US3887672A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of saddle-shaped discs from expandable styrene polymers
Assignee: BASF SE
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Filing: 1972-11-02
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Granted: 1975-06-03
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Expires: 1992-11-02
Abstract
Abstract Manufacture of expandable styrene polymers which on expansion provide oval saddle-shaped discs suitable for use as bulk cushioning material. In the process, cylindrical extrudates of expandable styrene polymers are deformed at form 70* to 90*C by means of rollers to form strands of oval cross-section, which strands are then sliced to form discs by cutting in the direction of the short axis of said oval cross-section.
Inventors
- 👤 Erhard Stahnecker
- 👤 Georg Ruppert
- 👤 Rolf Moeller
- 👤 Rupert Schick
- 👤 Ludwig Zuern
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 11:22
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/56; B29C44/5627; B29C44/5636; B29C48/00; B29C48/001; B29C48/0022; B29C2793/00; B29C2793/0027; B29C48/03; B29C48/04; B29C59/00; B29C59/02; B29C59/04; B29K; B29K2025/00; B29K2105/00; B29K2105/04; B29L; B29L2031/00; B29L2031/712; B29L2031/7138; B29L2031/714; B29L2031/772; Y; Y10; Y10S; Y10S206/00; Y10S206/814; Y10S261/00; Y10S261/72; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
159 words
A PROCESS FOR THE MANUFACTURE OF SADDLE-SHAPED DISCS FROM STYRENE POLYMERS WHICH COMPRISES: PASSING MOLTEN STYRENE POLYMERS CONTAINING AT LEAST 50% BY WEIGHT OF POLYMERIZED STYRENE UNITS THROUGH AN EXTRUDER AT MELT TEMPERATURES OF FROM 90* TO 150*C TO FORM CYCLINDRICAL EXTRUDERS CONTAINING AN EXPANDING AGENT; PASSING SAID EXTRUDATES THROUGH A COOLANT AT SUCH A RATE THAT NO EXPANSION TAKES PLACE, THE RESIDENCE TIME IN THE COOLING BATH BEING SUCH THAT THE EXTRUDATE REMAINS INTERNALLY PLASTIC; SHAPING SAID EXTRUDATES BY PASSING THE EXTRUDATES AT TEMPERATURES OF FROM 70* TO 90*C BETWEEN ROLLERS TO FORM STRANDS HAVING AN OVAL CROSS-SECTION; SLICING SAID SHAPED STRANDS IN THE DIRECTION OF THE SHORT AXIS OF SAID OVAL CROSS-SECTION TO FORM DISCS OF WHICH THE RATIO OF THICKNESS TO SHORT AXIS IS FROM 1:5 TO 1:10, THETHICKNESS BEING MEASURED IN THE MACHINE DIRECTION OF THE EXTRUDATE; AND THEREAFTER FOAMING SAID DISCS TO FORM PARTICLES HAVING A BULK DENSITY OF FROM 4 TO 15 G/L.
Claim 2
Dependent Claim
159 words
A PROCESS FOR THE MANUFACTURE OF SADDLE-SHAPED DISCS FROM STYRENE POLYMERS WHICH COMPRISES: PASSING MOLTEN STYRENE POLYMERS CONTAINING AT LEAST 50% BY WEIGHT OF POLYMERIZED STYRENE UNITS THROUGH AN EXTRUDER AT MELT TEMPERATURES OF FROM 90* TO 150*C TO FORM CYCLINDRICAL EXTRUDERS CONTAINING AN EXPANDING AGENT; PASSING SAID EXTRUDATES THROUGH A COOLANT AT SUCH A RATE THAT NO EXPANSION TAKES PLACE, THE RESIDENCE TIME IN THE COOLING BATH BEING SUCH THAT THE EXTRUDATE REMAINS INTERNALLY PLASTIC; SHAPING SAID EXTRUDATES BY PASSING THE EXTRUDATES AT TEMPERATURES OF FROM 70* TO 90*C BETWEEN ROLLERS TO FORM STRANDS HAVING AN OVAL CROSS-SECTION; SLICING SAID SHAPED STRANDS IN THE DIRECTION OF THE SHORT AXIS OF SAID OVAL CROSS-SECTION TO FORM DISCS OF WHICH THE RATIO OF THICKNESS TO SHORT AXIS IS FROM 1:5 TO 1:10, THETHICKNESS BEING MEASURED IN THE MACHINE DIRECTION OF THE EXTRUDATE; AND THEREAFTER FOAMING SAID DISCS TO FORM PARTICLES HAVING A BULK DENSITY OF FROM 4 TO 15 G/L.
References Cited (Backward Citations)
US2945261A
Cited
US3033806A
Cited
US3066382A
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US3296661A
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US3188264A
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US3400037A
Cited
US3723237A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |