US3782873A
Expired / Lapsed
US
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Thickness control apparatus for polymeric film structures
Assignee: EIDP Inc
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Filing: 1970-12-08
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Granted: 1974-01-01
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Expires: 1990-12-08
Abstract
Abstract An apparatus is provided for manufacturing film structures of organic thermoplastic polymeric materials of improved thickness uniformity across the width thereof. Briefly, the method comprises measuring the thickness of a film structure at any location across the width thereof before stretching, measuring the thickness of said film structure at any location across the width thereof after stretching, computing the cumulative mass values of said film structure across the width thereof before and after stretching, and adjusting the thickness of said film structure at any point across the width thereof before stretching responsive to deviation from a preselected value in thickness of said film structure after stretching corresponding to the cumulative mass value of said film struture before and after stretching.
Inventors
- 👤 F Lynnknowles
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:53
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C48/00; B29C48/25; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92114; B29C2948/92133; B29C2948/92152; B29C2948/92504; B29C2948/92609; B29C2948/92628; B29C2948/92647; B29C2948/92819; B29C2948/92923; B29C48/03; B29C48/07; B29C48/08
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
226 words
Apparatus for manufacturing film structures of organic thermoplastic polymeric material comprising in combination extruding means for continuously extruding a self-supporting film structure of organic thermoplastic polymeric material onto cooling means adjacent said extruding means for cooling said film structure; stretching means adapted to stretch said film structure in at least one of its two planar directions of length and width; first film thickness measuring means intermediate said cooling means and said stretching means for measuring the thickness of said film across the width thereof and adapted to transmit a first signal that is a function of the thickness of said film structure at any point across the width of said film; second film thickness measuring means adjacent said stretching means for measuring the thickness of said film across the width thereof after stretching and adapted to transmit a second signal that is a function of the thickness of said film structure at any point across the width thereof after stretching; and means adapted to receive and accumulate said first signal and said second signal and compute the cumulative values thereof and transmit a deviation signal of a magnitude based upon a comparison of said second signal with a reference standard to adjustment means responsive to said deviation signal adapted to adjust the thickness of said film structure at any location across the width thereof before stretching.
Claim 2
Dependent Claim
226 words
Apparatus for manufacturing film structures of organic thermoplastic polymeric material comprising in combination extruding means for continuously extruding a self-supporting film structure of organic thermoplastic polymeric material onto cooling means adjacent said extruding means for cooling said film structure; stretching means adapted to stretch said film structure in at least one of its two planar directions of length and width; first film thickness measuring means intermediate said cooling means and said stretching means for measuring the thickness of said film across the width thereof and adapted to transmit a first signal that is a function of the thickness of said film structure at any point across the width of said film; second film thickness measuring means adjacent said stretching means for measuring the thickness of said film across the width thereof after stretching and adapted to transmit a second signal that is a function of the thickness of said film structure at any point across the width thereof after stretching; and means adapted to receive and accumulate said first signal and said second signal and compute the cumulative values thereof and transmit a deviation signal of a magnitude based upon a comparison of said second signal with a reference standard to adjustment means responsive to said deviation signal adapted to adjust the thickness of said film structure at any location across the width thereof before stretching.
Claim 3
Dependent Claim
30 words
The apparatus of claim 1 wherein said adjustment means comprise heating means disposed intermediate said cooling means and said stretching means adapted to heat selected portions of said film structure.
Claim 4
Dependent Claim
26 words
The apparatus of claim 1 wherein said adjustment means comprise orifice lip controllers adapted to adjust the opening of the orifice lips of said extruding means.
Claim 5
Dependent Claim
162 words
Apparatus for controlling the thickness of a film structure of organic thermoplastic polymeric material that is stretched in at least one of its two planar directions of length and width which comprises: means for measuring the film thickness in each of a plurality of hypothetical lanes across the width of the film before and after stretching; means for determining any average deviation of the film thickness in each lane after stretching from a preselected value; means for determining the cumulative mass value to a deviating lane by integrating the measured thickness values from one edge of the film to the lane; means for determining the location of the lane in the unstretched film which has a cumulative mass value corresponding to that of the deviating lane in the stretched film; and means for making the appropriate adjustment in a thickness controlling means which affects the determined lane in the unstretched film in order to bring the deviating lane to the desired value.
Claim 6
Dependent Claim
162 words
Apparatus for controlling the thickness of a film structure of organic thermoplastic polymeric material that is stretched in at least one of its two planar directions of length and width which comprises: means for measuring the film thickness in each of a plurality of hypothetical lanes across the width of the film before and after stretching; means for determining any average deviation of the film thickness in each lane after stretching from a preselected value; means for determining the cumulative mass value to a deviating lane by integrating the measured thickness values from one edge of the film to the lane; means for determining the location of the lane in the unstretched film which has a cumulative mass value corresponding to that of the deviating lane in the stretched film; and means for making the appropriate adjustment in a thickness controlling means which affects the determined lane in the unstretched film in order to bring the deviating lane to the desired value.
Claim 7
Dependent Claim
31 words
The apparatus of claim 4 including: means for transmitting a deviation signal that is a function of the film thickness deviation for making the appropriate adjustment in the thickness controlling means.
Claim 8
Dependent Claim
40 words
The apparatus of claim 4 wherein the thickness of said film structure at any point across the width thereof before stretching is adjusted by varying the opening of orifice lips in an extruding die from which said film structure issues.
Claim 9
Dependent Claim
32 words
The apparatus of claim 4 wherein the thickness of said film structure at any point across the width thereof before stretching is adjusted by heating said film structure and thereafter stretching it.
Claim 10
Dependent Claim
223 words
Apparatus for controlling the thickness of a film structure of organic thermoplastic polymeric material that is stretched in at least one of its planar directions of length and width which comprises: means for sensing the thickness of said film structure at any location across the width thereof before stretching; means for transmitting first control signals that are a function of the thickness of said film structure at any point across the width thereof before stretching; means for sensing the thickness of said film structure at any location across the width thereof after stretching; means for transmitting second control signals that are a function of the thickness of said film structure at any point across the width thereof after stretching; means for accumulating said first control signals and said second control signals for computing cumulative mass values of said film structure across the width thereof before and after stretching; means for determining any average deviation of the film structure thickness at each location after stretching from a preselected value; means for determining the cumulative mass value to a deviating location by integrating the measured thickness values from one edge of the film structure to the location; and means for transmitting a deviation signal to a thickness control means for adjusting the thickness at any point across the width of said film structure before stretching.
Claim 11
Dependent Claim
223 words
Apparatus for controlling the thickness of a film structure of organic thermoplastic polymeric material that is stretched in at least one of its planar directions of length and width which comprises: means for sensing the thickness of said film structure at any location across the width thereof before stretching; means for transmitting first control signals that are a function of the thickness of said film structure at any point across the width thereof before stretching; means for sensing the thickness of said film structure at any location across the width thereof after stretching; means for transmitting second control signals that are a function of the thickness of said film structure at any point across the width thereof after stretching; means for accumulating said first control signals and said second control signals for computing cumulative mass values of said film structure across the width thereof before and after stretching; means for determining any average deviation of the film structure thickness at each location after stretching from a preselected value; means for determining the cumulative mass value to a deviating location by integrating the measured thickness values from one edge of the film structure to the location; and means for transmitting a deviation signal to a thickness control means for adjusting the thickness at any point across the width of said film structure before stretching.
Claim 12
Dependent Claim
40 words
The apparatus of claim 8 wherein the thickness of said film structure at any point across the width thereof before stretching is adjusted by varying the opening of orifice lips in an extruding die from which said film structure issues.
Claim 13
Dependent Claim
32 words
The apparatus of claim 8 wherein the thickness of said film structure at any point across the width thereof before stretching is adjusted by heating said film structure and thereafter stretching it.
Claim 14
Dependent Claim
180 words
Apparatus for manufacturing a film structure of organic thermoplastic polymeric material of improved thickness uniformity across the width thereof which comprises: means for measuring the thickness of the film structure at a plurality of locations across the width thereof between a quench drum and a heating device and before it is stretched; means for measuring the thickness thereof between a stretching device and A film roll and after it is stretched; means for determining any average deviation of the film structure thickness at each location after stretching from a preselected value; means for determining the cumulative mass value to a deviating location by integrating the measured thickness values from one edge of the film structure to the location; means for determining the location in the unstretched film structure which has a cumulative mass value corresponding to that of the deviating location in the stretched film structure; and means for making the appropriate adjustment in a film structure thickness controlling means which affects the determined location in the unstretched film in order to bring the deviating location to the desired value.
Claim 15
Dependent Claim
180 words
Apparatus for manufacturing a film structure of organic thermoplastic polymeric material of improved thickness uniformity across the width thereof which comprises: means for measuring the thickness of the film structure at a plurality of locations across the width thereof between a quench drum and a heating device and before it is stretched; means for measuring the thickness thereof between a stretching device and A film roll and after it is stretched; means for determining any average deviation of the film structure thickness at each location after stretching from a preselected value; means for determining the cumulative mass value to a deviating location by integrating the measured thickness values from one edge of the film structure to the location; means for determining the location in the unstretched film structure which has a cumulative mass value corresponding to that of the deviating location in the stretched film structure; and means for making the appropriate adjustment in a film structure thickness controlling means which affects the determined location in the unstretched film in order to bring the deviating location to the desired value.
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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) | 1976-12-31 | 1977-07-02 | 1978-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-31 | 1981-07-02 | 1982-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-31 | 1985-07-02 | 1986-01-01 | $7700.00 | Window Closed / Lapsed |