US3685804A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mixing apparatus and method
Assignee: Sterling Extruder Corp
•
Filing: 1970-10-26
•
Granted: 1972-08-22
•
Expires: 1990-10-26
Abstract
Abstract A mixing apparatus and method for mixing materials, such as plastics, comprising an outer stator member and an inner rotor member mounted for rotation and axial movement therein. The apparatus has a charging end and an exit end; and both the rotor and stator have cooperating screw threads along their lengths for feeding material through the apparatus. An extensive mixing section, defined by the cooperating threads of the rotor and stator, extends from the charging end toward the exit end of the apparatus. In this section, the cumulative groove depth of the rotor and stator is progressively smaller at locations nearer the exit end of the apparatus. An intensive mixing section is provided at the exit end of the apparatus for further mixing the material after it passes through the extensive mixing section. In the extensive mixing section, the interface defined between the threads on the rotor and stator forms a cylindrical surface while the interface defined between the threads in the intensive mixing section forms a conically tapered surface. Axial relative adjustment of the rotor and stator changes the clearance between the rotor and stator in the intensive mixing section to vary the extent of mixing but such adjustment does not have any appreciable effect on the mixing in the extensive mixing section of the apparatus.
Inventors
- 👤 Manfred D Stansfield
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:37
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/76; B29C48/765; B29C48/766; B29C48/767; B29B; B29B7/00; B29B7/30; B29B7/34; B29B7/38; B29B7/40; B29B7/42; B29B7/421; B29B7/428; B29B7/429; B29B7/58; B29B7/60; B29B7/603; B29B7/80; B29B7/86; B29C48/395; B29C48/397; B29C48/505; B29C48/52; B29C48/56; B29C48/68; B29C48/685; B29C48/686; B29C48/687; B29C48/688; B29C48/03
Claims Analysis
Total Claims: 59
Claim 1
Independent Claim
203 words
In a mixing apparatus having an inner screw member and a cooperating relatively rotatable outer screw member disposed thereabout, a material charging end and an exit end, the improvement wherein: a. said inner and outer screw members each have an extensive mixing section extending from the charging end of the machine toward the exit end thereof with at least one helical thread defined by land and adjacent groove convolutions, 1. said lands being narrower than the grooves with the Lands of said inner screw member located on a first surface and the lands of said outer screw member located on a second surface disposed in radially opposite cooperating alignment with said first surface, 2. the depth of opposite grooves in the inner and outer screw members varying at least once, one from a minimum to a maximum and the other from a maximum to a minimum along at least a portion of said extensive mixing section, to pass the material from one member to the other as it is fed axially through said machine, and 3. the cumulative depth of the opposite grooves being progressively smaller at locations nearer the exit end of the machine along said portion of the extensive mixing section.
Claim 2
Dependent Claim
203 words
In a mixing apparatus having an inner screw member and a cooperating relatively rotatable outer screw member disposed thereabout, a material charging end and an exit end, the improvement wherein: a. said inner and outer screw members each have an extensive mixing section extending from the charging end of the machine toward the exit end thereof with at least one helical thread defined by land and adjacent groove convolutions, 1. said lands being narrower than the grooves with the Lands of said inner screw member located on a first surface and the lands of said outer screw member located on a second surface disposed in radially opposite cooperating alignment with said first surface, 2. the depth of opposite grooves in the inner and outer screw members varying at least once, one from a minimum to a maximum and the other from a maximum to a minimum along at least a portion of said extensive mixing section, to pass the material from one member to the other as it is fed axially through said machine, and 3. the cumulative depth of the opposite grooves being progressively smaller at locations nearer the exit end of the machine along said portion of the extensive mixing section.
Claim 3
Dependent Claim
61 words
the depth of opposite grooves in the inner and outer screw members varying at least once, one from a minimum to a maximum and the other from a maximum to a minimum along at least a portion of said extensive mixing section, to pass the material from one member to the other as it is fed axially through said machine, and
Claim 4
Dependent Claim
61 words
the depth of opposite grooves in the inner and outer screw members varying at least once, one from a minimum to a maximum and the other from a maximum to a minimum along at least a portion of said extensive mixing section, to pass the material from one member to the other as it is fed axially through said machine, and
Claim 5
Dependent Claim
39 words
the depth of opposite grooves in the inner and outer screw members varying, one from a minimum to a maximum and the other from a maximum to a minimum along at least a portion of said intensive mixing section.
