Abstract: Apparatus for manufacturing hollow plastic articles, comprising a mold comprising a first part provided with at least one row of a number of cavities located next to each other and a second part provided with at least one row of a number of cores located next to each other, while the number of cores is twice the number of cavities, and the cores comprise two sets of cores, each set arranged in a manner corresponding to the position of the cavities, and means are provided for moving the second mold part back and forth in a direction transverse to the direction of opening and closing of the mold. A cooling device comprises a number of cooling cavities located between the cavities of a row and at both ends of the row of cavities. The cores of the two sets alternate with each other in a row of cores.

Abstract: An injection blow molding machine utilizing an extruder and having interchangeable machine tooling components, for manufacturing injection blow molded articles of different configurations and sizes, includes a stationary machine platen; a movable machine platen which is movable toward and away from the stationary machine platen along a machine axis, to close and open a mold; opposite support rails mounted to the movable platen; a shuttle plate mounted on the movable machine platen between the opposite support rails for movement with the movable machine platen and movable perpendicular to the machine axis and having a rear surface in close proximity to the movable machine platen; core pin retainers mounted on the shuttle plate for movement therewith, each core pin retainer holding an interchangeable core pin that receives a parison to be blown into a bottle; slides movably mounted on the shuttle plate for movement with the shuttle plate and movable toward and away from each other in close proximity to a front

Abstract: A hot fillable plastic container having a body with a neck surrounding a dispensing aperture, the neck having an inner wall and an outer wall spaced therefrom to thereby provide a gap between the inner wall and outer wall which functions as a thermal insulation means. The neck is thus able to better withstand the temperatures encountered during the filling operation without deformation.

Abstract: A method for forming an inner thread of a preform is provided, in which an injection core can be removed after molding the inner thread on an inner surface of a neck portion with the base portion of the injection core by enlarging the diameter of the neck portion by blowing air. An inner wall 42b with a transferred inner thread is molded by using a barrel spacer 16 inserted removably into a neck mold 6 from an injection mold 1 side and a base portion 10a of the injection core 10 that has a thread pattern 12 on the outer surface and is inserted into the injection mold 1 through the neck mold 6. While the temperature of the inner wall 42b is high enough for deforming, the spacer 16 is removed to form an expansion space in the neck mold.

Abstract: A double-walled container is formed by gas assist injection molding. Thereafter, the container is further processed by 1) inserting a gas between the container layers, 2) injecting a colored liquid between the container layers, 3) evacuating the void space between the container layers, or 4) pressurizing the space between the container layers.

Abstract: In an injection stretch blow molding method, at least one injection molded preform is transferred from a preform molding section to a blow molding section by way of a transfer section and the at least one preform is blow molded into at least one container in the blow molding section. In the preform molding section the at least one preform is injection molded in an upright state with an open neck section thereof facing upward. In the transfer section, the at least one upright preform is turned upside-down and transferred to the blow molding section in an inverted state. Then, the blow molding section blow molds at least one container from the at least one inverted preform.

Abstract: A method of injection molding a multi-layer preform from a combination of virgin and recycled plastic such as PET so that the resultant blow molded bottle has a reduced tendency for bottom failure in spite of the use of the recycled plastic. A mold cavity for injection molding the preform is provided and includes an injection gate located along a sidewall of the cavity rather than at a conventional location in the closed end of the cavity which forms the bottom of the preform. The plastic material is injected through the gate in the sidewall which avoids the presence of crystalline "slugs" in the bottom region of the preform. This creates a preform and resultant blow molded bottle with a much more durable bottom which is not subject to various types of cracking.

Abstract: A method of recycling mixed post-consumer plastics waste includes the steps of providing mixed post-consumer plastics waste including polyolef in and non-polyolefin components, and melt-compounding the waste so as to form a continuous phase including a blend of the polyolefin components with the non-polyolefin components microdispersed therein. Preferably, the waste also includes one or more intrinsic compatibilizers, and the method includes the intrinsic compatibilizers at least partially compatibilizing the microdispersed components in the continuous phase.

