US4664957A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flexible sack for carrying bulk materials
Assignee: DSM BV
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Filing: 1985-07-03
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Granted: 1987-05-12
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Expires: 2005-07-03
Abstract
Abstract Flexible (single use) sack for transporting goods, such as bulk goods, having a weight of at least 3000 N. It comprises a fabric woven from polypropylene tapes and/or threads and exhibits a mean strip breaking strength of at least 550 N per 50 mm. Sacks with an improved safe working load which can be more readily handled, are obtained by using tapes or threads comprising a matrix of 75-85% B.W. of polypropylene and 25-15% B.W. of polyester, preferably polyethylene terephthalate. The polyester is preferably present in the form of fibrils.
Inventors
- 👤 Gustaaf M. W. van de Pol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:50
CPC Classifications
B; B65; B65D; B65D88/00; B65D88/16; B65D88/1612; B65D88/1618; B65D88/1675; B65D88/1681; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1334; Y10T428/1345; Y10T428/1352; Y10T428/1362
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
165 words
Flexible sack for carrying substances, such as bulk materials with a weight of at least 3000 N, the sack being substantially formed of a woven fabric of polypropylene tapes and/or threads, the fabric having a mean strength of at least 550 N/50 mm in warp and/or weft direction, the polypropylene being provided with an additive, characterized in that the fabric is wholly or partly built up of tapes and/or threads substantially formed of a matrix of polypropylene incorporating a polyester, preferably polyethylene terephthalate, and in that the matrix is used in an amount of 75-85% by weight, based on the total weight of the tapes or thread, and the polyester in an amount of 25-15% by weight, based on the total weight of the tapes or threads, and in that the mean fabric strength in the warp and/or weft direction is 2500 to 8000 N/50 mm and the fabric weights are 100 to 400 grams/m 2 , preferably approximately 200 to 280 grams/m 2 .
Claim 2
Dependent Claim
165 words
Flexible sack for carrying substances, such as bulk materials with a weight of at least 3000 N, the sack being substantially formed of a woven fabric of polypropylene tapes and/or threads, the fabric having a mean strength of at least 550 N/50 mm in warp and/or weft direction, the polypropylene being provided with an additive, characterized in that the fabric is wholly or partly built up of tapes and/or threads substantially formed of a matrix of polypropylene incorporating a polyester, preferably polyethylene terephthalate, and in that the matrix is used in an amount of 75-85% by weight, based on the total weight of the tapes or thread, and the polyester in an amount of 25-15% by weight, based on the total weight of the tapes or threads, and in that the mean fabric strength in the warp and/or weft direction is 2500 to 8000 N/50 mm and the fabric weights are 100 to 400 grams/m 2 , preferably approximately 200 to 280 grams/m 2 .
Claim 3
Dependent Claim
38 words
Sack according to claim 1, characterised in that the matrix of polypropylene forms approx. 80% by weight of the total weight of the tapes, and the polyester approx. 20% by weight of the total weight of the tapes.
Claim 4
Dependent Claim
26 words
Sack according to claim 1, characterised in that the polyester is present in the matrix of polypropylene in the form of a large number of fibrils.
Claim 5
Dependent Claim
24 words
Sack according to claim 1, characterised in that the sack is so constructed that an SWL value not exceeding 30,000 N may be applied.
Claim 6
Dependent Claim
34 words
Sack according to claim 1, characterised in that the elongation at break in the direction of the warp and/or the weft of the fabric is 5% to 25%, and preferably approx. 9 to 18%.
Claim 7
Dependent Claim
34 words
Sack according to claim 1, characterised in that the fabric contains 4 to 8 tapes per cm, and preferably approx. 5 to 6 tapes per cm, in the direction of both warp and weft.
Claim 8
Dependent Claim
36 words
Sack according to claim 1, characterised in that both the weft and/or the warp of the fabric is formed of tapes each having a linear density of decitex 1500 to 2500 decitex, preferably approximately decitex 2200.
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) | 1990-05-11 | 1990-11-10 | 1991-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-11 | 1994-11-10 | 1995-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-11 | 1998-11-10 | 1999-05-12 | $7700.00 | Window Closed / Lapsed |