NBSIR 77-1236

file cop-.

DO NOT REMC

The Measurement of Fabric

Flammability Parameters in

Experiments Simulating Human

Movement in Burn Accidents

E. A. Zawistowski, J. F. Krasny, E. Braun,

R. Peacock and N. Williams

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

June 1977

Final Report

U. S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS

NBSIR 77-1236

THE MEASUREMENT OF FABRIC

FLAMMABILITY PARAMETERS IN

EXPERIMENTS SIMULATING HUMAN

MOVEMENT IN BURN ACCIDENTS

E. A. Zawistowski, J. F. Krasny, E. Braun,

R. Peacock and N. Williams

Center for Fire Research

Institute for Applied Technology

National Bureau of Standards

Washington, D.C. 20234

June 1977

Final Report

U.S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Dr. Sidney Harman, Under Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Acting Director
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CONTENTS

Page

LIST OF FIGURES iv

Abstract 1

1. INTRODUCTION 1

2. THE APPAREL FIRE MODELING APPARATUS (AFMA) .... 3

2.1. Description of AFMA 4

2.2. Data Acquisition and Computation 5

2.3. Typical Movement Simulation Procedure ... 6

3. RESULTS AND DISCUSSION 7

3.1. Consideration of Controllable Variables

and Their Effect on Observations 7

3.1.1. Tilt Variables 7

3.1.2. Free-Hanging Burns 8

3.2. Comparison of Free-Hanging Burns and Burns

with Contact Due to Tilting 9

3.3. Total Heat Transfer in Tilting Experiments . 9

3.3.1. Heat Transfer Patterns 90 Seconds

After Ignition 12

3.4. Effect of Undergarments 12

4. CONCLUSIONS 12

5. REFERENCES 13

iii
LIST OF FIGURES

Page

Figure 1. Side View of A.FMA 15

Figure 2. Details of Semicylinder Construction . . . 16

Figure 3. Effect of Timing of Tilt on Heat

Distribution Patterns 17

Figure 4. Effect of Angle of Semicylinder on Heat

Distribution Patterns (No Tilting) .... 18

Figure 5. Heat Distribution Patterns Resulting from

Free-Hanging Burns and from Burns with

Contact Due to Tilting 19

Figure 6

Heat Transfer Patterns of Various Fabrics . 20

Figure 7. Effect of Underwear Fabrics on Heat

Distribution Patterns 21

IV
THE MEASUREMENT OF FABRIC FLAM?1ABILITY IN

EXPERIMENTS SIMULATING HUMAN MOVEMENT IN BURN ACCIDENTS

E. A. Zawistowski^ , J. F. Krasny, E. Braun,

R. Peacock and N. Williams^

Abstract

This paper describes results of experiments

simulating the phenomena occurring during burns of

apparel items. Fabrics were burned near a semicylinder which was covered by 54 heat sensors.

The areas which received various heat loads (corresponding to various depth of burn injury in reallife flammable garment accidents) were recorded.

In most cases, the semicylinder was moved during

the burn, so that the burning fabrics made contact

with it, simulating movement by the victim during

a garment burn. This caused rapid extinguishment

in some but not all fabrics. Results are reported

for 40 fabrics varying in fiber content, and fabric

construction and weight.

Key words: Accident; apparel; burn injury; fabric

flammability; fabrics; fire; garments; heat

transfer; injury hazard; simulation.

1. INTRODUCTION

The potential of a burning garment to cause burn injury

to the wearer, the "potential burn injury hazard," can be

considered a complex function of:

1) ease of ignition.

2) flame-spread rate.

3) heat transferred to the wearer, and

4) ease of extinguishment.

^At the time this paper was being written, E. A. Zawistowski

was a Research Associate for Man-Made Fiber Producers

Association at the National Bureau of Standards. His current address is Avtex Fibers, Inc., Front Royal, VA.

,

22630. N. Williams was working as a Mechanical Engineer

for the National Bureau of Standards in the summer of 1975.

1
Injury severity is determined by:

1) amount of heat transferred to the body, and

2) area over which this heat is distributed.

