US3708362A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of plastics materials
Assignee: Dunlop Holdings Ltd
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Filing: 1968-06-28
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Granted: 1973-01-02
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Expires: 1988-06-28
Abstract
Abstract The invention provides an improved method and apparatus for the reticulation of cellular material such as polyurethane foam, by means of which a continuous sheet of foam can be reticulated in a continuous fashion. The sheet is held between platens, the air in the cells of the sheet is replaced by a combustible gaseous medium which is then ignited resulting in reticulation of the foam. The sheet can then be advanced through the platens and an adjacent unreticulated portion then subjected to a repetition of the method. The method and apparatus can also be used in a similar way for bonding together into a coherent fibrous body a mass of strands of thermoplastic material such as polypropylene fibers.
Inventors
- 👤 I Biggs
- 👤 J Winchcombe
- 👤 J Windsor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 06:23
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/42; D04H1/4282; D04H1/4291; B; B29; B29C; B29C44/00; B29C44/34; B29C44/56; B29C44/5627; B29C44/5636; D04H1/4326; D04H1/4334; D04H1/54; D04H1/58; D04H1/64; D04H1/68
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
42 words
A method according to claim 1, in which after said part of the sheet has been treated, the sheet is advanced so that an adjacent untreated portion of the sheet comes between the platens, and the method of claim 1 is repeated.
Claim 2
Dependent Claim
42 words
A method according to claim 1, in which the combustible gaseous medium is introduced into the cells of said part of the sheet by expelling substantially all the air from the cells and then filling the cells with the combustible gaseous medium.
Claim 3
Dependent Claim
50 words
A method according to claim 1, in which the combustible gas is introduced into the cells of said part of the sheet by replacing part of the air in the cells with a gaseous fuel which mixes with the air remaining in said cells to form said combustible gaseous medium.
Claim 4
Dependent Claim
37 words
A method of bonding together a sheet of a mass of strands of thermoplastic material according to claim 1, in which the strands comprise a material selected from the group consisting of polypropylene, nylon, and polyethylene terephthalate.
Claim 5
Dependent Claim
33 words
A method according to claim 1, in which the combustible gaseous medium comprises a mixture of oxygen and a gas selected from the group consisting of hydrogen, coal gas, natural gas and propane.
Claim 6
Dependent Claim
26 words
A method according to claim 1, in which the combustible gaseous medium is a mixture comprising (a) oxygen and (b) coal gas, natural gas or propane.
Claim 7
Dependent Claim
14 words
A method according to claim 1, in which the combustible gaseous medium is non-reducing.
Claim 8
Dependent Claim
27 words
A method according to claim 1, in which the air in the sheet material is expelled from the cells by direct displacement with the combustible gaseous medium.
Claim 9
Dependent Claim
49 words
A method according to claim 9, in which the combustible gaseous medium is introduced into the sheet material in a central zone of the part of the sheet between the platens and allowed to spread through said part, thereby displacing the air outwardly to the edges of the sheet.
Claim 10
Dependent Claim
54 words
A method according to claim 1, in which the combustible gaseous medium is introduced into the sheet of the mass of strands by squeezing said part of the sheet to expel a substantial amount of air and then allowing said part to expand while in contact with a supply of the combustible gaseous medium.
Claim 11
Dependent Claim
17 words
A method according to claim 1, in which the cellular material is a polyether or polyester polyurethane.
Claim 12
Dependent Claim
52 words
A method according to claim 1, in which the combustible gaseous medium is introduced into the sheet of cellular material by squeezing said part of the sheet to expel a substantial amount of air and then allowing said part to expand while in contact with a supply of the combustible gaseous medium.
References Cited (Backward Citations)
US3468096A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-01-02 | 1976-07-03 | 1977-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-02 | 1980-07-03 | 1981-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-02 | 1984-07-03 | 1985-01-02 | $7700.00 | Window Closed / Lapsed |