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US3929939A Expired / Lapsed US ⏱️ 0.0 years remaining

Large void-free polyethylene castings comprising high density polyethylene in a low density polyethylene matrix

Assignee: Monsanto Research Corp
•
Filing: 1973-12-13
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Granted: 1975-12-30
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Expires: 1993-12-13
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Abstract

Abstract Large void-free castings of polyethylene can be made by blending high density polyethylene pellets with low density polyethylene powder, followed by heating to above the melting point of the low density polyethylene and below, or only slightly above, the melting point of the high density polyethylene. Flame proofing additives, crosslinking agents and other materials can be readily incorporated into the blend before fusing. The mixture of high density and low density polyethylene significantly reduces the amount of shrinkage which takes place during the cooling from the melting temperature to ambient temperature. The low density polyethylene should have a sufficiently low melt viscosity so that it will flow under small pressures above the melting temperature.

Inventors

  • 👤 Ival O Salyer
  • 👤 Charles J North

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-26 22:48
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/005; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; C08J2323/00; C08J2323/02; C08J2323/04; C08J2323/06; C08L2205/00; C08L2205/02; C08L2205/025; C08L2312/00

Claims Analysis

Total Claims: 3
Claim 1
Independent Claim 37 words
A COMPOSITE MATERIAL WHICH COMPRISES 50 TO 75 WEIGHT PERCENT HIGH DENSITY POLYETHYLENE PELLETS HAVING A SIZE RANGE OF ABOUT ONE-SIXTEENTH INCH TO ONE-FOURTH INCH IN A MATRIX OF 25 TO 50 WEIGHT PERCENT LOW DENSITY POLYETHYLENE.
Claim 2
Dependent Claim 37 words
A COMPOSITE MATERIAL WHICH COMPRISES 50 TO 75 WEIGHT PERCENT HIGH DENSITY POLYETHYLENE PELLETS HAVING A SIZE RANGE OF ABOUT ONE-SIXTEENTH INCH TO ONE-FOURTH INCH IN A MATRIX OF 25 TO 50 WEIGHT PERCENT LOW DENSITY POLYETHYLENE.
Claim 3
Dependent Claim 20 words
A composite of claim 1 wherein the polyethylene is crosslinked with about 0.5 to about 5.0 weight percent dicumyl peroxide.

References Cited (Backward Citations)

US2919474A Cited
US3231636A Cited
US3511742A Cited
US3474051A Cited
US3478132A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-12-29 1979-06-30 1979-12-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-12-29 1983-06-30 1983-12-30 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-12-29 1987-06-30 1987-12-30 $7700.00 Window Closed / Lapsed

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