Method for printing low-density polymer structures

Patent metadata

Field	Value
Publication number	US-11111359-B2
Application number	US-201916403995-A
Country	US
Kind code	B2
Filing date	May 6, 2019
Priority date	May 5, 2018
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A method of forming a low-density three-dimensional article is provided. The method includes printing a low-density composition on a substrate to form at least one layer comprising the low-density composition. The low-density composition includes a (P) polymer component and (M) a microsphere component in a ratio by volume (P):(M). The method also includes selectively controlling a density of the low-density composition during printing to give the at least one layer on the substrate. Selectively controlling the density of the low-density composition includes varying the ratio (P):(M) during printing. The method further includes repeating the printing and selectively controlling the density of the low-density composition to form additional layer(s), thereby forming the low-density three-dimensional article. A low-density three-dimensional article prepared in accordance with the method is also provided.

First claim

The invention claimed is:

1. A method of forming a low-density three-dimensional article, said method comprising:
A) printing a low-density composition on a substrate via extrusion deposition to form at least one layer comprising the low-density composition, wherein the low-density composition is a thermoplastic comprising a polymer component (P) and a microsphere component (M) in a ratio by volume (P):(M);
B) selectively controlling a density of the low-density composition during printing A) by varying the ratio (P):(M) during extrusion deposition of the low-density composition to give the at least one layer on the substrate; and
C) repeating A) and B) to form additional layer(s).

2. The method of claim 1 , wherein the polymer component (P) comprises an acrylonitrile-butadiene-styrene (ABS) resin.

3. The method of claim 1 , wherein the polymer component (P) comprises a polyamide resin.

4. The method of claim 1 , wherein the microsphere component (M) comprises hollow glass microspheres.

5. The method of claim 4 , wherein the low-density composition comprises the hollow glass microspheres of the microsphere component (M) in an amount of from 10 to 50 vol. %, based on the total volume of the low-density composition.

6. The method of claim 4 , wherein the hollow glass microspheres comprise soda-lime-borosilicate glass.

7. The method of claim 4 , wherein the hollow glass microspheres comprise an average diameter of from 10 to 50 μm.

8. The method of claim 1 , wherein the microsphere component (M) comprises expandable microspheres.

9. The method of claim 8 , wherein the expandable microspheres comprise an average diameter of from 10 to 15 μm at room temperature and an average diameter of from 35 to 45 μm during printing.

10. The method of claim 8 , wherein the expandable microspheres are further defined as expandable thermoplastic microspheres.

11. The method of claim 10 , wherein the expandable thermoplastic microspheres each comprise a thermoplastic shell disposed about a hydrocarbon composition.

12. The method of claim 10 , wherein the low-density composition comprises the expandable thermoplastic microspheres of the microsphere component (M) in an amount of from 2 to 5 wt. %, based on the total weight of the low-density composition.

13. The method of claim 1 , wherein the low-density composition further comprises a carbon fiber filler.

14. The method of claim 13 , wherein the low-density composition comprises the carbon fiber filler in an amount of from greater than 0 to 30 wt. % based on the weight of the polymer component (P).

15. The method of claim 1 , further comprising preparing the low-density composition prior to deposition, wherein preparing the low-density composition comprises combining the polymer component (P) and the microsphere component (M) at a preparation temperature greater than a melting temperature of the polymer component (P), such that the low-density composition is flowable at the preparation temperature.

16. The method of claim 15 , wherein the preparation temperature is from 190 to 260° C.

17. The method of claim 15 , wherein printing A) comprises depositing the low-density composition at a printing temperature to form the at least one layer, and wherein the printing temperature is equal to or greater than the preparation temperature.

Assignees

• Ut Battelle Llc

Inventors

• Kunc Vlastimil
• Lindahl John M
• Love Lonnie J
• Post Brian K
• Hassen Ahmed
• Liu Peng
• Sudbury Thomas Zeke

Classifications

• C08K7/28 Primary

  Glass · CPC title

• B33Y70/10

  Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials · CPC title

• B33Y80/00 Primary

  Products made by additive manufacturing · CPC title

• B29C64/165

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

• C08K7/06

  Elements · CPC title