Film forming head

Claim 2

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define an internal cavity and a discharge orifice, the improvement wherein a head portion has a convex curved peripheral portion and a straight peripheral portion tangent to each end of said curved portion, and an elongated orifice extending along and through said curved and straight peripheral portions communicating with said internal cavity.

Claim 3

A film forming head as set forth in claim 1, including a concave portion adjacent said gap, at least in part defining said cavity and an adjacent lip portion forming a juncture therewith, internally of the head, said juncture being inwardly of and closely conforming in shape with the exterior surface of the head portions that define the orifice.

Claim 4

A film forming head as set forth in claim 2, wherein the cavity is defined by a flat wall in a plane passing through said orifice and by an opposed concave wall.

Claim 5

A film forming head as set forth in claim 2 wherein said lip portion is flat and extends from said juncture to the exterior surface of the head along the full length of the orifice.

Claim 6

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define the orifice and an internal cavity that opens through said orifice, the improvement comprising head portions shaped to create said orifice in the form of a narrow elongated gap with a central portion that extends along a part-circular path and two end portions contiguous with the central portion that extend tangentially to and outwardly from the part-circular path at an angle of 20*-35* away from an imaginary radial line bisecting the path of said central portion, said head portions and orifice serving to direct extruded resin material biaxially and form a sheet substantially wider than the orifice.

Claim 7

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define the orifice and an internal cavity that opens through said orifice, the improvement comprising head portions shaped to create said orifice in the form of a narrow elongated gap with a central portion that extends along a part-circular path and two end portions contiguous with the central portion that extend tangentially to and outwardly from the part-circular path at an angle of 20*-35* away from an imaginary radial line bisecting the path of said central portion, said head portions and orifice serving to direct extruded resin material biaxially and form a sheet substantially wider than the orifice.

Claim 8

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define the orifice and an internal cavity that opens through said orifice, the improvement comprising head portions shaped to create said orifice in the form of a narrow elongated gap with a central portion that extends along a part-circular path and two end portions contiguous with the central portion that extend tangentially to and outwardly from the part-circular path, a concave portion adjacent said gap, at least in part defining said cavity and an adjacent lip portion forming a juncture therewith, internally of the head, said juncture being inwardly of and closely conforming in shape with the exterior surface of the head portions that define the orifice, said lip portion being flat and extending from said juncture to the exterior surface of the head along the full length of the orifice, and the width of said lip between said juncture ane said exterior surface being greater along the central portion of the gap than along the end portions, said head portions and orifice serving to direct extruded resin material biaxially and form a sheet substantially wider than the orifice.

Claim 9

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define the orifice and an internal cavity that opens through said orifice, the improvement comprising head portions shaped to create said orifice in the form of a narrow elongated gap with a central portion that extends along a part-circular path and two end portions contiguous with the central portion that extend tangentially to and outwardly from the part-circular path, a concave portion adjacent said gap, at least in part defining said cavity and an adjacent lip portion forming a juncture therewith, internally of the head, said juncture being inwardly of and closely conforming in shape with the exterior surface of the head portions that define the orifice, said lip portion being flat and extending from said juncture to the exterior surface of the head along the full length of the orifice, and the width of said lip between said juncture ane said exterior surface being greater along the central portion of the gap than along the end portions, said head portions and orifice serving to direct extruded resin material biaxially and form a sheet substantially wider than the orifice.

Claim 10

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define the orifice and an internal cavity that opens through said orifice, the improvement comprising head portions shaped to create said orifice in the form of a narrow elongated gap with a central portion that extends along a part-circular path and two end portions contiguous with the central portion that extend tangentially to and outwardly from the part-circular path, a concave portion adjacent said gap, at least in part defining said cavity and an adjacent lip portion forming a juncture therewith, internally of the head, said juncture being inwardly of and closely conforming in shape with the exterior surface of the head portions that define the orifice, said lip portion being flat and extending from said juncture to the exterior surface of the head along the full length of the orifice, said cavity further being formed by an interior wall confronting said lip and having a greater cross-section remote from said orifice than proximate said orifice, the concave portion forming the juncture with the lip being sloped from centrally of the cavity toward said confronting wall in an outward direction to the lip, whereby said cavity converges from a central region toward said orifice to provide for smooth acceleration of the viscous resin material within the head in a direction toward the orifice, said head portions and orifice serving to direct extruded resin material biaxially and form a sheet substantially wider than the orifice.

Claim 11

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define the orifice and an internal cavity that opens through said orifice, the improvement comprising head portions shaped to create said orifice in the form of a narrow elongated gap with a central portion that extends along a part-circular path and two end portions contiguous with the central portion that extend tangentially to and outwardly from the part-circular path, a concave portion adjacent said gap, at least in part defining said cavity and an adjacent lip portion forming a juncture therewith, internally of the head, said juncture being inwardly of and closely conforming in shape with the exterior surface of the head portions that define the orifice, said lip portion being flat and extending from said juncture to the exterior surface of the head along the full length of the orifice, said cavity further being formed by an interior wall confronting said lip and having a greater cross-section remote from said orifice than proximate said orifice, the concave portion forming the juncture with the lip being sloped from centrally of the cavity toward said confronting wall in an outward direction to the lip, whereby said cavity converges from a central region toward said orifice to provide for smooth acceleration of the viscous resin material within the head in a direction toward the orifice, said head portions and orifice serving to direct extruded resin material biaxially and form a sheet substantially wider than the orifice.

Claim 12

A film forming head as set forth in claim 7 wherein an inlet passage enters said cavity at a location remote from said orifice and in general alignment therewith.

Claim 13

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define an internal cavity and a discharge orifice, the improvement wherein a head portion has a convex curved peripheral portion and a straight peripheral portion tangent to each end of said curved portion, and a continuous elongated orifice extending along said curved and straight peripheral portions and located in a plane through said curved and straight peripheral portions, said orifice communicating with said internal cavity.

Claim 14

In a film forming head for receiving a viscous resin material under substantial pressure and forming a thin extruded sheet thereof via an extruding orifice, in which head portions define an internal cavity and a discharge orifice, the improvement wherein a head portion has a convex curved peripheral portion and a straight peripheral portion tangent to each end of said curved portion, and a continuous elongated orifice extending along said curved and straight peripheral portions and located in a plane through said curved and straight peripheral portions, said orifice communicating with said internal cavity.

Claim 15

A film forming head for receiving viscous resin material under pressure and forming a resin film therefrom comprising: a body having a cavity formed therein with an interior wall which is concave in a plane passing through said body, the exterior of said body being formed with a surface which is convex in said plane and generally parallels said interior cavity wall; an extruding orifice extending between said exterior surface and interior wall and being elongate in said plane; an inlet passage formed in said body extending into said cavity; said concave interior cavity wall and convex exterior body surface defining a centrally disposed arcuate portion and lateral side portions generally tangent to said central portion, said orifice extending in its longitudinal dimension along said dide and central portions; whereby resin material is receivable in said cavity an will extrude radially outwardly from said cavity through said orifice to form a sheet of resin film and the orifice at said central portion will project the extruded film generally radially thereof while the orifice along said lateral side portions will project it substantially perpendicularly therefrom.

Claim 16

A film forming head for receiving viscous resin material under pressure and forming a resin film therefrom comprising: a body having a cavity formed therein with an interior wall which is concave in a plane passing through said body, the exterior of said body being formed with a surface which is convex in said plane and generally parallels said interior cavity wall; an extruding orifice extending between said exterior surface and interior wall and being elongate in said plane; an inlet passage formed in said body extending into said cavity; said concave interior cavity wall and convex exterior body surface defining a centrally disposed arcuate portion and lateral side portions generally tangent to said central portion, said orifice extending in its longitudinal dimension along said dide and central portions; whereby resin material is receivable in said cavity an will extrude radially outwardly from said cavity through said orifice to form a sheet of resin film and the orifice at said central portion will project the extruded film generally radially thereof while the orifice along said lateral side portions will project it substantially perpendicularly therefrom.

Claim 17

A film forming head as set forth in claim 10 wherein said side portions slope tangentially outwardly and away from said central portion so as to project extruded film laterally outwardly and forwardly of the head.

Claim 18

A film forming head as set forth in claim 11 wherein each said side portion slopes at an angle of 20*-35* away from an imaginary radial line bisecting said central portion.

Claim 19

A film forming head as set forth in claim 10 wherein confronting but spaced faces of said body substantially parallel to said plane define the orifice, at least one of said faces includes a lip connecting said exterior surface with said interior cavity wall, and the lip has a greater wiDth along said central portion than along said side portions.

Claim 20

A film forming head as set forth in claim 10 wherein said inlet passage enters said cavity at a location remote from said orifice and in general alignment therewith.

Claim 21

A film forming head as set forth in claim 14 further comprising means disposed in said inlet passage to interrupt flow of viscous resin material into said cavity.

Claim 22

A film forming head as set forth in claim 10 wherein said body is formed by a base part defining said interior wall and a portion of said exterior surface and defining said lip therebetween, and a cap part having an exterior surface portion mated to said portion of said exterior surface of the base part and mounted to said base part with a planar wall confronting and spaced from said lip to provide said confronting, spaced, faces of said orifice.