High-precision modeling filament

• US 20050129941A1
• Filed: 02/02/2005
• Published: 06/16/2005
• Est. Priority Date: 09/21/2001
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Priedeman, William R. Jr., Comb, James W., Skubic, Robert L., Batchelder, John Samuel, Leavitt, Paul J.
• Granted Patent: US 7,122,246 B2
• Time in Patent Office: Days
• US Class Current: 428/364
• CPC Class Codes: B29C 2948/92123 Diameter or circumference
• CPC Class Codes: B29C 2948/92409 Die; Nozzle zone
• CPC Class Codes: B29C 2948/92523 Force; Tension
• CPC Class Codes: B29C 2948/92571 Position, e.g. linear or angular
• CPC Class Codes: B29C 2948/9259 Angular velocity
• CPC Class Codes: B29C 2948/92619 Diameter or circumference
• CPC Class Codes: B29C 2948/92904 Die; Nozzle zone
• CPC Class Codes: B29C 2948/92933 Conveying, transporting or storage of articles
• CPC Class Codes: B29C 2948/92952 Drive section, e.g. gearbox, motor or drive fluids
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/625 characterised by the ratio of the threaded length of the screw to its outside diameter [L/D ratio]
• CPC Class Codes: B29C 48/92 Measuring, controlling or regulating
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y10T 428/2913 Rod, strand, filament or fiber
• CPC Class Codes: Y10T 428/298 Physical dimension

Abstract

Disclosed is a modeling filament for use as feedstock in a fused deposition modeling liquifier, and a method for manufacturing the filament. The diameter and standard deviation of the filament are controlled to meet various tolerance requirements of jam resistance, slip resistance, model strength, liquifier overflow prevention and hysteresis-free transient response. Standard deviation of the filament diameter is matched to a filament target diameter. The resulting filament is used to form high-quality models.

Claims

1. A feedstock of solid material for use in an extrusion apparatus, the feedstock comprising:

a filament having a length of greater than 20 feet, having an average diameter, and having a standard deviation of the diameter of less than or equal to 0.0004 inches.

2. The feedstock of solid material of claim 1, wherein the standard deviation is less than or equal to 0.0003 inches.

3. The feedstock of solid material of claim 1, wherein the average diameter is between 0.069-0.074 inches.

4. The feedstock of solid material of claim 1, wherein d_L is approximately 0.076 inches.

5. The feedstock of solid material of claim 1, wherein the average diameter is between 0.071-0.072 inches and the standard deviation of the diameter is less than or equal to 0.0003.

6. The feedstock of solid material of claim 1, wherein the average diameter is between 0.072-0.073 inches and the standard deviation of the diameter is less than or equal to 0.00015.

7. A feedstock of solid material for use in an extrusion apparatus, comprising:

a thermoplastic filament having a length of greater than 20 feet, having an average diameter <

d_F>

, and having a standard deviation of the diameter according to the relationship

σ

_F≦

0.007·

<

d_F>

inches.

8. The feedstock of solid material of claim 7, wherein the average filament diameter is between 0.069-0.074 inches.

9. The feedstock of solid material of claim 7, wherein the standard deviation is less than or equal to 0.0004 inches.

10. A feedstock of solid material for use in an extrusion apparatus that includes a liquifier having an inner diameter d_L, which receives a feedstock of a solid material and a tip which deposits said material in molten form in roads having a width W and a height L, the feedstock of solid material comprising:

filament having a length of greater than 20 feet, having an average diameter <

d_F>

according to the relationship 0.84 d_L<

<

d_F>

<

d_L−

6σ

_F and having a standard deviation σ

_F of;

${\mathrm{\sigma <br><br>}}_F\le <br><br>\frac{2<br><br>{\mathrm{LWS}}_s}{3<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>d_t<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{\Delta <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>S_g}$

where S_S is a

maximum allowable seam gap at a junction of two roads, and Δ

S_g is expected average movement of a meniscus within the liquifier.

11. The feedstock of solid material of claim 10, wherein <

d_F>

is between 0.069-0.074 inches and σ

_F is less than or equal to 0.0004 inches.

12. The feedstock of solid material of claim 10, wherein <

d_F>

is between 0.071-0.072 inches and σ

_F is less than or equal to 0.0003 inches.

13. The feedstock of solid material of claim 10, wherein <

d_F>

is between 0.072-0.073 inches and σ

_F is less than or equal to 0.00015 inches.