US4329052A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for the measurement of cell size in a foam structure
Assignee: Pactiv LLC
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Filing: 1979-03-28
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Granted: 1982-05-11
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Expires: 1999-03-28
Abstract
Abstract A method and apparatus are provided to continuously monitor and measure the average size of individual foam cells contained in a foam structure, such as polystyrene foam for example, as it is being fabricated. Such an arrangement permits the prompt adjustment of process conditions and/or the concentration of nucleating agents in the extrusion system in the event the size of the individual cells in the foam structure varies from a preselected standard.
Inventors
- 👤 Edward A. Colombo
- 👤 James T. Tsai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:09
CPC Classifications
B; B29; B29C; B29C44/00; B29C44/34; B29C44/60; G; G01; G01N; G01N15/00; G01N15/02; G01N15/0205
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
101 words
A continuous method for controlling the average individual cell size of a moving plastic foam structure continuously emerging from a production extrusion source which comprises: illuminating a portion of the surface of said foam structure; receiving and collecting the light which is transsmitted through said foam with a detector photocell; continuously electrically measuring the amount of light energy received by said photocell whereby said light energy measurement is correlated to average cell size; and controlling production process parameters to obtain a foam structure of predetermined average cell size in response to a predetermined amount of light energy received by said photocell.
Claim 2
Dependent Claim
101 words
A continuous method for controlling the average individual cell size of a moving plastic foam structure continuously emerging from a production extrusion source which comprises: illuminating a portion of the surface of said foam structure; receiving and collecting the light which is transsmitted through said foam with a detector photocell; continuously electrically measuring the amount of light energy received by said photocell whereby said light energy measurement is correlated to average cell size; and controlling production process parameters to obtain a foam structure of predetermined average cell size in response to a predetermined amount of light energy received by said photocell.
Claim 3
Independent Claim
95 words
An apparatus for continuously controlling the average individual cell size of a moving plastic foam structure emerging from a production extrusion source which comprises: a light source; means for moving said foam structure past said light source; means for receiving and transmitting light which is transmitted through said foam structure to a photocell device; means for measuring the electrical energy output of said photocell device for direct correlation to average cell size; and means responding to said electrical energy output to control production process parameters to obtain a foam structure of predetermined average cell size.
Claim 4
Independent Claim
95 words
An apparatus for continuously controlling the average individual cell size of a moving plastic foam structure emerging from a production extrusion source which comprises: a light source; means for moving said foam structure past said light source; means for receiving and transmitting light which is transmitted through said foam structure to a photocell device; means for measuring the electrical energy output of said photocell device for direct correlation to average cell size; and means responding to said electrical energy output to control production process parameters to obtain a foam structure of predetermined average cell size.
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) | 1985-05-10 | 1985-11-09 | 1986-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-05-10 | 1989-11-09 | 1990-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-05-10 | 1993-11-09 | 1994-05-11 | $7700.00 | Window Closed / Lapsed |