METHOD AND APPRATUS FOR MANUFACTURE OF 3D OBJECTS
The current three-dimensional object manufacturing technique relies on the deposition of a pseudoplastic material in gel aggregate state. The gel flows through a deposition nozzle because the applied agitation and pressure shears the bonds and induces a breakdown in the material elasticity. The elasticity recovers immediately after leaving the nozzle, and the gel solidifies to maintain its shape and strength.
1 . A pseudoplastic material for manufacture of three-dimensional objects comprising:
20-96 weight-% of epoxy resin;
0-30 weight % of oxetane;
0-30 weight-% of polyol;
0.5-6 weight-% of at least one cationic photoinitiator;
0-30 weight-% of at least one rheology modifier; and
0-30 weight-% of at least one performance additive/filler; and
wherein the pseudoplastic material is formulated to form the three-dimensional objects by extruding a layer of the pseudoplastic material and curing the extruded layer to form a cured extruded layer, and successively extruding and curing layers of the pseudoplastic material upon the cured extruded layer; and
wherein the pseudoplastic material is formulated to be cured by cationic curing.
2 . The pseudoplastic material according to claim 1 , wherein the epoxy resin is at least one of a group of resins consisting cycloaliphatic epoxies.
3 . The pseudoplastic material according to claim 1 , wherein the epoxy resin comprises at least one of modified and unmodified Bisphenol A, Oxiranes oxides of alkadienes, alkenes, cycloalkadienes and cycloalkenes.
4 . The pseudoplastic material according to claim 1 , wherein the oxirane comprises at least one selected from a group consisting of Cyclohexanol, 4,4′-(1-methylethylidene)bis, polymer with (chloromethyl) oxirane, hydrogenated Bisphenols A, 3′,4′-Epoxycyclohexane)methyl 3,4-epoxycyclohexylcarboxylate, Bis(7-oxabicyclo[4.1.0]hept-3-ylmethyl) adipate.
5 . The pseudoplastic material according to claim 1 , wherein the oxetane comprises at least one selected from a group consisting of vinyl ethers, TMPO-3-ethyl-3-hydroxymethyloxetane, 2-Oxepanone, polymer with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 2-oxepanone, polymer with 2,2-bis(hydroxymethyl)-1,3-propanediol.
6 . The pseudoplastic material according to claim 1 , wherein the polyol comprises at least one selected from a group consisting of chain extenders such as 2-Oxepanone, polymer with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol, 2-oxepanone, polymer with 2,2-bis(hydroxymethyl)-1,3-propanediol.
7 . The pseudoplastic material according to claim 1 , wherein the cationic photoinitiator comprises at least one of a group of cationic photoinitiators consisting of Iodonium (4-methylphenyl)[4-(2-methylpropyl)phenyl]-, hexafluorophosphate(1-) (1:1) (4-methylphenyl)[4-(2-methylpropyl) phenyl]-, hexafluorophosphate in propylene carbonate, triarylsulfonium hexafluorophosphate with sensitizer, 4,4′-dimethyl-diphenyl iodonium hexafluorophosphate, and 3-ethyl-3-hydroxymethloxetane.
8 . The pseudoplastic material according to claim 1 , wherein the cationic photoinitiator sensitizer comprises at least one of a group of sensitizers consisting of 9,10-Dibutoxyanthracene and Isopropylthioxanthone to enhance reactivity of the cationic photoinitiator and extend curing radiation range to longer wavelengths.
9 . The pseudoplastic material according to claim 1 , wherein the rheology modifier comprises at least one of a group of rheology modifiers consisting of attapulgite clays, bentonite clays, organoclays, treated and untreated synthetic silicas, and fumed silica.
10 . The pseudoplastic material according to claim 1 , wherein the performance additive/filler comprises at least one of a group of filers consisting of pigments, glass beads, Kevlar fibers, nylon fibers, flame retardants, impact modifiers clay and silica.
11 . The pseudoplastic material according to claim 1 , wherein a first viscosity of the material before extrusion is in a range of about 120,000.00 mPa·s to about 500,000.00 mPa·s at atmospheric pressure; and/or wherein a second viscosity of the material when a force is applied is in a range of about 250 to about 700 mPa·s.
12 . The pseudoplastic material according to claim 1 , wherein the psuedoplastic material is extruded in layers to form the three-dimensional objects having a cantilever ratio of at least 1:4.
13 . The pseudoplastic material according to claim 1 , wherein the pseudoplastic material is curable by ultraviolet radiation with a wavelength in a range of 360 to 485 nm.
14 . The pseudoplastic material according to claim 1 , wherein the pseudoplastic material can be extruded onto an earlier extruded layer of cured pseudoplastic material and then cured to form a bond between the cured layers of pseudoplastic material.
15 . The pseudoplastic material according to claim 1 , wherein a bond is strong enough to support a later extruded layer of the pseudoplastic material in a suspended state.
16 . The pseudoplastic material according to claim 1 , wherein the psuedoplastic material can form a three-dimensional object free of any conventional support structures when extruded in layers and cured.