Claim 6
Dependent Claim
39 words
the depth of opposite grooves in the inner and outer screw members varying, one from a minimum to a maximum and the other from a maximum to a minimum along at least a portion of said intensive mixing section.
Claim 7
Dependent Claim
62 words
The improvement in a mixing apparatus according to claim 1 wherein: a. said inner and outer screw members each have an intensive mixing section at the exit end of the machine with a major part of the opposite peripheries of said inner and outer screw members located in third and fourth surfaces, respectively, disposed in radially opposite cooperating alignment with each other.
Claim 8
Dependent Claim
28 words
The improvement in a mixing apparatus according to claim 2 wherein: a. said first and second surfaces are cylindrical; and b. said third and fourth surfaces are tapered.
Claim 9
Dependent Claim
27 words
the cumulative depth of the opposite grooves being progressively smaller at locations nearer the exit end of the machine along said portion of the extensive mixing section.
Claim 10
Dependent Claim
27 words
the cumulative depth of the opposite grooves being progressively smaller at locations nearer the exit end of the machine along said portion of the extensive mixing section.
Claim 11
Dependent Claim
27 words
The improvement in a mixing apparatus according to claim 3 wherein: a. said third and fourth surfaces are conically tapered toward the exit end of said machine.
Claim 12
Dependent Claim
35 words
The improvement in a mixing apparatus according to claim 4 wherein: a. said inner and outer screw members are movable axially relative to each other to vary the clearance between said third and fourth surfaces.
Claim 13
Dependent Claim
37 words
The improvement in a mixing apparatus according to claim 5 wherein: a. the inner and outer screw members in said intensive mixing section each have at least one helical thread defined by land and adjacent groove convolutions,
Claim 14
Dependent Claim
58 words
The improvement in a mixing apparatus according to claim 5 wherein: a. the opposite groove depths in said extensive mixing section vary a plurality of times between minimum and maximum to pass material at least once from the inner member to the outer member and back to the inner member as it is fed axially of said machine.
Claim 15
Dependent Claim
46 words
The improvement in a mixing apparatus according to claim 5 wherein: a. the cumulative groove depth of said inner and outer screw members immediately upstream of said intensive mixing section is equal to or greater than the maximum clearance obtainable between said third and fourth surfaces.
Claim 16
Dependent Claim
79 words
The improvement in a mixing apparatus according to claim 5 wherein: a. said third and fourth surfaces are movable relative to each other to vary the shear rates obtainable in the intensive mixing section over a predetermined range; and b. the cumulative groove depth of said inner and outer screw members immediately upstream of said intensive mixing section is of value providing a shear rate thereat about equal to the shear rate at the lower end of said range.
Claim 17
Dependent Claim
40 words
The improvement in a mixing apparatus according to claim 9 further including: a. cooling means disposed immediately upstream of said intensive mixing section for cooling the material to increase its viscosity and the shear work to which it is subjected.
Claim 18
Dependent Claim
44 words
The improvement in a mixing apparatus according to claim 5 wherein: a. the extensive mixing section includes a venting section intermediate its ends with the cumulative depth of the grooves of the inner and outer screw members at said venting station being substantially uniform.
Claim 19
Dependent Claim
50 words
The improvement in a mixing apparatus according to claim 11 wherein: a. the outEr member at said venting station has a smooth inner surface; b. the grooves in the inner member at said venting section are at a maximum for partial filling with the material being fed through the machine.
Claim 20
Dependent Claim
53 words
The improvement in a mixing apparatus according to claim 11 wherein: a. the depth of the opposite grooves in the inner and outer screw members on axially opposite sides of said venting section vary at least once, one from a minimum to a maximum and the other from a maximum to a minimum.
Claim 21
Dependent Claim
34 words
The improvement in a mixing apparatus according to claim 13 wherein: a. the cumulative depth of the opposite grooves upstream of said venting section is continuously progressively smaller at locations nearer said venting station.
Claim 22
Dependent Claim
35 words
The improvement in a mixing apparatus according to claim 14 wherein: a. the cumulative depth of the opposite grooves disposed immediately downstream of the venting section is progressively smaller at locations nearer said exit end.
Claim 23
Dependent Claim
67 words
The improvement in a mixing apparatus according to claim 15 wherein: a. the opposite groove depths upstream of said venting section vary a plurality of times between minimum and maximum to pass material at least once from the inner member to the outer member and back to the inner member with the material being in said inner member as it is fed axially into said venting section.
Claim 24
Dependent Claim
32 words
The improvement in a mixing apparatus according to claim 16 wherein: a. the groove depth of the inner screw member is at a maximum at said venting section and immediately downstream thereof.
Claim 25
Dependent Claim
48 words
The improvement in a mixing apparatus according to claim 16 wherein: a. the groove depth of the inner screw member is at a maximum at the charging end of the machine; and b. the outer member at the charging end of the machine has a smooth inner surface.
Claim 26
Dependent Claim
41 words
The improvement in a mixing apparatus according to claim 2 wherein: a. said inner and outer screw members in said intensive mixing section are movable toward and away from each other to vary the clearance between said third and fourth surfaces.
Claim 27
Independent Claim
66 words
The method of mixing material including at least one polymeric material comprising the steps of: a. heating said material to a temperature sufficient to effect melting thereof; b. removing heat from the material after melting thereof to preclude an appreciable decrease in its viscosity and thereby optimize the shear work to which it is subjected; and c. thereafter intensively mixing the material with a shearing action.
Claim 28
Independent Claim
66 words
The method of mixing material including at least one polymeric material comprising the steps of: a. heating said material to a temperature sufficient to effect melting thereof; b. removing heat from the material after melting thereof to preclude an appreciable decrease in its viscosity and thereby optimize the shear work to which it is subjected; and c. thereafter intensively mixing the material with a shearing action.
Claim 29
Dependent Claim
24 words
The method according to claim 20 wherein: a. said material is in a dry, solid, state as it is heated to effect melting thereof.
Claim 30
Dependent Claim
32 words
The method according to claim 20 wherein: a. said polymeric material includes a first part consisting of a first polymeric material and a second part consisting of a second different polymeric material.
Claim 31
Dependent Claim
19 words
The method according to claim 20 wherein: a. said material includes a polymeric material and a non-polymeric additive material.
Claim 32
Dependent Claim
18 words
The method according to claim 20 wherein: a. said material includes a polyvinyl chloride and a plasticizer therefor.
Claim 33
Dependent Claim
17 words
The method according to claim 20 wherein: a. said polymeric material is a high density linear polyethylene.
Claim 34
Dependent Claim
42 words
The method according to claim 20 wherein: a. said material includes a first part consisting of a first polymeric material and a second part defining a masterbatch consisting of an additional amount of said first polymeric material with predispersed additive material therein.
Claim 35
Dependent Claim
18 words
The method according to claim 26 wherein: a. said additive material is carbon black or a color pigment.
Claim 36
Dependent Claim
58 words
The method according to claim 20 wherein: a. said material is a shear sensitive material which undergoes a physical or chemical change when subjected to combined shear rates and temperatures of predetermined values; and b. the combined shear rates and temperatures to which said material is subjected during thE entire mixing thereof is kept below said predetermined values.
Claim 37
Dependent Claim
16 words
The method according to claim 28 wherein: a. said material includes a polyethylene and dicumyl peroxide.
Claim 38
Dependent Claim
14 words
The method according to claim 28 wherein: a. said material includes precharged, expandable polypropylene.
Claim 39
Dependent Claim
16 words
The method according to claim 28 wherein: a. said material includes polypropylene and chopped glass fibers.
Claim 40
Dependent Claim
14 words
The method according to claim 28 wherein: a. said material is rigid polyvinyl chloride.
Claim 41
Dependent Claim
22 words
The method according to claim 20 including the step of: a. extensively mixing said material to in part create said initial heating.
Claim 42
Dependent Claim
25 words
The method according to claim 33 including the step of: a. continuously moving said material along a predetermined path during said extensive and intensive mixing.
Claim 43
Dependent Claim
32 words
The method according to claim 34 including the step of: a. progressively increasing the shear rate to which the material is subjected during at least the last part of said extensive mixing.
Claim 44
Dependent Claim
40 words
The method according to claim 35 wherein: a. the shear rate to which the material is subjected during said intensive mixing is no less than the shear rate to which the material is subjected immediately prior to said intensive mixing.
Claim 45
Dependent Claim
29 words
The method according to claim 36 wherein: a. the shear rate to which the material is subjected during said intensive mixing is between about 50 to 5,000 reciprocal seconds.
