US4386119A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wet process and apparatus for rendering cellulosic insulation particles fire-retardant
Assignee: Individual
•
Filing: 1980-09-02
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Granted: 1983-05-31
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Expires: 2000-09-02
Abstract
Abstract Particulate cellulose insulation material is rendered fire retardant by a wet process requiring considerably less fire retardant composition than normally employed in the usual dry processes or in wet processes proposed heretofore, and yielding a product with significantly enhanced insulating properties. Impregnation of a cellulosic insulating material, such as waste paper in finely divided form, with an aqueous solution of a non-hygroscopic fire retardant composition, such as boric acid, a borate, or the composition of U.S. Pat. No. 3,983,040, is carried out under conditions whereby a minimum amount of water is first utilized for the purpose of dissolving the fire retardant composition and to serve as a carrier in distributing it throughout the cellulosic insulating material. For example, only from about 14 to 45% by weight of add-on water is utilized in the presence of from about 5 to 10% by weight of the fire retardant composition and preferably in the presence of a surfactant. The so-treated insulation material is then maintained in a hot and humid atmosphere, as in a closed conditioning bin, for a prolonged period of time prior to drying.
Inventors
- 👤 Samuel M. Draganov
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 00:33
CPC Classifications
D; D21; D21C; D21C9/00; D21C9/001; D21C9/002; C; C04; C04B; C04B30/00; C08; C08K; C08K3/00; C08K3/38; C09; C09K; C09K21/00; C09K21/02; Y; Y10; Y10S; Y10S428/00; Y10S428/92; Y10S428/921
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
165 words
A wet process for producing a fire-retardant, cellulosic, insulation material having superior insulating properties by the use of considerably less fire-retardant composition than normally employed in conventional dry processes, comprising the steps of applying to the component particles of a mass of finely divided, cellulosic insulation material an aqueous solution of a nonhygroscopic, boric acid or borate fire-retardant composition, said solution containing an effective amount of but considerably less fire-retardant composition than normally employed in conventional dry processes and having substantially no more add-on water than will be effective to dissolve said composition and distribute it under hot and humid conditions maintained for a prolonged period of time; thereafter maintaining the so-treated wet mass of finely divided cellulosic insulation material under hot and humid conditions for a period of time sufficiently prolonged to achieve substantially full distribution of said fire-retardant composition with respect to the individual particles of said mass; and withdrawing fully conditioned material from said mass and subjecting it to a drying treatment.
Claim 2
Dependent Claim
165 words
A wet process for producing a fire-retardant, cellulosic, insulation material having superior insulating properties by the use of considerably less fire-retardant composition than normally employed in conventional dry processes, comprising the steps of applying to the component particles of a mass of finely divided, cellulosic insulation material an aqueous solution of a nonhygroscopic, boric acid or borate fire-retardant composition, said solution containing an effective amount of but considerably less fire-retardant composition than normally employed in conventional dry processes and having substantially no more add-on water than will be effective to dissolve said composition and distribute it under hot and humid conditions maintained for a prolonged period of time; thereafter maintaining the so-treated wet mass of finely divided cellulosic insulation material under hot and humid conditions for a period of time sufficiently prolonged to achieve substantially full distribution of said fire-retardant composition with respect to the individual particles of said mass; and withdrawing fully conditioned material from said mass and subjecting it to a drying treatment.
Claim 3
Dependent Claim
45 words
A process according to claim 1, wherein the particles of cellulosic material initially carry the fire-retardant composition on their surfaces as a substantially dry powder, and the aqueous solution of such fire-retardant composition is formed by adding the water to the mass of cellulosic material.
Claim 4
Dependent Claim
31 words
A process according to claim 1, wherein heat and humidity are supplied by injecting a hot vapor into the mass of material as wetted by the aqueous solution of fire-retardant composition.
Claim 5
Dependent Claim
16 words
A process according to claim 3, wherein the hot vapor is supplied from the drying step.
Claim 6
Dependent Claim
24 words
A process according to claim 3, wherein water is added by spraying the cellulosic particles therewith prior to the injection of the hot vapor.
Claim 7
Dependent Claim
43 words
A process according to claim 5, wherein spraying of the mass of cellulosic material is effected as said material is discharged from a grinding mill in which size reduction of crude cellulosic material is carried out and the fire-retardant material is mixed therewith.
Claim 8
Dependent Claim
75 words
A process according to claim 6, wherein the hot vapor is introduced into the flowing stream of the sprayed material in a closed conduit; the resulting heated and humidified material is deposited into the top of a conditioning bin and maintained therein for the time period required as it descends to the bottom of the bin; conditioned material is withdrawn from the bottom of the bin; and the withdrawn material is passed through a dryer.
Claim 9
Dependent Claim
24 words
A process according to claim 7, wherein the conditioned material withdrawn from the bin is treated by milling to increase fluffiness prior to drying.
Claim 10
Dependent Claim
25 words
A process according to claim 1, wherein the conditioning is carried out for a time period of from about ten minutes to about one hour.
Claim 11
Dependent Claim
37 words
A process according to claim 1, wherein drying of the mass of cellulosic material is carried out to yield an insulation product having a free moisture content of from about 5 to about 10 percent by weight.
Claim 12
Dependent Claim
14 words
A process according to claim 1, wherein a surfactant is included in the solution.
Claim 13
Dependent Claim
27 words
A process according to claim 1, wherein the amount of add-on water utilized is from about 14 to about 45 percent by weight of the cellulosic material.
Claim 14
Dependent Claim
27 words
A process according to claim 1, wherein the amount of add-on water utilized is from about 18 to about 25 percent by weight of the cellulosic material.
Claim 15
Dependent Claim
14 words
A process according to claim 1, wherein the cellulosic insulation material is pulverized paper.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-05-30 | 1986-11-29 | 1987-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-30 | 1990-11-29 | 1991-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-30 | 1994-11-29 | 1995-05-31 | $7700.00 | Window Closed / Lapsed |