Patent US4643940A successfully refreshed from Google Patents.
US4643940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low density fiber-reinforced plastic composites
Assignee: Unitika Ltd
•
Filing: 1984-08-06
•
Granted: 1987-02-17
•
Expires: 2004-08-06
Abstract
Abstract This invention is a novel high void volume fiber-reinforced resin composite having a continuous matrix of a thermoplastic resin and from about 10 to 50 percent by weight of randomly oriented short reinforcing fibers. A process for making such low density composites is also disclosed.
Inventors
- 👤 Ken M. Shaw
- 👤 Ritchie A. Wessling
- 👤 Larry D. Yats
- 👤 Selim Yalvac
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:45
CPC Classifications
C; C08; C08J; C08J9/00; C08J9/0085; D; D21; D21H; D21H25/00; D21H25/04; D21H25/06; B; B29; B29C; B29C44/00; B29C44/02; B29C44/10; B29K; B29K2105/00; B29K2105/06; B29K2105/12; B29K2105/14; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; C08J9/04; C08J9/06; C08J9/10; C08J9/102; C08J9/103; Y; Y10; Y10S; Y10S428/00; Y10S428/91; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249955; Y10T428/249958; Y10T428/25; Y10T428/252; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
82 words
A fiber-reinforced composite prepared by an aqueous slurry process and heat expanded in thickness to a void volume of from about 20 to about 90 percent by volume, said composite comprising a continuous matrix comprising a solid thermoplastic resin and, distributed throughout said matrix, from about 10 to 50 percent by weight of the composite of randomly oriented reinforcing fibers wherein said fibers have an average length from about 0.125 to 1.00 inch and an aspect ratio of at least about 40.
Claim 2
Dependent Claim
82 words
A fiber-reinforced composite prepared by an aqueous slurry process and heat expanded in thickness to a void volume of from about 20 to about 90 percent by volume, said composite comprising a continuous matrix comprising a solid thermoplastic resin and, distributed throughout said matrix, from about 10 to 50 percent by weight of the composite of randomly oriented reinforcing fibers wherein said fibers have an average length from about 0.125 to 1.00 inch and an aspect ratio of at least about 40.
Claim 3
Dependent Claim
10 words
The composite of claim 1 wherein the fibers comprise glass.
Claim 4
Dependent Claim
13 words
The composite of claim 1 wherein said thermoplastic resin comprises polyethylene or polypropylene.
Claim 5
Dependent Claim
14 words
The composite of claim 1 wherein said thermoplastic resin comprises a polyvinyl aromatic resin.
Claim 6
Dependent Claim
17 words
The composite of claim 1 wherein said continuous matrix further comprises the solids of a polymeric binder.
Claim 7
Dependent Claim
17 words
The composite of claim 5 wherein said continuous matrix further comprises the solids of a flocculating agent.
Claim 8
Dependent Claim
21 words
The composite of claim 1 wherein said reinforcing fibers comprise from about 20 to 40 percent by weight of the composite.
Claim 9
Dependent Claim
15 words
The composite of claim 1 having a void volume from about 30 to 70 percent.
Claim 10
Dependent Claim
20 words
The composite of claim 1 wherein said continous fiber reinforced matrix contains at least one shaped low void volume section.
Claim 11
Dependent Claim
24 words
The composite of claim 1 or 9 having on each major surface thereof a smooth resin layer from about 0.05 to 1 mil thick.
Claim 12
Dependent Claim
13 words
The composite of claim 1 wherein the major portion of voids are open-celled.
Claim 13
Dependent Claim
109 words
A fiber-reinforced composite comprising a continuous matrix which comprises a solid the thermoplastic resin and, distributed throughout said matrix, from about 10 to 50 percent by weight of the composite of randomly oriented reinforcing fibers, said fibers having an average length of from about 0.125 to 1.0 inch and an aspect ratio of at least about 40, said matrix having a void volume of from about 20 to about 90 percent by volume and being prepared by heating a densified fiber-reinforced resin sheet to a temperature above the resin's softening temperature, whereby the sheet is expanded in a direction perpendicular to that of a plane defined by said sheet.
Claim 14
Dependent Claim
109 words
A fiber-reinforced composite comprising a continuous matrix which comprises a solid the thermoplastic resin and, distributed throughout said matrix, from about 10 to 50 percent by weight of the composite of randomly oriented reinforcing fibers, said fibers having an average length of from about 0.125 to 1.0 inch and an aspect ratio of at least about 40, said matrix having a void volume of from about 20 to about 90 percent by volume and being prepared by heating a densified fiber-reinforced resin sheet to a temperature above the resin's softening temperature, whereby the sheet is expanded in a direction perpendicular to that of a plane defined by said sheet.
Claim 15
Dependent Claim
24 words
The composite of claim 12 wherein the temperature to which the densified sheet is heated is less than that at which the resin degrades.
Claim 16
Dependent Claim
38 words
The composite of claim 12 wherein the temperature to which the densified sheet is heated is less than that at which viscosity of the resin becomes so low that the densified sheet loses its physical shape or integrity.
Claim 17
Dependent Claim
18 words
The composite of claim 12 wherein the expanded sheet is cooled below the softening temperature of the resin.
References Cited (Backward Citations)
US3515625A
Cited
US3621092A
Cited
US3707434A
Cited
US4113908A
Cited
US4015039A
Cited
US4025686A
Cited
US4426470A
Cited
US4481241A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-16 | 1990-08-18 | 1991-02-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-16 | 1994-08-18 | 1995-02-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-16 | 1998-08-18 | 1999-02-17 | $7700.00 | Window Closed / Lapsed |