federal aviation administration relationship …...15 6/11/2020 additive manufacturing fire testing...

Presented to: International Aircraft Materials Fire

Test Forum

By: Steve Rehn

Date: 6/11/2020

Federal AviationAdministration

Relationship Between 3-D

Printed Materials and

Flammability

2Additive Manufacturing Fire Testing6/11/2020 Federal Aviation

Administration

Introduction

• 3D printing introduces all

new variables in material

construction

• Variables include:

– Printing orientation

– Infill percentage

– Raster angle

– Layer thickness

– Raster width


Administration

Test Plan

• Determine worst case scenario for each

variable in flammability testing in order to

simplify future testing

• Vary printing parameters in several different

materials and sample thicknesses

• Test using vertical Bunsen Burner

• Analyze test results to determine how future

testing can be simplified and reduced


Administration

Calculating Infill Percentage

• Infill percentage calculated from Insight program material

estimate

• Create toolpath of single layer

• Delete outer contours to only calculate infill

• Divide material used by material used in solid sample to get

infill %

Sparse: 0.100 in3 material Solid: 0.435 in3 material

ൗ0.100 0.435 = 23.0%


Administration

Print Infill Patterns

• Tested with Ultem Support (PES) and Ultem

9085 (PEI) materials

• Several infill patterns and percentages

• Tested infill by itself and with solid outer

layers


Administration

Print Infill Patterns

Hexagonal

(29.7%)

Hexagram

(32.4%)

Permeable

Triangular (32.4%)

Sparse

(23.0%)Sparse DD

(44.8%)


Administration

Infill Only

• PES Material

• 0.060” sample thickness

• Every sample tested burned

until chamber filled with

smoke and put out fire


Administration

Varying Infill with Solid Outer Layers

• Tested 0.10” thickness

• 2 solid outer layers, rest is hollow infill

– On 0.10”, 2 solid layers, 6 infill, 2 solid layers

• Two materials – Ultem Support (PES) and

Ultem 9085 (PEI)

• 12-second vertical Bunsen burner for both

materials, 60s VBB for Ultem 9085


Administration

Varying Infill – Ultem Support

• 8 samples per

infill pattern


Administration


218.8

87.268.6

27.8

49.1

14.9

9.4

1

10

100

1000

20% 30% 40% 50% 60% 70% 80% 90% 100%

Flam

e Ti

me

(s)

-lo

g sc

ale

Infill Percentage (%)

0.10" PES Infill Percentage 12 s VBB Flame Time (log scale)


Administration


• Good correlation

between infill

percentage and test

results

• Less infill % causes

more burning

0

5

10

15

20

25

30

35

40

45

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

20% 30% 40% 50% 60% 70% 80% 90% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage (%)

0.10" PES Infill Percentage 12 s VBB Results

Avg. Burn Length Avg Flame Time


Administration

Varying Infill – Ultem 9085 (PEI)

• Same layer configuration – 2 solid outer layers, 6 inner infill

layers (0.10 inch thickness)

– 12-second test, 4 samples per infill pattern

0

0.5

1

1.5

2

2.5

3

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0% 20% 40% 60% 80% 100%

Flam

e T

ime

(s)

Bu

rn L

en

gth

(in

)

Infill Percentage

Ultem 9085 0.10" Infill Percentage 12s VBB

Burn Length Flame Time

0

0.5

1

1.5

2

2.5

3

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0% 20% 40% 60% 80% 100%

Flame Tim

e (s)

Bu

rn L

en

gth

(in

)

Infill Percentage

Ultem 9085 0.10" Infill Percentage 12s VBB Avg.

Average Burn Length Average Flame Time


Administration

Varying Infill – Ultem 9085

• Same layer configuration – 2 solid outer layers, 6 inner infill

layers (0.10 inch thickness)


0

0.5

1

1.5

2

2.5

3

3.5

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage

Ultem 9085 0.10" Infill Percentage 60s VBB


0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

0% 20% 40% 60% 80% 100%

Flame Tim

e (s)

Bu

rn L

engt

h (

in)

Infill Percentage

Ultem 9085 0.10" Infill Percentage 60s VBB Avg.



Administration


• Infill only – 0.06 inch thickness

• Same tests as completed by Airbus

– Have not reconciled infill % calculation yet


Administration


• Infill only, 0.06 inch thickness


0

2

4

6

8

10

12

14

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage

Ultem 9085 0.06" Infill Only 12s VBB


0

2

4

6

8

10

12

14

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0% 20% 40% 60% 80% 100%

Flame Tim

e (s)

Bu

rn L

engt

h (

in)

Infill Percentage

Ultem 9085 0.06" Infill Only 12s VBB Avg.



Administration




0

0.5

1

1.5

2

2.5

3

3.5

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage



0

0.5

1

1.5

2

2.5

3

3.5

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

0% 20% 40% 60% 80% 100%

Flame Tim

e (s)

Bu

rn L

engt

h (

in)

Infill Percentage




Administration




0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00

0.05

0.10

0.15

0.20

0.25

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage



0.00

0.20

0.40

0.60

0.80

1.00

1.20

0.00

0.05

0.10

0.15

0.20

0.25

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage




Administration




0.00

0.50

1.00

1.50

2.00

2.50

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage



0.00

0.50

1.00

1.50

2.00

2.50

0.00

0.20

0.40

0.60

0.80

1.00

1.20

0% 20% 40% 60% 80% 100%

Flam

e Ti

me

(s)

Bu

rn L

engt

h (

in)

Infill Percentage




Administration


• Infill only, 0.06 inch vs. 0.20 inch thickness

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

0% 20% 40% 60% 80% 100%

Bu

rn L

engt

h (

in)

Infill Percentage

Ultem 9085 Varying Thickness 12s VBB

0.06 inch 0.20 inch

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

0% 20% 40% 60% 80% 100%B

urn

Len

gth

(in

)

Infill Percentage

Ultem 9085 Varying Thickness 60s VBB

0.06 inch 0.20 inch


Administration


• Infill w/ solid outer layers, 0.10 inch vs. 0.25 inch thickness

– 12-second VBB

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0% 20% 40% 60% 80% 100%

Bu

rn L

engt

h (

in)

Infill Percentage

Ultem Support Varying Thickness 12s VBB

0.10 inch 0.25 inch

0

5

10

15

20

25

30

35

40

45

0% 20% 40% 60% 80% 100%Fl

ame

Tim

e (s

)

Infill Percentage

Ultem Support Varying Thickness 12s VBB

0.10 inch 0.25 inch


Administration

Additive Manufacturing VBB AC

• Began writing advisory circular for vertical

Bunsen burner testing of 3D printed

materials

– Details most severe case for each variable in order

to reduce/simplify testing

– For example, lower infill % is more severe than

higher infill %, therefore testing lower infill

substantiates higher infill.

– Will have separate section for PEI-based materials

– Can discuss further in task group meeting


Administration

Conclusion

• Less infill percentage is more severe case

than more infill

• Agrees with Airbus test results using Ultem

9085

– Have not made direct comparison yet because of

infill percentage calculation

• Thinner samples is more severe than thicker

• Next parameter to test

– Raster angle?

– Raster width?


Administration

Contact:Steven Rehn

Federal Aviation Administration

William J. Hughes Technical Center

Fire Safety Branch, Bldg. 203

Atlantic City Int’l Airport, NJ 08405

(609) 485-5587

[email protected]

Questions?


Administration

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federal aviation administration relationship …...15 6/11/2020 additive manufacturing fire testing...

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