Blown film coextrusion line with polygonal extruder arrangement
AssigneeBbs GmbH
InventorsHenry G. Schirmer, Roger Blaine Trivette, Matthew G. Hampshire
Life of this patent
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Abstract
A blown film coextrusion line includes a support frame, a plurality of extruders each mounted to the support frame and extending upward at an angle, and a downward facing blown film coextrusion die connected to distal ends of each of the plurality of extruders and receiving individual polymer streams from them. The blown film coextrusion line is compact and sturdy and eliminates much of the floor space and towered mounting structure that was required for conventional blown film coextrusion lines. A corresponding method of making a multilayer coextruded blown film is also provided.
Claims25
A method of making a multilayer coextruded blown film, comprising the steps of:
- extruding a first polymer stream upward at a first angle from horizontal toward a downward facing blown film coextrusion die using a first extruder;
- extruding a second polymer stream upward at a second angle from horizontal toward the downward facing blown film coextrusion die using a second extruder;
- and
- extruding a third polymer stream upward at a third angle from horizontal toward the downward facing blown film coextrusion die using a third extruder;
- feeding the first, second and third polymer streams into the downward facing blown film coextrusion die;
- and
- coextruding the first, second and third polymer streams using the downward facing blown film coextrusion die as a downward facing bubble to make the multilayer coextruded blown film;
- wherein the method further comprises the step of at least one of a) raising the first, second and third extruders and the blown film coextrusion die to increase a length of the bubble and b) lowering the first, second and third extruders and the blown film coextrusion die to decrease a length of the bubble.
A method of making a multilayer coextruded blown film, comprising the steps of:
- extruding a first polymer stream upward at a first angle from horizontal toward a downward facing blown film coextrusion die using a first extruder;
- extruding a second polymer stream upward at a second angle from horizontal toward the downward facing blown film coextrusion die using a second extruder;
- and
- extruding a third polymer stream upward at a third angle from horizontal toward the downward facing blown film coextrusion die using a third extruder;
- extruding a fourth polymer stream upward at a fourth angle from horizontal toward the downward facing blown film coextrusion die using a fourth extruder
- feeding the first, second, third and fourth polymer streams into the downward facing blown film coextrusion die;
- and
- coextruding the first, second, third and fourth polymer streams using the downward facing blown film coextrusion die as a downward facing bubble to make the multilayer coextruded blown film;
- wherein the first, second, third and fourth angles are each about 30 to about 60 degrees from horizontal and the method further comprises the step of at least one of a) raising the first, second, third and fourth extruders and the blown film coextrusion die to increase a length of the bubble and b) lowering the first, second, third and fourth extruders and the blown film coextrusion die to decrease a length of the bubble.
A method of making a multilayer coextruded blown film, comprising the steps of:
- extruding a first polymer stream upward at a first angle from horizontal toward a blown film coextrusion die using a first extruder that is connected to an inlet of the blown film coextrusion die;
- extruding a second polymer stream upward at a second angle from horizontal toward the blown film coextrusion die using a second extruder that is connected to an inlet of the blown film coextrusion die;
- and
- extruding a third polymer stream upward at a third angle from horizontal toward the blown film coextrusion die using a third extruder that is connected to an inlet of the blown film coextrusion die;
- feeding the first, second and third polymer streams into the blown film coextrusion die;
- and
- coextruding the first, second and third polymer streams using the blown film coextrusion die as a downward facing bubble to make the multilayer coextruded blown film;
- wherein the method further comprises the step of at least one of a) raising the first, second and third extruders and the blown film coextrusion die in tandem to increase a length of the bubble and b) lowering the first, second and third extruders and the blown film coextrusion die in tandem to decrease a length of the bubble.
Dependencies are inferred from the claim text.