at an interface corresponding to the location on the article wall from which the projection extends; (b) injecting blow gas into the interior of said preform when the combination mold is closed and while said preform is at a temperature in the PET stretch orientation range to conform said preform to the blow mold cavity and produce said article with said substantially smooth exterior surface free of article-encircling grooves at the location of said injection molded projection; (c) injecting molten polyethylene tere¬ phthalate into the injection mold cavity substantially immediately subsequent to conforming the preform to the blow mold cavity with blow gas and prior to opening the combination mold and exhausting the blow gas and removal of said article from said blow mold cavity, thereby forming an integral injection molded projection bonded to said substantially smooth groove- less exterior section of said wall of the hollow blow molded article at the interface whereat the injection mold cavity communicates with the blow mold cavity; (d) opening the combination mold; and (e) removing the hollow blow molded article with integral injection molded projection from the combination mold. 2. A method of making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling grooves, comprising the steps of: (a) blow molding a hollow blow molded article which is substantially smooth and free of article-encircling grooves; (b) inserting said hollow blow molded article of polyethylene terephthalate into the article-receiving cavity of a combination mold having a cavity for receiving the blow molded hollow article, which has a substantially smooth exterior surface free of article-encircling grooves, and an injection mold cavity, wherein said article-receiving cavity has an interior wall surface that substantially conforms to the exterior surface of the hollow article, said article-receiving cavity interior wall surface being free of relatively movable parts when said mold is closed, said injection mold cavity defines the projec¬ tion extending from said exterior wall section of the article, and said article-receiving mold and injection mold cavities being in communication with each other at an interface corresponding to the location on the article wall from which the projection extends; (c) injecting gas into the interior of said hollow article when said combination mold is closed to hold said location on said wall of said hollow article proximate said interface in said article-receiving cavity whereat said mold cavities communicate; (d) injecting molten polyethylene tere¬ phthalate into the injection mold cavity while the gas is injected into the interior of the hollow article to form an integral injection molded projection bonded to 5 said substantially smooth grooveless exterior section of said wall of the hollow blow molded article proxi¬ mate said interface whereat said injection mold cavity communicates with said article-receiving cavity; and (e) removing the hollow blow molded article 0 with integral injection molded projection from the combination mold. 3. In a single stage process for making a hollow blow molded article of polyethylene tere- 5 phthalate wherein a PET preform is injection molded, its temperature is conditioned to be uniform through¬ out and within the stretch orientation range for PET, the preform is blown in a blow mold, and the blown article is ejected from the blow mold, the improvement o for making a hollow blow molded article of poly¬ ethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling grooves, said improvement comprising: (a) inserting the temperature conditioned preform of polyethylene terephthalate into the blow mold cavity of a combination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein the blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, the blow mold cavity interior wall surface being free of relatively movable parts when the blow mold is closed, the blow mold cavity interior wall surface being free of inwardly extending circum¬ ferential ridges communicating with said injection mold cavity at the interface, the injection mold cavity defines the projection extending from the exterior wall section of the article, and the blow mold and injection mold cavities being in communi¬ cation with each other at an interface corresponding to the location on the article wall from which the projection extends; (b) injecting blow gas into the interior of the preform when the combination mold is closed to conform the preform to the blow mold cavity and produce said article with said substantially smooth exterior surface free of article-encircling grooves at the location of said injection molded projection; (c) injecting molten polyethylene tere¬ phthalate into the injection mold cavity substantially immediately subsequent to conforming the preform to the blow mold cavity with said blow gas and prior to opening the combination mold and exhausting the blow gas and removal of said article from said blow mold cavity, to form an integral injection molded projec- tion bonded to said substantially smooth grooveless exterior section of said wall of the hollow blow molded article at the interface whereat the injection mold cavity communicates with the blow mold cavity; and (d) removing the hollow blow molded article with integral injection molded projection from the combination mold. 4. A method of making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves, comprising: (a) inserting a preform of polyethylene terephthalate into a blow mold having an interior wall surface which defines the exterior surface of the hollow article, the blow mold cavity interior wall surface being free of relatively movable parts when said mold is closed, the blow mold cavity interior wall surface being free of inwardly extending circum¬ ferential ridges; (b) injecting blow gas into the interior of the preform when the blow mold is closed to conform the preform to the blow mold interior wall surface and produce an article with a substantially smooth exterior surface free of article-encircling grooves; (c) placing a fixture for internally supporting at least that portion of the wall of the article to which the injection molded projection is to be attached in operative supporting relationship to the hollow blow molded article of polyethylene tere¬ phthalate; (d) injecting molten polyethylene tere¬ phthalate into an injection mold which defines the integral projection to be attached to the blow molded article, the injection mold being free of relatively movable parts, the injection mold having an inlet opening for feeding molten polyethylene terephthalate into the injection mold and an exit opening located proximate the exterior wall section of an article supported on the fixture, said injecting occurring while said fixture internally supports the exterior wall section of said blow molded article in commu¬ nicating relationship with the exit opening of the injection mold to form an integral injection molded projection bonded to said substantially smooth grooveless exterior section of the wall of the hollow blow molded article at the location whereat the injection mold exit opening communicates with the article; and (e) terminating the operative supporting relationship of the fixture and the hollow blow molded article with integral injection molded projection. 5. A method of making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves, comprising: (a) introducing extruded polyethylene terephthalate in substantially tubular form into the blow mold cavity of a combination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein the blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, the blow mold cavity interior wall surface being free of relatively movable parts when the mold is closed, the blow mold cavity interior wall surface being free of inwardly extending circumferential ridges communicating with the injec¬ tion mold cavity at the interface, the injection mold cavity defines the projection extending from the exterior wall section of the article, and the blow mold and injection mold cavities being in communication with each other at an interface corre¬ sponding to the location on the article wall from which the projection extends? (b) injecting blow gas into the interior of the tubular polyethylene terephthalate when the combination mold is closed to conform the two to said blow mold cavity and produce the article with the substantially smooth exterior surface free of article-encircling grooves at the location of the injection molded projection; (c) injecting molten polyethylene tere¬ phthalate into the injection mold cavity substantially immediately subsequent to conforming the tubular polyethylene terephthalate to the blow mold cavity with the blow gas and prior to opening the combination mold and exhausting the blow gas and removal of the article from the blow mold cavity, to form an integral injection molded projection bonded to said substan¬ tially smooth grooveless exterior section of the wall of the hollow blow molded article at the interface whereat the injection mold cavity communicates with the blow mold cavity; and (d) removing the hollow blow molded article with integral injection molded projection from the combination mold. 6. An apparatus for making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves, comprising: (a) a combination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein said blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, said blow mold cavity interior wall surface being free of relatively movable parts when said mold is closed, said blow mold cavity interior wall surface being free of inwardly extending circu - ferential ridges communicating with said injection mold cavity at the interface, said injection mold cavity defines the projection extending from said exterior wall section of the article, and said blow mold and injection mold cavities being in communica- tion with each other at an interface corresponding to the location on the article wall from which the projection extends; (b) means for opening and closing said combination mold; (c) means for inserting a preform of polyethylene terephthalate into said blow mold cavity of said combination mold; (d) means for injecting blow gas into the interior of the preform when said combination mold is closed to conform the preform to said blow mold cavity and produce said article with said substantially smooth exterior surface free of article-encircling grooves at the location of said injection molded projection; (e) means for injecting molten polyethylene terephthalate into said injection mold cavity, said means being actuated substantially immediately subse¬ quent to conforming the preform to the blow mold cavity with said blow gas and prior to opening said combination mold and exhausting said blow gas and removal of said article from said blow mold cavity, to form an integral injection molded projection bonded to said substantially smooth grooveless exterior section of said wall of the hollow blow molded article at said interface whereat said injection mold cavity communi¬ cates with said blow mold cavity; and (f) means for removing the hollow blow molded article with integral injection molded projec¬ tion from said combination mold, said means being actuated subsequent to operation of said molten injection means and opening of said combination mold. 7. An apparatus for making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves, comprising: (a) means for making a hollow blow molded article which is substantially smooth and free of article-encircling grooves; (b) a combination mold having a cavity for receiving the previously blow molded hollow article having a substantially smooth exterior surface free of article-encircling grooves and an injection mold cavity wherein said article-receiving cavity has an interior wall surface that substantially conforms to the exterior surface of the hollow article, said article-receiving cavity interior wall surface being free of relatively movable parts when said mold is closed, said injection mold cavity defines the projec- tion extending from said exterior wall section of the article, and said article-receiving mold and injection mold cavities being in communication with each other at an interface corresponding to the location on the article wall from which the projection extends; (c) means for opening and closing said com¬ bination mold; (d) means for inserting the previously formed hollow blow molded article of polyethylene terephthalate into said article-receiving cavity of said combination mold; (e) means for injecting gas into the interior of said previously formed hollow article