Patent US4379808A successfully refreshed from Google Patents.
US4379808A
Expired / Lapsed
US
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Sheet type forming board and formed board products
Assignee: ROCK-TENN COMPANY A CORP OF
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Filing: 1980-06-30
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Granted: 1983-04-12
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Expires: 2000-06-30
Abstract
Abstract A sheet type forming board for use in heat forming processes without the need for pre-soaking or pre-steaming required of prior hardboard materials. The forming board sheet has at least one layer containing cellulose fibers, a polyolefin, and an inorganic filler. Its moisture content is preferably 4-12%. A multi-layered sheet, wherein plys are joined together, is typically used to achieve the desired thickness and composite sheet composition. The formed products are light weight and have a number of desirable advantages, including rigidity, embossing and graining fidelity, and dielectric processability.
Inventors
- 👤 John N. Cole
- 👤 David A. Hettel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:11
CPC Classifications
B; B32; B32B; B32B29/00; B32B29/02; B27; B27N; B27N3/00; B27N3/06; D; D21; D21H; D21H11/00; D21H11/14; D21H13/00; D21H13/10; D21H13/12; D21H13/14; D21H17/00; D21H17/63; D21H17/67; D21H17/68; D21H27/00; D21H27/30; B32B2262/00; B32B2262/02; B32B2262/0253; B32B2262/06; B32B2262/062; Y; Y10; Y10T; Y10T156/00; Y10T156/10; Y10T156/1002; Y10T428/00; Y10T428/25; Y10T428/253; Y10T428/254; Y10T428/31504; Y10T428/31551; Y10T428/31634; Y10T428/31645; Y10T428/31855; Y10T428/3188; Y10T428/31895; Y10T428/31971; Y10T428/31975; Y10T428/31978; Y10T428/31982; Y10T442/00; Y10T442/60; Y10T442/69; Y10T442/692; Y10T442/699
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
63 words
A forming board sheet for use in a heat forming process, comprising at least a first layer consisting essentially of (a) cellulose fibers, (b) a solid particulate polyolefin, and (c) an inorganic filler and having a moisture content of between approximately 4-12% by weight, whereby said forming board is easily formable in a conventional hot press without the requirement of pre-soaking and/or pre-steaming.
Claim 2
Dependent Claim
63 words
A forming board sheet for use in a heat forming process, comprising at least a first layer consisting essentially of (a) cellulose fibers, (b) a solid particulate polyolefin, and (c) an inorganic filler and having a moisture content of between approximately 4-12% by weight, whereby said forming board is easily formable in a conventional hot press without the requirement of pre-soaking and/or pre-steaming.
Claim 3
Dependent Claim
14 words
The forming board sheet of claim 1 wherein said sheet consists of multiple layers.
Claim 4
Dependent Claim
28 words
The forming board sheet of claim 2 wherein a second layer of paperboard material is joined to at least said first layer to form a multiple layer sheet.
Claim 5
Dependent Claim
26 words
The forming board sheet of claim 1 wherein said first layer consists essentially of by weight 43-73% cellulose fibers, 12-30% polyolefin fibers, and 15-45% inorganic filler.
Claim 6
Dependent Claim
25 words
The forming board sheet of claim 4 wherein said polyolefin fibers are selected from the group consisting of polypropylene fibers, polyethylene fibers, and mixtures thereof.
Claim 7
Dependent Claim
28 words
The forming board sheet of claim 5 wherein said inorganic filler is selected from the group consisting of talc, glass fibers, wollastonite, mineral fibers, clay, and calcium carbonate.
Claim 8
Dependent Claim
22 words
The forming board sheet of claim 6 wherein said cellulose fibers comprise at least in part secondary fibers from recycled corrugated board.
Claim 9
Dependent Claim
27 words
The forming board sheet of claim 7 wherein said first layer consists by weight of approximately 65% cellulose fibers, approximately 15% polypropylene fibers, and approximately 20% talc.
Claim 10
Dependent Claim
64 words
A formed board comprising a forming board sheet which has been treated by a heat forming process without pre-soaking and/or pre-steaming to produce a shaped structural product, said forming board sheet having at least a first layer consisting essentially of (a) cellulose fibers, (b) a solid particulate polyolefin, and (c) an inorganic filler and having a moisture content of between approximately 4-12% by weight.
Claim 11
Dependent Claim
64 words
A formed board comprising a forming board sheet which has been treated by a heat forming process without pre-soaking and/or pre-steaming to produce a shaped structural product, said forming board sheet having at least a first layer consisting essentially of (a) cellulose fibers, (b) a solid particulate polyolefin, and (c) an inorganic filler and having a moisture content of between approximately 4-12% by weight.
Claim 12
Dependent Claim
25 words
The formed board of claim 9 wherein said first layer consists essentially of by weight 43-73% cellulose fibers, 12-30% polyolefin fibers, and 15-45% inorganic filler.
Claim 13
Dependent Claim
26 words
The formed board of claim 10 wherein said first layer consists by weight of approximately 65% cellulose fibers, approximately 15% polypropylene fibers, and approximately 20% talc.
Claim 14
Dependent Claim
28 words
The formed board of claim 9 wherein a second layer of paperboard material is joined to at least said first layer to form multiple layer shaped structural product.
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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) | 1986-04-11 | 1986-10-11 | 1987-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-04-11 | 1990-10-11 | 1991-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-04-11 | 1994-10-11 | 1995-04-12 | $7700.00 | Window Closed / Lapsed |