Abstract: A plastic preform from which a plastic container is blow molded. The preform replaces a three layer preform by providing a preform which is of a five layer construction in the base forming portion thereof and wherein a secondary material which forms the core layer of the three layer preform construction is divided into an inner intermediate layer and an outer intermediate layer by a third injection of material. The third injected material is preferably the same material as the primary material which is first injected. This results in the reduction of the cost of the preform and also provides remaining in the injection nozzle a quantity of the last injected material which is the same as the first injected material for the following preform in the same preform injection mold cavity.

Abstract: It has been found that when layered preforms are being injection molded utilizing at least two materials, it is possible to maintain the same horizontal and vertical pitch of adjacent cavities as is possible when each mold cavity is being filled with a single material. Most particularly, it has been found that when the percentage of the material to be injected into a mold cavity is relatively high, it is possible to utilize a single metering pot for four adjacent mold cavities. On the other hand, if one of the materials to be injected into a mold cavity constitutes a relatively low percentage of the volume of a mold cavity, it has been found that a small metering pot must be provided for each of the cavities of the four cavity mold.

Abstract: A polyester preform which is injection molded preferably of PET and wherein the preform is provided with a molded neck finish or neck portion inlcuding threads which are molded to a high tolerance and wherein the neck finish may receive a closure cap of the type having a tamper indicating band which engages over a retaining bead also molded to a high tolerance as part of the neck finish. In order to maintain the container which is blow molded from the preform in axial alignment with the neck finish and thus eliminate the perpendicularity problem, a ring of the preform immediately below the flange which functions as the capping ring, is heated to a high temperature and crystallized. In a like manner, the end sealing surface is also heated to a high temperature and crystallized. The remainder of the neck finish remains in its amorphous state without disturbing the configuration of either the threads or the retaining bead.

Abstract: A blow molded container which is formed of a polyester resin which has formation and shape characteristics wherein it may be hot filled with a liquid at a temperature on the order of 180.degree.-185.degree. F. with a maximum volumetric shrinkage of no greater than 1 percent. The container is formed from a specially configurated injection molded preform which is initially stretched axially only on the order of 25 percent, after which the preform is inflated and blow molded within a blow mold to a configuration which resists vacuum collapse or paneling of the body.

Abstract: An injection molded plastic preform for forming by blow molding a container such as a bottle. The preform is of a laminated construction and in the body area includes inner and outer layers of the same plastic and an intermediate layer of a different plastic. The bottom portion of the preform is provided with a core layer of still a third plastic with the injection temperature of the third layer being sufficient to erode the contacted part of the intermediate layer which is of a lower melt temperature. The third plastic may be the same plastic as the first plastic, but injected at a higher temperature. Generally speaking, the neck finish of the preform will be of a single layer of the first material, the body of the preform will be of a three ply construction which is also true of the bottom with there being an intermediate area of five ply where the bottom core layer projects into the lower portion of the intermediate layer.

Abstract: A blown plastic container of a type normally blown from a single resin preform, such as PET, wherein the bases of a three layer construction with at least one layer either being PET having a high IV or a resin which has a high Tg. The secondary resin may either be in the form of a core layer injected into the base of the injection molded preform or in the form of initially injected inner and outer base layers. By utilizing a small amount of the second resin, greater strength can be obtained together with a greater resistance to cracking at higher temperatures as well as the reduction in the overall weight of the resultant container.

Abstract: In the blow molding of a container from a preform in a heated blow mold wherein the container has formed as part of the preform a neck portion which remains unoriented, there is a tendency for the neck portion to distort relative to the body so that there is a perpendicularity problem. In accordance with this invention, the problem has been solved by either crystallizing that portion of the preform which remains unoriented in the blow molding of the container so as to both provide a clear line of demarcation between the unoriented and biaxially oriented portion of the container and to increase the glass temperature of the preform portion so as to prevent shrinkage due to conductive heating.

Abstract: A blow molded container which is formed of a polyester resin which has formation and shape characteristics wherein it may be hot filled with a liquid at a temperature on the order of 180.degree.-185.degree. F. with a maximum volumetric shrinkage of no greater than 1 percent. The container is formed from a specially configurated injection molded preform which is initially stretched axially only on the order of 25 percent, after which the preform is inflated and blow molded within a blow mold to a configuration which resists vacuum collapse or paneling of the body.

Abstract: This relates to the formation of a preform for a container which is formed primarily of PET and like saturated polyesters which are to be utilized in the packaging of a hot fill liquid and like product, particularly a container wherein a metal closure is to be utilized. The preform is of a laminated construction with the body of the preform being of a five layer construction and the neck finish portion being primarily of a three layer construction including outer layers of PET or like saturated polyester and a core formed of a high Tg polymer. The same high Tg polymer would be in the form of thin layers in the body of the preform between inner and outer layers and a core.

Abstract: This relates to the base configuration of a biaxially oriented blow molded thermoplastic resin container. It has been found that by assigning more space to the ribs between adjacent legs and feet, during the blow molding of a preform, there is proportionally less thinning of the material of the preform in accordance with the greater width of rib, thereby providing greater strength in the high stress area of the base structure with a resultant lesser failure due to stress cracking.

Abstract: A returnable/refillable container in the form of a blow molded polyester biaxially oriented bottle having a physical and structural relationship providing for the maintenance of aesthetic and functional viability over a minimum of five trips wherein each trip comprises (1) an empty state caustic wash followed by (2) contaminant inspection and product filling/capping, (3) warehouse storage, (4) distribution to wholesale and retail locations, and (5) purchase, use and empty storage by the consumer followed by return to a bottler. The container is obtained utilizing a specific preform configuration and reheat blow process wherein the sidewall of the resultant container has a percent crystallinity of 24-30 at a total preform draw ratio of 7-9/1. The container is formed utilizing recently developed process techniques to optimize strain induced sidewall crystallization.

Abstract: A hybrid reheating of polyester preforms which are to be stretch blown into containers wherein the reheating coupled with the controlled quick initiation of the blow stretch operation after final reheating produces a container which may be filled with a hot fill without there being any disadvantageous shrinkage of the container. The reheating is by way of a specific combination of quartz oven reheating and radio frequency reheating together with specific equilibrations of the temperature cross sectionally of the preform body. Polyester preforms may be reheated to a cross sectional center temperature ranging from 225.degree. F. to 260.degree. F. and stretch blow molded without undesirable surface crystallization occuring while the ability of the container to be filled with a hot filled substantially without shrinkage is increased.

Abstract: A returnable/refillable container in the form of a blow molded polyester biaxially oriented bottle having a physical and structural relationship providing for the maintenance of aesthetic and functional viability over a minimum of twenty trips wherein each trip comprises (1) an empty state caustic wash followed by (2) contaminant inspection and product filling/capping, (3) warehouse storage, (4) distribution to wholesale and retail locations, and (5) purchase, use and empty storage by the consumer followed by return to a bottler. The container is obtained utilizing a specific preform configuration and reheat blow process wherein the sidewall of the resultant container has a percent crystallinity of 28-30 at a total preform draw ratio of 7-9/l. The container is formed utilizing recently developed process techniques to optimize strain induced sidewall crystallization.

Abstract: This relates to a method of forming a thermal/collapse-resistant highly oriented polyester container for use in hot fill applications. In accordance with the method of a polyester preform is reheated and then placed in a blow mold cavity whereat the preform is distended to match the blow mold cavity to form an intermediate article including a container having an oriented end unit receiving finish of a diameter materially greater than the diameter of the preform. The method is characterized in that in providing the preform the composition of the polyester, the draw ratio during distending of the preform and reheat conditions are all controlled to provide a container with a sidewall and finish density in the range of 1.350 to substantially but less than 1.370 grams/cubic centimeter.

Abstract: This relates to a preform which is injection molded and which is especially intended for use in the blow molding of a container suitable for receiving a hot fill product. Most particularly, the neck finish of the preform, which becomes the neck finish of the resultant blow molded container, is reinforced against axial compression or foreshortening as may occur when the neck finish is heated to a temperature approaching the glass transition temperature of the polyester from which the neck finish is formed. So as to resist deformation of the neck finish, the neck finish is provided on the interior surface (mouth) thereof with a plurality of axially extending, radially inwardly projecting, circumferentially spaced ribs. If the thread means of the neck finish for receiving a closure is of the interrupted type, there will be at least one rib for each thread element.

Abstract: This relates to the formation of wide mouth bottles and jars for receiving a hot fill product where the jars and bottles are formed of a suitable polyester such as PET. The bottle or jar is initially formed as part of an intermediate article including an upper adapter portion which is reusable so that substantially all of the resultant bottle and jar, particularly the neck finish thereof is biaxially oriented. The intermediate article is formed from a preform which is blow molded within a conventional type of blow mold. In the reheating of the preform, that portion of the preform which becomes the neck finish of the bottle or jar is heated to a higher temperature than the remainder of the preform and to a temperature wherein thermal crystallization in addition to strain crystallization occurs. This results in the neck finish having a higher density than other portions of the bottle or jar and being more resistant to shrinkage during hot filling.

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: 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: This relates to a heating system and process for reheating preforms prior to delivering the preforms to a blow molder. The heating system utilizes different types of heating units, one of which will heat the preform wall more highly at the interior surface and the other of which will heat the preform wall at the exterior surface. By effectively controlling the heat input to a preform from each heating unit and by controlling the outputs of the different heating units in combination, the desired temperature profile through the preform wall may be obtained substantially without any time in the oven being provided for heat equilibration and at the same time a maximum heating effort may be effected to produce the necessary heating of a preform within a minimal time and more uniformly than heretofore possible.

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.