초록 ▼

A method and apparatus for producing a thermoplastic container-shaped intermediate or article having biaxially oriented side walls and a bottom having an unoriented portion surrounded by a biaxially oriented transparent portion. In the method, a sheet of thermoplastic at its orientation temperature

A method and apparatus for producing a thermoplastic container-shaped intermediate or article having biaxially oriented side walls and a bottom having an unoriented portion surrounded by a biaxially oriented transparent portion. In the method, a sheet of thermoplastic at its orientation temperature is secured over the mouth of a forming tube. A plunger having a circumscribing sharp edged lip and a plunger follower sandwich the thermoplastic sheet and the plunger and plunger follower are driven into the forming tube while preventing the circumscribed portion of the thermoplastic from becoming oriented. Thereafter the thermoplastic is blow formed to yield a container-shaped intermediate. The final container is formed by heat shrinking the intermediate onto a male form having a predetermined size, shape and texture. The apparatus includes the forming tube, plunger, plunger follower and pressurized air for performing the method.

대표청구항 ▼

A method for producing a thermoplastic, container-shaped intermediate, said intermediate comprised of sidewalls and a bottom wherein said sidewalls are biaxially oriented and said bottom has a central portion that is unoriented surrounded by a biaxially oriented portion, said method comprising: secu

A method for producing a thermoplastic, container-shaped intermediate, said intermediate comprised of sidewalls and a bottom wherein said sidewalls are biaxially oriented and said bottom has a central portion that is unoriented surrounded by a biaxially oriented portion, said method comprising: securing a sheet of thermoplastic at its orientation temperature in a forming tube; providing a plunger and a plunger follower, the plunger and plunger follower being axially aligned and the plunger including a circumscribing sharp edged lip about a select area of a leading surface of the plunger for gripping said thermoplastic sheet; plug forming said thermoplastic sheet in a first stage with the plunger and plunger follower wherein a portion of said thermoplastic sheet is gripped by the lip between the plunger and plunger follower so that the portion of the thermoplastic sheet circumscribed by the lip is prevented from becoming oriented; and blow forming said plug formed thermoplastic to yield said container-shaped intermediate.