Abstract: This specification discloses an improved apparatus and method for making bi-axially oriented containers in an injection blow molding machine. The parison is brought to the blow mold at orientation temperature, and the end of a reciprocating element is brought into contact with the end of the parison and is shaped to prevent the end of the parison from shifting off center as the parison is blown and stretched axially while it expands circumferentially to obtain bi-axial orientation. The reciprocating element prevents the parison from shifting laterally in the blowing mold so that the stretching and the wall thickness of the blown article is uniform.

Abstract: Articles, such as containers, can have their barrier properties improved either by using a small percentage of fluorine or other materials in the gas that is used at the blowing station of an injection blow molding machine. Some of these materials, such as fluorine, are a hazard to operators of the machine. This invention encloses the operational stations so that the blowing gas mixture cannot escape into the atmosphere of the shop where the blow molding machine is operating. An inert gas such as nitrogen is mixed with the fluorine gas, and the enclosing housing is purged when the machine is shut down at the end of a run.

Abstract: This specification discloses an improved apparatus and method for making bi-axially oriented containers in an injection blow molding machine. The parison is brought to the blow mold at orientation temperature, and the end of a reciprocating element is brought into contact with the end of the parison and is shaped to prevent the end of the parison from shifting off center as the parison is blown and stretched axially while it expands circumferentially to obtain bi-axial orientation. The reciprocating element prevents the parison from shifting laterally in the blowing mold so that the stretching and the wall thickness of the blown article is uniform.

Abstract: This specification discloses apparatus for connecting handles, or other parts, to plastic injection blow molded containers such as buckets, pitchers and other articles; the handles being parts that are not molded integral with the blow molded containers, but that are stiffer and stronger parts than the blow molded walls of the containers. The blow molded element is made with recesses for receiving the bales, or handles, and is made flexible so that end portions of the handles can be forced into the recesses by expanding the entrances to the recesses. The fit is designed to give the maximum undercut that cannot be pulled out of the mold without damaging the part. The mating part can be made to snap in with a design that minimizes the ability to remove it, such as for a paint can.

Abstract: This specification discloses apparatus for connecting handles, or other parts, to plastic injection blow molded containers such as buckets, pitchers and other articles; the handles being parts that are not molded integral with the blow molded containers, but that are stiffer and stronger parts than the blow molded walls of the containers. The blow molded element is made with recesses for receiving the bales, or handles, and is made flexible so that end portions of the handles can be forced into the recesses by expanding the entrances to the recesses. The fit is designed to give the maximum undercut that can be pulled out of the mold without damaging the part. The mating part can be made to snap in with a design that minimizes the ability to remove it, such as for a paint can.

Abstract: The injection blow molding machine of this specification moves oriented containers. Parisons applied to core rods move from an injection mold to a conditioning station that provides time for the full thickness of the parison to come to the same temperature. The parisons are then transferred, by a transfer device, to other core rods on a second indexing head of the machine which carries the parisons to a stretch-blow station at which they are stretched to obtain orientation. After the parisons are blown to final size, they are stripped from the core rods of the second indexing head. The transfer device turns the parisons to 180.degree. in a plane of their axial length in order to transfer them from one core rod to another.

Abstract: This improvement in injection blow molding machines provide simple and effective apparatus for adjusting the location of the clamping apparatus that holds a mold closed with the holding force applied at or close to alignment with the center of pressure of the air that is introduced into the mold cavity. The invention is primarily for use with the blowing mold where the center of pressure varies widely from one mold to another, depending upon the size and shape of the cavities in which the parison on a core rod is expanded to fill the mold cavity.

Abstract: This blow molding machine overcomes the tendency of the parison to sag toward the bottom side of the core or for air currents to unevenly cool the parison, while at the same time allowing the parison to be cooled from the core side and then outside to the desirable orienting temperature, so that at the subsequent blow, or stretch-blow station, a bi-axially oriented container is produced having uniform wall distribution. As a means of intensifying the cooling on the outside, in order to speed up the operation, provisions are made to enclose the parison with an open end cylinder having means of introducing a flow of air in a tangential manner so that it circulates around the parison as the parison is rotated.

Abstract: Plastic blown ware is made by expanding a molten plastic tubular blank into contact with the wall of a mold cavity. This invention evacuates air from the part of the cavity around the outside of the blank to increase the pressure differential across the tube wall during the blowing period and to help prevent the plastic from pulling away from the cavity wall during cooling and shrinkage. The invention makes blown ware by compounding the plastic with a blowing agent and by controlling the bubble size and wall thickness by changing the pressure on opposite sides of the blown article to whatever pressure will permit the gas bubbles and the plastic to expand to the desired size during cooling and setting of the plastic.

Abstract: Multi-cavity molds, such as used for injection blow-molding apparatus, have manifolds through which molten plastic is supplied from a plasticizer to the individual mold cavities. Some plastic molding materials, referred to as "heat-sensitive," deteriorate if they remain in the manifold for any substantial length of time. This manifold is constructed with its cross-section and branch passages correlated in such a way that there is no space in the manifold where plastic can accumulate out of the stream of feeding plastic. By keeping the plastic moving, in all parts of the manifold during each injection operation, deterioration of heat-sensitive plastic in the manifold is avoided.

Abstract: This is a method for injection blow molding plastic articles having an opening at both ends. Parisons are injected over core rods that extend all the way across the cavity of an injection mold so that the core rod extends beyond both ends of the parison. The parison is injected by "subterranean" gating, and cylindrical ends of the parison are confined in the blowing mold while the portions of the parison between the ends are blown by opening a blowing fluid outlet intermediate the ends of the core rod. Grooves in the core rod near both ends of the parison prevent shrinkage of the plastic as it cools and prevent shortening of the length of the parison.

Abstract: A parison for blow molding is applied to a core rod by successive injection operations in different injection molds. The material for the first layer is injected into the end of the mold cavity remote from the neck portion of the core rod, in the usual manner. The second layer is injected into the second injection mold cavity adjacent to the neck of the core rod to flow over the first layer in a direction from the cooler part of the first layer toward the hotter part. The twolayer parison is then transferred to a blowing mold where it is blown in the usual way.