US5143778A
Expired / Lapsed
US
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Laminate structural plastic material
Assignee: Individual
•
Filing: 1990-10-31
•
Granted: 1992-09-01
•
Expires: 2010-10-31
Abstract
Abstract An improved laminated structural material; an improved method of forming a relatively rigid structural article such as a pallet; and an improved structural article using the invention laminated structural material. The invention article is formed by separately extruding relatively thin outer skin layers of a 25% talc filled polyethylene material and a relatively thick central core layer of an essentially virgin polyethylene material; bonding the layers together to form a composite laminate strip including the relatively thin talc filled outer skins and the thick central core layer of virgin polyethylene; severing the strip to form upper and lower sheets; heating the upper and lower sheets in an oven to place them in a flowable condition; delivering the upper and lower sheets respectively to upper and lower molds carried by upper and lower platens of a press; vacuum forming the upper and lower sheets respectively to the upper and lower molds; and thereafter bringing the platens of the press together to selectively knit or fuse the upper and lower sheets together to form the article. The article produced by the invention methodology costs only slightly more than an article formed of virgin polyethylene material and yet has vastly superior stiffness characteristics as compared to the virgin polyethylene article while retaining substantially all of the superior impact characteristics of the virgin polyethylene article.
Inventors
- 👤 Lyle H. Shuert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:47
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/32; B32B27/06; B32B27/12; B32B27/18; B32B27/20; B65; B65D; B65D19/00; B65D19/0004; B65D19/0006; B65D19/0008; B65D19/002; B65D19/0024; B65D19/0028; B32B2250/00; B32B2250/03; B32B2250/40; B32B2323/00; B32B2323/04; B65D2519/00; B65D2519/00004; B65D2519/00009; B65D2519/00014; B65D2519/00034; B65D2519/00049; B65D2519/00069; B65D2519/00258; B65D2519/00263; B65D2519/00273; B65D2519/00283; B65D2519/00288; B65D2519/00313; B65D2519/00318; B65D2519/00328; B65D2519/00338; B65D2519/00398; B65D2519/00432; B65D2519/00547; B65D2519/00552; B65D2519/00557; B65D2519/00562; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24942; Y10T428/2495; Y10T428/25; Y10T428/251; Y10T428/31504; Y10T428/31786; Y10T428/31855; Y10T428/31909; Y10T428/31913
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
82 words
A laminate structural material comprising: central inner core layer formed of a polyolefin material essentially devoid of reinforcing filler materials; and a pair of outer skin layers sandwiching said core layer therebetween and each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of filler material in said inner core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer.
Claim 2
Dependent Claim
82 words
A laminate structural material comprising: central inner core layer formed of a polyolefin material essentially devoid of reinforcing filler materials; and a pair of outer skin layers sandwiching said core layer therebetween and each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of filler material in said inner core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer.
Claim 3
Dependent Claim
14 words
A structural material according to claim 1 wherein: said layers are formed of polyethylene.
Claim 4
Dependent Claim
21 words
A structural material according to claim 1 wherein: said reinforcing filler material in said skin layers comprises an inorganic filler material.
Claim 5
Dependent Claim
16 words
A structural material according to claim 3 wherein: said filler material comprises a siliceous filler material.
Claim 6
Dependent Claim
22 words
A structural material according to claim 4 wherein: said filler material is selected from the group consisting of talc, mica or quartz.
Claim 7
Dependent Claim
13 words
A structural material according to claim 5 wherein: said filler material comprises talc.
Claim 8
Dependent Claim
19 words
A structural material according to claim 6 wherein: said talc comprises approximately 15-50% by weight of said skin layers.
Claim 9
Dependent Claim
19 words
A structural material according to claim 7 wherein: said talc comprises approximately 25% by weight of said skin layers.
Claim 10
Dependent Claim
28 words
A structural material according to claim 1 wherein: said core layer has a thickness at least twice as great as the thickness of each of said skin layers.
Claim 11
Dependent Claim
28 words
A structural material according to claim 9 wherein: said core layer has a thickness at least trice as great as the thickness of each of said skin layers.
Claim 12
Independent Claim
105 words
A method of forming a laminate structural material comprising the steps of forming a central inner core layer formed of a polyolefin material essentially devoid of reinforcing filler material and a pair of outer skin layers each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of reinforcing filler material in said inner core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer; bonding said layers together with said core layer sandwiched between said skin layers to form said laminate structural material.
Claim 13
Independent Claim
105 words
A method of forming a laminate structural material comprising the steps of forming a central inner core layer formed of a polyolefin material essentially devoid of reinforcing filler material and a pair of outer skin layers each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of reinforcing filler material in said inner core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer; bonding said layers together with said core layer sandwiched between said skin layers to form said laminate structural material.
