US6468464B1
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US
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Method and apparatus for injection molding parts
Assignee: Adcuram Maschinenbau Holding GmbH
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Filing: 2000-01-25
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Granted: 2002-10-22
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Expires: 2020-01-25
Abstract
Abstract The invention relates to a method and an apparatus for injection molding parts, which comprises a mixture of at least one plastic material and at least one additive in the form of fibrous or powdered fillers or reinforcement materials. The method comprises the following steps: a) plasticizing a mixture of the plastic material with the fillers or reinforcement materials, in a reciprocating screw plasticizing and injection unit, by rotating a plasticizing and injection screw, which is disposed in a preplasticizing cylinder so that it can move rotationally and axially; b) expelling the plasticized mixture of plastic material and filler or reinforcement material by the axial movement of the plasticizing and injection screw, from the reciprocating screw plasticizing and injection unit, into a mixing element; c) homogenizing the mixture of plastic material and filler or reinforcement materials in the mixing element, by a mixer, which is disposed movably in the mixing element and which is driven by a mechanical drive; and d) expelling the homogenized mixture of plastic material and filler or reinforcement materials from the mixing element into an injection molding tool. The combination of a reciprocating screw unit and a “dynamic mixer” achieves a gentle processing especially of long-fiber additives.
Inventors
- 👤 Helmut Eckardt
- 👤 Jurgen Ehritt
- 👤 Karl-Heinz Hill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:08
CPC Classifications
B; B29; B29C; B29C45/00; B29C45/17; B29C45/46; B29C45/58; B29C45/581; B29C45/26; B29C45/27; B29C45/30; B29C45/53; B29C45/54; B29C2045/308; B29C2045/583
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
131 words
A method for injection molding parts, comprising the following steps: a) plasticizing a mixture of a plastic material and fillers or reinforcement materials in a reciprocating screw plasticizing and injection unit, by rotating a plasticizing and injection screw; b) expelling the plasticized mixture of plastic material and filler or reinforcement material by the axial movement of the plasticizing and injection screw, from the reciprocating screw plasticizing and injection unit, into a mixing element; c) homogenizing the mixture of plastic material and filler or reinforcement materials in the mixing element, by a mixer, which is disposed movably in the mixing element and which is driven by a mechanical drive; and d) expelling the homogenized mixture of plastic material and filler or reinforcement materials from the mixing element into an injection molding tool.
Claim 2
Independent Claim
131 words
A method for injection molding parts, comprising the following steps: a) plasticizing a mixture of a plastic material and fillers or reinforcement materials in a reciprocating screw plasticizing and injection unit, by rotating a plasticizing and injection screw; b) expelling the plasticized mixture of plastic material and filler or reinforcement material by the axial movement of the plasticizing and injection screw, from the reciprocating screw plasticizing and injection unit, into a mixing element; c) homogenizing the mixture of plastic material and filler or reinforcement materials in the mixing element, by a mixer, which is disposed movably in the mixing element and which is driven by a mechanical drive; and d) expelling the homogenized mixture of plastic material and filler or reinforcement materials from the mixing element into an injection molding tool.
Claim 3
Dependent Claim
14 words
The method of claim 1 , wherein the fillers include fibrous or powdered fillers.
Claim 4
Dependent Claim
28 words
The method of claim 1 , wherein the reinforcement materials are selected from the group consisting of glass fibers, carbon fibers, wood fibers, chalk, mineral fillers, and talc.
Claim 5
Dependent Claim
27 words
The method of claim 1 , wherein the filler or reinforcement materials are conducted to the already at least partially melted plastic material in a preplasticizing cylinder.
Claim 6
Dependent Claim
72 words
The method of claim 1 , wherein step d) of claim 1 comprises the following component steps: d1) expelling the homogenized mixture of plastic material and filler or reinforcement materials from the mixing element into a melt storage unit; d2) accumulating in the melt storage unit an amount of mixture sufficient to produce a molded part; and d3) expelling the accumulated mixture from the melt storage unit into the injection molding tool.
Claim 7
Dependent Claim
49 words
The method of one of the claim 5 , wherein the mixture of plastic material and filler or reinforcement material, which has been expelled from the mixing element or from the melt storage unit, has admixed to it another plastic component before being injected into the injection molding tool.
Claim 8
Dependent Claim
45 words
The method of claim 1 , the mixing element is filled up by at least two parallel reciprocating screw plasticizing and injection units, of which at least one reciprocating screw plasticizing and injection unit processes a mixture of plastic material and filler or reinforcement material.
Claim 9
Dependent Claim
33 words
The method of claim 1 , wherein the mixer performs a rotational motion at a time-varying rate, according to an rpm profile that is stored in the control of the injection molding machine.
Claim 10
Dependent Claim
27 words
The method of claim 8 , wherein the mixer does not rotate while the mixture is being plasticized in accordance with step a) of claim 1 .
Claim 11
Dependent Claim
26 words
The method of claim 1 , wherein the plasticizing and injection screw is disposed in a preplasticizing cylinder so that it can move rotationally and axially.
Claim 12
Independent Claim
138 words
An apparatus for injection molding parts, comprising: at least one reciprocating screw plasticizing and injection unit for plasticizing a mixture of plastic material and filler or reinforcement materials, by means of a plasticizing and injection screw, the plasticizing and injection unit configured to receive a first source of plastic material to be melted and a second source of filler or reinforcement materials to be partially mixed with at least partially melted plastic material; and an injection molding tool, into which the plasticized mixture of plastic material and filler or reinforcement materials is injected; wherein a mixing element is disposed between the reciprocating screw plasticizing and injection unit and the injection molding tool, the mixing element comprising a mixer which is driven by a mechanical drive, to homogenize the mixture of plastic material and the filler or reinforcement materials.
Claim 13
Independent Claim
138 words
An apparatus for injection molding parts, comprising: at least one reciprocating screw plasticizing and injection unit for plasticizing a mixture of plastic material and filler or reinforcement materials, by means of a plasticizing and injection screw, the plasticizing and injection unit configured to receive a first source of plastic material to be melted and a second source of filler or reinforcement materials to be partially mixed with at least partially melted plastic material; and an injection molding tool, into which the plasticized mixture of plastic material and filler or reinforcement materials is injected; wherein a mixing element is disposed between the reciprocating screw plasticizing and injection unit and the injection molding tool, the mixing element comprising a mixer which is driven by a mechanical drive, to homogenize the mixture of plastic material and the filler or reinforcement materials.
Claim 14
Dependent Claim
22 words
The apparatus of claim 11 , wherein a melt storage unit is disposed between the mixing element and the injection molding tool.
Claim 15
Dependent Claim
24 words
The apparatus of claim 12 , wherein the melt storage unit has means for injecting the accumulated plastic material into the injection molding tool.
Claim 16
Dependent Claim
44 words
The apparatus of claim 11 , wherein at least one other reciprocating screw plasticizing and injection unit is present to admix another plastic component to the mixture of plastic material and filler or reinforcement materials, before their being injected into the injection molding tool.
Claim 17
Dependent Claim
19 words
The apparatus of claim 11 , wherein at least two parallel reciprocating screw plasticizing and injection units are present.
Claim 18
Dependent Claim
20 words
The apparatus of claim 11 , wherein the plasticizing and injection screw is designed as a triple or multi-zone screw.
Claim 19
Dependent Claim
26 words
The apparatus of claim 11 , wherein the plasticizing and injection screw is designed as a screw equipped with a mixing section or a barrier section.
Claim 20
Dependent Claim
18 words
The apparatus of claim 11 , wherein the plasticizing and injection screw is designed as a venting screw.
Claim 21
Dependent Claim
19 words
The apparatus of claim 11 , wherein the infeed device is designed as a transport screw or metering device.
Claim 22
Dependent Claim
26 words
The apparatus of claim 18 , wherein an ejection section of the infeed device is disposed in the venting section of the plasticizing and injection screw.
Claim 23
Dependent Claim
24 words
The apparatus of claim 12 , wherein a check valve, or a seal, is disposed between the mixing element and the melt storage unit.
Claim 24
Dependent Claim
15 words
The apparatus of claim 21 , wherein the check valve is a ball check valve.
Claim 25
Dependent Claim
13 words
The apparatus of claim 21 , wherein the seal is a cross-pin seal.
Claim 26
Dependent Claim
15 words
The apparatus of claim 11 , further comprising a source of fibrous or powdered fillers.
Claim 27
Dependent Claim
22 words
The apparatus of claim 11 , further comprising a source of glass fibers, carbon fibers, wood fibers, chalk, mineral fillers, or talc.
Claim 28
Dependent Claim
26 words
The apparatus of claim 11 , wherein the plasticizing and injection screw is disposed in a preplasticizing cylinder so that it can move rotationally and axially.
Claim 29
Independent Claim
131 words
A method for injection molding parts, comprising: a) plasticizing, in a preplasticizing cylinder, a plastic material to provide at least a partially plasticized material, the plastic being provided to the preplasticizing cylinder by a first source; b) partially mixing in at least one filler or at least one reinforcement material to the at least partially plasticized material in the preplasticizing cylinder by rotating a plasticizing screw to provide a partially mixed mixture, the at least one filler or the at least one reinforcement material being provided to the preplasticizing cylinder by a second source; c) expelling the partially mixed mixture into a mixer; d) substantially mixing the partially mixed mixture to provide a substantially mixed material in the mixer; and e) expelling the substantially mixed material into an injection molding tool.
Claim 30
Independent Claim
131 words
A method for injection molding parts, comprising: a) plasticizing, in a preplasticizing cylinder, a plastic material to provide at least a partially plasticized material, the plastic being provided to the preplasticizing cylinder by a first source; b) partially mixing in at least one filler or at least one reinforcement material to the at least partially plasticized material in the preplasticizing cylinder by rotating a plasticizing screw to provide a partially mixed mixture, the at least one filler or the at least one reinforcement material being provided to the preplasticizing cylinder by a second source; c) expelling the partially mixed mixture into a mixer; d) substantially mixing the partially mixed mixture to provide a substantially mixed material in the mixer; and e) expelling the substantially mixed material into an injection molding tool.
Claim 31
Dependent Claim
64 words
The method of claim 27 , wherein in step a), the at least one filler or the at least one reinforcement material is partially mixed with the at least partially plasticized material at a point along the plasticizing screw that does not mechanically stress the at least one filler or the at least one reinforcement material to the point of being damaged or broken.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2005-10-21 | 2006-04-22 | 2006-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2009-10-21 | 2010-04-22 | 2010-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2013-10-21 | 2014-04-22 | 2014-10-22 | $7700.00 | Window Closed / Lapsed |