Ease of ignition and linear (not area) flame spread

rate are measured in many flammability tests. Recent studies

have, however, suggested a lack of correlation between size

of the burn injury suffered by apparel victim fires, and the

linear flame spread rate of remainders of garments recovered

from accidents [1]2. Patterns of heat transfer (area and

quantitative measurements of the heat received) from burning

garments have been studied in mannequin experiments [2-5]

The most sophisticated experiments along this line are still

in progress, and results relating potential burn injury to

garment configuration, fabric weight, construction and fiber

content should become available in due course [6].

Only recently, workers in the field have shown an

interest in extinguishability of fabrics. Buchbinder [7]

has analyzed the human reactions and attempts at extinguishment in real-life garment fire accidents. She reports that

running was the most frequent first reaction, followed by

rolling on the ground, wrapping in a rug or beating the

flames with the hands, and removal of clothing (the latter

seemed to be the most effective reaction in terms of minimizing the burn injuries) . Many victims tried more than one

of the above methods to extinguish the fire. It is obvious

that no single laboratory extinguishment experiment could

simulate all these reactions. Below is a list of possible

"extinguishment scenarios" and of laboratory research efforts

to simulate them:

Running: the University of Maryland is investigating

the effect of air speed on heat output and/or extinguishment of fabrics [8].

Extinguishment due to contact of the burning fabrics

with surfaces on both fabric sides: this is the

extinguishing mode when the victim rolls on the floor,

is wrapped in a blanket, or attempts to beat out the

fire. Work with a device which clamped burning fabrics

on both sides was first undertaken at NBS [9], and was

continued at the University of Maryland [8]

The

University has also investigated the relative importance

of the effects of the vicinity of a heat sink and of

oxygen concentration on extinguishment [8]

The

Massachusetts Institute of Technology has worked on the

2 Numbers in brackets refer to references listed at the end

of this paper.

2
development of a test method based on measurement of

the flame spread rate of fabrics near but not touching

two surfaces [10].

Extinguishment due to contact of the burning fabrics

with one surface: this simulates the contact of burning garments with the victim due to his movement.

Experiments in this area are discussed in the present

report.

2. THE APPAREL FIRE MODELING (APPARATUS (AFMA)

The apparatus used in this work is based on a simplified

geometrical arrangement which simulates the salient features

of the garment-body system. It consists of a semicylinder,

approximately 60 cm (24 in) high and 18 cm (7 in) in diameter

representing the simulated body, e.g., a torso or leg. The

simulated body is covered almost in its entirety with heat

sensors. It can be moved during a burn to change the garment

fabric distance from several inches to full contact. The

apparatus is thus designed to simulate movement of the

victim when he becomes aware that his clothing is on fire.

Specifically, movement which results in various modes of

garment-body contact can be simulated.

Obviously, the manner in which the contact between the

body and burning fabric occurs in real life garment fires

covers a wide spectrum. AFMA permits investigation of the

heat transfer patterns from a burning fabric during the two

extreme points of the spectrum: (1) from a burning fabric

which at some time during the burn makes excellent contact

with the substrate and (2) from a fabric which remains freehanging during the course of the burn. Results obtained

under these two conditions permit comparisons of the burn

injury potential of fabrics in a way not previously attempted

Among the measurements which can be made are heat flux

to each of the 54 sensors, with the fabric free hanging at

specified distances, or with the fabric brought into contact

with the cylinder some time after ignition (fabrics do not

generally ignite when in contact with a heat sink) . Contact

can be established at a predetermined (a) time after ignition

(b) fabric distance burned, or (c) heat flux observed on the

semicylinder. The heat distribution patterns before, during

and after contact can be studied by means of computer printout, and should provide information about heat transfer (and

thus injury potential) from burning fabrics before and

during extinguishment. Other effects to be studied in the

future are that of air impinging on the burning fabric, and

of covering the burning fabric with, e.g., a blanket. The

technical details of the apparatus are given below.

3
2.1. Description of AFMA

A side-view schematic representation of the semicylindrical apparatus is shown in figure 1. The fabric is mounted

on a hinged frame so that it is in the same semicylindrical

configuration as the surface of the semicylinder. It maintains a perpend^icular alignment with respect to the floor

until the instant of contact with the semicylinder. The

frame on which the fabric is mounted pivots from the top of

the semicylinder. When the fabric is in the free-hanging

position, the semicylinder leans forward on a pivot at an

approximate angle of 20 degrees from the vertical. When the

semicylinder is pulled to the rear the mounted fabric maintains the vertical position and approaches the semicylinder

surface. When the semicylinder attains vertical alignment,

the fabric makes contact with and conforms to the semicylinder which leans about five degrees to the rear to further

enhance f abr ic-to-sur f ace contact.

Figure 2 illustrates details of the semicylinder construction. The semicylinder surface consists almost entirely

of heat flux sensors. "Transite," an asbestos cement sheet,

2.54 cm (1 in) thick, was cut into 10 cm (3.9 in) radius

"brake-shoes" which were grooved to accept three copper

sensors' each. Each sensor is a copper sheet 0.11 cm (43

mil) thick, 7.62 cm (.3 in) by 2.54 cm (1 in), bent to a

10.16 cm (4 in) radius. Three chrortiel-alumel thermocouples

are peened into each 'sensor. The thermocouple wires^ are

threaded through holes in. the transite "brake-shoes," then

wired in parallel to give an average reading for the sensor

surface'. The thermocouple wires are brought to a terminal'

strip which is housed on the inner surface of the semicylinder. Eighteen of these "brake-shoes," are alternately

stacked with 0.59 cm (1/16 in) transite spacers and bolted

together. The resulting semicylinder is 58.4 cm (22 in)

high. The semicylinder surface is blackened by painting

with a flat black paint.

Sensors were calibrated in vertical banks of five using

a quartz panel which delivered an even heat flux over their

area. Calibration was done for three radiant heat flux

levels: 0.25 J/cm^s (0.06 cal/cm^s) , 0.37 J/cm^s (0.085

cal/cm^s) , and 0.44 J/cm^s (0.105 cal/cm^s). The constant

thus determined for each sensor was utilized in computer

calculations

4
2.2. Data Acquisition and Computation

During the experiment, the sensors are scanned every

three seconds with a Digital Data Acquisition System (DAS)

and data recorded on magnetic tape. Computer programs are

used to calculate the heat transferred to the surface in

accumulated J/cm^ for each scan.

One computer program provides the following information^

in the form of pictorial printouts of the surface with;

1) the cumulative heat received by each sensor after

each scan,

2) the maximum heat received by each sensor during the

total duration of the burn,

3) the difference between heat received at time of

fabric-semicylinder contact and the maximum heat

received (see 2) for each sensor, and

4) the difference in heat before and after the instant

of contact for each sensor — this is the heat rise

upon contact.

4 Another computer program was utilized to calculate the

percent surface area which could, in the first approximation,

be expected to suffer second degree and deeper burns.

Occurrence of a second degree burn depends both on the total

heat received by the skin and the rate at which it is received

[11] . Thus a second degree burn can be expected if heat is

delivered to the skin at a rate of 1.05 J/cm^s over 8 seconds. This represents a total heat input of 8.4 J/cm^.

But, for the same degree of injury the total heat input to

the skin can be twice as much, 16.8 J/cm^, if the heat is

delivered at a rate of 0.28 J/cm^s over 60 seconds. The

heat input values in this work were, as described earlier,

measured by blackened copper sensors, 0.11 cm thick and

backed by asbestos cement. There is no reason to believe

that heat sensed in this manner would not be the same heat

as sensed by the skin, which is also considered a black

body. However, when contact between sensor and burning

fabric occurs, it is conceivable that heat may be carried

away at a faster rate through the copper than through skin.

One could assume that extinguishment of burning fabrics upon

3 Data and raw-data are copied into mass storage for reference

and subsequently transferred to Tape 1477 on file on the

Computer Service Division of NBS for future reference.

4 Copies of these programs are on file in the Center for Fire

Research, Program for Fire Prevention-Products, at NBS.

