Abstract: Method and apparatus for making multilayer injection molded plastic articles. In one embodiment, a relatively thin inner sleeve layer is molded in a first mold cavity on a core, the first mold cavity being heated to maintain an outer surface of the inner sleeve layer at an elevated temperature, and the core and sleeve layer are transferred to a second mold cavity to mold a relatively thick outer layer over the sleeve layer while the outer surface is at the elevated temperature, where the elevated temperature is selected to provide melt adhesion between the inner sleeve and the outer layer during the second molding step. In another embodiment, a method of injection molding is provided in which a first thermoplastic material is used to form a first preform portion having an average percent crystallinity of at least about 30%, and a second thermoplastic material is injection molded to form a second preform portion which remains substantially amorphous.

Abstract: Process for controlling the change of intrinsic viscosity and transesterification during solid stating of a polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) blend, with an effective amount of an ethylene glycol compound. The process enables the production of a copolymer based on predefined initial and final IV's and final transesterification level, by varying the solid-stating time and/or effective amount of ethylene glycol. In one embodiment, a relatively greater amount of post-consumer PET (e.g., 70%) having an IV of on the order of 0.72-0.73, is incorporated in the blend to provide a final IV on the order of 0.80-0.85, and a moderate, controlled level of transesterification; the blend is used to injection mold a sleeve layer of a preform. In another embodiment, a substantially transparent neck finish for a preform is made from a PEN/PET blend having an amount of ethylene glycol which enables substantial transesterification, without excessive increase in IV.

Abstract: A method of making a polyester container having an enhanced level of crystallinity in the sidewall while maintaining a low level of crystallinity in a thickened base portion. The container is particularly useful as a refillable container which can withstand higher caustic wash temperatures and exhibits reduced flavor carryover, or as a hot-fill container. According to the method, a sidewall-forming section of a preform is initially expanded, heated to contract and crystallize the same, and than reexpanded; a base-forming portion of the preform is shielded from the heat treatment and is expanded either before or after the heat treatment step.

Abstract: A multi-segment filter system is provided for continuous filtration of high viscosity materials, such as polymer melts. In particular, each segment comprises a filter screen positioned between a bottom breaker plate and a top cover plate. The filter screen has a fixed alignment in relation to the breaker plate and cover plate, to prevent the formation of undesirable gaps. In one example, the alignment is fixed through positioning of pins extending from the breaker plate and passing through apertures in the filter screen and cover plate. Two pins are preferably positioned on the breaker plate in a nonsymmetric manner to ensure that a multilayered filter screen is positioned adjacent the breaker plate in a desired orientation. Successive segments are positioned on end and preferably include overlapped filter screen portions, thus eliminating any gaps between each segment. Overlapping coupling connections may also be provided in adjacent breaker plates.

Abstract: A method of manufacturing a handled plastic container which includes the steps of: a) positioning a preformed handle and a synthetic resin preform within an open blow mold without mutual engagement of said handle and preform; said handle including upper retaining means and lower retaining means and said preform including a molded engagement portion adapted to engage with the upper retaining means of the handle; b) causing the upper retaining means of the handle to interconnect with the engagement portion of the preform after the handle and preform have been separately positioned within the blow mold; and c) stretch blow molding the preform in the blow mold wherein said blow molding stretches the preform beneath the engagement portion into blow mold to form a container and expands the sidewall of the preform so as to retain the upper retaining means of the handle in interconnecting relation with the engagement portion of the preform.

Abstract: A preform and container each having a crystallized neck finish and method of making the same, wherein the method involves introducing a first thermoplastic material into a first mold section to form a substantially crystallized neck portion of a preform, and introducing a second thermoplastic material into a second mold section to form a substantially amorphous body-forming portion of a preform. The first material may have a substantially higher crystallization rate than the second material, and/or the first mold section may be at a higher temperature than the second mold section. In one embodiment, an indexer carrying two core sets is movable between first and second cavity sets for sequentially molding the neck portions on the first core set in the first cavity set, and then transferring the cores and neck portions to the second cavity set for molding the body-forming portions.

