EP0963824A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Cross-linked molded plastic bearings
Assignee: DePuy Products Inc
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Filing: 1999-06-09
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Granted: —
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Expires: 2019-06-09
Abstract
Abstract A method is provided for forming a plastic prosthesis bearing, net-shape bearing, near net-shape bearing or plastic stock from which such a bearing can be formed. The method includes the steps of providing plastic resin in powdered form, subjecting the powdered resin to irradiation to cross-link the resin, and molding the irradiated powder. The irradiated powder is molded by applying heat and pressure to form the powder into a desired solid plastic shape, the heating being sufficient to melt the powder.
Inventors
- 👤 Donald E. Mcnulty
- 👤 Todd Smith
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 21:35
CPC Classifications
B; B29; B29C; B29C67/00; B29C67/0037; B29B; B29B13/00; B29B13/08; B29C43/00; B29C43/006; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/085; B29C35/0866; B29C2035/0877; B29C2791/00; B29C2791/004; B29C2791/005; B29C2791/006; B29C43/02; B29C43/16; B29K; B29K2023/00; B29K2023/04; B29K2023/06; B29K2023/0658; B29K2023/0683; B29K2105/00; B29K2105/25; B29K2105/251; B29K2995/00; B29K2995/0037; B29K2995/0087; B29K2995/0089; B29L; B29L2031/00; B29L2031/753; B29L2031/7532
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
74 words
A method for forming a plastic prosthesis bearing, net-shape
bearing, near net-shape bearing or plastic stock from which such a bearing can be
formed, the method comprising the steps of providing plastic resin in powdered form, subjecting the powdered resin to irradiation to cross-link the resin, and molding the irradiated powder by applying heat and pressure to form
the powder into a desired solid plastic shape, the heating being sufficient to melt the
powder.
Claim 2
Dependent Claim
17 words
The method of claim 1 in which the irradiation step is
accomplished in an oxygen reduced atmosphere.
Claim 3
Dependent Claim
17 words
The method of claim 1 in which the molding step is
accomplished in an oxygen reduced atmosphere.
Claim 4
Dependent Claim
17 words
The method of claim 1 in which the molding step involves
pressure from 1,000 to 70,000 psi.
Claim 5
Dependent Claim
20 words
The method of claim 1 in which the molding step is at a
temperature of 250° F to 500° F.
Claim 6
Dependent Claim
21 words
The method of claim 1 in which the irradiation step is at a level
of 2 to 100 Mrads gamma radiation.
Claim 7
Dependent Claim
22 words
The method of claim 1 in which the irradiation step is at a level
of 2 to 5 Mrads of gamma radiation.
Claim 8
Dependent Claim
22 words
The method of claim 1 in which the irradiation step is at a level
of 2 to 20 Mrads of gamma radiation.
Claim 9
Dependent Claim
43 words
The method of claim 1 in which the irradiation step comprises
the steps of placing resin powder in pouches formed from a breathable plastic
membrane, placing the pouches in a container, and providing an oxygen reduced
atmosphere in the container during the irradiation.
Claim 10
Dependent Claim
29 words
The method of claim 9 in which the molding step involves
transferring the pouches containing the irradiated resin to the molding press where the
heat and pressure are applied.
Claim 11
Dependent Claim
21 words
The method of claim 10 in which the molding step involves a
temperature greater than the melting point of the resin.
Claim 12
Dependent Claim
14 words
The method of Claim 1 in which the plastic is an olefinic plastic
resin.
Claim 13
Dependent Claim
11 words
The method of Claim 1 in which the plastic is UHMWPE.
Claim 14
Independent Claim
84 words
A method for forming a plastic prosthesis bearing, net-shape
bearing, near net-shape bearing or plastic stock from which such a bearing can be
formed, the method comprising the steps of providing plastic resin in powdered form, subjecting the powdered resin to irradiation to cross-link the resin, heating the powder resin within a mold to a temperature at or above the
melting point of the resin for a time sufficient to form the powder into a desired solid
plastic shape and quench the free radicals.
Claim 15
Dependent Claim
17 words
The method of claim 14 in which the irradiation step is
accomplished in an oxygen reduced atmosphere.
Claim 16
Dependent Claim
17 words
The method of claim 14 in which the heating step is
accomplished in an oxygen reduced atmosphere.
Claim 17
Dependent Claim
17 words
The method of claim 14 in which the heating step involves
pressure from 1,000 to 70,000 psi.
Claim 18
Dependent Claim
20 words
The method of claim 14 in which the heating step is at a
temperature of 250° F to 500° F.
Claim 19
Dependent Claim
21 words
The method of claim 18 in which the irradiation step is at a level
of 2 to 100 Mrads gamma radiation.
Claim 20
Dependent Claim
22 words
The method of claim 14 in which the irradiation step is at a level
of 2 to 5 Mrads of gamma radiation.
References Cited (Backward Citations)
No citation records indexed.
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