PUBLICATIONS A 1 1 1 Q 4 0 fl 5 7 4 3

NBSIR 84-2943

New Concepts for Measuring

Flame Spread Properties

J.G. Quintiere and

M. Harkleroad

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

November 1984

Sponsored in part by:

U.S. Department of Transportation

Federal Aviation Administration

Technical Center

Atlantic City Airport, NJ 08405

100

.U56

84-2943

IS 84

• iTHIfUL ffCKBAW U7 ST A PDiiM

NBSIR 84-2943

NEW CONCEPTS FOR MEASURING

FLAME SPREAD PROPERTIES

J.G. Quintiere and

M. Harkleroad

U S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Fire Research

Gaithersburg, MD 20899

November 1984

Sponsored in part by:

U.S. Department of Transportation

Federal Aviation Administration

Technical Center

Atlantic City Airport, NJ 08405

7 «

co O*

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

TABLE OF CONTENTS

Page

LIST OF TABLES . iv

LIST OF FIGURES v

NOMENCLATURE xi

Abstract 1

1. INTRODUCTION 2

2. EXPERIMENTAL PROCEDURE 5

2.1 Ignition 5 2.2 Flame Spread 6

2.3 Sample Preparation 8

3. ANALYSIS 8

3.1 Ignition 9

3.2 Flame Spread 12

4. RESULTS 16

5. DISCUSSION 19

6. CONCLUSIONS 23

7. ACKNOWLEDGMENTS 23

8. REFERENCES 24

APPENDIX A. CORRELATION OF IGNITION RESULTS 47

APPENDIX B. CORRELATION OF SPREAD RESULTS 78

APPENDIX C. SPREAD AND IGNITION RESULTS 114

-iii-
LIST OF TABLES

Table 1.

Table 2.

Table 3.

Table BPage

Ignition and flame spread characteristics under

constant irradiance conditions

Flame spread properties

Properties of common materials

. External irradiance and ignition procedure for spread

velocity tests

-iv-
LIST OF FIGURES

Page

Figure 1

.

Schematic of test apparatus

Figure 2. Normalized irradiance over the sample

Figure 3. Ignition results for fiberboard

Figure 4. Flame position as a function of time for a fiberglass

roofing shingle

Figure 5. Flame position after delayed ignition of hardboard

Figure 6. Equilibrium surface temperatures as a function of

external radiant heating in the test apparatus

Figure 7. Correlation of ignition results for fiberboard

(see figure 2)

Figure 8. Comparison of measured and approximate values for F(t):

particle board

Figure 9. Comparison of measured and approximate values for F(t):

aircraft panel

Figure 10. Correlation of spread velocity for a fiberglass shingle

(see figure 4)

Figure 11. Correlation of spread velocity for hardboard

(see figure 5)

Figure 12. Spread and ignition results for plywood

Figure 13. Spread and ignition results for rigid polyurethane foam ...

Figure 14. Spread and ignition results for gypsum board

Figure 15. Spread and ignition results for an asphalt shingle

Figure 16. Spread and ignition results for PMMA

Figure A-l. Correlation of ignition results for PMMA Polycast

(1.59 mm)

Figure A-2. Correlation of ignition results for PMMA Type G

(1.27 cm)

Figure A-3. Correlation of ignition results for flexible foam

(2.54 cm)

-v-
LIST OF FIGURES (continued)

Page

Figure A-4. Correlation of ignition results for rigid foam (2.54 cm) ..

Figure A-5. Correlation of ignition results for polyisocyanurate

(5.08 cm)

Figure A-6. Correlation

(1.52 mm) .

.

of ignition results for polycarbonate

Figure A-7

.

Correlation

(5.08 cm) .. of ignition results for polystyrene

Figure A-8. Correlation of ignition results for hardboard (6.35 mm) ...

Figure A-9. Correlation of ignition results for hardboard (3.175 mm) ..

Figure A-10. Correlation

board (1.27

of

cm)

ignition results for Douglas fir particle

Figure A-ll. Correlation

(0.635 cm) . of ignition results for plywood , plain

Figure A-12

.

Correlation

(1.27 cm) .

.

of ignition results for plywood, plain

Figure A-13. Correlation of ignition

nitrocellulose paint) .

.

results for hardboard (3.4 mm.

Figure A-14. Correlation

gloss paint)

of ignition results for hardboard (3.4 mm.

Figure A-15. Correlation of ignition

(1.27 cm, stock)

results for particle board

Figure A-16. Correlation

(1.27 cm) .. of ignition results for plywood , FR

Figure A-17. Correlation

(Si 19M) .... of ignition results for carpet (acrylic)

Figure A-18. Correlation

board

of ignition results for fiber insulation

Figure A-19. Correlation of ignition results for asphalt shingle

Figure A-20. Correlation of ignition results for GRP (2.24 mm)

Figure A-21. Correlation of ignition results for GRP (1.14 mm)

Figure A-22. Correlation of ignition results for fiberglass shingle ....

-vi-
LIST OF FIGURES (continued)

Page

Figure A-23. Correlation of ignition results for gypsum board,

Figure A-24. Correlation of ignition results for carpet (nylon/wool) ...

Figure A-25. Correlation of ignition results for carpet // 2 (wool)

Figure A-26. Correlation of ignition results for carpet #2

(wool, treated)

Figure A-27. Correlation of ignition results for carpet #1

(wool, stock)

Figure A-28. Correlation of ignition results for aircraft panel

(epoxy fiberite)

Figure A-29. Correlation of ignition results for gypsum board

(1.27 mm, common)

Figure A-30. Correlation of ignition results for gypsum board, FR

(1.27 cm)

Figure B-l. Correlation of spread velocity for PMMA polycast

(1.59 mm)

Figure B-2. Correlation of spread velocity for polyurethane

(S353M, 30 mm)

Figure B-3. Correlation of spread velocity for PMMA Type G

(1.27 cm)

Figure B-4. Correlation of spread velocity for flexible foam

(2.54 cm)

Figure B-5. Correlation of spread velocity for rigid foam (2.54 cm) ...

Figure B-6. Correlation of spread velocity for polyisocyanurate

(5.08 cm)

Figure B-7. Correlation of spread velocity for polycarbonate

(1.52 mm)

Figure B-8. Correlation of spread velocity for hardboard (6.35 mm) ....

Figure B-9. Correlation of spread velocity for hardboard (3.175 mm) ...

Figure B-10. Correlation of spread velocity for hardboard

(S159M, 1.0 cm)

-vii-
LIST OF FIGURES (continued)

Page

Figure B-ll. Correlation

board (1.27

of

cm)

spread velocity for Douglas fir particle

Figure B-12. Correlation of spread velocity for wood panel (S178M) .....

Figure B-13. Correlation of spread velocity for chipboard (S118M)

Figure B-14. Correlation

(0.635 cm) .

of spread velocity for plywood, plain

Figure B-15. Correlation

(1.27 cm) .. of spread velocity for plywood, plain

Figure B-16. Correlation of

nitrocellulose

spread

paint)

velocity for hardboard (3.4 mm,

Figure B-17. Correlation

gloss paint)

of spread velocity for hardboard (3.4 mm,

Figure B-18. Correlation of spread

(1.27 cm, stock) ..... velocity for particle board

Figure B-19. Correlation of spread velocity for carpet (acrylic)

Figure B-20. Correlation of

density (S119M)

spread velocity for fiberboard , low

Figure B-21. Correlation

board

of spread velocity for fiber insulation

Figure B-22. Correlation of spread velocity for asphalt shingle

Figure B-23. Correlation of spread velocity for fiberglass shingle .....

Figure B-24. Correlation of spread velocity for GRP (2.24 mm)

Figure B-25. Correlation of spread velocity for GRP (1.14 mm)

Figure B-26

.

Correlation

paper (S160)

of spread velocity for mineral wool, textile

Figure B-27. Correlation

(S142M) ....

of spread velocity for gypsum board, wallpaper

Figure B-28. Correlation of spread velocity for carpet #2 (wool)

Figure B-29. Correlation of spread velocity for carpet #2

(wool treated)

-viii-
LIST OF FIGURES (continued)

Page

Figure B-30. Correlation of spread velocity for carpet #1

(wool, stock) ...................

Figure B-31. Correlation of spread velocity for aircraft panel

(epoxy fiberite)

Figure B-32. Correlation of spread velocity for gypsum board, FR

(1.27 cm)

Figure B-33. Correlation of spread velocity for gypsum board

(1.27 mm, common)

Figure C-l Spread and ignition results for polyurethane

(S353M, 30 mm)

Figure C-2. Spread and ignition results for PMMA Type G (1.27 cm)

Figure C-3. Spread and ignition results for flexible foam (2.54 cm) ...

Figure C-4. Spread and ignition results for polycarbonate (1.52 mm) ...

Figure C-5. Spread and ignition results for polyisocyanurate

(5.08 cm)

Figure C-6. Spread and ignition results for polystyrene (5.08 cm)

Figure C-7. Spread and ignition results for hardboard (6.35 mm)

Figure C-8. Spread and ignition results for hardboard (3.175 ram)

Figure C-9. Spread and ignition results for hardboard (S159M,

1.0 cm)

Figure C-10. Spread and ignition results for Douglas fir particle

board (1.27 cm)

Figure C-ll. Spread and ignition results for wood panel (S178M)

Figure C-l 2. Spread and ignition results for chipboard (S118M)

Figure C-l 3. Spread and ignition results for plywood, plain

(0.635 cm)

Figure C-l 4. Spread and ignition results for hardboard (3.4 mm, gloss

paint)

Figure C-l 5. Spread and ignition results for hardboard (3.4 mm,

nitrocellulose paint)

-ix-
LIST OF FIGURES (continued)

Page

Figure C-16. Spread

stock)

and ignition results for particle board (1.27 cm,

Figure C-17. Spread and ignition results for plywood, FR (1.27 cm)

Figure C-18. Spread and ignition results for carpet (acrylic)

Figure C-19. Spread

(S119M)

and ignition results for fiberboard, low density

Figure C-20. Spread and ignition results for fiber insulation board ....

Figure C-21. Spread and ignition results for fiberglass shingle

Figure C-22. Spread and ignition results for GRP (2.24 mm)

Figure C-23. Spread and ignition results for GRP (1.14 mm)

Figure C-24. Spread and ignition

paper (S160)

results for mineral wool, textile

Figure C-25. Spread

(S142M)

and ignition results for gypsum board, wallpaper

Figure C-26. Spread and ignition results for carpet (nylon/ wool)

Figure C-27. Spread and ignition results for carpet #2 (wool)

Figure C-28. Spread and ignition results for carpet #2 (wool treated) ..

Figure C-29. Spread and ignition results for carpet #1 (wool, stock) ...

Figure C-30. Spread and

fiberite) , ignition results for aircraft panel (epoxy

Figure C-31

.

Spread and

(1.27 cm) , ignition results for gypsum board, FR
NOMENCLATURE

b parameter in eq. (5)

c specific heat

C parameter in eq. (12)

D Damkohler number (see reference 1, 11, 12)

F(t) thermal response function, eqns . (1, 2, 5)

g gravitational acceleration

h heat loss coefficient

h

c convective heat transfer coefficient

k thermal conductivity

i length scale

• it q heat transfer per unit time and per unit area

• M q o,ig critical flux for ignition

q o ,s critical flux for spread

• M q e external radiant flux

t time

tm characteristic equilibrium time, eq. (5)

T temperature

T

f adiabatic flame temperature

T

00 ambient and initial temperature

T

s surface temperature before flame effects

T

ig ignition temperature

T

s ,min minimum temperature for spread

V flame (pyrolysis front) velocity

V

a opposed gas velocity

X distance along sample

-xi-
00

a

coordinate normal to sample exposed surface

mass fraction of oxygen in ambient

density

flame heating parameter, eq. (8)

flame length

Stef an-Boltzmann constant

-xii-
NEW CONCEPTS FOR MEASURING FLAME SPREAD PROPERTIES

J.G. Quintiere and M. Harkleroad

Abstract

An experimental procedure is described which can be used to derive data

relevant to the prediction of ignition and flame spread on materials. It

offers a direct method for determining material property data suitable for use

in mathematical fire models. The apparatus utilizes a radiant heat source

capable of supplying up to 6.5 W/ cm to a vertically oriented specimen. The

test results pertain to piloted ignition of a vertical sample under constant

and uniform irradiation, and to lateral flame spread on a vertical surface due

to an external applied radiant heat flux. The results can be used to display

the maximum velocity and ignition time as a function of irradiance. Critical

or minimum irradiances for spread and ignition are determined. An empirical

correlation, based on heat conduction principles, is found to correlate the

ignition data and also provides a more general interpretation for the flame

spread results. Further analyses of the data yield effective values for the

thermal inertia of the material (kpc) , its ignition temperature, and a parameter related to flame temperature. These parameters appear to be phenomenological constants for each material, rather than factors dependent on the

apparatus. Results are presented for a wide range of materials. Suggestions

for extending the results to other flame spread conditions are presented.

Key words: carpets; composites materials; fire tests; flame spread;

ignition; material properties; measurements; plastics; wood

- 1 -
1 . INTRODUCTION

Test methods for the flammability of materials differ widely among and

within countries. Yet research on flame spread and ignition has developed to

permit, at least conceptually, a universal framework for their description.

Moreover, certain essential material data are needed to enable the researcher

to assess his theories and correlations against experimental results.

Consequently, it appears logical to organize that process so that material

flammability tests might supply the data needed in theoretical models of

ignition and flame spread. This paper will present such a process.

In considering flame spread it is realized that it depends on the

orientation of the material and on the conditions of the surrounding fluid.

It is interesting that several principal standard flammability tests consider

distinct modes of flame spread. Generally, flame spread can be divided into

spread in an opposed gas flow (i.e., the ambient gas flow is in the opposite

direction to the propagating flame front) and spread in a concurrent flow

(i.e., the local gas flow is in the same direction as the propagating flame).

The opposed flow case is typified by ASTM E162, Standard Test Method for

Surface Flammability of Materials Using a Radiant Heat Energy Source, in which

the flame spread is downward on an inclined sample and the opposed flow is

buoyancy-induced primarily by the flame. In contrast, ASTM E84, Standard Test

Method for Surface Burning Characteristic of Burning Materials, is an example

of concurrent spread along a ceiling-mounted material in which the ambient

flow is held fixed. Also ASTM E648, Standard Test Method for Critical Radiant

Flux of Floor-Covering Systems Using a Radiant Heat Energy Source, is another

example of opposed flow spread under natural convection for an upward facing

-2 -
horizontal surface. Except for ASTM E648, these test results are expressed in

terms of indices which have no relationship to particular physical or chemical

data. However, this does not preclude the possibility of an interpretation of

these data in more scientific terms. To derive these scientific results

mathematical solutions of the flame spread processes are needed.

The literature on flame spread and ignition is abundant, and reviews on

flame spread by Fernandez-Pello and Hirano [1] and on ignition by Kanury [2]

provide good sources of information. From results found there, and in particular from analyses by deRis [3] on opposed-flow spread and Sibulkin and Kim

[4] on upward (concurrent) spread it can be shown that common combustible

2 materials respond to flame spread and to ignition (for exposures >2 W/ cm ) as

thermally thick materials for thicknesses greater than approximately 1 mm.

Thus, the semi-infinite-solid solutions for ignition and spread will most

often apply, and may even apply to thin materials on a thick substrate where

some effective properties of the composite solid must be considered. Yet,

under low heat transfer conditions, as would occur in the early development of

compartment fires, the thickness of the solid and the conditions at its back

surface are important to its temperature rise. Thus, under these developing

fire conditions, the upstream surface temperature can be assumed to be the

initial temperature of the solid. In other words, even when a temperature

gradient is present in the solid only about 1 mm of its depth responds to the

flame heat transfer and the temperature over that depth represents the initial

temperature. Fernandez-Pello [5] has shown that this is a valid representation for downward spread under external radiant heating.

-3 -
From an examination of the simplest solutions for flame spread [3, A]

under the thermally thick assumption, several common parameters emerge. One

is the product of the solid's conductivity, density and specific heat (kpc);

another is a critical surface temperature to produce fuel vapors from the

solid - this can be considered as an "ignition temperature". Since the

theoretical results do not consider melting, charring, regression, or temperature effects on the solid's properties, the parameter kpc must be considered

as an effective property when such theories are applied to realistic flame

spread conditions. Also, the ignition temperature must be viewed as a

modeling parameter in the formula, rather than the exact surface temperature

of the solid when a flammable mixture is produced. Moreover, both of these

parameters occur in the simplest models for ignition [2]. Hence the determination of these quantities offer a consistent way of relating test data to

theoretical models. For flame spread, however, these two parameters are not

sufficient to describe the various modes of spread. From deRis' result for

opposed flow spread, at least a flame temperature is required; and for concurrent

spread, the downstream flame length and flame heat transfer to the surface are

required [4], The former case is perhaps resolvable, and will be examined

here. The prospects of resolving the latter case will be discussed later.

The present work considers a method for deriving the parameters: kpc,

ignition temperature, and a flame temperature factor, suitable for use in

models for piloted ignition and opposed flow flame spread. The apparatus used

here was developed by Robertson [6]; subsequent studies [7,8,9] describe the

evolution of the use of the apparatus and the interpretation of its results.

Here, we attempt to provide a more general interpretation of these previous

results, a compilation of results for a wide range of materials, and a guide

for others who wish to explore this procedure.

-4-
2 . EXPERIMENTAL PROCEDURE

The apparatus consists basically of a gas-fired (air-natural gas) radiant

panel and a framed sample-holder assembly to contain a vertically oriented

sample. A schematic of the arrangement is shown in figure 1. The radiant

panel is inclined from the sample orientation so as to yield an incident heat

flux distribution along the center of the sample as shown in figure 2. By

varying the fuel-air flow rate to the panel, the incident heat flux at 50 mm

O could be varied from 1.5 to 7 W/cm . Thus, the normalized heat flux result in

figure 2 represents the geometric radiation factor for this apparatus, and

served as a calibration reference in subsequent flame spread measurements.

2.1 Ignition

Ignition results were obtained for small samples mounted over the 0 to

110 mm region of nearly uniform heat flux as shown in figures 1 and 2.

Initially the incident heat flux was measured at the 50 mm position. Once

stable conditions were recorded, the sensor was removed and the sample was

mechanically mounted in place. The mounting process could be done in several

seconds or less, so that ignition times of this magnitude will be subject to

uncertainty. It was found important to upwardly extend the plane of the

sample surface with a steel plate. This enabled the boundary layer containing

the pyrolyzed gases and the induced air flow to be maintained above the

sample. An acetylene-air pilot flame located approximately 25 mm from the top

of the sample and 5 mm from the steel extension plate interrupted this

boundary layer mixture. This plate and pilot arrangement insured a sustained

pilot flame, ignition based on the mixture concentration generated at the

-5 -
sample, and a propensity for flame propagation upstream through the boundary

layer to the sample face. Sustained ignition was noted and its time recorded

when continuous combustion was visible at the center of the specimen. In most

cases this was unambiguous, but on approaching the minimum flux for ignition

fq" . 1, oscillatory or incomplete surface combustion was sometimes observed.

^ o,ig ; ’

In some cases of, for example, melting or delaminating materials, judgement

was necessary in deciding on a primary ignition time when spurious effects

occurred. The data were recorded for a series of decreasing flux conditions

until a minimum flux, below which ignition would not occur, was found. An

example of a typical set of results is shown in figure 3 for fiber insulation

2 board. Here, no ignition would occur below 1.4 W/cm .

2.2 Flame Spread

A test for flame spread was initiated by selecting the proper external

heat flux at the 50 mm position. If the ignition pilot flame was used, the

external heat flux was required to exceed the minimum flux for ignition. The

optimum procedure is to adjust q"(50) to be slightly greater than q" . . In

° > i§

obtaining the flame spread data, it should be realized that the ignition

process itself is unimportant, but q"(50) must be greater than q" . Indeed,

o > iS

several ignition techniques were explored and two distinct processes will be

illustrated.

The sample size for flame spread spans the frame length as shown in

figure 1. Once the external heat flux was set and stabilized, the calibration

board was removed and the sample was inserted in place. This was done

manually and took several seconds. Following sample ignition, a flame propa-

-6 -
gated in the direction of decreasing external flux (figure 2). Its position

(x) was recorded as a function of time measured from the instant of sample

insertion. Varying degrees of curvature of the flame front were observed so

that the flame position was based on the centerline of the sample. The curvature of the propagating front was primarily caused by the nature of its

initial shape following ignition. It was not obviously dependent on sample

edge or air flow effects. Except near extinction, the curved front advanced

uniformly. These mid-front positions were recorded until the flame stopped.

Two examples of results are shown in figures 4 arid 5. Figure 4 illustrates

results for a fiberglass-based roofing shingle in which q^(50) was set at

3.0 W/ cm" compared to its ^

of 2.1 W/cm . The ignition pilot was used and

ignited the sample in slightly more than one minute. The results in figure 5

are for a hardboard wood product which was exposed to a heat flux distribution

2 of q^(50) = 3.0 W/cm for more than 11 minutes before a pilot flame initiated

ignition. This long pre-heating method was used to insure that thermal equilibrium would exist under flame spread conditions. Although considerable

charring and gasification occurs under long preheat conditions over the region

where q"(x) > q" . , this should not affect the flame spread results. To

e o , lg

ignite the sample in this case a small diffusion flame was slowly moved along

the bottom edge of the sample in the x-direction until ignition occurred. The

idea was to initiate the flame spread process at T

g (x) = T^g. Regardless of

the ignition process, surface flame spread will only occur where the external

heating conditions cause surface temperatures less than the ignition temperature. Once ignition temperature is reached at the surface this implies that

sufficient degradation (volatilization, charring, etc.) is present to sustain

ignition. Hence the introduction of a pilot flame at these conditions will

cause surface ignition. Although rapid gas-phase propagation is perceived in

-7 -
the preheating operational mode, it does not relate to "surface" flame spread

and the data are not recorded or are applicable as such. Most of the data

were taken when either of these two ignition techniques was used to initiate

flame spread. In both cases a preheating time at a position x was achieved

before the arrival of the flame front. It will be shown that the analysis of

the data can account for these variations in preheat times.

2.3 Sample Preparation

All samples tested were conditioned at approximately 55% relative

humidity and 20-22 °C. Aluminum foil was wrapped around the edges and back to

prevent the release of volatiles from these surfaces. The samples were

supported in the spring-loaded frame by a calcium silicate board 13 mm thick.

Other backing materials of lower density and conductivity were employed to a

limited extent and were found to have an insignificant effect on the results.

3. ANALYSIS

The objectives in analyzing the data have been to seek consistent results

for a material, to simplify the process of analysis, and to generalize the

results beyond the context of the test apparatus. Since a test procedure has

evolved with practice, no attempt has been made to standardize testing, to

automate the data analysis, or to evaluate statistical deviations. The

emphasis has been on describing the physical significance of the data and

streamlining the procedure. The following analysis forms the bare essence of

the general features of ignition and flame spread. It is intended as a framework for interpreting data in a generally useable form for prediction. It

-8-
does not purport to address all possible factors that could represent a

specific material. Where features, such as melting, variable properties, and

diathermancy, are present they would be accounted for by effective values of

the properties in the simple inert thermal model described subsequently.

3.1 Ignition

The framework for analyzing and interpreting the ignition data is the

thermal conduction model for ignition with a critical surface temperature.

This is fully discussed by Kanury [2] and was utilized successfully by Simms

[10] in ignition studies of wood materials. Those results suggest that the

form of solution for the surface temperature (T

g

) under constant external

radiant heat flux (q^) can be given as

• M F(t) ( 1 )

where T^ is the ambient and initial temperature, h is the surface heat loss

coefficient, and F(t) is a function of time and thermal properties of the

solid. Although an exact expression can be given for F(t) under conditions of

constant properties and a thermally thick (semi-infinite) or a finite thick

solid, it will be determined empirically. This approach is motivated by the

limits of the thermally thick solid solution, and by the preponderant form of

the ignition results in these tests. For the semi-infinite solid under these

heating conditions it can be shown [7] that

|

2h /t

) /irk pc

1, t

t -* small

> large

( 2 )

-9 -
The thermal model for ignition is that T

g = T

lg at ignition, and thus the

ignition time can be determined from an expression of the form of eq. (1).

Moreover, the critical radiant flux is found at long time where F(t) becomes

asymptotic to unity. Thus, from eq. (1)

q" . = h (T. " T ) o,ig v lg

(3)

when F(t) + 1. Here, the heat loss coefficient is understood to include both

radiative and convective effects. In general, the steady-state energy balance

which holds after long heating time can be written as follows:

q" - q" = eo(t

4 - T4

) + h (T - T ) = h(T - T ) (4) k

v s cv s

a>J K scoJ

where q£ is the conductive loss into the solid due to its finite thickness, e

is the surface emissivity which is usually greater than 0.8 for common combustibles under infra-red conditions, and h

c is the convective heat transfer

coefficient. For the conditions and materials used in this study it can be

estimated that q£ is less than ten percent of q^.

Surface temperature measurements as a function of external radiant flux

are shown in figure 6 for several materials. The idealized material represents q" = 0 and e « 1 while a low bulk density aircraft panel and a wood

particle board demonstrate departure from the ideal conditions. A theoretical

result based on e = 1 and h

c

= 15 W/nr K, characteristic of the natural convection conditions in the test apparatus, provides a good overall fit to the

idealized data. It is assumed that this theoretical curve, applicable to the

test apparatus, can be used to infer surface temperature for a material under

- 10-
long-time heating conditions. Thus, from an experimental determination of

q" t. can be found from the theoretical curve in figure 6 and h can be

M o ,ig ig

subsequently computed from eq. (3). The data in figure 6 suggest that the

true surface temperature can be as much as 50°C below the inferred idealized

temperature

.

Within the framework of eqns. (1-3), an empirical result has been found

to successfully describe all of the ignition results from the apparatus. The

results have been correlated by the expression

f( t)

bit, t < t ’ — m

1, t > t ’ — m

(5)

where, for each material, b is a constant, and tm

is a characteristic time

indicative of the time to reach thermal equilibrium since F(t) = 1 at t = tm

.

An example of a typical fit to the data is shown in figure 7 for the results

of the fiber insulation board (figure 3). The parameters b and tm

are found

from the slope and intercept, respectively. This correlation, although not

theoretically justified, must account for variable property effects which are

significant for the range of temperatures encountered; and must account for

the effect of heat losses from the back of the sample and the backing board.

Thus this result is characteristic of the apparatus to some extent.

Having obtained eq. (5) to represent the ignition results, it can be

related to the thermally thick result in eq. (2). Since eq. (5) implies the

results hold for small times as well as up to t

ffl , then the parameter b can be

related to kpc. Hence an effective kpc can be computed:

- 11 -
kpc m- ( 6 )

Here, the value for h is determined at T^g from eq. (3)

3.2 Flame Spread

The formula derived by deRis [3] for the thermally thick case can be used

as a framework to analyze and generalize the flame spread data. That result,

modified to account for an elevated solid temperature, is given as

V

V ( kpc) (t, - T V

_a g

v f ig J

kpc (T. - T ) 2

v ig s

J

(7)

where (kpc) refers to the gas-phase properties, T^ is the flame temperature,

g

and V

a

is the opposed flow gas velocity. Several studies, both experimental

and theoretical [1], have used this formula to correlate results for a wide

range of conditions including chemical kinetic effects which reduce the spread

velocity to a point where extinction occurs. Notable among them are the work

of Fernandez-Pello et al [11] who examined the affect of ambient oxygen

concentration and opposed velocity on flame spread over horizontal PMMA, and

the work of Altenkirch et al [12] who examined the effects of oxygen, gravity,

and pressure on the downward spread over PMMA. These studies show that the

spread velocity normalized by the value given in eq. (7), for which T^ is

computed as the stoichiometric adiabatic flame temperature, is solely a function of a Damkohler number (D) which represents the ratio of the residence

time of the gas in the flame to the chemical reaction time. Thus, they find

that this dimensionless spread velocity decreases from a value of approximately one to some finite value at extinction as D decreases, or in other

- 12-
words, as chemical kinetic effects become relatively more important. These

results provide important guidance for generalizing opposed flow spread

results for a wide range of conditions, but do not address their applicability

to different materials.

In order to deal with differences among materials, eq. (7) is represented

in this analysis as

V

k pc (T. -T )'

v xg SJ

( 8 )

where $ can be considered to represent the numerator of eq. (7) and any

effects of the Damkohler number under the test conditions. Thus $ depends on

the test conditions, but some insight can be given to extending it. For

example, under the lateral (or downward) spread conditions in the apparatus,

V , is induced by natural convection, and that characteristic velocity is

CL given by [3]

For typical values in air (e.g., T^ = 2080°C, T^ = 22°C,

(k/pc) = 0.216 x 10^ m^/s, g = 9.8 m/s^), it is found that V„ is 11 cm/s, a

S

a value consistent with measurements [2]. Also, opposed flow speeds of this

magnitude or less tend to have an insignificant effect on the spread rate

[11]. Thus, this suggests that the natural convection conditions of the

apparatus configuration mitigate effects of V_ on the results, in contrast to

a the sensitivity of spread rate to V

a at high oxygen concentrations. But

extension to higher flow speeds in air must require a modification of <t> based

- 13 -
on its dependence on V in accordance with the correlations of Fernandez-Pello

et al [11].

Another factor influencing $ is seen to be the flame temperature. Under

stoichiometric and adiabatic conditions it can be shown [12] that this temperature is approximately given by

T

f

YoxAH

00 ox

cg

( 10 )

where Y is the ambient oxygen concentration, c_ is the specific heat of

OX y 00 O

the gas, and AH

qx

is the heat of combustion per unit mass of oxygen which is

generally a constant (13 kJ/g) for most fuels. Equations (7), (8) and (10)

suggest that $ depends on Y^

x m

where n 2, and in fact it is found that n

increases as extinction conditions are approached [1]. Moreover, the effects

of non-adiabaticity, decreasing Damkohler number, and other departures from

the ideal conditions assumed in eq. (7) should decrease $. Under natural

convection conditions with values for PMMA at Y = 0.23 with an adiabatic

ox, 00 flame temperature of 2080°C and an ignition temperature of 390°C [11], $ was

O O computed as 10. (kW) /m . Thus it is expected that <3E> should range from this

order of magnitude to smaller values for materials tested in air under natural

convection conditions. For other conditions the value of $ must be modified

accordingly.

Eq. (8) then forms the basis for analyzing the test data. For direct

application it must be put in terms of the heating conditions encountered in

the apparatus. Several assumptions are necessary. First, it is assumed that

one dimensional conduction applies at any position x as shown in figure 2.

- 14 -
From figure 2, an appropriate length scale in the x-direction which accounts

for the flux distribution was taken as

q" ( x) / q" ( 50 ) l =-7 (ID

x h KM/mo)}

which can be greater than 200 ram. If is taken as the thickness of the

material, say l 10 mm; then conduction in the x-direction compared to

conduction in the y-direction J is f l / l ) < 1/400. Hence the one dimensional K y x ' —

assumption is justifiable. Second, the surface temperature rise is assumed to

be given by eq. (1) where F(t) is given by eq. (5). This is an empirical, but

reasonable approximation, as illustrated by the results shown in figure 8 for

particle board and in figure 9 for an aircraft honeycomb multi-layered panel.

The measured values for F(t) were computed from surface temperatures using eq.

(1) for several q" conditions. These are the same materials illustrated in

e figure 6 at steady-state conditions. With these assumptions, (i.e., using

eqs. (1) and (3)) eq. (8) is expressed as

v’

1/2 - c (q”

>lg - q“(x) • F(t)), (12)

where C is a constant related to $>. This equation can be used to analyze the

flame spread data as illustrated in figures 4 and 5. Although F(t) must be

determined from the ignition data, q” ^

can be found directly from the spread

data as well as from the ignition data. The process proceeds as follows. The

local slope of the position-time data is computed to yield the velocity as a

function of x or equivalently q”(x). Herein, a three-point running leastsquares fit was used to find V. The function F(t) is applied to q” at the

corresponding flame position and elapsed time from the initiation of heating.

- 15 -
By plotting these results as V

-1//2 against F(t), both C, the slope, and

q" the intercept, can be found. Figures 10 and 11 illustrate this process

for the data corresponding to the fiberglass shingle of figure 4 and the

hardboard of figure 5, respectively. For the shingle F(t) < 1 for most of the

data, while F(t) = 1 for all of the data from the hardboard test. Although

not clearly shown by these data, it is common to find departures from this

— 1/2 — 1/2

V ' relationship at large values of V

' where extinction sometimes appears

to cause a greater negative slope, and at small values of V

' where greater

uncertainties are likely in the data. Nevertheless, this analysis yields

q" , C and q” , the minimum external flux for spread.

O , lg o , s

Agreement between q^ ^

found from this process and q^ ^

found from the

ignition experiments demonstrates consistency and the complementary relationship between piloted ignition and flame spread. Having found these values,

their counterparts in the temperature formulation can be computed. It follows

from eqns. (1), (3), (6), (8) and (12) that

$ = ~ /(Cb)

2

. (13)

TT

A minimum surface temperature for spread (T

g m^n

) can be found from figure 6

and q"

g

, the irradiance at the position the flame stops.

4. RESULTS

Although the parameters $, kpc, T^g and T

g m^n

are the most useful in

generalizing these results, it is interesting to consider the maximum spread

velocity (F(t) = 1) and the ignition time as a function of the external

- 16 -
radiant heat flux. This might be considered as a "flammability diagram" for

the material over the range of heating conditions in the apparatus. It

applies under conditions of constant irradiance and for flame spread under

long heating times. Several of these diagrams are shown for a varied set of

materials: plywood (figure 12), rigid polyurethane foam (figure 13), gypsum

board (figure 14), an asphalt shingle (figure 15), and a polycast polymethylmethacrylate (PMMA) (figure 16). All are shown at the same coordinate scales,

the analytical curves according to the values of C, b, etc. are shown with the

data, and only velocity data for which F(t) = 1 or t >_ is plotted. These

results show a range of heating conditions, q" _< q” q" . , over which only

opposed flow flame spread can occur; and a domain, q^ > q^

^ , for which only

piloted ignition is possible. Of course, flame spread can occur for

q" > q" . , but only for heating times below which T_ < T^„. Since q" . is

e o,ig’ jo s ig o,ig

considered to be the same for ignition and flame spread in the theory, the

vertical asymptotic values of the spread and ignition results should coincide.

The extent to which they do indicates the consistency in the results and

perhaps their accuracy as well.

A more extensive listing of results is given in table 1. It should be

pointed out that the materials tested came from several sources, all of whom

were interested in the performance of these materials in fire. In many cases,

therefore, additional measurements were made for these materials. In table 1

the materials have been listed by their generic names and grouped into categories of woods, plastics, carpets and composites (laminates). Painted

surfaces have been included with the wood materials. Except for the hardboard

painted with nitrocellulose paint, all of the laminated materials displayed a

single flame front. However, delamination of the surface coating preceded

- 17 -
flame spread for some laminates. The case of the nitrocellulose paint

displayed an initial rapid surface spread due to the paint. This was then

followed by a slower spread with continued burning behind the front. Only

this latter result has been reported due to the rapidity of the first phenomenon. The results presented in table 1 can be used to construct the flammability diagrams as shown in figures 12-16. The applicability of these

diagrams depends on the heating conditions. In contrast, table 2 lists

results that are more general and can be construed as "flame spread

properties". There, the results are ordered in terms of ignition temperature.

These results, the ignition temperature, the minimum temperature for spread,

the effective kpc, and the $ value, all can be used to predict piloted ignition and opposed flow spread under natural convection conditions regardless of

the heating conditions. Only the surface temperature need be computed for the

specific heating conditions. Also it is recognized that an estimation of kpc

from eq. (2) and the ignition data reported may be too approximate to be

acceptable. Consequently, $/kpc is reported to skirt this possible

uncertainty since $/kpc is the primary parameter needed anyway. Moreover,

when ignition data were not recorded for a material, the ignition temperature

and $/kpc values were derived for table 2 by using the flame spread data

alone. In all other cases T^g was derived from the ignition data. In many

cases the flame spread results were derived from several tests in which the

heating conditions varied with respect to irradiance and pre-heating times.

-18
5. DISCUSSION

Although no direct check on the kpc values was attempted, a compilation

of thermal properties for common materials under normal environmental conditions is given in table 3. Those values for kpc appear to be generally lower

than the correspondingly similar materials listed in table 2. Several reasons

can be offered to explain why kpc derived from ignition data and eq. (2) will

be higher than the associated ambient value for kpc. Firstly, both k and c

increase with temperature, and thus some higher than ambient temperature value

must be used to compute temperature rise to ignition. Secondly, ignition

requires the production of a gaseous fuel from the heated solid. Thus, the

enthalpy changes required in pyrolysis, vaporization, and melting in some

instances must be included in the derived kpc values. These endothermic

effects will be reflected in an increase in the kpc parameter for an inert

thermal ignition model. Thirdly, the kpc values may be higher due to effects

of sample thickness and the heat sink effects of the support board behind the

sample. Except for these last sources of error, which should be further

examined, it would appear that the derived kpc values are the proper values to

use in the flame spread models that utilize an inert-ignition temperature

model for the solid. In summary the kpc values of table 2 appear somewhat

high but credible under the circumstances of the models.

The results tabulated for the ignition temperatures appear plausible

since values quoted in the literature for PMMA and cellulosics range from 300

to 400°C for piloted conditions [1,2]. Of course, these values should not

necessarily be construed as precise surface temperatures, just approximate

indications thereof. This follows because T^g is a derived temperature from

- 19 -
an approximate model. As long as the piloting conditions and models of ignition and flame spread are consistent with inert solid models, it is probably a

good general value to use. Moreover, since the ignition temperature is just a

surrogate condition for a gas-phase flammability limit, it is possible to

expect that it may depend to some extent on sample size and orientation and on

oxygen concentration. For example, it may increase somewhat for charring

materials as the oxygen concentration is reduced since more fuel will be

necessary to produce a combustible mixture, but solid oxidation effects may

offset this increase.

The values for $ are particularly intriguing. If one examines the correlations of Fernandez-Pello et al [11] and Altenkirch et al [12], $ can be

expressed as

$ = V (k pc) (T. - T ) 2 f(D) (14)

a g f ig

where f(D) is a function of the Damkohler number. The flame temperature (T^)

represents the energy available and although the adiabatic flame temperature

is nearly constant for most hydrocarbons, it will decrease with a reduction of

oxgyen in the atmosphere or an addition of an inert diluent to the solid. The

f(D) will contain the chemical kinetic effects and the gas transport times

available for combustion as dependent on V

a

. As the oxygen concentration is

reduced, D, and also f(D) at least for PMMA [1], are sharply reduced.

O O Previously, a reference value for $ was computed as 10 (kW) /m based on

Tf = 2080°C, T^g = 390°C, V

a = 11 cm/ s and Y

qx

= 0.23 nominally representative of PMMA spreading under opposed flow natural convection conditions.

The results in table 2 show $ ranges from roughly 1 to 15 (kW)Vm .

-20-
Sufficient data are not available to assess these results against the dimensionless correlations for spread rate in terms of D since they are only available for PMMA [11,12]. Nevertheless, the range of values inferred for $ from

the PMMA correlations appears consistent with the results for all the

materials in table 2 since f(D) for PMMA ranges from approximately 0.1 to

slightly greater than 1. Although this consistency may be fortuitous it does

offer some credibility and perhaps insight into the magnitude of $. Of

course, the computation of $ does depend on the estimate for kpc (or b) so

that any uncertainties in that estimation will affect the value for $.

Table 2 also lists the minimum surface temperature (T

g m^ n

) required for

spread under the conditions of the experiment. It was computed using figure 6

from the critical external irradiance at the position at which the flame

stopped. This generally occurred at a finite spread velocity, or in other

words, the flame spread velocity does not approach zero continuously as the

surface temperature approaches T

g m-^ n

« Borgeson and Tien [13] have developed

a theoretical model for a thin fuel which shows these same characteristics.

They found that as the surface temperature is decreased, the gas phase combustion zone at the leading edge of the flame recedes in the direction of the

opposed air flow. The reduction in forward heat transfer and a decrease in

the pyrolysis zone appears responsible for the cessation of flame spread. Of

course, for the range of fuels listed in tables 1 and 2, other effects could

be responsible for extinction. Indeed, surface heat losses in charring

materials, and significant regression effects for some of the foam plastics

could be contributory. In any case, this temperature limit is a significant

characteristic, and in fact, is related to the measurement of results in ASTM

E648. It should be noted, however, that due to the limits of the flux condi-

-21 -
tions in the apparatus, values of T

g min < 80 °C could apply to much lower

temperatures

.

Extended use of the results in table 2 might be considered in practical

engineering analyses of fire spread. Current knowledge must be used to guide

the necessary assumptions. For example, the results here show that the same

ignition temperature can be used to describe piloted ignition and opposed flow

flame spread. Thus, it might be assumed that the same value would be applicable under concurrent spread conditions. If the ambient oxygen or flow

velocity varies, it is necessary to infer resultant changes in opposed flow

spread from the Damkohler-number correlations [11,12]. As a first approximation, for natural convection conditions in room fires, the values of $ in

table 2 might be modified by (Y

qx ^/Q.233) to account for vitiation conditions. Under concurrent flow spread conditions, Sibulkin and Kim [4] derived

an approximate expression for spread velocity over a thermally thick solid

which is given as

(q “) 2

«f v

i

T

(15)

kpc ( T

ig

- T

s>

where q" is the average flame heat flux over the surface downstream of the

pyrolysis zone, and 6^ represents the flame length over this heated region.

Thus, to utilize this formula in an analysis of fire growth it will be necessary to understand the behavior of q" and 6^ in terms of material properties

and environmental conditions. Although this is feasible, it has not yet been

demonstrated. Nevertheless, the denominator can be estimated from the current

results of table 2.

-22-
6. CONCLUSIONS

It has been shown that it is feasible to derive ignition and flame spread

properties for a wide range of materials. Ignition temperatures range from

about 250 to 600°C, may be overestimated by 50°C at most, and consistent

values were found for piloted ignition and flame spread. The derived kpc

values applicable to flame spread over thermally thick solids tend to be

higher, but in relative agreement, with literature values for similar

materials under normal room conditions. A parameter $ has been defined which

is representative of the available flame energy, and applies to opposed flow

flame spread. These three parameters respectively correspond to (1) the

conditions necessary for combustion (T^ ) , (2) the time response of the

material to heat (kpc), and (3) the energy available for spread ($>). Evidence

suggests that these properties, although not fundamental, can be generally

used in mathematical models to predict the performance of materials. Although

the results given here only apply to natural convection conditions in opposed

air flow, extension to other environmental conditions or to concurrent flow

spread is possible.

7 . ACKNOWLEDGMENTS

The authors are indebted to Dr. A.F. Robertson for the basic design of

the apparatus. Mr. D. Walton was responsible for obtaining much of the heat

transfer data for the apparatus. Various people and organizations contributed

materials for analysis. They include the following: (1) A.F. Robertson,

materials tested by ISO (International Standards Organization); (2) Bjorn

Sundstrom (National Testing Institute, Boras, Sweden) materials used in room

- 23-
fire studies; (3) E. Braun, materials used in solar energy applications;

(4) B. Lee, materials used in evaluating a standard room fire test;

(5) J. White of Weyerhauser; and (6) T. Eklund of the Federal Aviation

Administration (FAA) Technical Center. Several others assisted in gathering

and processing the data; namely, D. Corley, R. Sumner, and B. Cooper.

This work was partially supported by the FAA Technical Center, Atlantic

City, NJ.

8. REFERENCES

[1] Fernandez-Pello , A.C. and Hirano, T., Combustion Science Technology,

Vol. 32, Nos. 1-4, June 1983, pp. 1-31.

[2] Kanury, A. Murty, "Ignition of Cellulosic Solids - A Review", Fire

Research Abstracts and Reviews, Factory Mutual Research Corporation,

Vol. 14, No. 1, 1972, pp. 24-72.

[3] DeRis, J.N., Twelth Symposium (International) on Combustion, The

Combustion Institute, 1969, pp. 241-252.

[4] Sibulkin, M. and Kim, J. , Combustion Science and Technology, Vol. 17,

1977, pp. 39-49.

[5] Fernandez-Pello, A.C. , Combustion Science and Technology, Vol. 17, 1977,

pp. 1-9.

[6] Robertson, A.F., "A Flammability Test Based on Proposed ISO Spread of

Flame Test", Third Progress Report, Intergovernmental Maritime

Consultative Organization, IMCO FP/215, 1979.

[7] Quintiere, J., Fire and Materials, Vol. 5, No. 2, 1981, pp. 52-60.

[8] Quintiere, J., Harkleroad, M. and Walton, D. , Combustion Science and

Technology, Vol. 32, 1983, pp. 67-89.

[9] Harkleroad, M. , Quintiere, J. and Walton, D. , "Radiative Ignition and

Opposed Flow Flame Spread Measurements on Materials", DOT/FAA/CT-83/28

,

Atlantic City Airport, NJ, August 1983.

[10]

Simms, D.L., Combustion and Flame, Vol. 7, September 1963, pp. 253-261.

-24-
Ill] Fernandez-Pello , A.C., Ray, S.R. and Glassman, I., Eighteenth Symposium

(International) on Combustion, The Combustion Institute, Pittsburg, PA,

1981, p. 519.

[12] Altenkirch, R.A. , Eichhorn, R. and Rigvi, A.R. , Combustion Science and

Technology, Vol. 32, 1983, pp. 49-66.

[13] Borgeson, R.A.

Vol. 32, 1983,

and Tien, J.S.,

pp. 125-136.

Combustion Science and Technology,

-25-
Ignition

and

Flame

Spread

Characteristics

Under

Constant

Irradiance

Conditions

0 LPl O 0 O 00 0 CSI U0 1 1 X

£ u o> CNI *—4 CNI vO 0 <r ON 0 U w >—1 CNJ —4 —1 <r on CO co CNI

CNI be e X G o

cr

CNI bo e X G

O S'

cr w

00 LP> 00 CM 00 P-4 0 CM 0 CM — CO

• • * . • • • • • • • • • • p—

r—i m CM «—

CM CO CM CM .—

CO «

1

CNI w B

~ u

o \ cr 3

'b- —

j

• • o o

'd- o o

x

o

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X

CD G

CO cb E /—

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co X rH G cb CO X CM B /“

cb rH CN| X 0 c

• • CJ E to- G . G X G 0 1 r- E E G *—1 X a X ' CM E m a co O N-X X a 00 G

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c c 1—

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m 0 4-1 X cb r-J j X O X •H . . .—1 1—i X G X —J X X iX

1—

cb cb X co cn bC c cb X -—^ cb

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iX X P-, CL, X X X X 3 X

G X) X X X ^N X X B X G CO G

G a G G g G S G /-N G —s O G C c cb

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cb O O 0 O 0 0 0 <r 0 c G 0 cb CM 0 X X

a O O 0 X x X x • X X X 0 1—

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3 3 3 X X X X CO X cb X U bO »—

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X 0-i X x, X X X X X O 0 s X X

26

Polyisocyanurate

(5.08cm)

0.9

0.4

1.7

2.1

Polystyrene

(5.08cm)

*

*

*

4.5
Polyurethane

(S353M)

X

27

Flame

spread

was

not

moasureable
Flame

Spread

Properties

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•—* •—

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cn CO CO i—

V-/

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E-* o CM o lO O' <r 00 O' <* in CM 00 CN 00 o CNl 00 lO CM CN rJ cn CO

COB

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CNl m r-N CO 00 m *—

O' O IN. 00 1—

r-J e cNi m O' CN O' <r CO ON NT O' in oo CM

Vw' /^N • • • • • • • • • • • • • • • IS UO 1 O' | CNl o 1 <r in CNl

I CNl

1 i—

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f—1

V

CO

CNJ-^S

/"n ^ CO CNl lO 00 CM o Nj- ID CN CM CM O' CM

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4*5 \ o 1

t < o | o o 1 r—

o o | o 1 o o o i—

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1

1 (X, CL, X 0 o C/0 •H 0

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a) rH 4-J S-i V—

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28
oa

mm CM

c cj UO o U0 uo in m m m o in o m m o O

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n- M3 m o o m CM CM CO e w CM CM CM CO CM CM CO si- m co sr vO vD

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CM CM CO O ON o 00 00 *

CM

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M3

<0 H

CM

3

uo VO Ocn

<- oo o r-< CM

CO

CM

CMco

-d- sr

-d-

/~s 3*4 CO 00 uo co CM o >3

* <r O M3 UO M3 00

CJ CM av UO vO CM o o m CM »—1 CM <r CO a S

.X o O o o o o o O o O o •—1 o o o

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«—

j

co co UO M3 o «—1 CM vO CM CO

<1

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r-S rH O sr <—

a • O rv 00

co o * uo 0) bO n m> w ps (-S CJ CM o

2 i-H • 4-1 e rH r-S E vs vs • • 03 o CM co •H o o rH .—

uo

Is «% (3 o v_s Is M3 o o cu M (U ' vs

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CO 03 O 3 3 C/3 3 3 c 03 4-4 03

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cu

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V

CQ 2 vs •H CJ CO 4-1 •H CO M3 Is

4-1 i—

-X CM PcS O rH MS U Is rv a >v

CO CJ CJ 6 sr 4-4 4-1 co bO 4-1 4-1 co a) E CO e cm o 4-J s •H o 3 —1 0) 01 •» i-t is cu CU Is 3 CJ 3 • o CO

4-1 4-4 CO C/3 CL CL B >•> cu CL a, CJ •H CO >v CO — 3 >v

Is CO Cl v-^ Is Is cO rH M3 Is Is Is i^H a r~H CL v-s >v rH

CO >% CO CO O O •H CO co •H >v o >v o

Cl, O CJ CJ Cb Ps Cb CJ CJ -5 o Ps o Ps Ps

M3

cC

a)

is3

co

cd

O C

C CJ

co co

(Q 4J 5

03

cfl aiIsa

0)

a>e

CO

co a

29

are

only

significant

to

two

places
Table 3 Properties of Common Materials

*

Material

Density

P

1 (kg/m3

)

Conductivity

k x 10 3

( kW/m-K )

Specific Heat

c (kJ/kg-K)

kpc

(kW/m2 -K) 2

s

Concrete, stone 2200 1.7 0.75 2.8

Polymethylmethacrylate

(PMMA)

1200 0.26 2.1 0.66

Gypsum board 950 0.17 1.1 0.18

Calcium silicate board 700 0.11 l.l 0.085

Particle board 650 0.11 2.0 0.14

Plywood 540 0.12 2.5 0.16

Cork board 200 0.040 1.9 0.015

Balsa wood 160 0.050 2.9 0.023

Polyurethane, rigid 32 0.020 1.3 0.0008

Polystyrene, expanded 20 0.034 1.5 0.0010

Compiled from various sources.

30
ACETYLENE-AIR

PILOT

(/) <

cc<

CL0. EE

oo

CSI

31

Figure

1.

Schematic

of

test

apparatus.
32

,

DISTANCEON

SPECIMEN

(mm
300

CD

in

CO

CM

o o o o O

m o in o m

CVJ CM r- T—

CM

T3u

COO

JOu

o

00

(S) 3WI1

33

EXTERNAL

FLUX

(W/cm
800

700

600

500

400

300

200

100

0

O

O

O

O

O

O

O

O

O

O

O

O

O

O

-O

O

O

O

_J | 400 800

TIME (s)

1200

are 4. Flame position as a function of time

for a fiberglass roofing shingle.

34
800

700

600

500

400

300

200

100

0 1000 2000 3000

TIME (s)

Figure 5. Flame position after delayed

ignition of hardboard.

35
700

Oo) 3anivu3dW3i 30Vdans

36

1

t I

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

INCIDENT

HEAT

FLUX

(W/cm

2)

Figure

6.

Equilibrium

surface

temperatures

as

a

function

of

external

radiant

heating

in

the

test

apparatus.-
Figure 7. Correlation of ignition results for

fiberboard (see Fig. 2).
33 4J 33 X

33 3 3 o 33 X

CO 3 3 3

(/) 3s 3i—1 3

LU M-l > Jg o 3

o*b=d 3 4-) h— O 3

CO e

•H •H 3 X 3 o & 3 e 0. o (X o 3

00333

00

'H

IX

38

particle

board.
RANGE

OF

MEASURED

VALUES

CM

CD

CO

CD

CM

CO

C3

CO

CD

CNI

CO

x)e

co X)

<u3m

CO

(UE

(0o

CO

'pH

k-l COCLEoa

ON

0) 3

oo

oo CO CM OO CO CM

39

approximate

values

for

F(t)

:

aircraft

panel.
znK

—

z/v

0

>

1 2 3

q" F(t) (W/cm2

)

Figure 10. Correlation of spread velocity for

a fiberglass shingle (see Fig. 4)

.

40
(lUOI/S)

3.0

O

O

\

\

EXTERNAL FLUX, q" (W/cm 2

)

Figure 11. Correlation of spread velocity for

hardboard (see Fig. 5).

41
SPREAD

RATE

(mm/s

)

PLYNOOD, PLAIN (1.27cm)

o

1 1 1 1 1 1 r

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

IRRflDIflNCE(N/cm

2

)

Figure 12. Spread and ignition results for

plywood.

42

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(

s
SPREAD

RATE

(mm/s

)

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

FORM, RIGID (2.54cm)

Figure 13. Spread and ignition results for

rigid polyurethane foam.

43

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
SPREAD

RAIE(mm/s)

GYPSUM BOARD, COMMON (1.27mm)

o

o •

CDCD

'

O

CD

'

O

tv

o

CD

o

LD

O

o

to

o

OJ

'

X

X

o

O .

CD

CD 0.0 1.0 2.0 3.0 4.0 5.0

IRRADIANCE(W/cm2

)

Figure 14. Spread and ignition results for

gypsum board.

6.0 7.0

44

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
SPREAD

RATE

(

mm/ )s

RSPHRLT SHINGLE

o

Figure 15. Spread and ignition results for an asphalt shingle.

45

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
SPRERD

RRTE(mm/s)

PMMR POLYCRST ( 1.59mm)

I RRFID I RNCE ( W/cm2

)

Figure 16. Spread and ignition results for

PMMA.

46

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
Appendix A. Correlation of Ignition Results

Ignition tests were conducted for a variety of materials including

plastics, woods and composites. The fit of these data correlated by eq. (5)

to the empirically derived function F(t) is shown in figures A-l to A-30. The

illustrated line fit favors the shorter times where the assumption of an

infinitely thick solid would be more valid [8,9]. For layered composite

materials, the data reflect results applicable to the ignition of the first

layer. However, it was not always obvious what role the underlayraent

materials played.

47
PUMA

POLYCAST

(1.59cm)

48

Figure

A-l.

Correlation

of

ignition

results

for

PMMA

Poly

cast

(1.59

mm).
PMMA

TYPE

G

(1.27cm)

in b /

6ro b

o

o II

o

in

ro

CM

if)

O'

CO

O

o

49

Figure

A-2.

Correlation

of

ignition

results

for

PMMA

Type

G

(1.27

cm).
FLEXIBLE

FOAM

(2.54cm)

50

Figure

A-3.

Correlation

of

ignition

results

for

flexible

foam

(2.54

cm).
RIGID

FOAM i oo o

in

cr

if)

OO

51

i^uio A

4.

Correlation

of

ignition

results

for

rigid

foam

(2.54

cm).
POLYISOCYANURATE

(5.08cm)

52

Figure

A-5

.

Correlation

of

ignition

results

for

polyisocyanurate

(5.08

cm).
POLYCARBONATE

(1.52mm)

53

Figure

A-6.

Correlation

of

ignition

results

for

polycarbonate

(1.52

mm).
POLYSTYRENE (5. 08

cm)

T

T i!LLfl Oo

CM

CO

cr

CO

Oo

54

Figure

A-7.

Correlation

of

ignition

results

for

polystyrene

(5.08

cm).
HARDBOARD

(6.35mm)

55

Figure

A-8.

Correlation

of

ignition

results

for

hardborad

(6.35

mm).
HARDBOARD

(3.175mrm)

56

Figure

A9.

Correlation

of

ignition

results

for

hardboard

(3.175

mm).
DOUGLAS

FR

PARTICLE

BOARD

(127cm) i

in oo o

inn

CT cn OO

57

Figure A

10.

Correlation

of

ignition

results

for

Douglas

fir

particle

board

(1.27

cm).
PLYWOOD,

PLAIN

(0.635cm)

TT t<ii<ii?bint

ID

Oo od

<N

CMc

(/) Oo

58

Figure

A-ll.

Correlation

of

ignition

results

for

plywood,

plain

(0.635

cm).
PLYWOOD,

PLAIN

(1.27cm)

59

Correlation

of

ignition

results

for

plywood,

plain

(1.27

cm).
HARDBOARD,

NITROCELLULOSE

PAINT

T

Oo o

to

(N

CM

</)

CT

GO O« o

60

Figure

A-13.

Correlation

of

ignition

results

for

hardboard

(3.4

mm,

nitrocellulose

paint).
HARDBOARD

(gloss

paint)

(3.4mm)

61 :

Lgure

A-14.

Correlation

of

ignition

results

for

hardboard

(3.4

mm,

gloss

paint).
PARTICLE

BOARD

(stock)

62

Figure

A-15.

Correlation

of

ignition

results

for

particle

board

(1/27

cm,

stock).
PLYWOOD,

FR

(1,27cm)

63

Figure

A-16.

Correlation

of

ignition

results

for

plywood,

FR

(1.27

cm).
CARPET

(acrylic)

64

Figure

A-17

.

Correlation

of

ignition

results

for

carpet

(acrylic)

(S119M)
FIBER

INSULATION

BOARD

65

Figure

A-18.

Correlation

of

ignition

results

for

fiber

insulation

board.
ASPHALT

SHINGLES

T

Oo

CM I

CT

CO Oo

66

Figure

A-19.

Correlation

of

ignition

results

for

asphalt

shingle.
GRP

(2.24mm)

cr

(/)

OO

Figure

A-20.

Correlation

of

ignition

results

for

GRP

(2.24

ram).
GRP

(1.14mm)

68

Figure

A-21.

Correlation

of

ignition

results

for

GRP

(1.14

mm)
FIBERGLASS

SHINGLE

T

O

in

CM

O'

CO OO

69

Figure

A-22.

Correlation

of

ignition

results

for

fiberglass

shingle.
GYPSUM

BOARD,

WALL

PAPER

(142M)

70

Figure

A-23.

Correlation

of

ignition

results

for

gypsum

board

wallpaper

(S142M)

.
CARPET

(NYLON/WOOL)

71

Figure

A-24

.

Correlation

of

ignition

results

for

carpet

(nylon/wool).
CARPET

#2

(wool)

72

Figure

A-25.

Correlation

of

ignition

results

for

carpet

#2

(wool)

.
CARPET

(wool,

treated)

73

Figure

A-26.

Correlation

of

ignition

results

for

carpet

#2

(wool,

treated).
CARPET

#1

(wool,

stock)

74

Figure

A-27.

Correlation

of

ignition

results

for

carpet

#1

(wool,

stock).
AIRCRAFT

PANEL

EPOXY

FIBERGLASS

75

Figure

A-28.

Correlation

of

ignition

results

for

aircraft

panel

(epoxy

fiberglass).
GYPSUM

BOARD,

COMMON

O

co OO oo

Figure

A-29.

Correlation

of

ignition

results

for

gypsum

board

(1.27

mm,

common).
GYPSUM

BOARD,

FR

(1.27cm)

77

Figure

A-30.

Correlation

of

ignition

results

for

gypsum

board,

FR

(1.27

cm).
Appendix B. Correlation of Spread Results

Flame spread tests were conducted for a variety of plastic, wood and

composite materials. The materials flame velocities were computed from a

running 3-point least square fit of the slope of the position-time data.

These computed velocities, correlated in terms of eq. (12) and plotted as

V-l/2 vs q^ F(t) are shown in figures B-l to B-33. The data represents

results for varied external irradiances for no pre-heat and pre-heated

materials. Table B-l lists these external radiant fluxes to the material

surface at the 50 mm position (q^ (50)) and indicates the ignition procedure,

i.e., no pre-heat and/or pre-heating of the specimen. The solid line,

indicating the slope, was drawn based on the core-data set, ignoring the ends

at high and low q^ F(t) values. The low end is near extinction and other

phenomena are suspected to influence the flame spread speed. The high end is

near ignition where spread velocities are high and ignition phenomena can

influence this speed. Figures B-3, B-4, B-5, B-ll and B-32 include data for

downward spread (9).

78
Table B-l.

External irradiance and Ignition procedure for spread velocity tests

q"(50)

^ A Figure // W/ cm

z No Preheat Preheat

1 3.0 X

2 3.0 X

3 3.0 X X

4 2.0 X X

5 3.0 X X

6 2.0 X

7 4.0 X

8 3.0 X

9 2.7 to 5.0 X

10 3.0 X

11 1.7 to 5.0 X X

12 3.0 X X

13 3.0 X

14 3.0 X

15 3.0 X

16 5.0 X

17 5.0 X

18 5.0 X

19 5.0 X

20 3.5 X

21 2.1 to 5.0 X

22 3.0 X

23 3.0 to 4.0 X

24 3.0 X

25 3.0 X

26 2.1 to 3.0 X

27 2.0 X

28 2.3 to 3.8 X

29 5.0 X

30 5.0 X

31 5.0 X

32 5.0 X

33 3.0 X

34 5.0 X

79
PMMA,

POLYCAST

(1.59mm)

80

Figure

B—

1.

Correlation

of

spread

velocity

for

PMMA

polycast

(1.59

mm).
POLYURETHANE

(30mm)

(S353M)

81

/

Figure

B-2.

Correlation

of

spread

velocity

for

polyurethane

(S353M,

30

mm).
PMMA,

TYPE

82

Figure

B-3.

Correlation

of

spread

velocity

for

PMMA

Type G

(1.27

cm).
FOAM,

FLEXIBLE

(2.54cm)

83

Figure

B-4

.

Correlation

of

spread

velocity

for

flexible

foam

(2.54

cm).
RIGID

FOAM

84

Figure

B-5.

Correlation

of

spread

velocity

for

rigid

foam

(2.54

cm).
POLYISOCYANURATE

(5.08cm)

85

figure

B

6.

Correlation

of

spread

velocity

for

polyisocyanurate

(5.08

cm).
POLYCARBONATE

(1.52mm)

86

Figure

B-7

.

Correlation

of

spread

velocity

for

polycarbonate

(1.52

mm).
HARDBOARD

(6.35mm)

87

Figure

B-8.

Correlation

of

spread

velocity

for

hardboard

(6.35

mm).
HARDBOARD

(3.175mm)

88

Figure

B-9.

Correlation

of

spread

velocity

for

hardboard

(3.175

iran)

.
HARDBOARD

(S159M)

89

Figure

B-10.

Correlation

of

spread

velocity

for

hardboard

(S159M,

1.0

cm).
PARTICLE

BOARD,

DOUGLAS

FIR

90

Figure

B-ll.

Correlation

of

spread

velocity

for

Douglas

fir

particle

board

(1.27

cm).
WOOD

PANEL

(S178M)

91

Figure

B-12.

Correlation

of

spread

velocity

for

wood

panel

(S178M).
CHIPBOARD

(S118M)

92

Figure

B-13.

Correlation

of

spread

velocity

for

chipboard

(S118M).
PLYWOOD,

PLAIN

(.635cm)

O

ro

(zA-)^

O

O

o

(0

N

£

0

u.

cr

o

o

93

Figure

B-14.

Correlation

of

spread

velocity

for

plywood,

plain

(0.635

cm).
PLYWOOD,

PLAIN

(1.27cm)

94

Figure

B-15.

Correlation

of

spread

velocity

for

plywood,

plain

(1.27

cm).
HARDBOARD,

NITROCELLULOSE

PAINT

T T T 1

O

in

(z/i-)A

o

o

o

cri

o

o

95

Figure

B-16.

Correlation

of

spread

velocity

for

hardboard

(3.4

mm,

nitrocellulose

paint).
HARDBOARD,

GLOSS

PAINT

(3.4mm)

96

Figure

B-17

.

Correlation

of

spread

velocity

for

hardboard

(3.4

mm,

gloss

paint).
PARTICLE

BOARD,

STOCK

T

T

O*

(Z/1-)

Oo o

(d

CM Eo\

L_

cr

Oo

97

Figure

B-18.

Correlation

of

spread

velocity

for

particle

board

(1.27

cm,

stock).
CARPET,

ACRYLIC

98

Figure

B-19.

Correlation

of

spread

velocity

for

carpet

(acrylic).
FERBOARD,

LOW

DENSITY

(SIMM)

99

Figure

B-20.

Correlation

of

spread

velocity

for

fiberboard,

low

density

(S119M)

.
FIBER

INSULATION

BOARD

O

rj (z/t-)A

100

Fibure

B-21.

Correlation

of

spread

velocity

for

fiber

insulation

board.
SHINGLE,

ASPHALT

i T T

1 r l r

O

*

(Z/l-)A

O

o

o

o

101

Figure

B-22.

Correlation

of

spread

velocity

for

asphalt

shingle.
SHINGLE,

FIBERGLASS

102

Figure

B-23.

Correlation

of

spread

velocity

for

fiberglass

shingle.
GRP

(2.24mm)

103

Figure

B-24.

Correlation

of

spread

velocity

for

GRP

(2.24

mm).
GRP

(1.14mm)

104

Figure

B-25.

Correlation

of

spread

velocity

for

GRP

(1.14

mm).
MINERAL

WOOL,

TEXTILE

PAPER

(S160M)

105

Figure

B-26.

Correlation

of

spread

velocity

for

mineral

wool,

textile

paper

(S160).
GYPSUM

BOARD,

WALL

PAPER

(S142M)

106

Figure

B-27.

Correlation

of

spread

velocity

for

gypsum

board,

wallpaper

(S142M)

.
CARPET

#2,

WOOL

107

Figure

R-28.

Correlation

of

spread

velocity

for

carpet

\\2

(wool).
CARPET

#2,

WOOL,

TREATED

108

Figure

B-29.

Correlation

of

spread

velocity

for

carpet

#2

(wool

treated).
CARPET

#1,

WOOL,

STOCK

109

Figure

B-30.

Correlation

of

spread

velocity

for

carpet

//I

(wool,

stock).
AIRCRAFT

PANEL

fl,

EPOXY

FIBERGLASS

no

Figure

B-31.

Correlation

of

spread

velocity

for

aircraft

panel

(epoxy

fiberglass).
GYPSUM

BOARD,

FR

ill

-32.

Correlation

of

spread

velocity

for

gypsum

board,

FR

(1.27

cm).
GYPSUM

BOARD,

COUMON

(1.27mm)

T 1 1 1 1 1 1 1 1

O

oj (Z/1-)

o

o

o

cri

SS

CM

E

o

L_

cr

O

O

112

Figure

B-33.

Correlation

of

spread

velocity

for

gypsum

board

(1.27

mm,

common).
1

AiiitiKis 1 £ i - £-31. - . w~

Jr = :r r _ t*.

331 3 jr IzTl'rl T = r 5
SPREAD

RATE

(mm/s

)

POLYURETHANE (S353M)

o

o

o

CP

o

CO

'

o

IN.

'

O

CD

O

LD

W.

X LEGEND

x = FLAME SPREAD

xj x

o

^

o

to

o

r\]

o

X

X

i

i

i

iX

X

o

o

o

0.0

Figure C-l.

1 .0 2.0 3.0 4.0 5.0 6.0 7.0

IRRflDIflNCE (W/cm2

) Spread and ignition results for polyurethane (S353M, 30 mm).

114

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(

s

)
SPRERD

RRTE(mm/s)

PMMR TYPE G ( 1 „27cm)

o

115

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(

s
SPREAD

RATE(mm/s)

FOAM, FLEXIBLE ( 2 . 54cm

]

1 1 1 1

1 i r

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

IRRADIANCE ( W/cm2

) Figure C-3. Spread and ignition results for flexible foam (2.54 cm).

116

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(s

]
SPREAD

RATE

(

mm/

]s

POLYCARBONATE (1.52mm)

o

o

<r

. o

LDid

. o

o

co

oLD

CM

O

OOCM

CO LJ

E—

CD

CD

E-* LJ

9 t-* ID

o

o

- oID

o

o

117
SPREAD

RATE

(mm/s

)

POLY I SOCYRNURRTE! (5.08cm)

o

o

o

CD

'

O

CD

'

O

cv

o

CD

O

LD

O

'

O

m

o

DO

'

CDo

LEGEND

x = ELAME SPREAD

o = PAINT IGNITION

*•©- =a=

CDo

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

IRRflDIflNCE(N/cm

2

) Figure C-5 . Spread and ignition results for polyisocyanurate (5.08 cm).

118

50.0

100.0

150.0

200.0

250.0

300.0

350.0

100.0

TIME

TO

IGNITE(s)
SPREAD

RATE

(mm/sl

POLYSTYRENE (5.08cm)

o

o

CT)

O

CD

O

Cs.

o

CD

O

LD

'

O

O

CD

'

O

CM

'

O

o

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.1

IRRADIANCE ( W/cm ) Figure C-6 . Spread and ignition results for polystyrene (5.08 cm)

119

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITEls)
SPRERD

RRTE(mm/s)

HRRDBORRD (6.35mm)

o

Figure C-7 . Spread and ignition results for hardboard (6.35 mm).

120
SPRERD

RRTE

(

mm/ )s

HRRDBORRD (3.175mm)

o

o

J_ o

7.

121

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(

s

)
SPREAD

RATE

(

mm/

s

)

HRRDBORRD CS159M

)

o

Figure C-9 . Spread and ignition results for hardboard (S159M, 1.0 cm).

122

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

Cs

)
SPREAD

RATE

(mm/s

)

DOUGLAS FIR PARTICLE BOARD, 1.27cm

o

123

°

I o

7.0

.27 cm).

Figure C-10.

50-0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

Cs

]
SPREAD

RflTE(mm/s)

WOOD PANEL (S178MJ

o

Figure C-ll. Spread and ignition results for wood panel (S178M)

.

124

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(s

J
SPREAD

RATE

(

mm/s

)

O

O -i

o

CHIPBOARD (SI 18M)

o

CD

O

CD

O

o

CD

O

LD

'

O

M-1

'

O

CO

'

CD

DO

'

O . 0.0 1.0

LEGEND

x = ELRME SPRERD

2.0 3.0 4.0 5.0 6.0

IRRRDIRNCE ( W/cm )

o

o'3-

o

LD

CO

O

CO

o

LDCM CO LJ

E—1

CD

E—

LJ

O ' in

o

o

CM

_ o^ o

- CD

in

-r

7 .

o

o

Figure C-12. Spread and ignition results for chipboard (S118M).

125
SPREAD

RATE(mm/s)

4.0

5.0

6.0

7.0

8.0

9.0

10.0

PLYWOOD^ PLAIN (0.635cm)

IRRflDIANCE(W/cm

2

)

Spread and ignition results for plywood, plain (0.635 cm).

126

Figure C-13.

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
HRRDBORRD (GLOSS PRINT ) , (3 . 4mm

)

o

127

Figure C-14.

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
SPRERD

RRTE

(mm/s]

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

HRRDBORRD (NITROCELLULOSE PRINT)

i i i i i r 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

IRRRDIRNCEtW/cm2

) Figure C-15. Spread and ignition results for hardboard (3.4 mm,

nitrocellulose paint).

128

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
PARTICLE BOARD (STOCK)

o

o

o

CD

'

O

CO

o

tv

' o

CD -_l \ ^

E

E

LJ

E—' o

S

U’ H

O

a=

n ^

CO

o

to

‘

o

C\]

o

o

X'>k

o

o

0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.1

IRRFIDIRNCE (W/cm2

) Figure C-16. Spread and ignition results for particle board (1.27 cm, stoc’r ).

129

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(s

)
SPREAD

RATE

(

mm/

s

)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0.0

Figure

PLYWOOD, FR (1.27cm)

—

I

1 ““I 1 1 i

1 .0 2.0 3.0 4.0 5.0 6.0 7.0

IRRADI ANCE (W/cm2

) '-17. Spread and ignition results for plywood, FR (1.27 cm).

130

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(

s

)
SPRERD

RRTE(mm/sJ

CARPET (ACRYLIC)

o

O o

Figure C-18. Spread and ignition results for carpet (acrylic).

131
SPREAD

RATE(mm/s)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

PIBERBOBRD, LON DENSITY (S119M)

Figure C-19. Spread and ignition results for fiberboard, low density (S119M).

132

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE(s)
SPRERD

RRTE

(

mm/ )s

FIBER INSULRTION BOARD

o

irrrdirnce: tw/cm2

)

. Spread and ignition results for fiber insulation board.

133

Figure C-20

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(

s

)
SPREAD

RATE

(mm/s

)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

FIBERGLASS SHINGLE

T T T

0.0 1.0 2.0 3.0 4.0 5.0 6.0

IRRflDIRNCE(W/cm2

) Spread and ignition results for fiberglass shingle.

134

7.0

Figure C-21.

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(s

)
GRP (2.24mm]

o

135

Figure 22.

SO.O

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

ts

)
o

O -I o

GRP (1.1 4mm

)

o

CD

O

CO

O

CSo

CO CO E

E

LlJ

E—

cn

oz

LO

' Q

az

n Tt-1

' LO

o

to “

o

no ~

o

o

0.0

1 l I I l

1

1.0 2.0 3.0 4.0 5.0 6.0

IRRRDIRNCE (W/cm2

) Spread and ignition results for GRP (1.14 mm).

136

o

o

LOLO

O

. o

o

to

. o

LO '—

TM CO LJ

E

1

• CD

o

^

OJ O

E—1 QJ

o E

* LO

. oo

- o

LO

CDO

7.0

Figure C-23.
SPREAD

RATE

(

mm/

s

)

MINERAL WOOL, TEXTILE PAPER ( S160M

)

137

Figure C-24.
SPREAD

RATE(mm/s)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

GYPSUM BOARD, NALL PAPER (S142M)

i

i

i *

i

i

i

i

i

i

i

i

i

i

0.0 1.0

oo

m

-1

. o

LD

CO

O

O

CO

o

o

LD

(M

OoCN]

CO LD

E—

CD

O

LJ

.O E—

LO

O

. OO

- o

LD

O

.O

2.0 3.0 4.0 5.0 6.0 7.0

IRRflDIflNCE ( W/cm ) Figure C-25. Spread and ignition results for gypsum board, wallpaper (S142M)

.

138
SPRERD

RRTE

(mm/s

)

CARPET (NYLON/WOOL BLEND)

1

1

l l i r~ 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0

IRRRDIRNCE (H/cm2

) Figure C-26. Spread and ignition results for carpet (nylon/wool).

139

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

C

s

)
CRRPET #2 (WOOL, UNTREATED)

o

IRRFIDIRNCE(W/cm

2

) Spread and ignition results for carpet #2 (wool).

140

Figure Figure C-27.

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(s

)
SPRERD

RRTE(mm/s)

CARPET»2 (WOOL, TREATED)

Figure C-28. Spread and ignition results for carpet #2 (wool treated) . 141
SPREAD

RATE

(

mm/

s

)

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

CARPET#! (WOOL, STOCK)

O . U -l.u

IRRADIANCE(W/cm

2

) Figure C-29. Spread and ignition results for carpet #1 (wool, stock).

142

O.D

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

TIME

TO

IGNITE

(s

)
SPREAD

RATE

(

mm/

s

)

AIRCRAFT PANEL EPOXY FIBERGLASS

IRRRDIRNCE (W/cm2) Figure C-30. Spread and ignition results for aircraft panel (epoxy fiberglass).

143

50.0

100.0

150.0

200.0

250.0

300.0

350.0

100.0

TIME

TO

IGNITE(s)
SPRERD

RRTE(mm/s)

GYPSUM BOARD, PR (1.27cm)

o

Figure C-31. Spread and ignition results for gypsum board, FR (1.27 cm).

144
(REV. 2 -60 ) 1. PUBLICATION OR 2. Performing Organ. Report No. 3. Publication Date REPORT NO.

NBSIR 84-2943 November 1984

U.4L OEPT. OF COMM.

MGL10GRAPHIC DATA

HjjjT (See instructions)

4. TITLE A4fD SUBTITLE

New Concepts fo-r Measuring Flame Spread Properties

i 5. AUTHOR(S) xi iTunn(<:i

J. G. Quintiere and M. Harkleroad

6. PERFORMING ORGANIZATION (If joint or other than NBS, see instructions)

NATIONAL BUREAU 94 STANDARDS

BBPARTUENT OF CMNIERCE

WASHINGTON, D.C. 3*234

7. Contract/Grant No.

t. Type of Report & Period Covered

3. SPONSORING ORGANISATION NAME AND COMPLETE ADDRESS (Street. City. State. ZIP)

U.S. Department of Transportation

Federal Aviatiou Administration

Technical Center

Atlantic City Airport, NJ 08405

10. SUPPLEMENTARY NOTES

| | Document describes a computer program; SF-185, FIPS Software Summary, is attached. TTABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here)

An experimental procedure is described which can be used to derive data relevant to the

prediction of ignition and flame spread on materials. The apparatus utilizes a radiant

heat source capable of supplying up to 6.5 W/cm^ to a vertically oriented specimen.

The test results pertain to piloted ignition of a vertical sample under constant and

irradiation, and to lateral flame spread on a vertical surface due to an external

applied radiant heat flux. The results can be used to display the maximum velocity and

ignition time as a function of irradiance. Critical or minimum irradiances for spread

and ignition are determined. An empirical correlation, based on heat conduction

principles, is found to correlate the ignition data and also provides a more general

interpretation for the flame spread results. Further analyses of the data yield

effective values for the thermal inertia of the material (kpc) , its ignition temperature, and a parameter related to flame temperature. These parameters appear to be

phenomenological constants for each material, rather than factors dependent on the

apparatus. Results are presented for a wide range of materials. Suggestions for

extending the results to other flame spread conditions are presented.

12. KEY WORDS (Six to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semi o ns carpets; composites materials; fire tests; flame spread; ignition;

material properties; measurements; plastics; wood

13. AVAILABILITY 14. NO. OF

Unlimited

PRINTED PAGES

| | For Official Distribution. Do Not Release to NTIS

| Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

154

15. Price

[X] Order From National Technical Information Service (NTIS), Springfield, VA. 22161 $16 .00

L . 1 • 04 )
)