US3950473A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing synthetic pulp from a film of a mixture of polypropylene and low density polyethylene
Assignee: JNC Corp
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Filing: 1973-05-21
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Granted: 1976-04-13
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Expires: 1993-05-21
Abstract
Abstract Synthetic pulp having a peculiar structure is prepared by making a composition consisting of 50 to 90 parts by weight of polypropylene having a melt flow rate of 30 to 150 and 50 to 10 parts by weight of low density polyethylene having a melt index of 0.5 to 10 into a film having a thickness of 70 μ or less, uniaxially stretching the film, cutting the stretched film to a predetermined length of 5 mm or less, and fibrillating the cut film by a crumpling and disintergrating action mainly by blows and air whirling stream. A suitable apparatus for such fibrillation is presented. Synthetic pulp thus prepared provides a paper-like material having superior properties by blending it with e.g. wood pulp.
Inventors
- 👤 Eitaro Iwahori
- 👤 Mitsuo Kurita
- 👤 Mitsumasa Uno
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:05
CPC Classifications
B; B02; B02C; B02C18/00; B02C18/06; B02C18/14; B02C18/148; B02C13/00; B02C13/10; B02C13/12; D; D01; D01G; D01G11/00; D21; D21B; D21B1/00; D21B1/04; D21B1/12; D21H; D21H13/00; D21H13/10; D21H13/12; D21H13/14; D21H5/00; D21H5/12; D21H5/20; D21H5/202; Y; Y02; Y02W; Y02W30/00; Y02W30/50; Y02W30/66; Y10; Y10S; Y10S264/00; Y10S264/47
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
190 words
A process for producing a synthetic pulp which comprises: a. making a composition consisting of 1. 50 to 90 parts by weight of polypropylene having a melt flow rate of 30 to 150 as measured at 230°C and under a load of 2.16 kg and 2. 50 to 10 parts by weight of low density polyethylene, into a film having a thickness of 70 μ or less, b. uniaxially stretching the resulting film to at least 8 times its original length, c. cutting the film thus stretched to lengths of 5 mm or less, and d. fibrillating the cut film lengths by passing them through at least two clearances having a distance of 5 mm or less formed between a plurality of linear projections on the inner peripheral surface of a cylindrical casing and the tip ends of at least two sets of a large number of vanes rotating therein at a peripheral speed of 92 - 100 m /sec. whereby a crumpling and disintegrating action mainly by blows and a whirling air stream is brought about to effect fibrillation, and e. recovering a synthetic pulp having the following characteristics
Claim 2
Dependent Claim
190 words
A process for producing a synthetic pulp which comprises: a. making a composition consisting of 1. 50 to 90 parts by weight of polypropylene having a melt flow rate of 30 to 150 as measured at 230°C and under a load of 2.16 kg and 2. 50 to 10 parts by weight of low density polyethylene, into a film having a thickness of 70 μ or less, b. uniaxially stretching the resulting film to at least 8 times its original length, c. cutting the film thus stretched to lengths of 5 mm or less, and d. fibrillating the cut film lengths by passing them through at least two clearances having a distance of 5 mm or less formed between a plurality of linear projections on the inner peripheral surface of a cylindrical casing and the tip ends of at least two sets of a large number of vanes rotating therein at a peripheral speed of 92 - 100 m /sec. whereby a crumpling and disintegrating action mainly by blows and a whirling air stream is brought about to effect fibrillation, and e. recovering a synthetic pulp having the following characteristics
Claim 3
Dependent Claim
132 words
the fibrils being branched in a developed manner from a trunk, 2. the trunks and fibrils being extended in various large and small creep or snake-like forms along the longitudinal direction thereof, 3. the sizes of the trunks substantially being less than 20 deniers and most of the sizes being less than 5 deniers, 4. as the sizes of the trunks are increased, the width is increased as compared with the thickness, 5. the length of the trunks being less than 5 mm, and the trunks having substantially uniform fiber lengths for any given length, 6. the fibers of each pulp being slightly entangled with one another when collected, and 7. the pulp being free from small twisted masses caused by firm entanglement of the fibers and free from molten small particles.
Claim 4
Dependent Claim
132 words
the fibrils being branched in a developed manner from a trunk, 2. the trunks and fibrils being extended in various large and small creep or snake-like forms along the longitudinal direction thereof, 3. the sizes of the trunks substantially being less than 20 deniers and most of the sizes being less than 5 deniers, 4. as the sizes of the trunks are increased, the width is increased as compared with the thickness, 5. the length of the trunks being less than 5 mm, and the trunks having substantially uniform fiber lengths for any given length, 6. the fibers of each pulp being slightly entangled with one another when collected, and 7. the pulp being free from small twisted masses caused by firm entanglement of the fibers and free from molten small particles.
Claim 5
Dependent Claim
30 words
A process according to claim 1, wherein the low density polyethylene has a melt index of 0.5 to 10 as measured at 190°C and under a load of 2.16 Kg.
Claim 6
Dependent Claim
30 words
A process according to claim 1, wherein the low density polyethylene has a melt index of 1.0 to 3.0 as measured at 190°C and under a load of 2.16 Kg.
Claim 7
Dependent Claim
20 words
A process according to claim 1, wherein the uniaxial stretching is carried out at a temperature of 120° - 150°C.
Claim 8
Dependent Claim
18 words
A process according to claim 1, wherein the fibrillating is carried out in the presence of a surfactant.
Claim 9
Dependent Claim
15 words
A process according to claim 1, wherein said fibrillating is carried out at least once.
Claim 10
Dependent Claim
25 words
A process according to claim 2, wherein the uniaxial stretching is carried out under a stretching ratio of 10 - 13 times the original length.
Claim 11
Dependent Claim
16 words
A process according to claim 5, wherein said surfactant is a dialkyl sulfosuccinate or its salt.
Claim 12
Dependent Claim
13 words
A process according to claim 5, wherein said surfactant is polyoxyethylene glycol ether.
Claim 13
Dependent Claim
35 words
A process according to claim 1 wherein the fibrillating is carried out in the presence of a dilute aqueous solution of a surfactant at a concentration of 0.5 to 3% by weight of the solution.
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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) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |