Material Change Similarity

Status Update

IAMFTWG Mobile, Alabama

March 7th, 2017

Rich Lyon, FAATC

Natalia Safronava, FAATC

Daniel Slaton, Boeing

Background:

• MCC was proposed to determine

similarity at the material level when

small changes are made to certified

materials.

• MCC guidance document was

posted on FAA website on June

2016

• Decision flow chart includes 2 MCC

parameters HRC and HR

• The proposed basis for comparing

HRC and HR was the reproducibility

limit from the ASTM D 7309 standard

HRC = HR

∆T

Problem: HR and HRC are not independent

Ignition Capacity

= ≈

HR2 T20W/g

2Tolerance =

Heat Released by Combustion

Heat Needed to Gasify Plastic

HR

T20W/g(°C)

Propose Single MCC Criterion for Small Change (Requires Verification by Industry)

HR = 5.9% ASTM repeatability

T = 1.2% ASTM repeatability

= ±6%

• Heat release (HR) and ignition temperature (≈ T20W/g ) are independent properties

• Both are important for flammability

• Both are easy to measure in MCC

0

0.2

0.4

0.6

0.8

1

100 200 300 400 500 600 700 800 900

Film T004C

on

ver

sio

n,

a

Temperature, C

0.05 Ignition Temperature

Procedure:

Integrate HRR vs time (curve)

Derive by C max (to get 0 to 1 scale)

Find value corresponding to 0.05

Record T

T ign 3020C

0

10

20

30

40

50

60

70

80

100 200 300 400 500 600 700 800 900

Film T004

HR

R, W

/g

Temperature, C

20 W/g

Procedure:

Plot HRR versus T from MCC experiment

Find value corresponding to 20 W/g

Record T

T ign 3250C

Possible methods to determine Tign

Ignition Capacity (HR/Tign) of Common Materials

400 J/g-°C

Heat Release (HR) from:

Principles and Practice of Microscale Combustion Calorimetry, FAA Final Report, DOT/FAA/TC-12/53, R1, April 2013

“Determining Ignition Temperature Using Dynamic Thermal Analysis,” R.E. Lyon et al., Proceedings of the 2017 Fire and Materials

Conference, San Francisco, CA, February 6-8, 2017.

Ignition Temperatures (T20W/g) From:

MCC Data for PC/ABS Blends Large Changes in HRR Signature, HR & Tign

ABS

PC 75% ABS

50% ABS

25% ABS

0/100

25/75

50/50

75/25

100/0

391

394

400

422

503

36.8

32.9

29.2

23.9

19.3

PC/ABS (w/w) Tign(°C)

HR (kJ/g)

Ignition Temperature, Tign

Heat Release, HR

MCC Data for PC/ABS Blends Large Changes in HR and Tign

ABS

PC

75% ABS

50% ABS

25% ABS

MCC Data for PC/ABS Blends Large Changes in HR/Tign

PC/ABS Blends (3-mm) in Cone Calorimeter At 35 kW/m2 External Heat Flux

PC

PC/ABS 75/25

PC/ABS 50/50

PC/ABS 25/75

ABS

• 7 different colors (black, white, red, brown, blue, yellow,

orange)

• 3 different suppliers

• OSU tests results ( pHRR, HR and smoke density ) are

available

• MCC tests results available.

• HR was measured

• Data reanalyzed to obtain Tign = T20W/g

Re-Examine Data from Previous Study to

Substantiate Paint Colors

(Ref. Industry Standardization Task Group Report, 2012)

Paint samples from 2011 study: Set C ( HSN)

OSU

MCC

0

10

20

30

40

50

60

black white blue red yel org yel inorg

pH

RR

0

5

10

15

20

25

30

black white blue red yel org yel inorg

2-m

in H

R

0

10

20

30

40

50

60

70

80

black white blue red yel org yel inorg

HR

/ T

ign

Paint samples from 2011 study

Set A ( Mankiewicz)

0

5

10

15

20

25

black white red brown blue yellow orang

e

pHRR for OSU

pH

RR

0

5

10

15

black white red brown blue yellow orange

2-min THR

2-m

in T

HR

MCC HR/T ign

0

10

20

30

40

50

black white red brown blue yellow orange

HR

/ T

ign

Paint samples from 2011 study

Set D ( MapAero)

0

5

10

15

20

25

30

black white blue red yellow

pH

RR

OS

U

0

2

4

6

8

10

12

black white blue red yellow

2-m

in T

HR

OS

U

0

10

20

30

40

50

60

black white blue red yellow

HR

/ T

ig

n

MCC test results on samples of white paint (2016)

0

10

20

30

40

50

60

70

80

100 200 300 400 500 600 700

Samples 1-5

Sample 1Sample 2Sample 3Sample 4Sample 5

HR

R (

W/g

)

Temperature (C)

Sample HRC sum HRR peak HR T peak T ign (int) T ign (20W/g) HR/T ign

1 150 75 9.0 487 276 366 24

2 148 73 8.5 485 303 384 22

3 151 79 8.8 488 283 313 28

4 144 71 8.5 483 294 383 22

5 140 71 8.6 483 267 383 22

Need OSU results for

comparison

Proposed Next Steps:

New round robin (including low flammability material like

phenolic)

Define standard methodology to define Tig

Modification to ASTM standard to include Tig

Definition of reproducibility limit for HR/Tig