US5221570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multilayered coextruded geomembrane
Assignee: LaSalle National Bank
•
Filing: 1991-09-03
•
Granted: 1993-06-22
•
Expires: 2011-09-03
Abstract
Abstract A multilayered coextruded geomembrane system utilized in a variety of applications including, but not limited to, landfills for the disposal of wastes, surface impoundments or ponds, heap leach pads for mining or methane barriers for building and floating covers reservoirs. The geomembrane consists of three or more polymeric layers with outside layers consisting of high density polyethylene at least 0.930 g/cm 3 and a very low density polyethylene inner core layer less than or equal to 0.920 g/cm 3 . The melt index of the very low and high density polyethylene is less than 2.0 and 1.0, respectively. Each outside layer of high density polyethylene is 10 to 40% of the total geomembrane thickness. The very low density polyethylene inner core layer is 20 to 80% of the total geomembrane thickness.
Inventors
- 👤 Cem Gokcen
- 👤 Gary Kolbasuk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 03:57
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B32B27/32; B32B27/18; B32B27/20; E; E02; E02D; E02D31/00; E02D31/002; E02D31/004; B32B2307/00; B32B2307/70; B32B2307/724; B32B2307/7242; B32B2307/726; B32B2307/7265; B32B2323/00; B32B2323/04; B32B2323/043; B32B2323/046; E02D2250/00; E02D2250/0015; E02D2300/00; E02D2300/0004; E02D2300/0006; E02D2300/0009; E02D2300/0015; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/24967; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
22 words
A multilayered coextruded geomembrane sheet material comprising: two high density polyethylene outer layers; and one very low density polyethylene inner core layer.
Claim 2
Dependent Claim
22 words
A multilayered coextruded geomembrane sheet material comprising: two high density polyethylene outer layers; and one very low density polyethylene inner core layer.
Claim 3
Dependent Claim
25 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein said high density polyethylene has a clear resin base density of about 0.930 to 0.945.
Claim 4
Dependent Claim
26 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein said very low density polyethylene has a clear resin base density of about 0.890 to 0.920.
Claim 5
Dependent Claim
21 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein said high density polyethylene has a melt index less than 1.0.
Claim 6
Dependent Claim
22 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein said very low density polyethylene has a melt index less than 2.0.
Claim 7
Dependent Claim
29 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein said sheet material has an overall thickness between 20 thousandths of an inch and 300 thousandths of an inch.
Claim 8
Dependent Claim
25 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein each said high density outer layer is approximately 10% to 40% of overall geomembrane thickness.
Claim 9
Dependent Claim
26 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein said very low density inner core layer is 20% . to 80% of overall geomembrane thickness.
Claim 10
Dependent Claim
25 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein each high density outer layer has a minimum thickness of 4 thousandths of an inch.
Claim 11
Dependent Claim
34 words
The multilayered coextruded geomembrane sheet material of claim 1 wherein one or more of said layers may include one or more of the following: carbon black, pigments, dyes, processing aids, stabilizers or other modifiers.
References Cited (Backward Citations)
US3874987A
Cited
US4053341A
Cited
US4324829A
Cited
US4357191A
Cited
US4404857A
Cited
US4565720A
Cited
US4657811A
Cited
US4678375A
Cited
US4661401A
Cited
US4767653A
Cited
US4732635A
Cited
US4514465A
Cited
US4567069A
Cited
US4539259A
Cited
US4716069A
Cited
US4767658A
Cited
US4741644A
Cited
US4721591A
Cited
US4764560A
Cited
US4725785A
Cited
US4719407A
Cited
US4720669A
Cited
US4784885A
Cited
US4740757A
Cited
US4755757A
Cited
US4751467A
Cited
US4751841A
Cited
US4810131A
Cited
US5139853A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-06-21 | 1996-12-21 | 1997-06-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-06-21 | 2000-12-21 | 2001-06-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-06-21 | 2004-12-21 | 2005-06-22 | $7700.00 | Window Closed / Lapsed |