when said combination mold is closed to hold said location on said wall of said hollow article proximate said interface in said article-receiving cavity whereat said mold cavities communicate; (f) means for injecting molten polyethylene terephthalate into said injection mold cavity to form an integral injection molded projection bonded to said substantially smooth grooveless exterior section of said wall of the hollow blow molded article proximate said interface whereat said injection mold cavity communicates with said article-receiving cavity; and (g) means for removing the hollow blow molded article with integral injection molded projec- tion from said combination mold. 8. An apparatus for making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves, comprising: (a) a blow mold having an interior wall surface which defines the exterior surface of the hollow article, said blow mold cavity interior wall surface being free of relatively movable parts when said mold is closed, said blow mold cavity interior wall surface being free of inwardly extending cir¬ cumferential ridges; (b) means for opening and closing said blow mold; (c) means for inserting a preform of polyethylene terephthalate into said blow mold; (d) means for injecting blow gas into the interior of the preform when said blow mold is closed to conform the preform to said blow mold interior wall surface and produce said article with said substan¬ tially smooth exterior surface free of article- encircling grooves; (e) a fixture for internally supporting at least that portion of the wall of the article to which the injection molded projection is to be attached; (f) means for placing said fixture in operative supporting relationship to a hollow blow molded article of polyethylene terephthalate; (g) an injection mold which defines the integral projection to be attached to said blow molded article, said injection mold being free of relatively movable parts, said injection mold having an inlet opening for feeding molten polyethylene terephthalate into said injection mold and an exit opening located proximate said exterior wall section of an article supported on said fixture; (h) means for injecting molten polyethylene terephthalate into said injection mold through said inlet opening while said fixture internally supports said exterior wall section of said blow molded article in communicating relationship with said exit opening of said injection mold to form an integral injection molded projection bonded to said substantially smooth grooveless exterior section of said wall of the hollow blow molded article at the location whereat said injection mold exit opening communicates with the article; and (i) means for terminating the operative supporting relationship of said fixture and the hollow blow molded article with integral injection molded projection. 9. In a single stage apparatus for making a hollow blow molded article of polyethylene tere¬ phthalate having means for injection molding a poly¬ ethylene terephthalate preform, means for conditioning the temperature of the preform to be substantially uniform throughout and within the stretch orientation temperature range for polyethylene terephthalate, means for blowing the preform in a blow mold, and means for ejecting the article from the blow mold, the improvement for making a hollow blow molded article of polyethylene terephthalate having an integral injec- tion molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling grooves, said improvement comprising: (a) a combination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein said blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, said blow mold cavity interior wall surface being free of relatively movable parts when said mold is closed, said blow mold cavity interior wall surface being free of inwardly extending circum¬ ferential ridges communicating with said injection mold cavity at the interface, said injection mold cavity defines the projection extending from said exterior wall section of the article, and said blow mold and injection mold cavities being in communica¬ tion with each other at an interface corresponding to the location on the article wall from which the projection extends; (b) means for inserting the temperature conditioned preform into said blow mold cavity of said combination mold; (c) means for injecting blow gas into the interior of the preform when said combination mold is closed to conform the preform to said blow mold cavity and produce said article with said substantially smooth exterior surface free of article-encircling grooves at the location of said injection molded projection; (d) means for injecting molten polyethylene terephthalate into said injection mold cavity said means being actuated substantially immediately subse¬ quent to conforming the preform to the blow mold cavity with said blow gas and prior to opening said combination mold and exhausting said blow gas and removal of said article from said blow mold cavity, to form an integral injection molded projection bonded to said substantially smooth grooveless exterior section of said wall of the hollow blow molded article at said interface whereat said injection mold cavity communi¬ cates with said blow mold cavity; and (e) means for removing the hollow blow molded article with integral injection molded projec¬ tion from said combination mold, said means being actuated subsequent to operation of said molten injection means and opening of said combination mold. 10. An apparatus for making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves, comprising: (a) a combination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein said blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, said blow mold cavity interior wall surface being free of relatively movable parts when said mold is closed, said blow mold cavity interior wall surface being free of inwardly extending circum¬ ferential ridges communicating with said injection mold cavity at the interface, said injection mold cavity defines the projection extending from said exterior wall section of the article, and said blow mold and injection mold cavities being in communica¬ tion with each other at an interface corresponding to the location on the article wall from which the projection extends; (b) means for opening and closing said combination