Patent US3857665A successfully refreshed from Google Patents.
US3857665A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polystyrene extruder die plate
Assignee: Braskem America Inc
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Filing: 1973-04-11
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Granted: 1974-12-31
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Expires: 1993-04-11
Abstract
Abstract Die plates for thermoplastic resin extruders are provided which have radial and annular ribs to reinforce the plate against deflection and distribute flowing polymer, radially disposed heating channels in the plate, and/or heating channels formed with metal inserts for a portion thereof.
Inventors
- 👤 F Kennedy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:03
CPC Classifications
B; B29; B29B; B29B9/00; B29B9/02; B29B9/06; B29B9/065; B29B7/00; B29B7/30; B29B7/58; B29B7/582; B29B7/80; B29B7/82; B29B7/826; B29C; B29C48/00; B29C48/03; B29C48/05; B29C48/25; B29C48/30; B29C48/345; B29C48/78; B29C48/86; B29C48/865; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92504; B29C2948/92704; B29C2948/92819; B29C2948/92857; B29C2948/92904; B29C48/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
133 words
An improved die plate for the continuous extrusion of molten thermoplastic resin, having a downstream face, an upstream face and connecting means for underwater die face pelletization devices, characterized by the downstream face being the downstream edge of a relatively thin metal web, said web containing a plurality of orifices for extrusion of thermoplastic resin into pellet form, a means integral with said web to resist deflection of said web, said means including: radial ribs extending from the upstream side of said web to the upstream face of said die plate, and annular ribs extending from the upstream side of said web to a position intermediate of said web and said upstream face of said die plate, said annular ribs intersecting said radial ribs, and said orifices being disposed between said annular ribs.
Claim 2
Dependent Claim
133 words
An improved die plate for the continuous extrusion of molten thermoplastic resin, having a downstream face, an upstream face and connecting means for underwater die face pelletization devices, characterized by the downstream face being the downstream edge of a relatively thin metal web, said web containing a plurality of orifices for extrusion of thermoplastic resin into pellet form, a means integral with said web to resist deflection of said web, said means including: radial ribs extending from the upstream side of said web to the upstream face of said die plate, and annular ribs extending from the upstream side of said web to a position intermediate of said web and said upstream face of said die plate, said annular ribs intersecting said radial ribs, and said orifices being disposed between said annular ribs.
Claim 3
Dependent Claim
28 words
The die plate of claim 1 having a central bore from said upstream face to said downstream face as the connecting means for underwater die face pelletization devices.
Claim 4
Dependent Claim
12 words
The die plate of claim 1 wherein said annular ribs are chords.
Claim 5
Dependent Claim
12 words
The die plate of claim 1 wherein said annular ribs are arcs.
Claim 6
Dependent Claim
20 words
The die plate of claim 1 wherein the leading edges of said ribs are streamlined to facilitate flow of plastic.
Claim 7
Dependent Claim
38 words
The die plate of claim 1 wherein said orifices are disposed in concentric circles about the central axis of said die plate and where no more than two rows of said orifices are disposed between adjacent annular ribs.
Claim 8
Dependent Claim
39 words
The die plate of claim 1 wherein said radial ribs contain transfer lines for heat exchange media flowing from an external source to said orifices, and where said annular ribs contain heaT exchange passageways for heating of said orifices.
Claim 9
Dependent Claim
23 words
The die plate of claim 7 wherein a radial rib provides heat exchange media to intersecting heat exchange passageways in said annular ribs.
Claim 10
Dependent Claim
37 words
The die plate of claim 1 wherein said annular ribs and said radial ribs are disposed to form compartments for receiving and distributing flowing plastic at a uniform flow rate across the area of the die plate.
Claim 11
Dependent Claim
68 words
The die plate of claim 7 wherein said heat exchange passageways have a portion of their cross-section integral with said web and have the remainder of said cross-section closed by a separate metallic member, said separate metallic member being oriented toward the downstream side of said web and being fastened to said web by a layer of weld metal disposed on the downstream side of said metallic member.
Claim 12
Dependent Claim
27 words
The die plate of claim 1 in combination with a thermoplastic resin extrusion machine adapted for extrusion of polystyrene wherein said die plate is disposed vertically downward.
References Cited (Backward Citations)
US3230582A
Cited
US3461495A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |