US3846522A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Forming of thermoplastic polymers
Assignee: Elpex Inc
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Filing: 1973-03-15
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Granted: 1974-11-05
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Expires: 1993-03-15
Abstract
Abstract Thermoplastic resin in comminuted form is subjected to compacting forces of magnitudes and rates, sufficient to shape an article in a retaining mold. Densities can be controlled within wide limits, by controlling the final compaction volume and force on the resin. Comminuted resin is heated, prior to forming, outside the mold, by utilizing spray-drying, fluidized-bed, infrared, dielectric heating, and others means individually or in combination, to attain the desired resin temperatures. Springback in forged plastics is minimized.
Inventors
- 👤 C Goldman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 06:50
CPC Classifications
B; B29; B29C; B29C43/00; B29C43/02; B29C43/16; B29C43/32; B29C43/36; B29C43/361; B29C35/00; B29C35/02; B29C35/08; B29C35/0805; B29C2035/0822; B29C2043/3205; B29C2043/3255; B29C2043/3615; B29C35/0244; B29C35/12; B29K; B29K2055/00; B29K2086/00; B29K2105/00; B29K2105/06; B29K2105/12; B29K2105/16; B29K2105/165; B29K2105/25; B29K2105/251
Claims Analysis
Total Claims: 44
Claim 1
Independent Claim
29 words
A METHOD OF FORMING A SHAPED PLASTIC ARTICLE IN A PRESS COMPRISING A REMOVABLE MOLD WHICH ARTICLE DOES NOT OBTAIN DIMENSIONAL STABILITY IMMEDIATELY AFTER BEING SHAPED THE METHOD COMPRISING:
Claim 2
Independent Claim
29 words
A METHOD OF FORMING A SHAPED PLASTIC ARTICLE IN A PRESS COMPRISING A REMOVABLE MOLD WHICH ARTICLE DOES NOT OBTAIN DIMENSIONAL STABILITY IMMEDIATELY AFTER BEING SHAPED THE METHOD COMPRISING:
Claim 3
Dependent Claim
16 words
HEATING COMMINUTED THERMOPLASTIC RESIN TO TEMPERATURES APPROACHING BUT BELOW THE POINT OF FUSION OF SAID RESIN;
Claim 4
Dependent Claim
16 words
HEATING COMMINUTED THERMOPLASTIC RESIN TO TEMPERATURES APPROACHING BUT BELOW THE POINT OF FUSION OF SAID RESIN;
Claim 5
Dependent Claim
61 words
PLACING THE HEATED COMMINUTED THERMOPLASTIC RESIN, WHICH HAS A BULK DENSITY OF 52 PERCENT OR LESS OF THE SOLID RESIN DENSITY, IN A REMOVABLE MOLD COMPRISING AN UPPER MEMBER AND A LOWER MEMBER, SAID MEMBERS IN UNLOCKABLE MATED POSITION, AT LEAST THE UPPER MEMBER HAVING A BORE WHICH ALLOWS THE PASSAGE OF THE COMMINUTED RESIN TO THE INTERIOR OF THE MOLD;
Claim 6
Dependent Claim
61 words
PLACING THE HEATED COMMINUTED THERMOPLASTIC RESIN, WHICH HAS A BULK DENSITY OF 52 PERCENT OR LESS OF THE SOLID RESIN DENSITY, IN A REMOVABLE MOLD COMPRISING AN UPPER MEMBER AND A LOWER MEMBER, SAID MEMBERS IN UNLOCKABLE MATED POSITION, AT LEAST THE UPPER MEMBER HAVING A BORE WHICH ALLOWS THE PASSAGE OF THE COMMINUTED RESIN TO THE INTERIOR OF THE MOLD;
Claim 7
Dependent Claim
61 words
placing the heated comminuted thermoplastic resin, which has a bulk density of 52 percent or less of the solid resin density, in a removable mold comprising an uppEr member and a lower member, said members in unlockable mated position, at least the upper member having a bore which allows the passage of the comminuted resin to the interior of the mold;
Claim 8
Dependent Claim
61 words
placing the heated comminuted thermoplastic resin, which has a bulk density of 52 percent or less of the solid resin density, in a removable mold comprising an uppEr member and a lower member, said members in unlockable mated position, at least the upper member having a bore which allows the passage of the comminuted resin to the interior of the mold;
Claim 9
Dependent Claim
56 words
A method of forming a shaped plastic article as noted in claim 1, in which the heating of the comminuted plastic resin is performed by exposing the resinous material, while being transported through a transparent conduit in a gaseous fluid, to one or more infra-red wavelengths which are 80% or more absorbed by the resinous material.