Claim 14
Dependent Claim
18 words
A method according to claim 11 wherein: said layers are formed and bonded together in a coextrusion process.
Claim 15
Dependent Claim
13 words
A method according to claim 12 wherein: said layers are formed of polyethylene.
Claim 16
Dependent Claim
20 words
A method according to claim 12 wherein: said reinforcing filler material in said skin layers comprises an inorganic filler material.
Claim 17
Dependent Claim
15 words
A method according to claim 14 wherein: said filler material comprises a siliceous filler material.
Claim 18
Dependent Claim
21 words
A method according to claim 15 wherein: said filler material is selected from the group consisting of talc, mica or quartz.
Claim 19
Dependent Claim
12 words
A method according to claim 16 wherein: said filler material comprises talc.
Claim 20
Dependent Claim
18 words
A method according to claim 17 wherein: said talc comprises approximately 15-50% by weight of said skin layers.
Claim 21
Dependent Claim
18 words
A method according to claim 16 wherein: said talc comprises approximately 25% by weight of said skin layers.
Claim 22
Dependent Claim
27 words
A method according to claim 11 wherein: said core layer has a thickness at least twice as great as the thickness of each of said skin layers.
Claim 23
Dependent Claim
27 words
A method according to claim 20 wherein: said core layer has a thickness at least trice as great as the thickness of each of said skin layers.
Claim 24
Independent Claim
85 words
A method of forming a relatively rigid structural article comprising the steps of: forming a central core layer of a first high impact plastic material; forming a pair of outer skin layers of a second plastic material having less impact strength than said first material but greater stiffness strength than said first material; bonding said layers together with said core layer sandwiched between said outer skin layers to form a laminate structural material; and thermoforming said laminate structure material to form said rigid structural article.
Claim 25
Independent Claim
85 words
A method of forming a relatively rigid structural article comprising the steps of: forming a central core layer of a first high impact plastic material; forming a pair of outer skin layers of a second plastic material having less impact strength than said first material but greater stiffness strength than said first material; bonding said layers together with said core layer sandwiched between said outer skin layers to form a laminate structural material; and thermoforming said laminate structure material to form said rigid structural article.
Claim 26
Dependent Claim
36 words
A method according to claim 22 wherein: said forming steps comprise heat extruding steps; and said bonding step comprises bringing the extruded layers together while still in a heated state to form a continuous laminate strip.
Claim 27
Dependent Claim
15 words
A method according to claim 22 wherein: said thermoforming step comprises a vacuum thermoforming step.
Claim 28
Dependent Claim
58 words
A method according to claim 23 wherein said structural article is a twin sheet article and wherein: said method includes the further step of severing said strip to form at least two individual sheets; and said thermoforming step comprises individually thermoforming said sheets and thereafter selectively fusing said sheets together to form said rigid twin sheet structural article.
Claim 29
Dependent Claim
83 words
A method according to claim 22 wherein: said central core layer is and is formed of a polyolefin material essentially devoid of reinforcing filler materials; and said outer layers comprise outer skin layers each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of reinforcing filler material in said inner core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer.
Claim 30
Dependent Claim
13 words
A method according to claim 26 wherein: said layers are formed of polyethylene.
Claim 31
Dependent Claim
20 words
A method according to claim 25 wherein: said reinforcing filler material in said skin layers comprises an inorganic filler material.
Claim 32
Dependent Claim
15 words
A method according to claim 28 wherein: said filler material comprises a siliceous filler material.
Claim 33
Dependent Claim
21 words
A method according to claim 29 wherein: said filler material is selected from the group consisting of talc, mica or quartz.
Claim 34
Dependent Claim
12 words
A method according to claim 30 wherein: said filler material comprises talc.
Claim 35
Dependent Claim
18 words
A method according to claim 31 wherein: said talc comprises approximately 15-50% by weight of said skin layers.
Claim 36
Dependent Claim
18 words
A method according to claim 32 wherein: said talc comprises approximately 25% by weight of said skin layers.
Claim 37
Dependent Claim
27 words
A method according to claim 22 wherein: said core layer has a thickness at least twice as great as the thickness of each of said skin layers.
Claim 38
Dependent Claim
27 words
A method according to claim 33 wherein: said core layer has a thickness at least trice as great as the thickness of each of said skin layers.
Claim 39
Independent Claim
77 words
A method of forming a pallet comprising the steps of: forming a central core layer of a high impact plastic material; forming a pair of outer layers of a second plastic material having less impact strength than said first material but greater stiffness strength than said first material; bonding said layers together with said core layer sandwiched between said outer layers to form a laminate structural material; and thermoforming said laminated structural material to form said pallet.
