Abstract: A method of making blown plastic articles of non-circular cross-section, having convex exterior portions, such as a bottle of rectangular or oval shape, or having localized protuberances. The article is blown from a pre-form of inverted shape, i.e., the convex article portions are formed from concave pre-form portions. Also, the concave, pre-form portions are of increased thickness to compensate for their greater subsequent expansion during blowing.During final blowing, the non-convex portions of the article are first formed against the mold cavity-thereby stabilizing the partly blown pre-form in the blow mold cavity-and the concave pre-form portions are then blown to their final convex shape to complete the article.

Abstract: A method particularly adapted for making pinched-shut, non-blown portions of a blown article, e.g. the non-blown handle openings in a blown plastic jug including engaging a localized portion of a blowable shape, which portion corresponds to a non-blown portion of the final blown article, with a blow mold projection prior to complete enclosure of the blown shape in the blow mold. Such engagement fixes the engaged portion to the blow mold for joint displacement during further blow mold closure. This engagement can be obtained by either (1) specifically shaping the blowable shape for engagement by the mold pinching portions or (2) utilizing retractable abutments carried by the mold itself.

Abstract: A method for blow molding plastic articles, particularly containers. The method involves shuttling a pre-form blow mold between a parison forming location and a pre-form blowing location, and the transfer of a blown pre-form to a fixed final blow mold. The movement of the pre-form blow mold, both in its shuttling movement and in its open and closing movement, is utilized to transfer the blown pre-form. A clamp arm is secured to each pre-form mold section for engaging the pre-form at the pre-form blowing location and for transferring the pre-form to the final blow mold as the pre-form blow mold moves.The clamp arms form the finish-defining portions of the final blow mold. When the pre-form blow mold is at its blowing location, the clamp arms register with the mold cavity of the fixed final blow mold to define the complete final article mold.

Abstract: Plastic containers having internal reinforcing ribs are formed by a molding operation including pre-blow and final-blow steps. The pre-blow step includes inflating a blowable plastic parison into contact with the cavity walls of a first blow mold to form a blown pre-form, the cavity walls of the first blow mold including a plurality of concave grooves to form a pattern of convex or proturburent ribs on the outer periphery of the pre-form. The final-blow step includes positioning the blown, ribbed pre-form within a second or final blow mold having a cavity defined by substantially smooth wall surfaces conforming to the exterior configuration of the desired container. Next, the pre-form is blown to stretch and expand against the cavity walls of the second mold, during which step the convex ribs on the exterior of the pre-form are flattened, forming concave portions intermediate convex reinforcing ribs on the internal wall surface of the container.

Abstract: This invention relates to a method of making a blown plastic container having a concave pressure bottom configuration by blowing a pre-form into a container having a flat bottom, then contacting and deforming the flat bottom to reform the flat bottom into the desired pressure bottom configuration. The flat bottom is reformed by blowing, or by mechanical contact, or both blowing and contact, at a temperature conducive to multi-axial orientation to provide a pressure bottom of increased strength. To facilitate the performance of the method utilizing an initial parison formed by free extrusion, the present invention further contemplates smoothing out any pinch flash and distributing it on the bottom of the parison, so that the pinch flash will not interfere with subsequent forming of the bottom of the final container as above described.

Abstract: This invention relates to a method of making a blown plastic containeer having an arcuate pressure bottom configuration, preferably provided with integrally formed multiple thickness support walls or "skirts" surrounding the bottom.The method of making such containers is by blowing the container in a blow mold having telescopically movable portions for physically contacting and deforming a blowable parison or preform positioned in the blow mold. The parison contact and deformation aids in forming the bottom and/or the surrounding support walls, while providing a favorable blow-up ratio during the blowing operation. Further, the method can be carried out under conditions causing multi-axial orientation in the final container.

Abstract: This invention relates to a method for blow molding articles, such as handled containers, having injection molded portions integrally formed with blow molded portions. The method includes forming a tubular blowable parison, blowing this parison in a pre-form mold, and then blowing the pre-form to its final shape in a final blow mold. The utilization of the pre-form mold as an intermediate step makes possible the formation of containers of enhanced physical characteristics, the elimination of external flash or waste portions, and the formation of a final article having an injection molded portion integrated with a biaxially oriented blown portion.The apparatus of the invention includes the means for forming the parison, the pre-form mold, the final blow mold and the means for correlating the operation of these portions of the apparatus to attain the operation of the overall method.

Abstract: This application discloses a method of and apparatus for blow molding plastic articles in two blowing stages. A freely extruded pendant tubular parison is first blown into a pre-form, then the pre-form, while at a temperature most conducive to orientation, is blown to its final configuration. By performing certain operations on the pre-form prior to the final blowing step, improved products can be made. For example, by pinching shut a portion of the pre-form, handled containers can be made on a free extrusion blow molding machine. By stretching the pre-form prior to final blowing, containers of increased top-load or stacking capability can be made.

Abstract: An improved apparatus for forming blow molded articles of enhanced physical characteristics by orienting the material during the formation of the article. A two-stage blowing operation is provided wherein a pre-form blow mold effects a uniform and controllable transfer of heat from a freely extruded tube. The pre-form is conditioned, both thermally and dimensionally, within the pre-form for most effective orientation during a subsequent final blowing operation. Manipulatively, the disclosed method provides a completely overlapped pre-blowing and final blowing operation, and more than one set of pre-blow and final blow molds may be utilized at a single extruder orifice, if desired. Further, the direction and extent of movement of the molds adapts the apparatus to presently existing blow molding machines, while increasing the machine output. Successively utilized blow tubes form and reform the open or blowing end of the tube to a final configuration.

Abstract: The present invention provides an apparatus for thermally conditioning a blowable shape or parison, prior to blow molding, so that a subsequent blowing operation can be carried out under conditions conducive to bi-axial orientation in the final blown article.More specifically, the parison is formed by conventional techniques, such as free extrusion or injection molding. The parison is then enclosed in a heat exchange chamber, having interior walls spaced substantially uniformly from the exterior of the parison, and the parison is exposed to a fluid heat transfer agent, so that the parison temperature is adjusted to that temperature at which the parison, upon expansion, will become bi-axially oriented. The fluid agent can either heat or cool the parison to the desired temperature.

Abstract: A method of blow molding plastic articles in two blowing stages. A freely extruded pendant tubular parison is first blown into a pre-form, then the pre-form, while at the temperature most conductive to orientation, is blown to its final configuration. By performing certain operations on the pre-form prior to the final blowing step, improved products can be made. For example, by pinching shut a portion of the pre-form, handled containers can be made on a free extrusion blow molding machine. By stretching the pre-form prior to final blowing, containers of increased top-load or stacking capabilities can be made. .Iadd.This application is a re-issue of U.S. Pat. 3,781,395, issued Dec. 25, 1973, matured from U.S. Pat. application Ser. No. 110,685, filed January 28, 1971. .Iaddend.