Solid freeform fabrication methods

• US 5,900,207 A
• Filed: 05/20/1997
• Issued: 05/04/1999
• Est. Priority Date: 02/08/1996
• Status: Expired due to Term

• Current Assignee: Rutgers University, Stratasys Incorporated
• Original Assignee: Rutgers The State University Old Queens, Stratasys Incorporated
• Inventors: Priedeman, William R. Jr., Langrana, Noshir, Bandyopadghyay, Amit, Agarwala, Mukesh, van Weeren, Remco, Safari, Ahmad, Jamalabad, Vikram R., Danforth, Stephen C.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US08/858,965
• Time in Patent Office: 714 Days
• Field of Search: 264/255, 264/308, 264/603, 264/604, 264/678, 364/468, 364/26, 419/1, 419/5, 419/36
• US Class Current: 264/603
• CPC Class Codes: B22F 1/10 Metallic powder containing lubricating or binding agents; Metallic powder containing organic material
• CPC Class Codes: B22F 1/103 containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent
• CPC Class Codes: B22F 10/18 by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF]
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B29B 7/48 with intermeshing devices, e.g. screws
• CPC Class Codes: B29B 7/582 for discharging, e.g. doors
• CPC Class Codes: B29B 7/72 Measuring, controlling or regulating
• CPC Class Codes: B29B 7/823 Temperature control
• CPC Class Codes: B29B 7/826 Apparatus therefor
• CPC Class Codes: B29C 41/36 Feeding the material on to the mould, core or other substrate
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 40/20 Post-treatment, e.g. curing, coating or polishing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: C03B 19/066 for the production of quartz or fused silica articles other processes specially adapted for the production of quartz or fused silica articles C03B20/00
• CPC Class Codes: C04B 2235/383 Alpha silicon carbide
• CPC Class Codes: C04B 2235/6021 Extrusion moulding
• CPC Class Codes: C04B 2235/6026 : Computer aided shaping, e.g. rapid prototyping
• CPC Class Codes: C04B 2235/6562 : Heating rate
• CPC Class Codes: C04B 2235/6565 : Cooling rate
• CPC Class Codes: C04B 2235/658 : Atmosphere during thermal treatment
• CPC Class Codes: C04B 2235/6583 : Oxygen containing atmosphere, e.g. with changing oxygen pressures
• CPC Class Codes: C04B 2235/767 : Hexagonal symmetry, e.g. beta-Si3N4, beta-Sialon, alpha-SiC or hexa-ferrites
• CPC Class Codes: C04B 2235/77 : Density
• CPC Class Codes: C04B 2235/85 : Intergranular or grain boundary phases
• CPC Class Codes: C04B 2235/96 : Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
• CPC Class Codes: C04B 2235/9615 : Linear firing shrinkage
• CPC Class Codes: C04B 2235/9623 : Ceramic setters properties
• CPC Class Codes: C04B 2237/368 : Silicon nitride
• CPC Class Codes: C04B 2237/704 : of one or more of the ceramic layers or articles
• CPC Class Codes: C04B 35/14 : based on silica
• CPC Class Codes: C04B 35/584 : based on silicon nitride
• CPC Class Codes: C04B 35/62665 : Flame, plasma or melting treatment
• CPC Class Codes: C04B 35/62695 : Granulation or pelletising devices for shaping artificial aggregates from ceramic mixtures B28B1/004
• CPC Class Codes: C04B 35/632 : Organic additives
• CPC Class Codes: C04B 35/63408 : Polyalkenes
• CPC Class Codes: C04B 35/63432 : Polystyrenes
• CPC Class Codes: C04B 35/63436 : Halogen-containing polymers, e.g. PVC
• CPC Class Codes: C04B 35/6346 : Polyesters
• CPC Class Codes: C04B 35/63488 : Polyethers, e.g. alkylphenol polyglycolether, polyethylene glycol [PEG], polyethylene oxide [PEO]
• CPC Class Codes: C04B 35/63492 : Natural resins, e.g. rosin
• CPC Class Codes: C04B 35/638 : Removal thereof
• CPC Class Codes: C04B 35/64 : Burning or sintering processes C04B33/32 takes precedence ; powder metallurgy B22F
• CPC Class Codes: D01F 1/10 : Other agents for modifying properties
• CPC Class Codes: Y02P 10/25 : Process efficiency
• CPC Class Codes: Y02P 40/57 : Improving the yield, e-g- reduction of reject rates

Abstract

A fused deposition process is used to form three-dimensional solid objects from a mixture including a particulate composition dispersed in a binder. The article is formed by depositing the mixture in repeated layers of predefined thickness, with each layer solidifying before the next adjacent layer is dispensed. Following formation and a binder removal step, the article may be at least partially densified to achieve preselected properties. The process permits three-dimensional articles to be formed relatively quickly and inexpensively, without the need for molds or other tooling.