Abstract: The present invention relates to a process for controlling the change of intrinsic viscosity and transesterification during solid stating of a polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) blend, with an effective amount of an alkylene glycol compound. The process enables the production of a copolymer based on predefined initial and final IV's and final transesterification level, by varying the solid-stating time and/or effective amount of alkylene glycol. In one embodiment, a relatively greater amount of post-consumer PET (e.g., 70%) having an IV of on the order of 0.72-0.73, is incorporated in the blend to provide a final IV on the order of 0.80-0.85, and a moderate, controlled level of transesterification; the blend is used to injection mold a sleeve layer of a preform.

Abstract: A method of manufacturing a handled plastic container which includes the steps of: a) positioning a preformed handle and a synthetic resin preform within an open blow mould without mutual engagement of said handle and preform; said handle including upper retaining means and lower retaining means and said preform including a moulded engagement portion adapted to engage with the upper retaining means of the handle; b) causing the upper retaining means of the handle to interconnect with the engagement portion of the preform after the handle and preform have been separately positioned within the blow mould; and c) stretch blow moulding the preform in the blow mould wherein said blow moulding stretches the preform beneath the engagement portion into blow mould to form a container and expands the sidewall of the preform so as to retain the upper retaining means of the handle in interconnecting relation with the engagement portion of the preform.

Abstract: Pressurized plastic container having the appearance of ribs but with substantially reduced creep and without delamination, i.e., having an enhanced shelf life compared to prior art ribbed containers. In multilayer containers, the scribe lines reduce delamination of the layer structure so as to avoid loss of transparency and/or barrier properties. The reduction in creep is particularly useful for smaller volume containers having a greater surface area to volume ratio.

Abstract: A moulding member defining a portion of a mould cavity for blow moulding an article in blow moulding apparatus, wherein said moulding member includes: (a) a backing member (5, 19) fixable to said blow moulding apparatus and having a wall which defines a recess in said backing member, and (b) a removable insert (3, 47) located in said recess and having a surface defining a portion of said mould cavity (11), wherein said backing member (5, 19) and said insert (3, 47) are located in register relative to each other by way of cooperating locating means (17, 73) on said insert and said backing member, respectively.

Abstract: A method of forming a multi-layer polyester preform and container, particularly suitable for refillable PET carbonated beverage bottles, having an interior layer of high copolymer polyester material which resists hazing in the preform injection stage, and at least one exterior layer of a polyester to achieve enhanced strain-induced crystallization in the exterior layer during blow molding. The container can withstand higher caustic wash temperatures and exhibits reduced flavor carryover from one product to another.

Abstract: A method of reducing uncontrolled flow of a molten polymer during the packing and cooling stage of an injection molding cycle. A plurality of polymers are injected between a mold cavity and core for making a multilayer plastic article such as a preform, having an exterior layer of a first polymer and an interior layer of a second polymer. In a tapered region of the mold, a minimum width of the tapered region is selected to prevent the second polymer from developing an enhanced leading/trailing edge effect which causes the second polymer to reverse flow during the packing and cooling stage. The method is particularly useful for making preforms for blow molded containers, such as a ketchup container, having a relatively long and thin neck profile. In addition, the method maintains the interior (barrier) layer a minimum distance from the top sealing surface of the preform, in order to prevent defective heat-bonded seals.

Abstract: A preform and container design for a pressurized refillable plastic container, such as a PET carbonated beverage container, having a base section with increased resistance to sprue cracking. Sprue cracking, which may be a problem in warmer climates, is believed to be caused in prior designs by an entrapment of material between the stretch rod tip and the blow mold base during blow molding of the container, which entrapment causes surface defects in the container adjacent the sprue. These surface defects expand during flexing of the container dome, caused by alternating cycles of thermal shrinkage and expansion during container cleaning and filling. Sprue cracking can be reduced by eliminating a depressed dish adjacent the sprue in prior known refillable containers, and may further be reduced by modifications to the preform and container wall thickness ratios and base clearance height.

Abstract: A multilayer preform and container, and method of forming the same, having at least one layer including polyethylene naphthalate (PEN) to provide enhanced oxygen barrier performance and thermal stability. The PEN layer may be a homopolymer, copolymer, or blend of PEN. In a first high-PEN embodiment, the exterior layer contains on the order of 80-100% PEN and 0-20% PET by total weight of the layer, and a core layer of a non-strain hardenable polyester such as PETG. In a second low-PEN embodiment, the exterior layer includes a strain hardenable low-PEN copolymer or blend including on the order of 1-20% PEN and 80-99% PET, and the core layer is a strain-hardenable polyester such as a low-copolymer PET. In a third mid-range PEN embodiment, the exterior wall includes a substantially amorphous PEN copolymer or blend containing on the order of 20-80% PEN and 80-20% of another polyester such as PET, and a strain-hardened core layer of polyester such as a low-copolymer PET.

Abstract: A hot-fillable plastic container having a panel section of a size suitable for gripping the container in one hand. The panel section includes two opposing vertically-elongated and radially-indented vacuum panels, and two opposing horizontally-disposed and radially-indented finger grips. Each vacuum panel preferably has an invertible central wall portion movable from a convex first position prior to hot-filling of the container, to a concave second position under vacuum pressure following hot-filling and sealing of the container.

Abstract: A substantially transparent package or preform made of a polymer composition including an aliphatic polyketone as an oxygen scavenger having the formula ##STR1## where n is the number of repeating units and R is hydrogen, an organic side chain, or a silicon side chain. The aliphatic polyketone may be advantageously combined with other thermoplastic polymers to provide the desired injection molding and stretch blow molding characteristics for making substantially amorphous injection molded preforms and substantially transparent biaxially oriented polyester containers. A multilayer container package may be provided having a core layer of the oxygen scavenging composition, and inner and outer layers of polyethylene terephthalate (PET). The container may further include layers of a high-oxygen barrier polymer such as ethylene vinyl alcohol (EVOH).

Abstract: A pasteurizable plastic container having movable panels to alleviate internal pressure changes during pasteurization in order to avoid uncontrolled permanent deformation of the container body. As molded, each panel has a shallow recessed central wall which during the increased temperature and pressurization of pasteurization, moves outwardly to alleviate at least part of the internal pressure. During cooling, the panels move back inwardly to alleviate at least part of the negative pressure. The container may further include hoop ribs in the land areas above and below the panels, an axially elongatable hoop rib in an upper shoulder section, and an angled heel portion adjacent the standing ring. These additional elements further restrict uncontrolled bulging of the post walls, which would lead to improper label application and/or excessive volume change.

Abstract: Process for controlling the rate of change of intrinsic viscosity and transesterification during solid stating of a polyethylene terephthalate (PET) and polyethylene naphthalate (PEN) blend, with an effective amount of an ethylene glycol compound. The process enables the production of a copolymer based on predefined initial and final IV's and final transesterification level, by varying the solid-stating time and/or effective amount of ethylene glycol. In one embodiment, a relatively greater amount of post-consumer PET (e.g., 70%) having an IV of on the order of 0.72-0.73, is incorporated in the blend to provide a final IV on the order of 0.80-0.85, and a moderate, controlled level of transesterification; the blend is used to injection mold a sleeve layer of a preform. In another embodiment, a substantially transparent neck finish for a preform is made from a PEN/PET blend having an amount of ethylene glycol which enables substantial transesterification, without excessive increase in IV.

Abstract: This relates to the packaging of a hot liquid product in a container having little resistance to internal vacuum wherein immediately after the container has been filled, the container is internally pressurized and closed. This particularly relates to an injection molded preform formed of a suitable polyester resin which is of a configuration related to an intended blow mold cavity whereby the desired biaxial orientation is obtained in the various portions of the resultant container and the wall thickness of the container base is increased so as to prevent undue stress enlargement and creep at high internal pressurization. Internal pressurization on the order of 40-45 psig is envisioned.

Abstract: This relates to a returnable/refillable container in the form of a blow molded polyester biaxially oriented bottle wherein the container includes a domed base construction wherein the wall thickness gradually and smoothly increases to a maximum at the center of the dome. This also relates to a specially configurated preform which is blow molded to form the container and a specially configurated blow mold cavity for receiving a preform having a lower axial projection in the fore of an elongated gate without crushing.