Extrudable Mixture for use in 3d Printing Systems to Produce Metal, Glass and Ceramic Articles of high purity and detail.

Abstract

There is disclosed an article which is formed of a solid-phase or liquid-phase sintered product of a metal powder, ceramic powder or glass powder. For manufacturing the article, an extrudable mixture which contains the material powder and a thermoplastic binder is shaped into a continuous filament suitable for use in fused filament 3D printers. The printed object is then invested in plaster or other castable refractory. The invested object is then subjected to heating. The heating process burns off the thermoplastic binder and sinters the powders of metal, glass or ceramic, leaving a pure metal, glass or ceramic object.

The extrudable mixture is produced by preparing a material powder, preparing thermoplastic binder, blending the material powder and the thermoplastic binder together. The most preferable extrudable mixture contains 80 to 92% by weight of metal powder, 8 to 20% by weight of thermoplastic binder, and 0.0 to 0.1% unavoidable impurities. The extrudable mixture is then extruded into a continuous filament suitable for use in various 3d printing hardware.

Claims

1. An extrudable mixture for use in the manufacture of a metal article, containing 80 to 92% by weight of a metal powder, 8 to 20% by weight of the thermoplastic binder mixed with said metal powder,

2. An extrudable mixture for use in the manufacture of a metal, glass or ceramic article according to claim 1, consisting essentially of: 80 to 92% by weight of a metal powder; 8 to 20% by weight of thermoplastic binder; Balance unavoidable impurities.

3. An extrudable mixture according to claim 2, wherein said metal, glass or ceramic powder has an average particle size of less than 100 μm to 400 μm.

4. An extrudable mixture according to claim 1, wherein said metal, glass or ceramic powder contains metal powder and powder of a binder material.

5. An extrudable mixture according to claim 1, wherein said powder contains metals, glass or ceramic.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 [0014] A. Continuous 3d Printer Filament [0015] B. Metal, Glass or Ceramic Powder [0016] C. Thermoplastic Binder

[0017] FIG. 2 [0018] A. 3D Printed Object [0019] B. Metal, Glass or Ceramic Powder [0020] C. Thermoplastic Binder

[0021] FIG. 3 [0022] A. 3d Printed Object [0023] B. Castable refractory

DETAILED DESCRIPTION OF THE INVENTION

[0024] The inventor has made an extensive study to obtain a metal, glass or ceramic article containing no binder, and have come to know that when a thermoplastic binder used it is removed entirely during the sintering process. Thus, the resulting article is free of binder, and is essentially comprised of a high purity sintered product of metal, glass or ceramic.

[0025] Thus, the metal article in accordance with the present invention consists essentially of a solid-phase sintered product of a metal, glass or ceramic powder free of any binder, and assumes the properties of the metal, glass or ceramic that the mixture contains.

[0026] According to the present invention, the article is manufactured by the steps of preparing an extrudable mixture containing powdered metal, glass or ceramic and a binder which is removable by heat, investing the object in plaster, and subjecting the mixture to a sintering operation.

[0027] More specifically, there is first prepared an extrudable mixture containing a metal, glass or ceramic powder and a thermoplastic binder.

[0028] Then, the extrudable mixture of powdered metal, glass or ceramic is printed into a prescribed shape, the printed object is encased, invested, in plaster, then sintered under predetermined conditions. Thus, the binder is removed during the sintering operation, while the shape is retained by the plaster investment, and a metal, glass or ceramic article free of the binder is manufactured.

[0029] Various modifications of the manufacturing method of a metal, glass or ceramic article will now be described. [0030] In the foregoing, if a coloring agent is mixed into the powdered glass or ceramic, a glassy layer of a desired color can be obtained. The shape of the article is of course arbitrary. [0031] Next, the extrudable mixture for use in the manufacture of the above metal, glass or ceramic article and the method for producing the same will be described. [0032] As previously mentioned, the extrudable mixture in accordance with the invention is characterized in that it contains a metal, glass or ceramic powder and a thermoplastic binder mixed with the powder. The use of the thermoplastic as the binder ensures that the binder is removed during the sintering step. For producing the extrudable mixture, a thermoplastic and metal, glass or ceramic powder are mechanically mixed, then shaped into the a feedstock to be used in 3d printing.

[0033] The reasons for the limitations on the composition of the most preferred extrudable mixture are as follows:

(a) Metal, Glass, Ceramic Powder

[0034] Powders of metal such as gold, silver, copper, platinum and their alloys, and glass and ceramic are main constituents for the extrudable material to be obtained. If the powder content is less than 80% by weight, desired effects cannot be obtained. On the other hand, if the content exceeds 92% by weight, the resulting extrudable material is inferior in extensibility and strength. Therefore, the content of the powder has been determined so as to range from 80 to 92% by weight. [0035] In addition, if the average particle size of the metal powder exceeds 400 μm, the extensibility and strength deteriorate. Therefore, it is preferable that the average particle size of the metal powder is no less than 100 um and no greater than 400 μm.

(b) Thermoplastic Binder

[0036] When heated, the thermoplastic becomes malleable, so that it is very easy to to feed through the 3d printer. However, if the binder content is less than 8% by weight, such an advantage cannot be obtained. On the other hand, if the metal content exceeds 92% by weight, it becomes difficult to print with the mixture. Therefore, the content of the thermoplastic binder is determined so as to range from 8 to 20% by weight.