17 . The pseudoplastic material according to claim 1 , wherein the pseudoplastic material can recover at least 30% of a first viscosity immediately upon being extruded and exposed to atmospheric pressure.
18 . The pseudoplastic material according to claim 1 , wherein the pseudoplastic material can recover at least 40% of the first viscosity immediately upon being extruded and exposed to atmospheric pressure.
19 . The pseudoplastic material according to claim 1 , wherein the pseudoplastic material can recover at least 50% of the first viscosity immediately upon being extruded and exposed to atmospheric pressure.
20 . The pseudoplastic material according to claim 1 , wherein the pseudoplastic material can recover 60% to 90% of the first viscosity immediately upon being extruded and exposed to atmospheric pressure.
21 . The pseudoplastic material according to claim 1 , wherein the psuedoplastic material can be extruded in layers to form the three-dimensional objects including cantilever objects having a cantilever ratio of at least 1:4 without use of structures to support uncured pseudoplastic material.
22 . The pseudoplastic material according to claim 1 , wherein the psuedoplastic material can be extruded in layers to form the three-dimensional objects including cantilever objects having a cantilever ratio of at least 1:5 without use of structures to support uncured pseudoplastic material.
23 . The pseudoplastic material according to claim 1 , wherein the psuedoplastic material can be extruded in layers to form the three-dimensional objects including cantilever objects having a cantilever ratio of 1:5 to 1:200 without use of structures to support uncured pseudoplastic material.
24 . The pseudoplastic material according to claim 1 , wherein a second viscosity is in a range of 250 to 700 mPa·s.
25 . The pseudoplastic material according to claim 1 , wherein a second viscosity is in a range of 250 to 700 mPa·s at a pressure of 0.1 to 30 bar.
26 . The pseudoplastic material according to claim 1 , wherein the first viscosity is in a range of 100,000 to 400,000 mPa·s at atmospheric pressure.
27 . A pseudoplastic material for manufacture of three-dimensional objects comprising:
0-30% acrylate oligomer;
0-30% acrylate monomer;
0.5-10% free radical photoinitiator;
30-70% epoxy resin;
0-30% oxetane;
0-30% polyol;
0.1-5% cationic photoinitiator;
0-5% sensitizer;
1-10% rheology modifier; and
0-30% performance improving additives/fillers; and
wherein the pseudoplastic material is formulated to form three-dimensional objects by extruding a layer of the pseudoplastic material and curing the extruded layer to form a cured extruded layer, and successively extruding and curing layers of the pseudoplastic material upon the cured extruded layer, the pseudoplastic material having a first viscosity when under atmospheric pressure and a second viscosity when under an extrusion pressure during extrusion, the second viscosity being less than the first viscosity, the second viscosity allowing the psuedoplastic material to flow when extruded from a three-dimensional printer, and the first viscosity allowing uncured psuedoplastic material to form the three-dimensional object including a cantilever object; and wherein the pseudoplastic material is a hybrid curable formulation.
28 . A method of forming a three-dimensional object comprising:
a) providing a highly viscous pseudoplastic material having a first viscosity and agitating the material to shear the pseudoplastic material and cause it to flow through a delivery system to an extrusion unit;
b) employing an extrusion unit to extrude a first strip of the pseudoplastic material in image-wise manner;
c) extruding a second strip of the pseudoplastic material, the second strip adjacent to the first strip and contacting the first strip at at least one contact point;
d) continuously illuminating the first and the second strip to harden the pseudoplastic material;
e) continue to extrude the pseudoplastic material in an image-wise manner and continuously illuminate extruded material to form a three-dimensional object; and wherein the pseudoplastic material is a hybrid curable formulation material.
29 . A method of forming a three-dimensional object comprising:
a) providing a highly viscous pseudoplastic material formulated for hybrid curing and having a first viscosity and agitating the material to shear the pseudoplastic material thereby decreasing viscosity to a second viscosity and to cause it to flow through a delivery system to an extrusion unit;
b) employing an extrusion unit to extrude a first portion of the pseudoplastic material in image-wise manner, the first portion having a cross section with a diameter;
c) illuminating the first extruded portion to harden the pseudoplastic material;
d) extruding a second portion of the pseudoplastic material adjacent to the first portion and contacting the first portion at at least one contact point, wherein a cross section of the second portion is shifted in an axis perpendicular to a gravitational force compared to the cross section of the first portion;
e) obtaining a common contact section between surfaces of the first and second extruded portions by forming an envelope into which a segment of the first portion protrudes by sliding, due to a gravitational force, of the second portion along circumference of surface of the first portion hardened in step c), wherein surface of the second portion wets surface of the first portion at the common contact section;
f) illuminating the extruded second portion to harden the pseudoplastic material and to form a bond between the first and second portions of pseudoplastic material at the common contact section;
g) adjusting relative position between extrusion unit and extruded second portion such that the second portion obtains location of extruded first portion of step b); and
h) repeating steps d) to g) until the three-dimensional object has been formed.