Claim 10
Dependent Claim
11 words
placing the heated comminuted resin in the cavity of the mold;
Claim 11
Dependent Claim
11 words
placing the heated comminuted resin in the cavity of the mold;
Claim 12
Dependent Claim
36 words
subjecting the comminuted resin to a controlled forging force so as to densify the comminuted resin to a coherent shaped article, having a density between 20 percent and 100 percent of that of the solid resin;
Claim 13
Dependent Claim
36 words
subjecting the comminuted resin to a controlled forging force so as to densify the comminuted resin to a coherent shaped article, having a density between 20 percent and 100 percent of that of the solid resin;
Claim 14
Dependent Claim
57 words
A method of forming a shaped plastic article as in claim 1, in which the thermoplastic resin is selected from the group consisting of polyethylenes, polypropylenes, polystyrenes, polyvinyl-chlorides, ethylene-vinyl acetate copolymers, polyesters, cellulosic polymers, polyurethanes, polysulfones, polycarbonates polyamides, polyacrylates, polyacrylonitriles, styrene-butadiene copolymers, ABS resins, including copolymers, graft polymers and heteropolymers of the above resins, fluorocarbons, epoxies, polyimides.
Claim 15
Dependent Claim
51 words
subjecting the comminuted resin, by means of a molding cap being slidably movable in the bore, to a forging force of such magnitude and rate of application such that the kinetic energy of the forging means is converted to sufficient thermal energy thereby forming a forged article from the comminutive resin;
Claim 16
Dependent Claim
51 words
subjecting the comminuted resin, by means of a molding cap being slidably movable in the bore, to a forging force of such magnitude and rate of application such that the kinetic energy of the forging means is converted to sufficient thermal energy thereby forming a forged article from the comminutive resin;
Claim 17
Dependent Claim
51 words
SUBJECTING THE COMMINUTED RESIN, BY MEANS OF A MOLDING CAP BEING SLIDABLY MOVABLE IN THE BORE, TO A FORGING FORCE OF SUCH MAGNITUDE AND RATE OF APPLICATION SUCH THAT THE KINETIC ENERGY OF THE FORGING MEANS IS CONVERTED TO SUFFICIENT THERMAL ENERGY THEREBY FORMING A FORGED ARTICLE FROM THE COMMINUTIVE RESIN;
Claim 18
Dependent Claim
51 words
SUBJECTING THE COMMINUTED RESIN, BY MEANS OF A MOLDING CAP BEING SLIDABLY MOVABLE IN THE BORE, TO A FORGING FORCE OF SUCH MAGNITUDE AND RATE OF APPLICATION SUCH THAT THE KINETIC ENERGY OF THE FORGING MEANS IS CONVERTED TO SUFFICIENT THERMAL ENERGY THEREBY FORMING A FORGED ARTICLE FROM THE COMMINUTIVE RESIN;
Claim 19
Dependent Claim
19 words
WITHOUT RELEASING THE PRESSURE PRODUCED BY THE FORGING FORCE REMOVING THE MOLD CONTAINING THE FORGED ARTICLE FROM THE PRESS;
Claim 20
Dependent Claim
19 words
WITHOUT RELEASING THE PRESSURE PRODUCED BY THE FORGING FORCE REMOVING THE MOLD CONTAINING THE FORGED ARTICLE FROM THE PRESS;
Claim 21
Dependent Claim
19 words
without releasing the pressure produced by the forging force removing the mold containing the forged article from the press;
Claim 22
Dependent Claim
19 words
without releasing the pressure produced by the forging force removing the mold containing the forged article from the press;
Claim 23
Dependent Claim
65 words
A method of forming a shaped plastic article as in claim 1, in which the thermoplastic resin contains fillers selected from the group consisting of mineral fillers in powder flake or bead form, mineral fillers in fibrous form, organic fibrous fillers occuring in nature, synthetic organic fibers, comminuted expanded polymers, cork, micro balloons of glass, micro balloons of carbon and micro balloons of thermosetting resins.
Claim 24
Dependent Claim
16 words
without releasing the pressure produced by the forging force, removing the mold from the forging means;
Claim 25
Dependent Claim
16 words
without releasing the pressure produced by the forging force, removing the mold from the forging means;
Claim 26
Dependent Claim
12 words
allowing the shaped article to reach a state of dimensional stability; and
Claim 27
Dependent Claim
12 words
allowing the shaped article to reach a state of dimensional stability; and
Claim 28
Dependent Claim
183 words
A method of forming a shaped plastic article, as noted in claim 1, in which the forging force is provided by a modified explosive forming unit, comprising an upper portion, in mating contact with the top section of a two piece mold, and a lower portion, in mating contact with the bottom section of a two piece mold, said top section including automotive inlet and exhaust ports and valves, means for igniting fuel mixtures, a piston fitted with rings, moveable within a cylinder chamber, the bottom of said piston having a rod member extending outwardly therefrom, concentrically, and of sufficient length and diameter, to engage with a cylindrical cavity in the top half of the two piece mold, and to provide compaction force to the resin contained in the mold, when the fuel mixture is ignited; a bottom piston fitted with rings, moveable within a lower cylinder chamber, said bottom piston supporting in intimate contact the bottom portion of the two piece mold, and resting a top a controllable restricting means, which will yield axially as the compacting force exceeds a predetermined value.
