3D printing process and molding produced by this process using lignosulfate

Patent metadata

Field	Value
Publication number	US-11820076-B2
Application number	US-202017772338-A
Country	US
Kind code	B2
Filing date	Oct 29, 2020
Priority date	Nov 1, 2019
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

The present invention relates to a material system for 3D printing, to a 3D printing process using a lignin-containing component or derivatives thereof or modified lignins, to soluble moldings that are produced by a powder-based additive layer manufacturing process and to the use of the moldings.

First claim

The invention claimed is:

1. A material system suitable for a 3D printing process or a 3D printing process material system comprising or consisting of:
a particle material and a printing liquid,
wherein the particle material includes an inorganic particle material or organic particle material,
wherein the printing liquid comprises or consists of:
i) a liquid component selected from the group consisting of water and an aqueous solution; and
ii) a lignin-containing component or derivatives thereof wherein the lignin content in the printing liquid is 10 to 35 percent.

2. The material system according to claim 1 , wherein the liquid component comprises polar organic or/and inorganic liquids,
wherein the printing liquid has a viscosity of 2 mPas-20 mPas.

3. The material system according to claim 2 , wherein
the printing liquid further comprises a surfactant, and has a surface tension of 20 mN/m-50 mN/m, or/and comprises defoaming agents, or/and
wherein the printing liquid contains further rheological and dispersing additives which improve the wetting of the components used, and corrosion inhibitors.

4. The material system according to claim 1 , wherein the particle material includes the organic particle material.

5. The material system of claim 4 , wherein the material system additionally contains a soluble starch hydrolysate, wherein
the dextrose equivalent of the starch hydrolysate is between 1 and 50;
wherein an alcohol content is between 0.5%-15%, the alcohols comprise simple alcohols, diols or polyols or mixtures of the above; and
the printing liquid has a viscosity of 2 mPas-20 mPas.

6. The material system according to claim 5 , wherein
the printing liquid further comprises a surfactant; and
the printing liquid has a surface tension of 20 mN/m to 50 mN/m; and
the printing liquid comprises a defoaming agent; and
the printing liquid comprises a rheological and dispersing additives which improve the wetting of the components used.

7. A 3D printing process comprising the steps of:
applying a particle material mixture onto a build plane,
selectively applying a printing liquid, wherein the printing liquid comprises:
i) a liquid selected from the group consisting of water and an aqueous solution; and
ii) a lignin-containing component or derivatives thereof, preferably lignosulfonate, for at least partial selective solidification,

and
repeating these steps until a desired part has been obtained;
wherein the lignin content in the printing liquid is 10 to 35 percent;
optionally wherein the part is a molding.

8. The 3D printing process according to claim 7 , wherein the obtained molding is separated from the non-solidified particle material mixture and the molding is subjected to a further heat treatment step and/or a treatment with microwave radiation.

9. The 3D printing process of claim 8 , wherein
the process comprises the step of tempering the build field or introducing energy into the applied particle material mixture, to 30° C. to 60° C.; and
the molding is subjected to a further heat treatment step and/or a treatment with microwave radiation.

10. The 3D printing process of claim 8 , wherein the particle material mixture is applied by means of a recoater,
the printing liquid is selectively applied with a print head, and
the molding is left in a powder bed at ambient conditions for 4 h-24 h, after completion of the printing process.

11. The 3D printing process of claim 10 , wherein the molding is dried and/or cured by sucking a gas or gas mixture, preferably ambient air, through the entirety of non-printed and printed areas after completion of the printing process, wherein suction preferably takes place 0.5 to 2 hours after the end of printing,
the molding has a strength of 150 N/cm 2 to 200 N/cm 2 ;
the process includes an additional step of:
i) subjecting the molding to a heat treatment for 0.5 to 7 hours at 30° C.-160° C., by means of an IR lamp, or
ii) subjecting the molding to a treatment with microwave radiation, the treatment taking place over a period of 2 to 30 minutes.

12. The 3D printing process of claim 11 , wherein the lignin-containing component includes lignosulfonate; and
the method comprises the step of tempering the build field or introducing energy into the applied particle material mixture, to 30° C. to 60° C.

13. The 3D printing process according to claim 7 , wherein the particle material mixture is applied by means of a recoater, or/and
wherein the printing liquid is selectively applied with a print head, or/and
wherein the molding is left in a powder bed at ambient conditions for 4 h-24 h, after completion of the printing process.

14. The 3D printing process according to claim 7 , wherein the molding is dried and/or cured by sucking a gas or gas mixture, through the entirety of non-printed and printed areas after completion of the printing process, wherein suction preferably takes place 0 h-24 h, after the end of printing, or/and
wherein in an additional step the molding is subjected to a heat treatment, wherein the molding is stored 0.5 h 7 h at 50° C.-140° C., or
wherein, in an additional step, the molding is subjected to a treatment with microwave radiation, the treatment taking place over a period of 2 min-30 min.

15. The 3D printing process according to claim 7 , wherein the surface of the molding is further coated or sealed.

16. The 3D printing process of claim 15 , wherein the lignin-containing component includes lignosulfonate; and
the method comprises the step of tempering the build field or introducing energy into the applied particle material mixture, to 30° C. to 60° C.

17. The 3D printing process according to claim 7 , with a material system comprising:
the particle material mixture and the printing liquid,
wherein the particulate material mixture includes a particle material selected from the group consisting of quartz sand, olivine sand, kerphalite, cerabeads, ceramics, and metal powder,
wherein the particle material is untreated,
wherein the printing liquid comprises:
i) a liquid component selected from the group consisting of water and an aqueous solution; and
ii) a lignin-containing component including lignosulfonate.

18. The 3D printing process of claim 7 , wherein particle material includes an organic particle material.

19. The method of claim 7 , wherein the method comprises a step of:
cold casting of a synthetic resin with the molding; or
casting of a hydraulically setting system with the molding; or
laminating with the molding.

20. A molding produced by a 3D printing process according to claim 7 , wherein the molding, left in the powder bed at ambient conditions for 4 h-24 h, has strengths of 80 N/cm 2 -150 N/cm 2 in the direction of printing and, after heat treatment for 1 h-7 h, at 30° C. 160° C. has strengths of more than 200 N/cm 2 .

21. A material system suitable for a 3D printing process or a 3D printing process material system comprising or consisting of:
a particle material and a printing liquid,
wherein the particle material includes an inorganic particle material,
wherein the printing liquid comprises:
i) a liquid component selected from the group consisting of water and an aqueous solution;
ii) a lignin-containing component or derivatives thereof; and
iii) a soluble starch hydrolysate, an alcohol, or a defoaming agent.

Assignees

• Voxeljet Ag

Inventors

• Gnüchtel Ingo
• Mögele Florian

Classifications

• B29C64/165 Primary

  using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber · CPC title

• B29C33/3807 Primary

  Resin-bonded materials, e.g. inorganic particles · CPC title

• B29C33/3814

  Porous moulds (adapted for vacuum forming B29C51/365) · CPC title

• B29C33/3842

  Manufacturing moulds, e.g. shaping the mould surface by machining · CPC title

• B29C64/264

  Arrangements for irradiation · CPC title