Layered manufacturing process for an object with different layer material and object with different layer material

Patent metadata

Field	Value
Publication number	US-11267192-B2
Application number	US-201716474176-A
Country	US
Kind code	B2
Filing date	Dec 22, 2017
Priority date	Dec 28, 2016
Publication date	Mar 8, 2022
Grant date	Mar 8, 2022

Abstract

A method for producing an object with layers of different materials in an additive manufacturing process comprises the following steps: •I) providing a construction material heated at least in part to a temperature above its glass transition temperature on a substrate, so that a layer of the construction material is obtained which corresponds to a first selected cross section of the object; •II) providing a construction material heated at least in part to a temperature above its glass transition temperature on a previously provided layer of the construction material, so that another layer of the construction material is obtained which corresponds to another selected cross section of the object and which is connected to the previously provided layer; •III) repeating step II) until the object is formed. In the individual steps II) in the method, the construction material is selected each time from a first construction material and a second construction material different from the first, the first construction material being a polycarbonate, polyester, polyester carbonate, polyimide, polylactic acid, polyvinyl chloride, polystyrene, polymethyl(meth)acrylate or mixtures of at least two thereof. Step II) is carried out at least once with the first construction material and step II) is carried out at least once with the second construction material. The invention further relates to an object that is obtainable using the method described above.

First claim

The invention claimed is:

1. A process for producing an article in an additive manufacturing method with layers of different materials, comprising the steps of:
I) providing a construction material heated at least to a temperature above its glass transition temperature on a carrier, such that a layer of the construction material is obtained, corresponding to a first selected cross section of the article;
II) providing a construction material heated at least partly to a temperature above its glass transition temperature on a previously provided layer of the construction material, such that a further layer of the construction material is obtained, corresponding to a further selected cross section of the article and bonded to the previously provided layer;
III) repeating step II) until the article is formed;
wherein the construction material in each of the individual steps II) is selected from a first construction material and a second construction material different therefrom, wherein the absolute difference in the refractive indices n 20 D between the first and second construction materials is ≥0.01,
wherein the first construction material comprises a polycarbonate, polyester, polyestercarbonate, polyamide, polylactide, polyvinylchloride, polystyrene, polymethyl(meth)acrylate or mixtures of at least two of these,
wherein step II) is conducted at least once with the first construction material and
wherein step II) is conducted at least once with the second construction material.

2. The process as claimed in claim 1 , wherein, in steps I) and II), providing the construction material comprises applying a filament of at least one construction material heated at least partly to a temperature above its glass transition temperature.

3. The process as claimed in claim 1 , wherein, in steps I) and II), providing the construction material comprises introducing energy on a powder layer of the construction material.

4. The process as claimed in claim 1 , wherein the number of steps II) using the first construction material is ≥80% to ≤120% of the number of steps II) using the second construction material.

5. The process as claimed in claim 1 , wherein the first and second construction materials are used alternately in the steps II).

6. The process as claimed in claim 1 , wherein the first construction material has a Vicat softening temperature of ≥150° C. to ≤220° C. according to DIN EN ISO 306, determined with a testing force of 50 N and a heating rate of 120 K/h.

7. The process as claimed in claim 1 , wherein the second construction material has a Vicat softening temperature of ≥100° C. to ≤170° C. according to DIN EN ISO 306, determined with a testing force of 50 N and a heating rate of 120 K/h.

8. The process as claimed in claim 1 , wherein the first construction material comprises a polycarbonate polymer having diphenol units derived from 4,4′-(3,3,5-trimethylcyclohexylidene)bisphenol.

9. The process as claimed in claim 1 , wherein the second construction material comprises a polyamide, a polyurethane, a polyester, a polyether, a polyimide, a polyetherketone, a polycarbonate, a polyestercarbonate, a polyformal, a polyacrylate, a polyolefin, a polyvinylchloride, a polyoxymethylene, copolymers of at least two of these, or mixtures thereof.

10. The process as claimed in claim 1 , wherein the second construction material comprises a thermoplastic polyurethane polymer.

11. The process as claimed in claim 10 , wherein the second construction material comprises a thermoplastic polyurethane elastomer having a melting range of ≥20° C. to ≤240° C. differential scanning calorimetry; second heating at a heating rate of 5 K/min) and a Shore hardness of ≥40 A to ≤85 D according to DIN ISO 7619-1.

12. The process as claimed in claim 10 , wherein the second construction material comprises a thermoplastic polyurethane elastomer obtained from the reaction of the following components:
a) at least one organic diisocyanate,
b) at least one compound having isocyanate-reactive groups and having a number-average molecular weight of ≥500 g/mol to ≤6000 g/mol and a number-average functionality of the sum total of the components b) of ≥1.8 to ≤2.5, and
c) at least one chain extender having a number-average molecular weight of 60-450 g/mol and a number-average functionality of the sum total of the chain extenders c) of 1.8 to 2.5.

13. The process as claimed in claim 10 , wherein the construction material comprises a thermoplastic polyurethane elastomer obtained from the reaction of a polyisocyanate component and a polyol component, wherein the polyol component comprises a polyester polyol having a no-flow point of ≥25° C. to ≤100° C. according to ASTM D5985.

14. The process as claimed in claim 1 , wherein the first construction material comprises a polycarbonate and the second construction material comprises a thermoplastic polyurethane polymer.

Assignees

• Covestro Deutschland Ag

Inventors

• Achten Dirk
• Büsgen Thomas
• Reichert Peter
• Degiorgio Nicolas
• Wehrmann Rolf
• Heuer Helmut Werner
• Wenz Eckhard

Classifications

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• C08G64/04

  Aromatic polycarbonates · CPC title

• B29C64/106

  using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B29K2075/00

  Use of {PU, i.e.} polyureas or polyurethanes {or derivatives thereof}, as moulding material · CPC title