Claim 29
Dependent Claim
12 words
allowing the forged article to reach a state of dimensional stability; and
Claim 30
Dependent Claim
12 words
allowing the forged article to reach a state of dimensional stability; and
Claim 31
Dependent Claim
12 words
ALLOWING THE FORGED ARTICLE TO REACH A STATE OF DIMENSIONAL STABILITY; AND
Claim 32
Dependent Claim
12 words
ALLOWING THE FORGED ARTICLE TO REACH A STATE OF DIMENSIONAL STABILITY; AND
Claim 33
Dependent Claim
12 words
RELEASING THE PRESSURE AND REMOVING THE STABILIZED, FORGED ARTICLE FROM THE MOLD.
Claim 34
Dependent Claim
12 words
RELEASING THE PRESSURE AND REMOVING THE STABILIZED, FORGED ARTICLE FROM THE MOLD.
Claim 35
Dependent Claim
12 words
releasing the pressure and removing the stabilized, forged article from the mold.
Claim 36
Dependent Claim
12 words
releasing the pressure and removing the stabilized, forged article from the mold.
Claim 37
Dependent Claim
26 words
A method of forming a shaped article as in claim 5, in which the compacting force is administered in a multiplicity of blows per molding cycle.
Claim 38
Dependent Claim
13 words
releasing the pressure and removing the stabilized shaped article from the mold cavity.
Claim 39
Dependent Claim
13 words
releasing the pressure and removing the stabilized shaped article from the mold cavity.
Claim 40
Dependent Claim
103 words
A method of forming a molded part, as noted in claim 5, in which the forging unit is brought into mating contact with the mold chamber, while the piston is moving, allowed to remain in contact with the mold member for a multiple number of strokes of the piston, until the moldable mass has been compacted to the desired degree, followed by retracting the forged unit to a position which is non mating with the mold member, and removing the mold member from the forging zone, where it may be opened, and from which may be removed, the formed and stabilized molded part.
Claim 41
Independent Claim
33 words
A method of forming a shaped plastic article in a forging means comprisiNg a removable mold which article does not obtain dimensional stability immediately after being shaped the method comprising the steps of:
Claim 42
Independent Claim
33 words
A method of forming a shaped plastic article in a forging means comprisiNg a removable mold which article does not obtain dimensional stability immediately after being shaped the method comprising the steps of:
Claim 43
Independent Claim
209 words
A method of forming a shaped plastic article, in a press comprising a removable mold, which article does not obtain dimensional stability immediately after being shaped, the method comprises the steps of: a. heating comminuted theremoplastic resin to temperatures approaching but below the point of fusion of said resin; b. placing the heated comminuted thermoplastic resin, which has a bulk density of 52 percent or less of the solid resin density, in a removable mold comprising an upper member and a lower member, said members in unlockable mated position, at least the upper member having a bore which allows the passage of the comminuted resin to the interior of the mold; c. subjecting the comminuted resin, by means of a mold cap being slidably movable in the bore to a forging force of such magnitude and rate of application such that the kinetic energy of the forging force is converted to sufficient thermal energy thereby forming a forged article from the comminuted resin; d. without releasing the pressure produced by the forging force, removing the mold containing the forged article from the press; e. allowing the forged article to reach a state of dimensional stability; and f. releasing the pressure and removing the stabilized, forged article from the mold.
Claim 44
Independent Claim
209 words
A method of forming a shaped plastic article, in a press comprising a removable mold, which article does not obtain dimensional stability immediately after being shaped, the method comprises the steps of: a. heating comminuted theremoplastic resin to temperatures approaching but below the point of fusion of said resin; b. placing the heated comminuted thermoplastic resin, which has a bulk density of 52 percent or less of the solid resin density, in a removable mold comprising an upper member and a lower member, said members in unlockable mated position, at least the upper member having a bore which allows the passage of the comminuted resin to the interior of the mold; c. subjecting the comminuted resin, by means of a mold cap being slidably movable in the bore to a forging force of such magnitude and rate of application such that the kinetic energy of the forging force is converted to sufficient thermal energy thereby forming a forged article from the comminuted resin; d. without releasing the pressure produced by the forging force, removing the mold containing the forged article from the press; e. allowing the forged article to reach a state of dimensional stability; and f. releasing the pressure and removing the stabilized, forged article from the mold.
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) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |