초록 ▼

A method of making a plastic container having a threaded wide-mouth finish includes providing a preform having at least an exterior surface of molded polyester construction. The preform is placed in a mold cavity having a first portion for forming a container body, a second portion adjacent to the f

A method of making a plastic container having a threaded wide-mouth finish includes providing a preform having at least an exterior surface of molded polyester construction. The preform is placed in a mold cavity having a first portion for forming a container body, a second portion adjacent to the first portion for forming a cylindrical finish wall without threads, and a third portion adjacent to the second portion for forming a trim dome or moil. The preform is expanded within the mold cavity to form a one-piece intermediate product that includes a body, a cylindrical wide-mouth finish wall and a moil. After removing the intermediate product from the cavity, the moil is severed from the end of the finish wall. At least one thread is then formed on the finish wall by engaging the finish wall with at least one thread-forming tool, which may be heated to facilitate the forming operation.

대표청구항 ▼

The invention claimed is: 1. A method of making a plastic container having a threaded wide-mouth finish, which comprises the steps of: (a) providing a preform of molded plastic construction, (b) placing said preform in a mold cavity having a first portion for forming a container body, a second por

The invention claimed is: 1. A method of making a plastic container having a threaded wide-mouth finish, which comprises the steps of: (a) providing a preform of molded plastic construction, (b) placing said preform in a mold cavity having a first portion for forming a container body, a second portion adjacent to said first portion for forming a cylindrical finish wall without threads, and a third portion adjacent to said second portion for forming a trim moil, (c) expanding said preform within said cavity to form a one-piece intermediate product that includes a body, a cylindrical wide-mouth finish wall having a diameter less than that of the body and without threads, and a trim moil, (d) removing said intermediate product from said mold cavity, (e) removing said trim moil, and (f) forming at least one thread on said cylindrical wide-mouth finish wall by engaging said cylindrical finish wall with at least one thread-forming tool. 2. The method set forth in claim 1 wherein said step (f) comprises exteriorly engaging said cylindrical finish wall with at least one first tool having at least one groove segment, and simultaneously interiorly engaging said cylindrical finish wall with at least one second tool having at least one rib segment, complimentary to said at least one groove segment, to force portions of said cylindrical finish wall into said groove segment and thereby form at least one external thread on said finish wall. 3. The method set forth in claim 2 wherein said step (f) includes heating one or both of said first and second tools. 4. The method set forth in claim 2 wherein said step (f) includes rotating one or both of said first and second tools and said intermediate product. 5. The method set forth in claim 2 wherein said step (f) includes exteriorly engaging said cylindrical finish wall with a plurality of said first tools and shrinking said cylindrical finish wall onto said second tool. 6. The method set forth in claim 2 wherein said preform provided in said step (a) has at least an exterior surface of PET construction. 7. The method set forth in claim 6 wherein said finish wall is of PET construction throughout. 8. The method set forth in claim 6 which includes the further step of crystallizing at least an exterior surface of said finish wall prior to or during said step (f). 9. A method of making a plastic container having a threaded wide-mouth finish, comprising the steps of: (a) placing a preform in a mold cavity and expanding the preform within the cavity to form an intermediate product having a body, a wide-mouth finish wall having a diameter less than that of the body and without threads, and a trim moil; (b) removing the trim moil; and (c) forming at least one thread on the wide-mouth finish wall by engaging the finish wall with at least one thread-forming tool. 10. The method of claim 9, wherein the mold cavity is a blow mold cavity and the expanding step includes blow molding. 11. The method of claim 9, wherein the at least one thread is formed as an external thread. 12. The method of claim 9, wherein the at least one thread-forming tool includes complimentary groove and rib segments and wherein during the forming steps the rib segment forces a portion of the finish wall into the groove segment to form the at least one thread. 13. The method of claim 9, wherein the at least one thread-forming tool is heated. 14. The method of claim 12, wherein the groove segment is provided on a first tool and the rib segment on a second tool. 15. The method of claim 14, wherein the first and second tools comprise a pair of rollers postionable on the interior and exterior of the finish wall. 16. The method of claim 15, wherein the rollers are heated. 17. The method of claim 9, wherein the forming step comprises cold-forming of the at least one thread. 18. The method of claim 9, wherein the at least one thread-forming tool comprises a plug positionable on the interior of the finish wall and at least one external former, movable radially inwardly against the exterior of the finish wall, to form the at least one thread. 19. The method of claim 18, wherein the at least one external former has a recessed thread portion and the internal plug has an external bead. 20. The method of claim 9, wherein the finish wall is heated during the thread-forming step. 21. The method of claim 9, wherein at least a portion of the finish wall is crystallized before or during formation of the at least one thread. 22. The method of claim 9, including swage-forming a top-sealing surface of the finish wall. 23. The method of claim 9, wherein the preform has at least an exterior surface of PET. 24. The method of claim 9, wherein the finish wall is of PET. 25. The method of claim 9, wherein the forming step comprises swage-forming.