Container head forming

#This invention relates to a technique for forming the shoulder and neck of a squeeze tube such as the type used for toothpaste. More particularly, this invention involves a technique for forming the inner wall of the shoulder and neck from an upward extension of the collapsible sidewall.

#The collapsible sidewall of the squeeze tube is cylindrical. The head portion has an inwardly extending shoulder and an upwardly extending substantially cylindrical neck. The neck is threaded to receive a cap.

#The shoulder and neck portions are normally molded as a rigid piece of, for example, polyethylene, onto the top of the sidewall. The plastic head frequently requires an impervious insert to prevent oxygen from passing into the container and to prevent flavorants and other constituents of the produce from passing out through the molded head. The sidewall is usually a multi-ply material having at least one metal ply to provide this impervious layer. One multi-ply sidewall arrangement is described in U.S. Pat. No. 3,295,725 issued to R. Brandt on Jan. 3, 1967 and impervious insert arrangements for the head are described in U.S. Pat. Nos. 3,260,411 issued to F. E. Dobson on July 12, 1966 and 3,565,293 issued to R. Schulty on Feb. 23, 1971.

#FIG. 1 is a perspective view of the end product of this invention.

#FIG. 2 is a longitudinal sectional view of the FIG. 2 product taken along the line 2--2.

#FIG. 3 illustrates the cylindrical starting material which forms the sidewall of the squeeze tube.

#The following description refers to the FIGS. all of which relate to a single embodiment of this invention. As illustrated in FIGS. 1 and 2 the product to which this invention is addressed is in a squeeze tube 20 having a collapsible sidewall 22 and rigid head portion 24. This head 24, which may be molded of polyethylene, has a shoulder 25 and a threaded neck 26. By virtue of the apparatus and technique of this invention, the impermeable sidewall 22 extends up and inward to form a layer between the head 24 and the interior of the container. Specifically, the sidewall 22 includes a shoulder portion 28 which is between the inner surface of the polyethylene shoulder 25 and the interior of the tube. The sidewall 22 also extends further up to provide a neck portion 29 between the polyethylene threaded neck 26 and the interior of the collapsible tube 20.

#The end product illustrated in FIGS. 1 and 2 is formed by molding the polyethylene head 24 onto an intermediate product having the configuration shown in FIG. 6. The forming of the FIG. 6 intermediate product requires the crimping and folding machinery illustrated in subsequent FIGS. and can best be understood by first appreciating the sequence of configurations formed from the cylinder 22.

#The cylinder 22 starts out as a collapsible cylinder as shown in FIG. 3 which cylinder normally is a multi-ply material having a metal foil layer sandwiched between inner and outer plastic layers. This structure is known in the art and therefore is not further discussed herein.