Patent US5288168A successfully refreshed from Google Patents.
US5288168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for lining outdoor fluid containment areas to facilitate electrical leak detection
Assignee: GSE Environmental LLC
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Filing: 1992-08-24
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Granted: 1994-02-22
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Expires: 2012-08-24
Abstract
Abstract An improved method and apparatus for waterproofing soil utilizing a flexible plastic sheet for providing a water barrier provides a system for readily detecting the presence of holes in the plastic material. The sheet includes a plastic layer which may be rendered electrically conductive by embedding conductive particles within it. The integrity of the sheet may then be monitored by establishing an electric field across the sheet and monitoring for sparks between the conductive plastic layer and a probe. Reliable and economical testing is possible, even in situation where electrical leak testing was not previously feasible.
Inventors
- 👤 John L. Spencer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:06
CPC Classifications
E; E02; E02D; E02D31/00; G; G01; G01M; G01M3/00; G01M3/40; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/256
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
104 words
A flexible thermoplastic sheet for forming a liner for an outdoor earthen fluid containment area, said thermoplastic sheet having an upper flexible plastic layer and a lower flexible plastic layer adapted to be positioned over said containment area, said lower plastic layer being adapted to sufficiently conduct electricity to enable detection of pin hole leaks in the liner by establishing a potential difference between a probe within the containment area and said lower plastic layer, said sheet being adapted to be maintained for flexure in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 2
Dependent Claim
104 words
A flexible thermoplastic sheet for forming a liner for an outdoor earthen fluid containment area, said thermoplastic sheet having an upper flexible plastic layer and a lower flexible plastic layer adapted to be positioned over said containment area, said lower plastic layer being adapted to sufficiently conduct electricity to enable detection of pin hole leaks in the liner by establishing a potential difference between a probe within the containment area and said lower plastic layer, said sheet being adapted to be maintained for flexure in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 3
Dependent Claim
18 words
The thermoplastic sheet liner as in claim 1, wherein said sheet is constructed of uniform high density polyethylene.
Claim 4
Dependent Claim
17 words
The thermoplastic sheet as in claim 1, wherein said lower layer contains conductive particles embedded within it.
Claim 5
Dependent Claim
19 words
The thermoplastic sheet of claim 3, wherein said lower layer has a volume resistivity of less than 280 ohm-cm.
Claim 6
Dependent Claim
18 words
The thermoplastic sheet of claim 3 having a volume resistivity of between about 10 and about 60 ohm-cm.
Claim 7
Dependent Claim
13 words
The thermoplastic sheet of claim 3, wherein said conductive particles include carbon black.
Claim 8
Dependent Claim
23 words
The thermoplastic sheet of claim 6 wherein said particles are from about 10 to about 25% by weight of the lower plastic layer.
Claim 9
Dependent Claim
18 words
The thermoplastic sheet of claim 3, wherein said sheet is formed of two co-extruded layers of plastic material.
Claim 10
Dependent Claim
13 words
The thermoplastic sheet of claim 1, wherein said layers are of different densities.
Claim 11
Dependent Claim
19 words
The thermoplastic sheet of claim 9, wherein said lower plastic layer is less dense than said upper plastic layer.
Claim 12
Dependent Claim
24 words
The thermoplastic sheet of claim 1, wherein said sheet is constructed of at least two layers, said layers being integrally bonded to one another.
Claim 13
Dependent Claim
12 words
The thermoplastic sheet of claim 11 wherein said layers are co-extruded together.
Claim 14
Dependent Claim
21 words
The thermoplastic sheet of claim 1, wherein said lower plastic layer is less than 20% of the thickness of the liner.
Claim 15
Dependent Claim
23 words
The thermoplastic sheet of claim 13, wherein said lower plastic layer is between about 5 to 10% of the thickness of the liner.
Claim 16
Dependent Claim
18 words
The thermoplastic sheet of claim 1, wherein said lower plastic layer forms an outward surface of said liner.
Claim 17
Dependent Claim
18 words
The thermoplastic sheet of claim 1, wherein said lower plastic layer is formed from low density polyethylene plastic.
Claim 18
Dependent Claim
15 words
The thermoplastic sheet of claim 16, wherein said upper plastic layer is high density polyethylene.
Claim 19
Dependent Claim
17 words
The thermoplastic sheet of claim 1 including a second plastic liner to provide additional protection against leaks.
Claim 20
Independent Claim
108 words
A method for waterproofing an area of soil comprising the steps of: (a) forming a flexible plastic sheet with a region capable of conducting sufficient electricity to enable pin hole leaks to be reliably located by establishing a potential difference between a probe within the containment area and said flexible plastic sheet; (b) covering the soil to be waterproofed with a plurality of said flexible sheets; (c) aligning said sheets in an abutting fashion to create a seam region between adjoining sheets; and (d) permanently joining said abutting sheets to provide a continuous and uninterrupted barrier of plastic facing the area from which liquid is to be barred.
Claim 21
Independent Claim
108 words
A method for waterproofing an area of soil comprising the steps of: (a) forming a flexible plastic sheet with a region capable of conducting sufficient electricity to enable pin hole leaks to be reliably located by establishing a potential difference between a probe within the containment area and said flexible plastic sheet; (b) covering the soil to be waterproofed with a plurality of said flexible sheets; (c) aligning said sheets in an abutting fashion to create a seam region between adjoining sheets; and (d) permanently joining said abutting sheets to provide a continuous and uninterrupted barrier of plastic facing the area from which liquid is to be barred.
