Coextrusion apparatus for flat film

Claim 2

A coextrusion flat film die assembly for thermo-extrudable materials, comprising: a die body of a given length and having at least two separate melt inlets for receiving a separate melt of said thermoextrudable materials; at least two manifold chambers positioned within said die body and being substantially coextensive with said die body, each of said chambers being in communication with one of said melt inlets; means for separating said manifold chambers from each other throughout the given length of said die body; at least two separate elongated relatively narrow first melt flow passages substantially coextensive with said die body, each of said first melt flow passages being in communication with a separate manifold chamber for relatively coarse melt flow control; at least two separate elongated relatively narrower second melt flow passages substantially coextensive with said die body, each of said second melt flow passages being in communication with a separate first melt flow passage for relatively fine melt flow control; at least two separate melt outlet slots substantially coextensive with said die body and having a relatively narrow width dimension, each of said outlet slots communicating with one of said second melt flow passages and each being defined by a substantially immovable inner wall and a relatively movable outer wall, means associated with each of said outlet slots for selectively varying the width dimension of each slot; and deckle means associated with each of said outlet slots affirmatively positioning side edges of adjacent slots in offsetting positions relative to each other.

Claim 3

A coextrusion flat film die assembly for thermo-extrudable materials, comprising: a die body of a given length and having at least two separate melt inlets for receiving a separate melt of said thermo-extrudable materials; at least two manifold chambers positioned within said die body and being substantially coextensive with said die body, each of said chambers being in communication with a separate melt inlet; means for separating said manifold chambers from each other throughout the given length of said die body; at least two separaTe elongated relatively narrow first melt flow passages substantially coextensive with said die body, each of said first melt flow passages being in communication with a separate manifold chamber for relatively coarse melt flow control; at least two separate elongated relatively narrower second melt flow passages substantially coextensive with said die body, each of said second melt flow passages being in communication with one of said first melt flow passages for relatively fine melt flow control; at least two separate melt outlet slots substantially coextensive with said die body and having a relatively narrow width dimension, each of said outlet slots communicating with one of said second melt flow passages and each being defined by a substantially immovable inner wall and a relatively movable outer wall; means associated with each of said outlet slots for selectively varying the width dimension of said slot; deckle means associated with each of said outlet slots positioning the side edges of adjacent slots in offset position; and heating means associated with said body for providing an independently selected temperature to each of said separate melts throughout its flow in the die body.

Claim 4

A coextrusion flat film die assembly for thermo-extrudable materials, comprising: a die body of a given length and having at least two separate melt inlets for receiving a separate melt of said thermo-extrudable materials; at least two manifold chambers positioned within said die body and being substantially coextensive with said die body, each of said chambers being in communication with a separate melt inlet; means for separating said manifold chambers from each other throughout the given length of said die body; at least two separaTe elongated relatively narrow first melt flow passages substantially coextensive with said die body, each of said first melt flow passages being in communication with a separate manifold chamber for relatively coarse melt flow control; at least two separate elongated relatively narrower second melt flow passages substantially coextensive with said die body, each of said second melt flow passages being in communication with one of said first melt flow passages for relatively fine melt flow control; at least two separate melt outlet slots substantially coextensive with said die body and having a relatively narrow width dimension, each of said outlet slots communicating with one of said second melt flow passages and each being defined by a substantially immovable inner wall and a relatively movable outer wall; means associated with each of said outlet slots for selectively varying the width dimension of said slot; deckle means associated with each of said outlet slots positioning the side edges of adjacent slots in offset position; and heating means associated with said body for providing an independently selected temperature to each of said separate melts throughout its flow in the die body.

Claim 5

A coextrusion flat flim die assembly for thermo-extrudable materials comprising, a pair of die body portions of a given length, each of said die body portions having: an inner and an outer wall; a separate melt inlet extending from said outer wall inwardly for receiving a separate melt of said thermo-extrudable material; a manifold chamber extending from said inner wall to said melt inlet and having a lower boundary terminating inside the plane of said inner wall; a pre-land surface joining said lower boundary of the manifold chamber and extending away from said manifold chamber substantially parallel to the plane of said lower boundary; a final land surface joining a lower boundary of said pre-land surface and extending away therefrom along a plane between the plane of said inner wall and the plane of said pre-land surface; a relatively deep groove extending from said outer wall inwardly toward said pre-land surface and terminating prior to said pre-land surface; at least one threaded bore extending from said outer wall into said groove; a bolt threaded into each of said bores for bearing against a groove wall below said bore; a centerplate member positioned between said die body portions for separating said manifold chambers, pre-land surfaces and final land surfaces of each body portion into separate melt flow passages; opposite surfaces of said centerplate member and said final land surfaces defining a pair of closely adjacent but separate offsetting outlet slots giving into space beyond the die; and heating means associated with each of said melt flow passages for independently regulating the temperature of each melt throughout a flow passage.

Claim 6

A coextrusion flat flim die assembly for thermo-extrudable materials comprising, a pair of die body portions of a given length, each of said die body portions having: an inner and an outer wall; a separate melt inlet extending from said outer wall inwardly for receiving a separate melt of said thermo-extrudable material; a manifold chamber extending from said inner wall to said melt inlet and having a lower boundary terminating inside the plane of said inner wall; a pre-land surface joining said lower boundary of the manifold chamber and extending away from said manifold chamber substantially parallel to the plane of said lower boundary; a final land surface joining a lower boundary of said pre-land surface and extending away therefrom along a plane between the plane of said inner wall and the plane of said pre-land surface; a relatively deep groove extending from said outer wall inwardly toward said pre-land surface and terminating prior to said pre-land surface; at least one threaded bore extending from said outer wall into said groove; a bolt threaded into each of said bores for bearing against a groove wall below said bore; a centerplate member positioned between said die body portions for separating said manifold chambers, pre-land surfaces and final land surfaces of each body portion into separate melt flow passages; opposite surfaces of said centerplate member and said final land surfaces defining a pair of closely adjacent but separate offsetting outlet slots giving into space beyond the die; and heating means associated with each of said melt flow passages for independently regulating the temperature of each melt throughout a flow passage.

Claim 7

A coextrusion flat film die assembly as defined in claim 3, including deckle means mounted in working relation with the outlet slots and operating to offset adjacent side edges of said slots.

Claim 8

A coextrusion flat film die assembly for thermo-extrudable materials comprising, a pair of die body portions of a given length, each of said die body portions having: an inner and an outer wall; a separate melt inlet extending from said outer wall inwardly for receiving a separate melt of said thermo-extrudable material; a manifold chamber extending from said inner wall to said melt inlet and having a lower boundary terminating inside the plane of said inner wall; a pre-land surface joining said lower boundary of the manifold chamber and extending away from said manifold chamber substantially parallel to the plane of said lower boundary; a final land surface joining a lower boundary of said pre-land surface and extending away therefrom along a plane between the plane of said inner wall and the plane of said pre-land surface; a relAtively deep groove extending from said outer wall inwardly toward said pre-land surface and terminating prior to said pre-land surface; at least one threaded bore extending from said outer wall into said groove; a bolt threaded into each of said bores for bearing against a groove wall below said bore; a centerplate member positioned between said die body portions for separating said manifold chambers, pre-land surfaces and final land surfaces of each body portion into separate melt flow passages; opposite surfaces of said centerplate member and said final land surfaces defining a pair of closely adjacent but separate offsetting outlet slots giving into space beyond the die; heating means associated with each of said melt flow passages for independently regulating the temperature of each melt throughout a flow passage; including deckle means mounted in working relation with the outlet slots and operating to offset adjacent side edges of said slots, said deckle means comprise a deckle carrier member mounted on the die body below the outlet slots for movement along the length of the die in a cross-machine direction and a deckle bar having first and second stepped portions, wherein said first step blocks a part of one outlet slot and the second step portion blocks a different portion of another outlet slot.

Claim 9

A coextrusion flat film die assembly for thermo-extrudable materials comprising, a pair of die body portions of a given length, each of said die body portions having: an inner and an outer wall; a separate melt inlet extending from said outer wall inwardly for receiving a separate melt of said thermo-extrudable material; a manifold chamber extending from said inner wall to said melt inlet and having a lower boundary terminating inside the plane of said inner wall; a pre-land surface joining said lower boundary of the manifold chamber and extending away from said manifold chamber substantially parallel to the plane of said lower boundary; a final land surface joining a lower boundary of said pre-land surface and extending away therefrom along a plane between the plane of said inner wall and the plane of said pre-land surface; a relAtively deep groove extending from said outer wall inwardly toward said pre-land surface and terminating prior to said pre-land surface; at least one threaded bore extending from said outer wall into said groove; a bolt threaded into each of said bores for bearing against a groove wall below said bore; a centerplate member positioned between said die body portions for separating said manifold chambers, pre-land surfaces and final land surfaces of each body portion into separate melt flow passages; opposite surfaces of said centerplate member and said final land surfaces defining a pair of closely adjacent but separate offsetting outlet slots giving into space beyond the die; heating means associated with each of said melt flow passages for independently regulating the temperature of each melt throughout a flow passage; including deckle means mounted in working relation with the outlet slots and operating to offset adjacent side edges of said slots, said deckle means comprise a deckle carrier member mounted on the die body below the outlet slots for movement along the length of the die in a cross-machine direction and a deckle bar having first and second stepped portions, wherein said first step blocks a part of one outlet slot and the second step portion blocks a different portion of another outlet slot.

Claim 10

A coextrusion flat film die assembly as defined in claim 4 wherein the deckle means comprise a pair of deckle rods, each extending from the die body outer wall into the separate melt flow passages above the outlet slots for a different distance so that said outlet slots have adjacent offset side edges.

Claim 11

A coextrusion flat film die assembly as defined in claim 4 including a plurality of deckle means mounted in working relation with the outlet slots to define a plurality of ribbon-like slots, each ribbon-like slot having side edges offset from adjacent ribbon-like slot side edges.

Claim 12

A coextrusion flat film die assembly as defined in claim 3 wherein the centerplate member is a rigid smooth straight member and the heating means is in the centerplate member.

Claim 13

A coextrusion flat film die assembly as defined in claim 3 wherein the threaded bores in one die body portion are atlernatingly staggered in relation to the threaded bores in the other die body portion, whereby reducing hills and valleys in composite extruded film so that a substantially uniform caliber of film is obtained.

Claim 14

A coextrusion flat film die assembly as defined in claim 3 wherein the heating means provides different temperatures to each of the melts ranging from about 0* to 200* F.

Claim 15

Means for flat film extrusion of thermoextrudable materials comprising; an elongated body provided with at least two separate melt passages, each passage having a feed end, a manifold chamber, a pre-land surface and a final land surface terminating in an outlet slot, said outlet slots being positioned adjacent to each other, means for feeding a thermo-extrudable material into each of said passages, means for heating said thermo-extrudable material in each of said passages to an individual temperature and deckle means associated with each of said outlets closing portions of adjacent side edges of said outlets in offset positions.

Claim 16

Means for flat film extrusion of thermoextrudable materials comprising; an elongated body provided with at least two separate melt passages, each passage having a feed end, a manifold chamber, a pre-land surface and a final land surface terminating in an outlet slot, said outlet slots being positioned adjacent to each other, means for feeding a thermo-extrudable material into each of said passages, means for heating said thermo-extrudable material in each of said passages to an individual temperature and deckle means associated with each of said outlets closing portions of adjacent side edges of said outlets in offset positions.

Claim 17

A die for extruding a thermoplastic sheet material comprising: means defining a plurality of outlet slots elongated in a cross-machine direction; said slots being spaced from each other transversely of said cross-machine direction; a plurality of manifold chambers for supplying plastic melt to said slots; heating means associated with each of said manifold chambers and said outlet slots for independently regulating the temperature of the plastic melt in each of said chambers and outlet slots, including a plurality of heaters in heat relation to said die, and each of said heaters being independently regulated to supply heat to the predetermined portion of the die, said heaters including as one feature sEparately controlled heaters disposed in a cross-machine direction.

Claim 18

A die for extruding a thermoplastic sheet material comprising: means defining a plurality of outlet slots elongated in a cross-machine direction; said slots being spaced from each other transversely of said cross-machine direction; a plurality of manifold chambers for supplying plastic melt to said slots; heating means associated with each of said manifold chambers and said outlet slots for independently regulating the temperature of the plastic melt in each of said chambers and outlet slots, including a plurality of heaters in heat relation to said die, and each of said heaters being independently regulated to supply heat to the predetermined portion of the die, said heaters including as one feature sEparately controlled heaters disposed in a cross-machine direction.

Claim 19

A die assembly as defined in claim 12 including deckle means mounted in working relation with the outlet slots and offsetting adjacent side edges of said slots.

Claim 20

A die as recited in claim 13 wherein the deckle means comprise at least a pair of deckle rods extending into the die in a cross-machine direction, said deckle rods being above and in spaced relation with said outlet slots, one rod being associated with each outlet slot.

Claim 21

A die for extruding a thermoplastic sheet material comprising: means defining a plurality of outlet slots elongated in a cross-machine direction; said slots being spaced from each other transversely of the cross-machine direction; a plurality of manifold chambers for supplying plastic melt to said slots: heating means associated with each of said manifold chambers and said outlet slots for independently regulating the temperature of the plastic melt in each of said chambers and offset slots; including deckle means mounted in working relation with the outlet slots to offset adjacent side edges of said slots, wherein the deckle means comprise a deckle carrier member mounted on the die body below the outlet slots for movement along the length of the die in a cross-machine direction and a deckle bar having first and second step portions, wherein said first step portions blocks a part of one outlet slot and the second step portion blocks a different portion of another outlet slot.

Claim 22

A die for extruding a thermoplastic sheet material comprising: means defining a plurality of outlet slots elongated in a cross-machine direction; said slots being spaced from each other transversely of the cross-machine direction; a plurality of manifold chambers for supplying plastic melt to said slots: heating means associated with each of said manifold chambers and said outlet slots for independently regulating the temperature of the plastic melt in each of said chambers and offset slots; including deckle means mounted in working relation with the outlet slots to offset adjacent side edges of said slots, wherein the deckle means comprise a deckle carrier member mounted on the die body below the outlet slots for movement along the length of the die in a cross-machine direction and a deckle bar having first and second step portions, wherein said first step portions blocks a part of one outlet slot and the second step portion blocks a different portion of another outlet slot.

Claim 23

A die for extruding a thermoplastic sheet material comprising: means defining a plurality of outlet slots elongated in a cross-machine direction; said slots being spaced from each other transversely of said cross-machine direction; a plurality of manifold chambers for supplying plastic melt to said slots; heating means associated with each of said manifold chambers and said outlet slots for independently regulating the temperature of the plastic melt in each of said chambers and outlet slots, including a plurality of heaters in heat relation to said die, and each of said heaters being independently regulated to supply heat to the predetermined portion of the die, wherein a plurality of threaded bores extend from the outside of the die toward said outlet slots, a corresponding plurality of bolts threaded into said bores to regulate the opening of the outlet slots, wherein the bores and the bolts are alternately staggered relative to each other on opposite sides of the die.

Claim 24

A die for extruding a thermoplastic sheet material comprising: means defining a plurality of outlet slots elongated in a cross-machine direction; said slots being spaced from each other transversely of said cross-machine direction; a plurality of manifold chambers for supplying plastic melt to said slots; heating means associated with each of said manifold chambers and said outlet slots for independently regulating the temperature of the plastic melt in each of said chambers and outlet slots, including a plurality of heaters in heat relation to said die, and each of said heaters being independently regulated to supply heat to the predetermined portion of the die, wherein a plurality of threaded bores extend from the outside of the die toward said outlet slots, a corresponding plurality of bolts threaded into said bores to regulate the opening of the outlet slots, wherein the bores and the bolts are alternately staggered relative to each other on opposite sides of the die.

Claim 25

A die for extruding thermoplastic sheet material comprising: means defining a plurality of slots elongated in a cross-machine direction, said slots being spaced from each other transversely of said cross-machine direction; a plurality of manifold chambers for supplying plastic material to said slots; deckle means associated with said slots which put at varying different positions at least one edge of each of said slots whereby edge beads in said sheet extruded from each of said slots will be offset with respect to the edge beads in the sheet extruded from the other of said slots.

Claim 26

A die for extruding thermoplastic sheet material comprising: means defining a plurality of slots elongated in a cross-machine direction, said slots being spaced from each other transversely of said cross-machine direction; a plurality of manifold chambers for supplying plastic material to said slots; deckle means associated with said slots which put at varying different positions at least one edge of each of said slots whereby edge beads in said sheet extruded from each of said slots will be offset with respect to the edge beads in the sheet extruded from the other of said slots.

Claim 27

A die as defined in claim 17 including deckle means mounted in working relation with the outlet slots to offset adjacent side edges of said slots.

Claim 28

A die as defined in claim 18 wherein the deckle means comprise a deckle carrier member mounted on the die body below the outlet slots for movement along the length of the die in a cross-machine direction and a deckle bar having first and second stepped portions, wherein said first step blocks a part of one outlet slot and the second step portion blocks a different portion of another outlet slot.

Claim 29

A die as defined in claim 18 wherein the deckle means comprise a pair of deckle rods, each extending from the outer wall of the die into the area between the manifold chambers and the outlet slots, each rod extending into the die a different distance so that said outlet slots have adjacent offset side edGes whereby the film at respectively corresponding edges of two adjacent slots comes out from the die in respectively offset positions.

Claim 30

A die as defined in claim 19 including a plurality of deckle means mounted in working relation with the outlet slots to define a plurality of ribbon-like slots, each ribbon-like slot having side edges offset from adjacent ribbon-like slot side edges.

Claim 31

The die recited in claim 17 and further including a plurality of heating means for regulating the temperature of the plastic melt in the manifold putting relatively different amounts of heat in different streams and also in different positions over the width of an individual stream.

Claim 32

The die recited in claim 17 wherein the die is comprised of at least two die portions, a centerplate member positioned between said die portions for separating the manifold chambers and slots into separate melt flow passages, said centerplate member being relatively thin to allow the slots to be closely spaced relative to each other, and extending in the outlet direction of the die all the way to the outlet end of the die to separate the slots in the outlet end.

Claim 33

The die recited in claim 17 and including pre-land surfaces in fluid communication with each of said manifold chambers and downstream therefrom, said die further including final land surfaces in fluid communication with each of said pre-land surfaces and the outlet slots, said final land surfaces being downstream of said pre-land surfaces, and pre-land surfaces, land surfaces and outlet slots all having a common plane surface along the same side of all three and being in generally streamline passages.