Apparatus for manufacturing biaxially oriented film with dimensional stability

Claim 1

An apparatus for collapsing an expanded thermoplastic tubing comprising a pair of supply rolls for receiving thermoplastic tubing, a plurality of mandrels having their axes in alignment to each other and to said supply roll to define a pass line for the tubing, certain ones of said mandrels being of progressively increasing diameters, the remaining one of said mandrels being furtherest from said supply rolls and being of a diameter less than the nearest adjacent preceding mandrel wherein said adjacent mandrel is one of said certain mandrels to thereby effect transverse controlled shrink-back of the expanded tubing, means operatively connected to said mandrels for pressurizing the chambers defined by the tubing and said mandrels to facilitate the stretching of the tubing, the outer edges of all of said certain mandrels cooperate with the tubing to define annular reservoirs, means for conveying heated liquid to said annular reservoirs to heat said tubing adjacent thereto and to act as a lubricant, said remaining mandrel and said tubing adjacent thereto cooperative to define a cylindrical shaped reservoir, means for supplying cooling liquid to said cylindrical reservoir for cooling said tubing passing adjacent thereto below the mastic state of said tubing.

Claim 2

An apparatus for collapsing an expanded thermoplastic tubing comprising a pair of supply rolls for receiving thermoplastic tubing, a plurality of mandrels having their axes in alignment to each other and to said supply roll to define a pass line for the tubing, certain ones of said mandrels being of progressively increasing diameters, the remaining one of said mandrels being furtherest from said supply rolls and being of a diameter less than the nearest adjacent preceding mandrel wherein said adjacent mandrel is one of said certain mandrels to thereby effect transverse controlled shrink-back of the expanded tubing, means operatively connected to said mandrels for pressurizing the chambers defined by the tubing and said mandrels to facilitate the stretching of the tubing, the outer edges of all of said certain mandrels cooperate with the tubing to define annular reservoirs, means for conveying heated liquid to said annular reservoirs to heat said tubing adjacent thereto and to act as a lubricant, said remaining mandrel and said tubing adjacent thereto cooperative to define a cylindrical shaped reservoir, means for supplying cooling liquid to said cylindrical reservoir for cooling said tubing passing adjacent thereto below the mastic state of said tubing.

Claim 3

An apparatus for processing thermoplastic tubing comprising a support member, said support member having first mandrel means with an increasing diameter in its longitudinal direction, a second mandrel mounted on said support member having an aNnular abutment on the lowermost end portion thereof, said annular abutment of said second mandrel having a diameter greater than the diameter of said first mandrel means, a third mandrel mounted on said support member having an annular abutment on the lowermost end portion and being of a diameter less than said annular abutment on said second mandrel, said first mandrel and said annular abutment of said second mandrel cooperative with the inner wall surface of said tubing to define a pair of annular liquid reservoirs, means operatively connected to said annular liquid reservoirs for supplying heated liquids to said reservoirs for heating said tubing, pressurizing means connected to said support member adjacent to said first and second mandrel means for pressurizing the chamber defined by said first and second mandrels and the inner surface of said tubing, said third mandrel and said abutment of said third mandrel being cooperative with the inner surface of said tubing to define a circular reservoir, and means operatively connected to said cylindrical reservoir for supplying cooling liquids to said cylindrical reservoir for annealing said tubing passing into contact therewith.

Claim 4

An apparatus for processing thermoplastic tubing comprising a support member, said support member having first mandrel means with an increasing diameter in its longitudinal direction, a second mandrel mounted on said support member having an aNnular abutment on the lowermost end portion thereof, said annular abutment of said second mandrel having a diameter greater than the diameter of said first mandrel means, a third mandrel mounted on said support member having an annular abutment on the lowermost end portion and being of a diameter less than said annular abutment on said second mandrel, said first mandrel and said annular abutment of said second mandrel cooperative with the inner wall surface of said tubing to define a pair of annular liquid reservoirs, means operatively connected to said annular liquid reservoirs for supplying heated liquids to said reservoirs for heating said tubing, pressurizing means connected to said support member adjacent to said first and second mandrel means for pressurizing the chamber defined by said first and second mandrels and the inner surface of said tubing, said third mandrel and said abutment of said third mandrel being cooperative with the inner surface of said tubing to define a circular reservoir, and means operatively connected to said cylindrical reservoir for supplying cooling liquids to said cylindrical reservoir for annealing said tubing passing into contact therewith.

Claim 9

An apparatus for manufacturing biaxially orientated film comprising support means; said support means having a reservoir for collecting liquid; an elongated support member having one end secured to said support means; at least a pair of spaced mandrels secured to said support means with their axes in alignment, and operative to receive a tubular thermoplastic member for passage thereover; one mandrel of said spaced mandrels being furthest from said support means supporting conduit means which supplies pressurized air for pressurizing the interior of said tubular member advancing toward said mandrels; the remaining ones of said mandrels being larger in diameter than said one mandrel for expanding said tubular member; other conduit means extending through said support member for communicating with the interior of said tubular members between said mandrels to provide selective pressurization of the interior of said tubular member, drive rolls mounted closely adjacent to said support means for pulling said tubular member over said mandrels to provide biaxial orientation to said tubing; at least a pair of laterally spaced knives mounted on said support member for splitting said tubular member into a film; an annular mandrel means having its axis in alignment with the axes of said spaced mandrels and located between said knives and said spaced mandrels; said annular mandrel means mounted on said support member; said annular mandrel means having a diameter less than the most closely adjacent one of said remaining mandrels to provide a shrink-back in said tubular member; said support member supporting means for heating said tubular material as it passes over said spaced mandrels; and cooling means connected to saiD annular mandrel means to provide means for cooling the tubular material as it passes thereover.

Claim 10

An apparatus for manufacturing biaxially orientated film comprising support means; said support means having a reservoir for collecting liquid; an elongated support member having one end secured to said support means; at least a pair of spaced mandrels secured to said support means with their axes in alignment, and operative to receive a tubular thermoplastic member for passage thereover; one mandrel of said spaced mandrels being furthest from said support means supporting conduit means which supplies pressurized air for pressurizing the interior of said tubular member advancing toward said mandrels; the remaining ones of said mandrels being larger in diameter than said one mandrel for expanding said tubular member; other conduit means extending through said support member for communicating with the interior of said tubular members between said mandrels to provide selective pressurization of the interior of said tubular member, drive rolls mounted closely adjacent to said support means for pulling said tubular member over said mandrels to provide biaxial orientation to said tubing; at least a pair of laterally spaced knives mounted on said support member for splitting said tubular member into a film; an annular mandrel means having its axis in alignment with the axes of said spaced mandrels and located between said knives and said spaced mandrels; said annular mandrel means mounted on said support member; said annular mandrel means having a diameter less than the most closely adjacent one of said remaining mandrels to provide a shrink-back in said tubular member; said support member supporting means for heating said tubular material as it passes over said spaced mandrels; and cooling means connected to saiD annular mandrel means to provide means for cooling the tubular material as it passes thereover.