Abstract: A heat-resistant container forming method includes a step of thermally shrinking a primary blow molded article in a heating furnace before secondary blow molding the primary blow molded article into a final product or container. Into the furnace, hot air which flows along the longitudinal direction of the first blow molded article and whose temperature enough to facilitate crystallization of the primary blow molded article. The primary blow molded article is thermally shrunk by exposing the entire circumferential surface of a barrel of the primary blow article to the hot air and by blowing the hot air longitudinally along the primary blow molded article to heat the barrel circumferentially uniformly. Since hot air touches the barrel as flowing longitudinally thereof, it is possible to increase the heat conductivity of boundary film of the primary blow molded article, without increasing the hot air temperature too high, so that temperature rise of the primary blow molded article is facilitated.

Abstract: The process selectively crystallizes a molecularly oriented thermoplastic container composed of portions thereof with different degrees of orientation. Portions of the container are heat treated at temperatures suitable to crystallize said portions according to the degrees of orientation thereof wherein the heat treatment takes place in a heating environment on an unconfined container. The selectively crystallized container is then sized in a finishing means.

Abstract: The present invention discloses an improved process for producing plastic containers with excellent resistance to permeation by solvents such as hydrocarbons, hydrocarbon fuels, and hydrocarbon fuels with organic additives including lower alkanols and ethers consistently and reliably. The process is related to a multi-step treatment of plastic containers in a controlled manner with fluorine containing gases while blow molding them. In the process of the present invention, a parison is formed from a pre-heated thermoplastic material, expanded within a closed mold by means of an inflating gas for conforming the parison to the shape of the mold, and subjected to multiple fluorination treatment steps to effect fluorination of the interior surface of the parison. In the first step of the multi-step fluorination treatment the parison is pressurized with a reactive gas containing from about 0.05 to about 0.

Abstract: An improved process and apparatus for blow molding of engineering plastic materials, using a mold and an extrusion machine with a die for producing a hollow plastic parison to be partially received in the mold. An extrusion operation and a preblowing operation with air from the die into the parison are concurrently commenced at a high extrusion speed and a low air pressure, with a material remaining in the die being integrated with an upstream portion of a preceding parison prepared in a preceding blow molding run, to complete the downstream parison. The upstream portion has a closed and free lower end prepared in the preceding run. The apparatus is provided with a pinching and cutting device for self-adhering and separating the completed parison above and in the vicinity of the mold to prepare the above mentioned closed free end.

Abstract: In general, it is difficult to mold properly sized automotive boots without flash to be removed from the top end thereof. In accordance with the present invention, such molding is achieved placing a tubular parison between a pair of mold halves, moving a blow pin assembly downwardly partly into the top end of the parison, closing the mold by moving the mold halves together, using fingers to stretch the open bottom end of the parison, moving a sizing mandrel into the bottom end of the parison, closing inserts on the bottom of the mold around the bottom end of the parison to size the latter, blowing the parison using air under pressure discharged from the blow pin, moving the blow pin assembly farther down into the parison to size and cut the top end of the parison, opening the inserts and removing the lower sizing mandrel, opening the mold, closing the stretching fingers, and removing the blow pin assembly from the boot, which is stripped from the mold.

Abstract: For purposes of producing barrier layers on the surfaces of thermoplastics, the surfaces are exposed to a treatment gas containing fluorine. The barrier layers are effective against mixtures of polar or non-polar substances such as, for instance, fuels containing methanol. In order to improve the barrier effect, the cooled-off treatment gas is left to act upon the surface, whose temperature at the beginning of exposure is kept between 60.degree. C. and 250.degree. C. [140.degree. F. and 482.degree. F.].

Abstract: An injection stretch blow molding process forms a hollow article having a thick-walled bottom wall by regulating the bottom region of an injection molded preform to a temperature lower than that of a barrel preform portion at a blow molding station. In the process, a bulged portion formed on the distal end of a stretching rod and regulated in temperature is brought into contact with the inner bottom and adjacent side walls of the preform which correspond to the bottom region of the hollow article to be formed into an increased wall thickness, before start of a biaxially stretch blow molding step wherein the preform having a potential heat provided in the injection molding step is biaxially stretched to form the hollow article. The region of the preform contacting the bulged end portion has a temperature lower than another region of the preform non-contacting the bulged end portion.

Abstract: A method and apparatus for forming a lightweight plastic bottle having a body and an integral handle includes pre-blowing a tubular parison positioned between partible blow mold sections, closing the blow mold sections to compression mold the handle and blowing the parison to form the body integral with the handle and a line of juncture between the body and the handle.

Abstract: A low molecular weight, flexible, biaxially oriented, dilatation catheter balloon comprising oriented polyethylene terephthalate, and having a calculated radial tensile strength of greater than about 25,000 psi.

Abstract: A biaxially oriented polyethylene terephthalate resin bottle-shaped container made by thermally crystallizing a neck portion of a preform, heating the preform, blow-molding the preform to form a primary intermediate molded bottle-shaped piece, raising the temperature of the primary intermediate molded bottle-shaped piece to a temperature greater than the temperature during blow-molding the preform to thermally contract the primary intermediate molded bottle-shaped piece to form a secondary intermediate molded bottle-shaped piece, and blow-molding the secondary intermediate molded bottle-shaped piece to form a bottle-shaped container.

Abstract: A multi-step blow molding process for producing fuel containers having excellent resistance to permeation by hydrocarbon fuels and organic fuel additives such as lower alkanols and ethers. In blow molding, a parison is formed from a thermoplastic material, expanded within a closed mold by means of an inflating gas for conforming the parison to the shape of the mold and fluorinated under conditions sufficient to effect surface fluorination of the interior of the parison. The parison is evacuated and the article recovered. The improvement in the blow molding operation comprises pressurizing the parison with a reactive fluorine containing gas containing from 0.1 to 1% fluorine by volume while the parison is at a temperature above its self supporting temperature and for a time sufficient to effect fluorination of the interior surface of the parison.

Abstract: The process involves the following steps:a. Expanding the blowing gas enclosed in the hollow body (VII) by opening the valve (8).b. Injecting, into the hollow body, via the valve (4), a mixture of inert gas and reactive gas contained in the storage enclosure (II) and recovered from prior treatment.c. Injecting, into the hollow body, an addition of reactive gas via the opening of the valve (6).d. Maintaining the enriched mixture in the hollow body (VII).e. Expanding this mixture contained in the hollow body and recovering the expanded mixture in the enclosures (IV) and (IV') via the valves (10), (14), (15), (16).f. Recycling this mixture to the sealed storage enclosure (II) by the agency of the compressor (VI) with a view to a subsequent fluorination cycle.g. Internal scavenging of the hollow body by nitrogen via the valve (1) and carrying away to a tower (VIII) for scrubbing and neutralising the residual reactive gas.

Abstract: A blow molding process of producing molded articles including the steps of extruding a parison of the plasticized material from a die into a gap between mold halves while the mold is open and blowing gas into the parison, while the mold is closed, to have the parison form a molded hollow article within the mold. The parison is heated before molding by heating the inner shell contoured parts of the mold at the surfaces thereof and the plasticized material at the outer surface by using an instantaneous radiation heater disposed in the mold half gap to partially encompass the parison while the mold is open and the inner shell contoured part is heated by a heating medium passed through the heat medium passages. The molded article is cooled by cooling the mold at the inner shell contoured parts thereof by flowing a cooling medium through the heat medium passages of the mold while the mold is closed. The cooling of the mold occurs alternately with the heating of the mold by the heating medium.

Abstract: A process for the manufacture of a polyethylene terephthalate (PET) container from a hollow amorphous PET preform which includes an open end and a closed end, the open end forming a neck section having dimensions already conformed to its final size and shape, the container being able to withstand relatively severe thermal conditions encountered when the container is filled with a hot liquid, without appreciable deformation, including the steps of: a) rapidly heating only the body of the PET preform, exclusive of the neck section, to a temperature at which subsequent longitudinal and transverse stretching cause no stresses in the PET; b) transferring the hot preform from step (a) to a mold whose walls are maintained at a temperature lower than the temperature of the hot preform body; c) longitudinally stretching the preform body while simultaneously transversely expanding it by blow-molding using a pressurized fluid so as to mold the preform body to the shape of the mold cavity; d) rapidly evacuating the press

Abstract: A molding apparatus and method are adapted to mold an article having a hollow blow molded portion and a substantially solid compression molded portion. Defined within a mold is at least a first cavity portion and a second cavity portion. A parison is positioned within the mold and blow gas is injected into the interior of the parison to inflate the parison within each of the cavity portions. A compression member is then moved from a retracted position within a recess in the mold to an extended position outside of such recess. The compression member presses a first portion of the parison against the mold interior surface which defines the first cavity portion so as to compression mold a first portion of the parison. Inflation of a second portion of the parison in the second cavity portion accomplishes blow molding of such second parison portion.

Abstract: A flat container may be produced by extruding a molten resin to form a parison, closing the bottom of the parison, preblowing the parison such that the inner surfaces do not contact together, drafting the parison in a molten state, expanding the parison with the outer edge of the parison extending beyond that of the cavity of a mold, pinching the expanded parison with the mold to fuse the outer edge portions together along the outer edge of the cavity, and forcing a pressurized fluid into the parison pinched by the mold so that the parison is shaped in close contact with the inside surfaces of the mold cavity.

Abstract: An apparatus and method for blow molding large hollow bodies, such as automotive fuel tanks and the like, is disclosed. A fluidized plastic material injection head is located above a given portion of rails. A plurality of mold carriers are disposed on the rails through wheels, each mold carrier carrying thereon mold halves. A clamping device is mounted on each mold carrier to clamp the mold halves together. A hydraulic press device is located near the injection head and presses the mold halves against each other to achieve a tight coupling of them when operated.

Abstract: Apparatus and method are provided for expanding an earlier-extruded portion (42) of extruded plastic tubing (38) or plastic parison (41) into a first container (96a), for expanding a later-extruded portion (43) of the extruded plastic tubing (38) or parison (41) into a second container (96b), for delaying exanding the second portion (43) with respect to expanding the first portion (42) into the first container (96a), and for subsequently separating the second container (96b) from the first container (96a).

Abstract: An expandable section plastic tube having utility, for example, in inflatable balloon section catheters, and a method of making the same. The tube formed of thermoplastic material is inserted in a wall defining member, such as a mold, having an enlarged section surrounding a portion of the tube. The tube portion is then heated to a thermal plastic temperature and is expanded into the enlarged section by a sudden application of pressure resulting in a thinning of the tube wall in the expanded area. Thereafter, the tube is cooled and removed from the mold. In the making of a catheter, one section of the tube to one side of the expanded area is inverted and drawn into the section of the tube on the other side of the expanded area whereby the expanded area forms a balloon end at one end of the telescoped tube sections.

Abstract: A method of making flat bottles with flat or concave bottom by free extrusion of a plastic tube includes blowing of an intermediate form with circular cross section and shaping the latter essentially mechanically to the flat bottle at simultaneous final blowing for achieving clean radii. It is essential that the intermediate form is blown at a length corresponding to about the height of the flat bottle, with a circumference in the body area of -1 to about -10%, however, in the bottom near area of the side walls from 0 to about +15%, with regard to the corresponding circumference of the flat bottle. The radius of curvature at the junction from the body wall to the bottom should correspond to about the radius of curvature at the junction from the body wall of the broad side of the flat bottle to its bottom. The bottom part corresponding to the pinched end of the tube is pinched off during shaping.

Abstract: A blow molding parison (10) being draped around a generally rectangular mold part (12) is spread from its extruded cylindrical shape into a generally rectangular shape (14), as it descends from an extrusion head (11). Before the open bottom (20) of the parison reaches a clamp (25) on the mold part, a jet of air is blown downward through the open bottom to draw in the parison's side and end regions (21 and 22 respectively). This reduces the size of parison (10) and helps it fit within the clamp and also forms the end regions (22) of the parison into a pair of opposed pleats (23) extending inward from the ends of the pinch-off line when clamp (25) closes. Further descending of the parison unfolds the pleats into gussets (24) extending toward corner regions (27) of mold part (12) so that the parison can drape around the mold part corners.

Abstract: A method and apparatus of forming a hollow partially crystalline heat set biaxially oriented polyethylene terephthalate container having a hemispherical base comprising blowing a heated parison at orientation temperature outwardly against the confines of a mold which is at heat setting temperature wherein the side wall and the major portion of the base of the container are subjected to a heat setting temperature and the center of the base of the container is subjected to a temperature not greater than 150.degree. C. so that the central portion is crystallized a substantially lesser amount than the side wall and the major portion of the base. The container is then quenched. The resultant container can be formed at a rapid cycle and has good drop impact properties and obviates the problems of sticking to the hot mold or blow out when the hot mold is opened.

Abstract: A process for blow molding and fluorination of a hollow thermoplastic article includes bringing a blank to rest against the inside wall of the blow mold as a result of introducing an inert blow gas. An inert gas/reaction mixture is then introduced in the hollow article for fluorinating the inside surface of the hollow article. After the inside surface of the hollow article has cooled off, the inert gas/reaction gas mixture is blown in below the melting point of the thermoplastic material.

Abstract: A hermetically sealed unitary liquid container of a thermoplastic material suitable for use in inhalation therapy is disclosed. The humidifier container comprises a body portion defined by an upstanding walled chamber having a bottom, a gas inlet duct unitary with the container body portion and defining a sealed gas inlet, and a sealed humidified gas outlet duct, both unitary with the container body portion. The container body portion constitutes a liquid reservoir and contains a predetermined amount of an aqueous aseptic or sterile aqueous liquid for humidifying a breathable gas. The gas inlet duct extends alongside the walled chamber, and has upper and lower end portions which are respectively situated above the container body portion and below usable liquid level in the container. The gas outlet duct communicates with the walled chamber above the usable liquid level. The gas inlet duct communicates with a gas diffuser defined by the container wall above the container bottom.

Abstract: Blow molding of a parison with a blow needle is aided by the use of a sealing member which includes at least one projection which completely surrounds the blow needle. During inflation of the parison, the projections come into sealing contact with the exterior surface thereof so as to effectively prevent leakage of blow gas from the interior of the parison around the blow needle.

Abstract: A novel method of blow molding and fluorinating plastic containers carried out in essentially three steps, including blow molding of the container at a first predetermined pressure in a mechanically locked mold with an inert gas, testing the mold for pressure tightness at a second higher level of pressure with an inert gas, and thereafter introducing a fluorine containing gas into the mold at a third level of pressure.

Abstract: A double-walled plastic box 20 is molded from a single parison 50 in an unlimited depth by closing the bottom of parison 50 and draping it downwardly over a core 60 so that a leading part of the parison forms an inside wall of the box and a following part of the parison forms an outside wall of the box. After parison 50 is draped over core 60, outer mold parts 61 close around the core and the draped parison; and the box is blown in a cavity between the core and the outer mold parts. The parison can be ballooned while draping down over the core to enlarge the parison to stand out from and surround the core, which can be raised during the draping process. Parison 50 can also be deballooned after draping to stay within the confines of outer mold parts 61 while core 60 raises and while the outer mold parts close.

Abstract: A double-walled plastic box 20 is molded from a single parison 50 in an unlimited depth by closing and holding a bottom region of the parison at the bottom of a cavity 30, bringing together parts of a core 40 above the cavity to close off an upper region of the parison, moving the core, the cavity, or both vertically to position the core within the cavity and invert the parison so that a lower region of the parison forms an outside wall of the box against an inside surface of the cavity and an upper region of the parison forms an inside wall of the box against an outer surface of the core. The parison is then blown into a double-walled box 20 in the shape of an enclosed space between the cavity and the core.