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: A method and apparatus for manufacturing hollow plastic articles having a wall which at least partly consists of at least one core layer and two outer layers covering the core layer on both sides, in particular suitable for manufacturing preforms for bottles, wherein use is made of an injection-molding machine with a mold comprising at least one mold cavity, and an injection nozzle which, via an injection channel in the mold, connects to the mold cavity and has a central material feed channel, a needle of a controllable needle valve, which needle is active in the central material feed channel and can close or release the part of the central material feed channel located adjacent the injection channel, and at least one further material feed channel, opening into the central material feed channel, wherein first a plastic material of a first type for forming the outer layers is fed to the mold cavity and then at least one plastic material of a second type for forming at least one core layer.

Abstract: A plastic container is formed by injection and blow molding wherein the injection molded body has an annular shoulder, an upper neck and a bottom wall with a central flat portion of substantially the same thickness as the wall of said body. An enlarged annular corner portion connects the bottom wall to the body and extends downwardly. The annular corner is sufficiently thick so as to form a substantially solid rim after bi-axial stretching during blow molding. The plastic parison for forming the container includes a body with an annular shoulder and an upper neck and also with the bottom wall having a central flat portion of substantially the same thickness as the body. The enlarged annular corner portion of the parison also connects to the body and extends downwardly to form a substantially solid rim. The thickness of the annular corner is sufficient to keep the annular corner from having a cavity formed in it during bi-axial stretching.

Abstract: A process for producing a molded product having excellent heat resistance, which including forming a composition including a crystalline polyamide by mixing together (a) 50-90% by weight of a hexamethylene adipamide component, (b) 5-40% by weight of a hexamethylene terephthalamide component, (c) 5-30% by weight of a hexamethylene isophthalamide component, components (a), (b) and (c) being based on the weight of the crystalline polyamide, and (d) 1-150 parts by weight of an elastomer, based upon 100 parts by weight of the crystalline polyamide; forming a melt polymer from the composition and applying shear to the melt polymer, the melting point (Tm) and crystallization temperature (Tc) of the crystalline polyamide being Tm.gtoreq.225.degree. C. and Tc.ltoreq.230.degree. C., respectively, and the melt viscosity of the crystalline polyamide varying greatly depending on the shear rate applied to the melt polymer and satisfying formulae (I) and (II):2,000,000.gtoreq..mu.a10.gtoreq.2,000 (I).mu.a10/.mu.a1000.

Abstract: In an injection blow-molding process the preform is purposely formed as a smooth walled tube closed at one end and without any thread or other cap attachment configuration about the mouth of the preform. The preform is moved to the bottle mold which completely forms the cap attachment configuration with the bottle in the blow-molding step. A processing dome is also formed from the preform in the blow-molding step to provide means to transfer the bottle to the trimmer which removes the dome. By using the smooth walled preform (without threads or any other cap fastening features), the bottle mold may utilize only a portion of the vertical height of the preform for the bottle. Bottle molds for a variety of bottle volumes and heights may employ the same preform and preform injection mold. The smooth walled preform also permits bottle molds with a variety of mouth diameters to be employed with the same preform injection mold.

Abstract: A blow molded plastic container and process for obtaining same including a supporting member in the hollow space of the container extending completely across the hollow space and integral with the inside wall face of the body portion of the container at two spaced locations thereof to support the inside wall face. The shape of the container is altered at areas of stress concentration so as to reduce stress at areas of stress concentration and thereby avoid excessive deformation at said areas.

Abstract: Compositions, methods, and systems for manufacturing articles, particularly containers and packaging materials, having a highly inorganically filled matrix. Suitable inorganically filled mixtures are prepared by mixing together an organic polymer binder, water, one or more aggregate materials, fibers, and optional admixtures in the correct proportions in order to form an article which has the desired performance criteria. The inorganically filled mixtures are molded to fashion a portion of the mixture into a form stable shape for the desired article. Once the article has obtained form stability, the article is removed from the mold and allowed to harden to gain strength. The articles may have properties substantially similar to articles presently made from traditional materials like paper, paperboard, polystyrene, plastic, or metal. They have especial utility in the mass production of containers, particularly food and beverage containers.

Abstract: The multi-chamber containers with a dispenser/doser are blow molded as a single integral item. They then are fitted with dip tubes with the dip tube fitment forming a seal in the transition of the container to the dispenser/doser. The dividing walls in the container are continued up into and through the dispenser/doser. A closure with a rotatable contact surface seals the container. The container preform is made by injection molding using an elongated gate pad in one embodiment in another embodiment an arrangement of recesses on the ends of the core projections with a complementary shaped gate pad. The webs of the container are of a thickness so that they flex upon a compression force being applied to the container walls.

Abstract: This invention relates to a bottle with an ear obtained by orientation blow molding, in which a mounting portion positioned at a predetermined height which has a large diameter and whose upper portion is composed of an outer wall in the form of an injection molded flange and an inner wall oriented internally thereof and placed in close contact therewith, said mounting portion having a predetermined width in an outer periphery thereof, is formed below a mouth portion of a bottle by injection orientation blow molding, an upper edge of said mounting groove is formed to have an edge having a plurality of notches at equal intervals, a mounting ring internally provided with a plurality of projecting surfaces positioned at the mounting groove through said notches is formed integral with a bended end of an ear, and the projecting surfaces of said mounting ring and the upper edge of said mounting groove are fitted with each other whereby the ear and the bottle are integrally connected.

Abstract: An article handling and conditioning system for use between associated machines and associated processes are disclosed. The system comprises at least one initial molding machine and a finishing machine; a device for receiving initially molded articles from the at least one initial molding machine prior to finishing in the finish machine; a first mechanism for accumulating devices for receiving and the initially molded articles; a mechanism for transporting the device for receiving and the initially molded articles from the initial molding machine to the first mechanism for accumulating; a mechanism for moving the devices for receiving and the initially molded articles through the first mechanism for accumulating; and a device for transferring the initially molded articles from the first mechanism for accumulating to the finishing machine.

Abstract: A parison forming apparatus excellent in working efficiency and a parison forming method are provided. A moving plate which possesses core feed rows composed of multiple core receiving holders for feeding the multiple heat resistant resin cores to the mold device, and parison takeout rows composed of multiple parison receiving holders for taking out and receiving already formed multiple parisons from the mold device, being formed at a distance of a specific pitch interval from the core feed rows, and feeds the heat resistant resin cores from the core feed rows into the mold device which is empty after the parisons are taken out.

Abstract: A container, especially a bottle, is made from a preform of polyethylene terephthalate (PET), where the preform has a mouth portion, a substantially conical upper portion extending from the mouth portion, and a cylindrical portion extending from the conical portion towards the bottom of the preform and having a substantially uniform wall thickness. When reshaping the preform, the shoulder of the container is formed substantially only of material which in the preform is located in the conical upper portion of the preform, while the cylindrical portion of the container is formed substantially only of material which in the preform is located in the cylindrical portion of the preform.

Abstract: The present invention is intended to prevent the deformation of a cylindrical mouth portion of a preform when a blow pressure acts thereon in a diameter expanding direction during biaxial orientation blow molding. During biaxial orientation blow molding, sealing of the blow pressure is accomplished by means of a neck ring P1 circumferentially provided on a lower end of the circumferentially provided on a lower end of the circumferential surface of a cylindrical mouth portion P2 of a preform to thereby make the blow pressure act uniformly on the whole area of the cylindrical mouth portion P2, whereby the unreasonable deformation of the cylindrical mouth portion P2 due to the ununiform application of blow pressure thereto can totally be eliminated.

Abstract: A process for making a transparent blow molded product made of a copolyester of PET and PEN that does not thermally deform at temperatures up to 85-87 C., and the product of that process, especially a transparent blow molded bottle. The copolyester is made by transesterifying a 20/80 (w/w) PEN/PET via melt extrusion at a temperature of from about 250 C. to about 290 C. for a time sufficient to produce about 1-20% transesterification of said polymers, forming a copolymer. The copolyester is then injection molded at a temperature of from 290 C. to about 320 C. to form a transparent preform in which the copolymer has a glass transition temperature of about 85 C. or higher and a melting point temperature of at least about 225 C. The copolymer is then thermo-stretch blow molded to form a transparent product.

Abstract: A preform mold assembly for the injection molding of a multi-layer preform for use in the blow molding of container. The preform mold assembly comprises a preform mold having a gate for receiving molten plastic material. The preform mold has a cavity with longitudinal axis and defines an inner surface. A core-pin is situated within the cavity and spaced from said inner surface. A preform cavity is formed between the inner surface of the cavity and the core-pin for receiving molten plastic from the gate. A threadsplit portion is situated within the cavity at a location remote from said gate. The inner surface of the cavity defines a plurality of flutes formed generally parallel to the cavity longitudinal axis and extend longitudinally along the inner surface of the mold to the threadsplit portion.