mold; (c) means for introducing extruded poly¬ ethylene terephthalate in substantially tubular form into said blow mold cavity of said combination mold for subsequent blowing; (d) means for injecting blow gas into the interior of the tubular polyethylene terephthalate when said combination mold is closed to conform the tube to said blow mold cavity and produce said article with said substantially smooth exterior surface free of article-encircling grooves at the location of said injection molded projection; (e) means for injecting molten polyethylene terephthalate into said injection mold cavity, said means being actuated substantially immediately subse¬ quent to conforming the tubular polyethylene tere¬ phthalate to the blow mold cavity with said blow gas and prior to opening said combination mold and exhausting said blow gas and removal of said article from said blow mold cavity, to form an integral injection molded projection bonded to said substan¬ tially smooth grooveless exterior section of said wall of the hollow blow molded article at said interface whereat said injection mold cavity communicates with said blow mold cavity; and (f) means for removing the hollow blow molded article with integral injection molded projec¬ tion from said combination mold, said means being actuated subsequent to operation of said molten injection means and opening of said combination mold. 11. An apparatus for making a hollow blow molded article of polyethylene terephthalate having an integral injection molded projection bonded to and extending from an exterior wall section thereof, comprising: (a) a combination blow mold and injection mold having a blow mold cavity and an injection mold cavity wherein said blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, said blow mold cavity exterior surface being free of relatively movable parts when said mold is closed, said injection mold cavity defining the projection extending from said exterior wall section of the article, and said blow mold and injection mold cavities being in communication with each other at an interface corresponding to the location on the article wall from which the projection extends; (b) means for opening and closing said combination mold; (o) means for inserting a preform of polyethylene terephthalate into said blow mold cavity of said combination mold; (d) means for injecting blow gas into the interior of the preform when said combination mold is closed to conform the preform to said blow mold cavity; (e) means for injecting molten polyethylene terephthalate into said injection mold cavity, said means being actuated substantially immediately subse¬ quent to conforming the preform to the blow mold cavity with said blow gas and prior to opening said combination mold and exhausting said blow gas and removal of said article from said blow mold cavity, to form an integral injection molded projection bonded to said exterior section of said wall of the hollow blow molded article at said interface whereat said injec¬ tion mold cavity communicates with said blow mold cavity; and (f) means for removing the hollow blow molded article with integral injection molded projec- tion from said combination mold, said means being actuated subsequent to operation of said molten injection means and opening of said combination mold. STATEMENTUNDERARTICLE19 The claims submitted herewith are being submitted in order to more clearly distinguish the claimed invention from the prior art. Nowhere in the prior art is there any teaching of a method and apparatus for producing a hollow polyethylene terephthalate blow molded article with an integral external projection, such as a handle, bonded to and extending from an exterior wall section thereof which is substantially smooth and free of article-encircling exterior grooves. Likewise, there is no teaching of a combination mold having a blow mold cavity and an injection mold cavity wherein the blow mold cavity has an interior wall surface which defines the exterior surface of the hollow article, the blow mold cavity interior wall surface is free of relatively movable parts when the mold is closed, the blow mold cavity interior wall surface is free of inwardly extending circumferential ridges communicating with the injection mold cavity at the interface, the injection mold cavity defines the projection from the exterior wall section of the article, and the blow mold and injection mold cavities are in communication with each other at an interface corresponding to the location on the article wall from which the projection extends. The method and apparatus of this invention are suitable for blow molding a PET preform, or by introducing extruded PET into the blow mold, subse¬ quently blow molding the article, and thereafter injection molding an external projection extending from a wall thereof. Nowhere in the prior art is there any teaching of an apparatus such as the apparatus claimed in claims 6-11, nor is there any teaching of a method for producing the hollow polyethylene terephthalate article with integral external projection using a combination mold as claimed in claims 1-5. With regard to new claims 6-11, which are directed to an apparatus for producing the above described hollow blow molded PET article with integral injection molded handle, those claims call for a combination mold having a blow mold cavity which is free of relatively movable parts and which is free of inwardly extending circumferential ridges. These requirements distinguish the newly submitted apparatus claims over the references cited, particularly, the EP,A,0232207 (Nissei) and JP, ,6322621 (Toyo Seikan Kaisha Ltd.) references. Nissei requires two separate molds, both of which are more complex than the single combination mold required for the apparatus of this invention. The articles produced using the Nissei and Toyo Seikan methods and apparatus require more material, due to the article encircling rings, and thus have a longer cycle time, thereby resulting in a lower output. Applicant asserts that the amended claims and the newly submitted claims clearly distinguish the present invention over the prior art.

Inventors: BELCHER SAMUEL L, BELCHER, SAMUEL, L.
Applicants: SABEL PLASTECHS INC, SABEL PLASTECHS, INC.
Application year: 1989
Main classification: B29C69
IPC codes: B29C45, B29C49, B29C69, B29C70, B29K67, B29L22