Abstract: Expanding the parison while the mold side parts defining the walls of the blow-molding chamber, one part per wall, are moved to mold closed positions causes flash to be pinched between each mold part and provides good wall thickness near the edges of the final product.

Abstract: In producing hollow bodies by blow molding from thermoplastic material, a preferably tubular preform is firstly formed, and is then expanded within the blowing mold under the effect of an inert gas under high pressure, until it bears entirely against the inside surface of the blowing mold. Thereafter, a reaction gas such as fluorine is introduced into the hollow body under a considerably lower pressure, while the hollow body is still in the mold, to treat the internal surface of the hollow body to render it impervious to gas and/or liquid. After the reaction has elapsed, a flushing and cooling gas is introduced into the hollow body and is then removed from the blowing mold after the hollow body has sufficiently set.

Abstract: A blow molding operation wherein centering rods are associated with preforms at least during the initial portion of the blowing cycle wherein the preforms are primarily axially elongated and wherein the freely suspended lower end of each preform must be guided against radial movement. In order to assure that the associated preform centering rods will remain in centering position with respect to the preforms at all times and will not engage the preforms so as axially to stretch the preforms, a control is provided for coordinating the advance of the preform centering rods with the introduction of blowing gas into the preforms, and thus with the axial elongation of the preforms due to internal blowing pressure.

Abstract: A method and a device for production of a temperature-stable, biaxially oriented container of thermoplastic material. In a first moulding stage a blank (40) is placed in a blow mould (12) after which a mandrel (15) extends the blank in its axial direction to a length exceeding the axial length of the future container. The length of the stretched material, in an axial section through the stretched blank, is then reduced at a predetermined temperature, and the reduction being made to a profile length substantially agreeing with the profile length for corresponding material portions in an axial section through the future container. In a second moulding stage the stretched blank is expanded to abut against the walls of the mould. The expansion takes place at a point in time for and/or at a speed allowing the reduction of the length of the stretched material, due to shrinkage to have time to be concluded before the material comes into contact with the walls of the mould.

Abstract: A pot-shaped blank is shaped from nylon by the injection moulding process. Onto the blank a pot-shaped outer layer of polyethylene is moulded. The coated blank is finish shaped to canister form by a blowing process. The result is a "bonded structure" that substantially prevents permeation of aromatic substances and acyclic and alicyclic compounds. The method is particularly suitable for manufacturing canisters to hold lead-free gasoline.

Abstract: A blow-molded thermoplastic body is made by a method which comprises the following steps: inflating a hollow parison within a mold cavity for causing the parison to expand and conform to inner wall surfaces defining the mold cavity, whereby the blow-molded body is shaped; further inflating the blow-molded body within the mold cavity for causing a wall portion of the body to expand beyond the mold cavity into a port cavity communicating with the mold cavity thereby reducing the thickness of the wall portion; applying a counter pressure on an outer face of the wall portion for moving the wall portion back in the direction of the mold cavity against an inflating pressure prevailing within the blow-molded body, whereby connecting portions attaching the wall portion to the blow-molded body are reduced in thickness; and discontinuing the application of the counter pressure for allowing the wall portion to be driven anew away from the mold cavity into the port cavity by the inflating pressure.

Abstract: A method and apparatus for molding plastic products of virtually any complicated configuration is provided. When a parison is extruded out of a nozzle, a separating agent, preferably oil, is supplied into the parison as a lubricant. Since a thin film of the separating agent is formed on the inside surface of the parison, portions of the inside surface do not stick together even if they are brought into contact from some reasons. This insures to mold a plastic product of a very complex configuration. Use of a separating agent also allows to form sheet-type products by dividing the parison into several sections as desired. This is a very efficient way of forming sheet-type products since at least two may be formed at the same time.

Abstract: Disclosed is a process of making an oriented and heat set blow molded bottle of poly(ethylene terephthalate) so that the bottles resulting from the process have a density over 1.3860 cc./gm. and an onset-of-shrinkage temperature over 80.degree. C. In the process preform preheated to a temperature suitable for orientation is biaxially stretched in a blow mold and then while the hollow article walls are still in contact with the blow mold walls, the article is raised to a higher heat setting temperature in the range of 200.degree.-250.degree. C. (except for the neck) thus heat setting the bottle, and while the article is still at a shrinkage resisting pressure exceeding atmospheric cooling the article to a temperature at which it maintains its shape when not pressurized but not below 100.degree. C. It is also particularly disclosed that this cooling step can be done outside the mold.

Abstract: In blow molding an article with a reverse fold, a profiled bar is positioned where the parting line of the mold is to be when the mold is closed. The bar provides a reverse fold in the plastic article during a pre-blow step. In operation, a pre-pinched parison is formed adjacent the bar and as the mold begins to close a small amount of pre-blow air is introduced into the parison folding it against and over the bar. After the mold is closed, blow air is introduced to form the part. A complex part with good wall distribution of material can be obtained by this method.

Abstract: A machine particularly useful for the blow molding of large thermoplastic articles such as cylindrical drums comprises a plurality of stations through which mold cavities are successively advanced. At a first station, containing a cart-mounted blow assembly an article is blow molded to substantially its final form in a cavity with the blow medium being introduced via a blow pin assembly operatively associated with the cavity after the blow assembly has been operatively engaged with the blow pin assembly. After the blowing operation has been completed, the blow assembly is operatively disengaged from the blow pin assembly and the cavity with the blown article is transported in a second station, the blow pin assembly traveling with the cavity. At the second station, an auxiliary blow assembly is operatively engaged with the blow pin assembly to circulate medium through the interior of the article.

Abstract: This relates to the supplying of blow molding gas to a blow molding system. Most particularly, this relates to a blow molding gas supply which includes a low pressure supply and a high pressure supply and wherein the high pressure blowing gas of the molding operation is used to replenish the low pressure supply, thereby eliminating the presently required separate outside supply.

Abstract: A technique is described for preparing molecular biaxially oriented hollow articles from thermoplastic materials. The invention involves forming a parison on a cooled core rod by injecting a hot thermoplastic material into a cavity formed by the core rod and a cooled injection mold, cooling the parison with low temperature coolant to a temperature within the orientation range of the thermoplastic material, transferring the parison to a stretch blow molding position and permitting the temperature of the parison to equilibrate itself. The parison is then stretched, oriented to yield the desired biaxially oriented article, cooled and ejected.

Abstract: A method for producing a hollow synthetic resin article, which comprises opening a split mold having an inner molding surface with a contour conforming to the configuration of the desired article, feeding a heated molding material of a thermoplastic synthetic resin in the form of a tube or two parallel-laid sheets into a space between the opposing mold members of the split mold, applying a negative pressure to vacuum suction holes provided in the molding surfaced and the parting surfaces of the split mold to vacuum-form the molding material, and while the negative pressure is being applied or after the application of the negative pressure is stopped, closing the mold to form the molding material into the final desired configuration.

Abstract: An elongate, rigid, tubular, biaxially oriented thermoplastic, hollow thin-walled shaped article is molded by (i) introducing into an elongate mold cavity, the internal configuration and dimensions thereof corresponding to the exterior surface area of the desired shaped article, and aligning along the longitudinal axis thereof, a hollow tubular thermoplastic preform heated to the biaxial orientation temperature of said thermoplastic; (ii) expanding under internal pressure said heated preform to simultaneously, both longitudinally and transversely, uniformly stretch same, at least to the natural biaxial drawing ratio thereof, but to a value in the transverse direction of less than 100% of that ultimately desired; (iii) next further expanding said heated preform, under increased internal pressure, completely against the internal walls of the mold cavity to thus completely shape said ultimately desired shaped article; and (iv) then cooling said desired shaped article and releasing all pressure therefrom.

Abstract: This relates to a blow molding apparatus wherein in lieu of the mold halves closing on a preform and thereafter the blowing operation initiated, the preform is shifted into one of the mold halves and thereafter advance of the stretch rod into the preform and movement of the blow head to a position closely adjacent the preform is effected before the closing of the mold is completed. Such arrangement permits a reduction in cycle time. This abstract forms no part of the specification of this application and is not to be construed as limiting the claims of the application.

Abstract: A process for preparing biaxially oriented hollow shaped articles, in particular bottles of thermoplastic material, by biaxial draw- and blow-molding comprises blow-molding a preform and subsequently maintaining the thermoplastic material in close contact with the hot walls of the mold at a temperature which is in the range from about the minimum effective temperature for biaxial orientation of the thermoplastic material to about 40.degree. C. above this temperature for a period of time which is sufficient to partially reduce internal residual stresses in the hollow shaped articles. Following this partial thermo-stabilization, the hollow shaped article preferably is subjected to cooling, whereby the pressure within the article is at least partially maintained or the shaped article is cooled or allowed to shrink and subsequently subjected to a second blow-molding procedure.

Abstract: This relates to a blow molding operation wherein centering rods are associated with preforms at least during the initial portion of the blowing cycle wherein the preforms are primarily axially elongated and wherein the freely suspended lower end of each preform must be guided against radial movement. In order to assure that the associated preform centering rods will remain in centering position with respect to the preforms at all times and will not engage the preforms so as axially to stretch the preforms, a control is provided for coordinating the advance of the preform centering rods with the introduction of blowing gas into the preforms, and thus with the axial elongation of the preforms due to internal blowing pressure.

Abstract: Biaxially oriented low cost polyolefin bottles of improved optical clarity, gloss, and strength, and useful for packaging materials such as liquid detergents, shampoos, pharmaceuticals and intravenous solutions, are prepared by stretch blow molding polypropylene homopolymer co-polymer and allomer parisons or preforms which are formed from low temperature melts at temperatures just above the melting points of the polymers and allomers, and are injected at constant rates against cold polished mold surfaces at relatively low pressures and at slow rates to avoid melt fractures. Melt temperatures of from 490.degree. to 700.degree. F. are preferred for polypropylene blow mold type polymers and allomers. Polished beryllium copper mold surfaces are desired for high luster gloss finishes. Mold temperatures of from 30.degree. to 80.degree. F. are preferred. Injection molding with a high compression ratio of 3 to 3.

Abstract: A device for improving the control of the shape of a parison of a blow molding machine. The device has an inner nozzle positioned below the lowermost level of the parison and directed upwardly toward the open end of the parison. The device may be adapted to pivot so that a deflector plate is moved below the finished part.

Abstract: A method for blow molding of containers with a thickened bead at the bottom end thereof by the steps of extruding a tubular parison, closing the mold thereabout, preblowing the parison within a mold cavity under low pressure so as to partially inflate the parison to a major extent, raising the bottom wall of the mold cavity so as to contact the partially inflated parison in a manner forming a thickened bead between bottom and surrounding adjacent mold cavity wall parts, and thereafter finish-blowing the parison within the mold cavity with a blow medium under high pressure so as to inflate the parison to the intended finished size before opening of the mold for removal of the container.

Abstract: Hollow shapes are blow molded with a special form of gate connecting the shapes to the parison from which they are blow molded and permitting subsequent degating of the shapes by ultrasonic mechanical vibration applied to the gates.

Abstract: Large blow molded objects are produced by extruding a generally tubular form in a horizontal direction so as to form a large pillow shaped object upon sealing. The sealed pillow shaped article is severed and conveyed to a mold having a predetermined configuration and blow molded into a desired shape. The horizontal production of the parison used for blow molding permits the production of large parisons without the sag associated with a vertical process and also permits continuous coextrusion of large parisons without the need for complex accumulating equipment.