Claims

1. In a process for making a three-dimensional article incorporating the steps of:

providing a mixture of a particulate composition dispersed in a binder;

dispensing the mixture from dispensing apparatus onto a build platform; and

during the dispensing step, moving the dispensing apparatus and build platform relative to one another to form the dispensed mixture into a three-dimensional article, the improvement comprising;

Providing as the binder in said mixture a binder including a plurality of organic components having melting temperatures in a range from a lowest melting temperature to a highest melting temperature, and said particulate composition including an organic material having a melting temperature greater than said highest melting temperature.

2. In a process for making a three-dimensional article incorporating the steps of:

providing a mixture of a particulate composition dispersed in a binder;

dispensing the mixture from dispensing apparatus onto a build platform; and

during the dispensing step, moving the dispensing apparatus and build platform relative to one another to form the dispensed mixture into a three-dimensional article, the improvement comprising;

Providing as the binder in said mixture a binder comprising a plurality of organic components including a polymer, a wax, an elastomer, and a tackifier.

4. A process as claimed in claim 2, wherein said binder includes between about 5 volume percent and about 50 volume percent of said polymer.

5. A process as claimed in claim 2, wherein said polymer is selected from the group consisting of polyvinyl alcohol, polyethylene, polyvinyl acetate, poly (vinyl ethers), poly (vinyl esters), vinyl ester copolymers, ethylene-vinyl acetate copolymers and combinations thereof.

6. A process as claimed in claim 2, wherein said binder includes between about 5 volume percent and about 50 volume percent of said wax.

7. A process as claimed in claim 2, wherein said wax is selected from the group consisting of paraffin waxes, microcrystalline waxes, synthetic hydrocarbon waxes, oxidized polyethylene waxes and combinations thereof.

9. A process as claimed in claim 2, wherein said elastomer is selected from the group consisting of polychloroprene, styrene-butadiene copolymer, natural rubber, neoprene, polyisoprene, polybutadiene and combinations thereof.

10. A process as claimed in claim 2, wherein said binder includes between about 5 volume percent and about 50 volume percent of said tackifier.

11. A process as claimed in claim 2, wherein said tackifier is selected from the group consisting of terpene and polyterpene resins, terpene phenolic resins, aliphatic petroleum hydrocarbon resins, rosins, rosin derivatives and combinations thereof.

12. A process as claimed in claim 2, wherein said binder further includes between about 1 volume percent and about 20 volume percent of a plasticizer.

13. A process as claimed in claim 12, wherein said plasticizer is selected from the group consisting of dibutyl phthalate, dihexylphthalate, triphenyl phosphate, (dipropylene glycol) butyl ether, diethyleneglycolmonoricinoleate and combinations thereof.

3. In a process for making a three-dimensional article incorporating the steps of:

providing a mixture of a particulate composition dispersed in a binder;

dispensing the mixture from dispensing apparatus onto a build platform; and

during the dispensing step, moving the dispensing apparatus and build platform relative to one another to form the dispensed mixture into a three-dimensional article, the improvement comprising;

Providing in said mixture a binder which includes between about 5 volume percent and about 50 volume percent of a polymer selected from the group consisting of polyvinyl alcohol, polyethylene, polyvinyl acetate, poly (vinyl ethers), poly (vinyl esters), vinyl ester copolymers, ethylene-vinyl acetate copolymers and combinations thereof;

between about 5 volume percent and about 50 volume percent of a wax selected from the group consisting of paraffin waxes, microcrystalline waxes, synthetic hydrocarbon waxes, oxidized polyethylene waxes and combinations thereof;

between about 20 volume percent and about 70 volume percent of an elastomer selected from the group consisting of polychloroprene, styrene-butadiene copolymer, natural rubber, neoprene, plyisoprene, polybutadiene and combinations thereof;

between about 5 volume percent and about 50 volume percent of a tackifier selected from the group consisting of terpene and polyterpene resins, terpene phenolic resins, aliphatic petroleum hydrocarbon resins, rosins, rosin derivatives and combinations thereof; and

between about 1 volume percent and about 20 volume percent of a plasticizer selected from the group consisting of dibutyl phthalate, dihexylphthalate, triphenyl phosphate, (dipropylene glycol) butyl ether, diethyleneglycolmonoricinoleate and combinations thereof.

8. A process as claimed in 2, wherein said binder includes between about 20 volume percent and about 70 volume percent of said elastomer.