Abstract: An integrally molded plastic container including a container body and a closure. The closure includes an orifice cap and sealing cap. The orifice cap is flexibly hinged to the neck portion adjacent to the container opening for pivoting movement from an open position to a closed position where the orifice cap closes the opening. The sealing cap is also flexibly hinged to the neck portion adjacent to the opening for pivoting movement relative to the orifice cap between a closed position where the sealing cap is in sealing relation with an orifice in the orifice cap and an open position where the sealing cap is out of sealing relation with the orifice.

Abstract: There is disclosed a method of manufacturing flexible elastomeric articles such as gloves, which comprises molding the glove body from a parison of the elastomeric material and stretching the stump portions into finger and thumb portions.

Abstract: A method for forming a polymer with a decreased surface energy. The method comprises the steps of mixing from about 99.5% to about 95.0% of a polymer selected from the group consisting of polyolefin and polyester with from about 0.5% to about 5.0% of a surface modifying agent having the structure R.sup.1 --A--Si(R.sup.2 R.sup.3)--O--[Si(R.sup.4 R.sup.5)--O].sub.n --Si--(R.sup.6 R.sup.7)--A--R.sup.8, and forming the mix of polymer and additive to a desired form. R.sup.1 and R.sup.8 are selected from the group consisting of derivatives of aliphatic or aliphatic/aromatic alcohols or mono-acids with a molecular weight of between about 250 to about 600 daltons, and A is selected from the group consisting of --O--, --NH--C(O)--NH--(CH.sub.2).sub.3 --, and --C(O)--NH--(CH.sub.2).sub.3 --. The agent is substantially intimately mixed with the polymer.

Abstract: The invention provides a light weight self-standing blow molded two liter carbonated beverage bottle having a unique petaloid base made from a monobase preform. The base comprises a petaloid design which has a plurality of at least three (preferably five) feet. The monobase preform has a thick reinforcing ring forming portion which remains unstretched during blowing. The reinforcing ring forming portion is thicker than both the sidewall forming portion and the gate area forming portion of the preform thereby resulting in increased stretching in both those areas. The reinforcing ring extends circumferentially around the base. By providing such a reinforcing ring, a bottle having a bigger foot radius and/or containing less material use can be realized. The resulting bottle has less stress whitening and greater stress crack resistance while at the same time using less material and/or having a larger radius than prior bottles.

Abstract: A preform (1), a method for blow molding a bottle, and a bottle (13) formed from the preform and by the method are disclosed for use with beverages and the like wherein the bottles usually contain such beverages under pressure. The preform is shaped so that the resultant bottle is provided with a product-containing portion having a preferred hemispherical end portion and an integral bottom portion including a void therein for defining a hollow base portion (4, 12) which, in one form, contains fluid under pressure for balancing pressures related to the pressurized product. The hollow base portion provides for efficient use of material, and a minimal number of manufacturing steps, for providing a stable base for the hemispherical end portion (11) of the product containing portion of the bottle.

Abstract: Process for the preparation of transparent re-usable bottles, which consists in moulding by injection-blow moulding cycle copolymers containing units deriving from terephthalic acid and ethylene glycol characterized in that said copolymers contain from 0.1 to 10% in moles of units deriving from aromatic diacids different from terephthalic acid and from 0.1-15% in moles of units deriving from aromatic hydroxyacids, making reference to the units deriving from terephthalic acid.

Abstract: Method of making a refillable polyester container having a low orientation base with improved resistance to caustic wash cracking. The method includes providing a preform with an upper base-forming thickened portion which resists axial elongation (thereby increasing the orientation of the body) and a lower base-forming tapered portion which decreases in thickness so as to gradually reduce the wall thickness of a central dome in the container base. The bottom of the preform base includes a central thickened region which is maintained in a recess during blowing to insure centering and prevent the formation of stress concentrations.

Abstract: Thread split inserts used in injection molding bottle preforms of polyethylene terephthalate (PET). Each insert has a curved inner surface. A pair of inserts are mounted in the mold facing each other so the inner surfaces combine to form an opening therethrough. The opening provides the portion of the cavity which forms the neck portion of the preform. Each of the thread split inserts has an enclosed conduit through which cooling fluid circulates to improve cooling and reduce molding cycle time. The cooling fluid conduit has three curved portions which extend around the curved inner surface. Two of the curved portions extend in one plane and the other curved portion of the cooling fluid conduit extends in a second parallel plane.