Claim 46
Independent Claim
63 words
The method of improving the molecular weight distribution of a polymeric material comprising the steps of: a. heating said material to a temperature sufficient to effect melting thereof; b. decreasing the temperature of the material after melting thereof to increase its viscosity and the shear work to which it is subjected; and c. thereafter intensively mixing the material at a high shear rate.
Claim 47
Independent Claim
63 words
The method of improving the molecular weight distribution of a polymeric material comprising the steps of: a. heating said material to a temperature sufficient to effect melting thereof; b. decreasing the temperature of the material after melting thereof to increase its viscosity and the shear work to which it is subjected; and c. thereafter intensively mixing the material at a high shear rate.
Claim 48
Independent Claim
87 words
The method of mixing material including at least one polymeric material comprising the steps of: a. extensively mixing said material at a temperature sufficient to effect melting thereof; b. progressively increasing to a predetermined value the shear rate to which the material is subjected during at least the last part of said extensive mixing; and c. intensively mixing said material immediately after the extensive mixing thereof and at the same time subjecting the material to a shear rate about equal to or greater than said predetermined value.
Claim 49
Independent Claim
87 words
The method of mixing material including at least one polymeric material comprising the steps of: a. extensively mixing said material at a temperature sufficient to effect melting thereof; b. progressively increasing to a predetermined value the shear rate to which the material is subjected during at least the last part of said extensive mixing; and c. intensively mixing said material immediately after the extensive mixing thereof and at the same time subjecting the material to a shear rate about equal to or greater than said predetermined value.
Claim 50
Dependent Claim
58 words
The method according to claim 39 wherein: a. the material is subjected to a shear rate increasing to a value from about 30 to about 500 reciprocal seconds during the last portion of said extensive mixing; and b. the material is subjected to a shear rate of between about 50 to 5,000 reciprocal seconds during said intensive mixing.
Claim 51
Dependent Claim
25 words
The method according to claim 40 including the step of: a. continuously moving the material along a predetermined path during said extensive and intensive mixing.
Claim 52
Dependent Claim
31 words
The method according to claim 41 including the step of: a. cooling the material immediately prior to said intensive mixing to increase the shear work to which the material is subjected.
Claim 53
Independent Claim
88 words
The method of improving the molecular weight distribution of a polymeric material comprising the steps of: a. extensively mixing said material at a temperature sufficient to effect melting thereof; b. progressively increasing to a predetermined value the shear rate to which the material is subjected during at least the last part of said extensive mixing; and c. intensively mixing said material immediately after the extensive mixing thereof and at the same time subjecting the material to a shear rate about equal to or greater than said predetermined value.
Claim 54
Independent Claim
88 words
The method of improving the molecular weight distribution of a polymeric material comprising the steps of: a. extensively mixing said material at a temperature sufficient to effect melting thereof; b. progressively increasing to a predetermined value the shear rate to which the material is subjected during at least the last part of said extensive mixing; and c. intensively mixing said material immediately after the extensive mixing thereof and at the same time subjecting the material to a shear rate about equal to or greater than said predetermined value.
Claim 55
Independent Claim
65 words
The method of mixing molten polymeric material and solid or liquid additive material comprising the steps of: a. combining said molten polymeric material and additive material; b. removing heat from the material afteR melting thereof to preclude an appreciable decrease in its viscosity and thereby optimize the shear work to which it is subjected; and c. thereafter intensively mixing the material with a shearing action.
Claim 56
Independent Claim
65 words
The method of mixing molten polymeric material and solid or liquid additive material comprising the steps of: a. combining said molten polymeric material and additive material; b. removing heat from the material afteR melting thereof to preclude an appreciable decrease in its viscosity and thereby optimize the shear work to which it is subjected; and c. thereafter intensively mixing the material with a shearing action.
Claim 57
Dependent Claim
26 words
The method according to claim 44 wherein: a. said polymeric material is rendered molten by a separate processing operation prior to combining with said additive material.
Claim 58
Dependent Claim
35 words
The method of mixing polymeric material and a liquid additive material according to claim 44 wherein: a. said polymeric material is polyvinyl chloride; and b. said additive material is a plasticizer for said polymeric material.
Claim 59
Dependent Claim
22 words
The method according to claim 46 wherein: a. said polymeric material is low density polyethylene; and b. said additive is a wax.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-22 | 1976-02-21 | 1976-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-22 | 1980-02-21 | 1980-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-22 | 1984-02-21 | 1984-08-22 | $7700.00 | Window Closed / Lapsed |