Solid freeform fabrication of shelled objects

Patent metadata

Field	Value
Publication number	US-2016107383-A1
Application number	US-201514985465-A
Country	US
Kind code	A1
Filing date	Dec 31, 2015
Priority date	Apr 25, 2010
Publication date	Apr 21, 2016
Grant date	—

Abstract

A method of layerwise solid freeform fabrication is disclosed. The method comprises, for each of at least a few of the layers, dispensing and hardening at least a first modeling material and a second modeling material to form a core region and one or more envelope regions at least partially surrounding the core region. In some embodiments, the ratio between the elastic moduli of adjacent regions, when hardened, is from about 1 to about 20.

First claim

What is claimed is:

1 . A computerized controller for a solid freeform fabrication (SFF) system, the computerized controller comprising a circuit and being configured to operate the SFF system to dispense and harden at least a first modeling material and a second modeling material to form a core region and one or more envelope regions at least partially surrounding said core region, thereby to fabricate an object being constructed from a plurality of layers and from a layered core constituting core regions and a layered shell constituting envelope regions, wherein a width of said envelope region is calculated separately for each layer, said width being defined within a plane engaged by said layer.

2 . The computerized controller according to claim 1 , wherein a width of said envelope region is non-uniform across said layer.

3 . The computerized controller according to claim 1 , being configured to operate the SFF system to dispense at least one of said first modeling material and said second modeling material to form at least one shell part parallel to said layers, wherein a material property characterizing said at least one shell part is different from a material property characterizing said core.

4 . The computerized controller according to claim 3 , wherein said at least one shell part comprises at least one layer which is dispensed subsequently to any layer having said core region and said one or more envelope regions.

5 . The computerized controller according to claim 3 , wherein said at least one shell part comprises at least one layer which is dispensed prior to any layer having said core region and said one or more envelope regions.

6 . The computerized controller according to claim 3 , wherein said at least one shell part has a thickness which is less than a lateral width of said envelope.

7 . The computerized controller according to claim 1 , wherein at least one of said core region and said envelope comprises said first and said second materials being interlaced over the respective region in a pixelated manner, and wherein for each of said first material and said second material, a relative surface density of said material in said core region is different from a relative surface density of said material in said envelope region.

8 . The computerized controller according to claim 1 , wherein said core region comprises said first and said second materials being interlaced over said core region in a pixelated manner, and wherein said envelope region comprises only said second material.

9 . A method of layerwise solid freeform fabrication, comprising, for each of at least a few of the layers:
dispensing and hardening at least a first modeling material and a second modeling material to form a core region and one or more envelope regions at least partially surrounding said core region, each of said regions being characterized by an Izod impact resistance (IR) value and a heat distortion temperature (HDT), when hardened, wherein for at least one pair of regions in said layer, an inner region of said pair is characterized by a lower IR value and higher HDT value relative to an outer region of said pair; thereby fabricating an object being constructed from a plurality of layers and a layered core constituting core regions and a layered shell constituting envelope regions.

10 . The method according to claim 9 , wherein said outer region is characterized by IR value of at least 40 J/m.

11 . The method according to claim 9 , wherein said inner region is characterized by HDT of at least 60° C.

12 . A method of layerwise solid freeform fabrication, comprising, for each of at least a few of the layers:
dispensing and hardening at least a first modeling material and a second modeling material to form a core region and one or more envelope regions at least partially surrounding said core region, wherein a heat deflection temperature (HDT) characterizing said core region is below about 50° C. and an HDT characterizing at least one of said envelope regions is above about 50° C.; thereby fabricating an object being constructed from a plurality of layers and a layered core constituting core regions and a layered shell constituting envelope regions.

13 . The method according to claim 12 , wherein for at least one pair of envelope regions, an HDT characterizing an inner envelope region of said pair is above 50° C., and an HDT characterizing an outer envelope region of said pair is below 50° C.

14 . The method according to claim 12 , wherein for at least one pair of regions in said layer, a characteristic HDT is higher for an outer region of said pair than for an inner region of said pair.

15 . A method of layerwise solid freeform fabrication, comprising, for each of at least a few of the layers:
dispensing and hardening at least a first modeling material and a second modeling material to form a core region and one or more envelope regions at least partially surrounding said core region, wherein a ratio between the elastic moduli of adjacent regions, when hardened, is from about 1 to about 20, and wherein a plurality of different layers of the structure have envelope regions of different widths, said widths being defined within a plane engaged by said layer.

16 . The method according to claim 15 , wherein for at least one pair of regions in said layer, a heat deflection temperature (HDT) characterizing an inner region of said pair is above 50° C., and an HDT characterizing an outer region of said pair is below 50° C.

17 . The method according to claim 15 , wherein for at least one pair of regions in said layer, a characteristic heat deflection temperature (HDT) is higher for an outer region of said pair than for an inner region of said pair.

18 . The method according to claim 15 , wherein each of said core and envelope regions is characterized by an elongation-at-break value (ε R ), when hardened, and wherein said characteristic ε R is higher for any of said envelope regions than for said core region.

19 . The method according to claim 15 , wherein said first modeling material and said second modeling material are characterized by a glass transition temperature (T g ) which is below 10° C.

20 . The method according to claim 19 , wherein a characteristic tensile tear resistance (TR) of said core region is lower than a characteristic TR of at least one of said envelope regions.

21 . The method according to claim 15 , wherein each of said regions is characterized by an Izod impact resistance (IR) value and a heat distortion temperature (HDT), when hardened, wherein for at least one pair of regions in said layer, an inner region of said pair is characterized a lower IR value and higher HDT value relative to an outer region of said pair.

Assignees

• Stratasys Ltd

Inventors

• Dikovsky Daniel
• Levy Avraham
• Napadensky Eduardo

Classifications

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title

• Y10T428/23

  Sheet including cover or casing · CPC title

• B33Y10/00 Primary

  Processes of additive manufacturing · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B29K2995/0015

  Insulating · CPC title