Abstract: A method for injection molding polyethylene terephthalate by employing a vent type injection unit as means for omitting preliminary drying the resin, wherein the unit does not develop a poor screw biting, and even when the molding material is an undried uncrystallized or crystallized PET, can feed a certain amount of the material at all times to injection mold a desired transparent molded form such as a preform, and use the preform to produce a thin-wall container at a low cost.

Abstract: An injection molding apparatus for a preform is disclosed, having an injection molding station (14) and a cooling and ejection station (16). In the injection molding station (14), neck cavity molds (60), injection core molds (50) and an injection cavity mold (42) are clamped and preforms (1) are injection molded. Thereafter, the injection cavity mold (42) is separated at a relatively high temperature. The preforms (1) are transferred to the cooling and ejection station (16) while being cooled by the injection core molds (50) and neck cavity molds (60). While the next preforms (1) are being injection molded in the injection molding station (14), in the cooling and ejection station (16) cooling of the preforms (1) continues. After cooling the preforms (1) to a temperature suitable for release, the injection core molds (50) are separated only through a stroke sufficient to allow a space to open between core pins (52) of the injection core molds 50 and the inner surface of the preforms (1).

Abstract: A blow molded plastic container including a supporting member in the hollow space of the container extending completely across the hollow space and integral with the inside wall face of the body portion of the container at two spaced locations thereof to support the inside wall face. The body portion defines regions that comprise at least two adjoining lobes which form a handgrip. The method injection molds a preform containing an inner wall, blow molds the preform into the shape of a precursor having adjoining lobes separated by depressions, removes the precursor from the blow mold, and applies internal pressure into the precursor to form the precursor into its final shape including lobes.

Abstract: A parison injection molding apparatus and method injection molds parsons, transfers them to cooling stations and then ejection stations. While at the injection molding station, cooling stations and during transfer therebetween up to the time they are ejected, the parisons are continuously cooled.

Abstract: A parison injection blow molding apparatus and method injection molds parisons, transfers them to cooling stations then to orient-stretch blow stations and thereafter ejection stations. While at the injection molding station, cooling stations and during transfer therebetween prior to being placed at the blow stations, the parisons are continuously cooled. The parisons are transferred to each station by an axially and laterally indexing platen.

Abstract: An apparatus forms multiple resin layered parisons that are cooled or blown into bottles. The individual resin layers are injection molded in sequence and the formed parisons are transferred to each cooling and molding station by an axially and laterally indexing platen.

Abstract: Bottle preforms are made by injection moulding a thermoplastic polymer, preferably a polyethylene terephthalate polymer, which contains metal particles, preferably particles of antimony, which are sufficiently fine for them not to be visible to the eye and which intrinsically absorb radiation in the wavelength region 500 nm to 2000 nm. The metal particles are present in an amount such that the reheat time of the polymer is less than the reheat time of the polymer in the absence of the metal particles. The metal particles contained in the polymer are generated in situ by incorporating into the polymer fine particles of a reducible metal compound and a reducing agent capable of reducing the metal compound to the metal and then reacting the metal compound with the reducing agent so as to produce the metal particles. Bottles are made from the bottle preforms by reheating the bottle preforms and then blow moulding bottles from the reheated preforms.

Abstract: A method of manufacturing a can body includes injection molding a preform including forming a bottom wall, a side wall, a curved shoulder and a flange extending outwardly from the shoulder. After molding, the preform is subjected to a stretch blow molding process to form the can body.

Abstract: A parison injection blow molding apparatus injection molds parisons, transfers them to cooling stations then to orient-stretch blow stations and thereafter ejection stations. While at the injection molding station, cooling stations and during transfer therebetween prior to being placed at the blow stations, the parisons are continuously cooled. The parisons are transferred to each station by an axially and laterally indexing platen.

Abstract: A parison injection molding apparatus injection molds parisons, transfers them to cooling stations and then ejection stations. While at the injection molding station, cooling stations and during transfer therebetween up to the time they are ejected, the parisons are continuously cooled.

Abstract: An injection stretch blow molding method sequentially circulates a plurality of neck mold moving units for supporting and conveying neck molds adapted to hold the neck portions of hollow containers and preforms used to mold the hollow containers at least through preform injection molding, blow molding and ejecting stations, the preform injection molding step, the blow molding step for blow molding the hollow containers from the preforms having their potential heat provided by the injection molding step and the product ejecting step being repeatedly carried out. The injection molding stations of M in number are provided for blow molding stations of N in number (M>N.gtoreq.1). Preforms are injection molded in each of the injection molding stations at an injection molding start time staggered from those of the other injection molding stations by time equal to N.times.T/M where T is an injection molding cycle time in each of the injection molding stations.

Abstract: An improved modular mold having adjustable height shims provided between upper and lower panel sections to adjust the volume and height of a PET beverage bottle. The shims are easily replaced and form part of a high-strength mold set which accepts customized shoulder and base portions.

Abstract: A degradable container which is excellent in transparency and impact strength and can be decomposed into nontoxic water and carbon dioxide in the natural environment within a relatively short period can be obtained by using the process for molding a container of an arbitrary shape from a thermoplastic composition having polylactic acid of lactic acids or a copolymer of lactic acids and other hydroxycarboxylic acids as a main component, preforming the composition and thereafter molding the container in a temperature range from Tg to Tg+60.degree. C. on the basis of the glass transition temperature Tg of the thermoplastic polymer composition and under the condition of a draw ratio of 6 times or less.

Abstract: A molding method for continuously carrying out the steps from injection molding of a synthetic resin preform to orientation blow molding thereof into a thin-wall-hollow molded article, characterized in that releasing of the preform from the injection mold is carried out during the state where the shape thereof can be maintained by a skin layer produced at the surface by quick cooling and the state where internal cooling is not yet finished and the temperature is high, and orientation blow molding of the preform is carried out within a time till a surface temperature of the preform which rises by its own internal temperature reaches a peak temperature.

Abstract: The present invention provides a blow molding process having the steps of conveying preforms to a blow molding stage while holding the preform by two rows of supporting plates, placing the preforms in two rows of blowing molds disposed corresponding to the supporting plates, blow molding the preform into hollow containers when tile blowing molds are in their closed positions, thereafter opening the blowing molds to remove the molded containers therefrom. On carrying out this blow molding process, the row pitch between the supporting plates is changed between one when the blowing molds are opened and another when the blowing molds are in the other conditions. By utilizing this process and an apparatus for carrying out the process, the row pitch between the supporting plates is not required to maintain the maximum pitch when the blowing molds are opened. Thus, the blow molding system may be reduced in size and occupying area.

Abstract: Toughened semi-crystalline thermoplastic polyester molding compositions consisting essentially of a polyester resin and an ionomer of ethylene, a softening comonomer and unsaturated carboxylic acid, such as ethylene/n-butyl acrylate/methacrylic acid.

Abstract: A plastic system for extruding injection molding and extruding a hollow tube from plastic containing heat sensitive material for thereafter forming into a plastic container by blowing including an extruder for melting the plastic and delivering it to an injection system for injecting the plastic into a manifold that delivers the plastic to the tubular cavities of an injection head including providing a static mixer adjacent each of the cavities. By such an arrangement, the plastic flow in each flow channel provides a uniform homogeneous plastic material such that streaks which may be caused by degraded plastic material or by different color material from a previous run are eliminated.

Abstract: A process for forming a container of acrylonitrile polymers by biaxial-orientation blow-molding a preform. A preform of thermoplastic resin, mainly acrylonitrile polymers, is irradiated with an electron beam or a gamma-ray. Immediately after the irradiation, the preform is heated at 40.degree. C. or higher to reduce residual acrylonitrile monomer in the preform to 0.1 ppm or less. Then, the preform is biaxial-orientation blow molded to form a container.

Abstract: A method of injection blow molding a synthetic resin bellows product having root portions and crest portions, each of which has the axially sectional form of a circular arc, and incline portions therebetween, for example, a plastic bellows product such as a constant-velocity joint boot, a steering boot or the like. The method is capable of molding a product having a thickness uniform throughout, and particularly, root portions having little dimensional variations. The method involves firstly molding the parison root portions or the root portions plus their adjacent areas into substantially the same shape as those of a final product by injection molding during molding of a parison, and then blow molding only the crest portions and the incline portions to obtain the shape of the final product.