Claim 22
Dependent Claim
16 words
The method of claim 19 including the step of creating a potential difference across said sheet.
Claim 23
Dependent Claim
22 words
The method of claim 20 including the step of causing a spark to be created where a hole exists in a sheet.
Claim 24
Dependent Claim
29 words
The method of claim 19, wherein said forming step includes the step of co-extruding a first plastic stream with a second plastic stream having conductive particles dispersed within it.
Claim 25
Dependent Claim
21 words
The method of claim 19, wherein the conductive regions of said sheets are electrically bridged to one another across the seam.
Claim 26
Dependent Claim
15 words
The method of claim 23, wherein said bridge is formed by depositing electrically conducting plastic.
Claim 27
Dependent Claim
109 words
A flexible thermoplastic liner for an outdoor earthen fluid containment area, said thermoplastic liner having an upper surface and a lower surface adapted to lie over said containment area, said liner having a flexible layer containing conductive particles, said layer being situated proximate to said lower surface, and being adapted to serve as a conductive region for the detection of liner holes by establishing a potential difference between a probe within the containment area and said layer containing conductive particles, said liner being adapted to be maintained for flexible in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 28
Dependent Claim
109 words
A flexible thermoplastic liner for an outdoor earthen fluid containment area, said thermoplastic liner having an upper surface and a lower surface adapted to lie over said containment area, said liner having a flexible layer containing conductive particles, said layer being situated proximate to said lower surface, and being adapted to serve as a conductive region for the detection of liner holes by establishing a potential difference between a probe within the containment area and said layer containing conductive particles, said liner being adapted to be maintained for flexible in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 29
Dependent Claim
20 words
The thermoplastic liner of claim 25, wherein said conductive particles have a surface area greater than 1000 m 2 /cm.
Claim 30
Dependent Claim
15 words
The thermoplastic liner of claim 26, wherein said conductive particles include furnace type carbon black.
Claim 31
Dependent Claim
20 words
The thermoplastic liner of claim 26, wherein said conductive particles have a surface area of about 1475 m 2 /cm.
Claim 32
Dependent Claim
120 words
A thermoplastic liner for an outdoor earthen fluid containment area, said thermoplastic liner having an upper surface and a lower surface adapted to lie on said fluid containment area, said liner having a conductive region encapsulated within said liner, said conductive region having a volume resistivity of less than 280 ohm-cm, said liner being flexible, such that said conductive region is adapted to sufficiently conduct electricity to enable detection of pin hole leaks in the liner by establishing a potential difference between a probe within the containment area and said conductive region, said liner being adapted and maintained for flexure in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 33
Dependent Claim
120 words
A thermoplastic liner for an outdoor earthen fluid containment area, said thermoplastic liner having an upper surface and a lower surface adapted to lie on said fluid containment area, said liner having a conductive region encapsulated within said liner, said conductive region having a volume resistivity of less than 280 ohm-cm, said liner being flexible, such that said conductive region is adapted to sufficiently conduct electricity to enable detection of pin hole leaks in the liner by establishing a potential difference between a probe within the containment area and said conductive region, said liner being adapted and maintained for flexure in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 34
Dependent Claim
18 words
The thermoplastic liner of claim 29, wherein said conductive region forms an outward facing surface of said liner.
Claim 35
Dependent Claim
19 words
The thermoplastic liner of claim 29, wherein said conductive region makes up less than 20% of the liner thickness.
Claim 36
Dependent Claim
18 words
The thermoplastic liner of claim 29, wherein said conductive region is formed of conductive particles embedded within plastic.
Claim 37
Dependent Claim
12 words
The thermoplastic liner of claim 32, wherein said particles are chemically inert.
Claim 38
Dependent Claim
22 words
The thermoplastic liner of claim 29, wherein said conductive region has a volume resistivity of between about 10 and about 60 ohm-cm.
Claim 39
Dependent Claim
116 words
A flexible thermoplastic liner for an outdoor earthern fluid containment area comprising at least two plastic layers, one of said layers being more conductive than the other of said layers, said more conductive layer being formed of plastic that is less dense than the plastic forming the less conductive layer, said more conductive layer being adapted to sufficiently conduct electricity to enable detection of pin hole leaks in the liner by establishing a potential difference between a probe within the containment area and said more conductive layer, said sheet being adapted to be maintained for flexure in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 40
Dependent Claim
116 words
A flexible thermoplastic liner for an outdoor earthern fluid containment area comprising at least two plastic layers, one of said layers being more conductive than the other of said layers, said more conductive layer being formed of plastic that is less dense than the plastic forming the less conductive layer, said more conductive layer being adapted to sufficiently conduct electricity to enable detection of pin hole leaks in the liner by establishing a potential difference between a probe within the containment area and said more conductive layer, said sheet being adapted to be maintained for flexure in use over said containment area so as to at least approximately conform to the shape of the containment area.
Claim 41
Dependent Claim
17 words
The thermoplastic liner of claim 35, wherein said more conductive layer is formed from low density polyethylene.
Claim 42
Dependent Claim
15 words
The thermoplastic liner of claim 36, wherein said less conductive layer is high density polyethylene.
Claim 43
Dependent Claim
20 words
The thermoplastic liner of claim 37, wherein the more conductive layer has a volume resistivity of less than 280 ohm-cm.
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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) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |