US4787948A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of elastic tapes from polyurethane
Assignee: Dow Produktions und Vertriebs GmbH and Co OHG
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Filing: 1987-06-29
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Granted: 1988-11-29
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Expires: 2007-06-29
Abstract
Abstract Process for the production of elastic tapes from thermoplastic polyurethane elastomers, wherein the thermoplastic is extruded to form a flat or tubular film and is slit in the usual manner, the extruded film being oriented lengthwise at least in the ratio of 1:1.5, cooled and stored until the modulus of elasticity has increased by at least 25%, measured according to DIN 53,455, before the film is slit, and the use of these tapes for the production of elastic seals.
Inventors
- 👤 Wolfgang Ermert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:48
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/02; B29C55/04; B29C55/06; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29K; B29K2075/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
110 words
In the production of elastic tapes by extruding a thermoplastic polyurethane elastomer to form a flat or tubular film, orienting the film and slitting the film into tapes, the improvement which comprises orienting the extruded film lengthwise with a take-off ratio of at least 1:1.5, cooling the film and storing it under tension until the modulus of elasticity, according to DIN 53,455, has increased by at least 25% prior to slitting, including the additional steps of stretching the tape, bonding the stretched tape to a substrate with a hot melt adhesive, cooling and releasing the stress, and subjecting the substrate-tape structure to a further heat treatment to shrink said tape.
Claim 2
Dependent Claim
110 words
In the production of elastic tapes by extruding a thermoplastic polyurethane elastomer to form a flat or tubular film, orienting the film and slitting the film into tapes, the improvement which comprises orienting the extruded film lengthwise with a take-off ratio of at least 1:1.5, cooling the film and storing it under tension until the modulus of elasticity, according to DIN 53,455, has increased by at least 25% prior to slitting, including the additional steps of stretching the tape, bonding the stretched tape to a substrate with a hot melt adhesive, cooling and releasing the stress, and subjecting the substrate-tape structure to a further heat treatment to shrink said tape.
Claim 3
Dependent Claim
14 words
The process according to claim 1, wherein the polyurethane elastomer is a polyurethane-polymer elastomer.
Claim 4
Dependent Claim
23 words
The process according to claim 1, wherein the extruded material forms a tubular film which is wound and stored under high winding tension.
Claim 5
Dependent Claim
22 words
The process according to claim 1, wherein the further heat treatment is carried out at a temperature of at least 60° C.
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) | 1991-11-29 | 1992-05-30 | 1992-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-29 | 1996-05-30 | 1996-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-29 | 2000-05-30 | 2000-11-29 | $7700.00 | Window Closed / Lapsed |