Claim 40
Independent Claim
77 words
A method of forming a pallet comprising the steps of: forming a central core layer of a high impact plastic material; forming a pair of outer layers of a second plastic material having less impact strength than said first material but greater stiffness strength than said first material; bonding said layers together with said core layer sandwiched between said outer layers to form a laminate structural material; and thermoforming said laminated structural material to form said pallet.
Claim 41
Dependent Claim
86 words
A method according to claim 36 wherein said pallet is a twin sheet pallet and wherein: said forming steps comprise heat extruding steps; said bonding step comprises bringing the extruded layers together while still in a heated state to form a continuous laminate strip; said method includes the further step of severing said strip to form an upper sheet and a lower sheet; and said thermoforming step comprises individually thermoforming said upper and lower sheets and thereafter selectively fusing said sheets together to form said pallet.
Claim 42
Dependent Claim
83 words
A plastic structural article characterized in that the article is formed of a laminate structural material comprising a central core layer formed of a first high impact plastic material and a pair of outer skin layers sandwiching said core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer therebetween and formed of a second plastic material having less impact strength than said first material but greater stiffness strength than said first material.
Claim 43
Dependent Claim
83 words
A plastic structural article characterized in that the article is formed of a laminate structural material comprising a central core layer formed of a first high impact plastic material and a pair of outer skin layers sandwiching said core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer therebetween and formed of a second plastic material having less impact strength than said first material but greater stiffness strength than said first material.
Claim 44
Dependent Claim
32 words
An article according to claim 38 wherein: said article is a twin sheet article formed from first and second sheets and each of said sheets is formed of said laminate structural material.
Claim 45
Dependent Claim
49 words
An article according to claim 39 wherein: said article is a pallet including a platform structure and a plurality of legs extending downwardly from said platform structure; and said legs and platform structure are each formed from deformed and selectively fused together portions of said first and second sheets.
Claim 46
Dependent Claim
65 words
An article according to claim 38 wherein: said first plastic material forming said central inner core layer comprises a polyolefin material essentially devoid of reinforcing filler materials; and said second plastic material comprising said outer layers comprises a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of reinforcing filler material in said inner core layer.
Claim 47
Dependent Claim
13 words
An article according to claim 41 wherein: said layers are formed of polyethylene.
Claim 48
Dependent Claim
20 words
An article according to claim 42 wherein: said reinforcing filler material in said outer layers comprises an inorganic filler material.
Claim 49
Dependent Claim
15 words
An article according to claim 43 wherein: said filler material comprises a silicious filler material.
Claim 50
Dependent Claim
21 words
An article according to claim 44 wherein: said filler material is selected from the group consisting of talc, mica or quartz.
Claim 51
Dependent Claim
12 words
An article according to claim 45 wherein: said filler material comprises talc.
Claim 52
Dependent Claim
18 words
An article according to claim 46 wherein: said talc comprises approximately 15-50% by weight of said outer layers.
Claim 53
Dependent Claim
18 words
An article according to claim 47 wherein: said talc comprises approximately 25% by weight of said outer layers.
Claim 54
Dependent Claim
27 words
An article according to claim 48 wherein: said core layer has a thickness at least twice as great as the thickness of each of said outer layers.
Claim 55
Dependent Claim
27 words
An article according to claim 49 wherein: said core layer has a thickness at least thrice as great as the thickness of each of said outer layers.
Claim 56
Dependent Claim
117 words
A twin sheet plastic structural article comprising first and second plastic sheets individually thermoformed and selectively fused together to form the twin sheet article, characterized in that said sheets are each formed of a laminate structural material comprising a central inner core layer formed of a polyolefin material essentially devoid of reinforcing filler material and a pair of outer skin layers sandwiching said core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer therebetween and each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of reinforcing filler material in said inner core layer.
Claim 57
Dependent Claim
117 words
A twin sheet plastic structural article comprising first and second plastic sheets individually thermoformed and selectively fused together to form the twin sheet article, characterized in that said sheets are each formed of a laminate structural material comprising a central inner core layer formed of a polyolefin material essentially devoid of reinforcing filler material and a pair of outer skin layers sandwiching said core layer, wherein said core layer has a thickness at least twice as great as the thickness of each skin layer therebetween and each formed of a polyolefin material having a percentage by weight of a reinforcing filler material higher than the percentage by weight of reinforcing filler material in said inner core layer.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1995-09-01 | 1996-03-02 | 1996-09-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-01 | 2000-03-02 | 2000-09-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-01 | 2004-03-02 | 2004-09-01 | $7700.00 | Window Closed / Lapsed |