5
contact with the AFMA may be somewhat more efficient than

upon contact with skin. The magnitude of this difference

could not be established without animal experiments designed

for this purpose. Extinguishment upon contact with shaved

animal skin has been observed by earlier workers, and qualitatively presented a similar phenomenon as the AFHA [3].

The portion of extinguishment which is due to exclusion of

oxygen from one fabric side should be the same for skin and

copper.

The above values for threshold second degree burns are

only approximate because occurrence of injury also depends

on the thickness of the skin which varies over the body of

any individual and between individuals. For the purpose of

the present comparison of the injury potential of fabrics,

fire heat levels were recorded: less than 8.4 J/cm^ (2.0

cal/cm^), 8.4 to 16.7 J/cm^ (2.0 to 3.9 cal/cm^) , to represent

heat levels at which potential second degree burns would occur; and three levels presenting progressively deeper burns,

16.8 to 41.9, 42 to 83.9 and 84+ J/cm^ (4.0 to 9.9, 10 to

19.9, and 20+ cal/cm^). The cumulative summations of area

at t^ese levels were printed out by the computer for each

scar^. The printouts representing the maximum heat flux in

any one ‘burn are the basis -of most of the discussion in this

report. Future reports will analyze other aspects of the

heat distribution patterns measured by the sensors during

each burn. v

‘

2.3. Typical +4ovement Simulation Procedure

'

' '

. Fabrics . The fabrics used in this work varied widely in

fiber content, construction and weight (see fig. 6) . They

are identified in the figures. Both storage of the fabrics

and the experiments were conducted in rooms at approximately

24 °C (75 °F) and 40% r.h.

Specimen Size . Specimens are approximately 63.5 cm (25 in)

in the warp or machine direction by 35.6 cm (14 in) in the

fill or crosswise direction.

Ignition Source . . Experiments are performed utilizing forced

ignition. Triangular paper tabs, 3.5 cm by 15 cm by 15 cm,

weighing approximately 0.08 g are cut from Whatman No. 2

filter paper and used for fabric ignitions. In general, one

paper tab is required to ignite fabrics which weighed up to

204 g/m^ (6 oz/yd^), two tabs for 238 to 306 g/m^ (7 to 9

oz/yd^) fabrics, and three tabs for 340 g/m^ (10 oz/yd^)

fabrics and over.

6
Paper tabs are affixed to the fabric specimen with one

staple, so that the base of the triangular paper tab is 15.2

cm (6 in) from the lower edge of the fabric, and centered

with its point down.

Specimen Mounting . With the AFMA semicylinder in the nontouching position, the longest specimen direction is held

vertically with the intended outside fabric surface facing

away from the semicylinder. The fabric is aligned so that

the bottom edge of both fabric and semicylinder matched.

The fabric is then clamped to the upper portion of the

frame, passed between the semicylinder and the vertical

members of the frame, and clamped to the side members of the

frame in such a way that the fabric conforms as best as

possible to the semicylinder surface. Any excess fabric is

then trimmed.

The Movement Simulation . With the semicylinder in the nontouching position, the paper tab is ignited and the DAS

started. The tilt is initiated at the predetermined point

of time or flame travel (see section 3.1) so that fabric

specimen - semicylinder contact is established. DAS scanning

is continued for an additional 18 seconds after extinguishment.

The semicylinder surface is then carefully scraped

clean of char and spot painted when necessary.

The Stationary Experiment . Fabric specimens are mounted and

ignited in the usual manner. The semicylinder is held at

approximately 10 degrees (see section 3.1.2) forward from

the vertical.

General Comments . During the course of the experiment,

small tenuous flames, re-ignition, etc. are allowed to

continue of their own volition. However, fabric edges

burning beyond the mounting frame are extinguished. Replicate

tests reproduced injury potential values differing generally

by about 10%.

3. RESULTS AND DISCUSSION

3.1. Consideration of Controllable Variables

and Their Effect on Observations

3.1.1. Tilt Variables

There are two major variables in the movement simulation

experiment: when to move, and how fast to move. A brief

consideration of these variables follows.

7
There are several instances when the tilt can be

initiated. The tilt can begin at:

1) a specific time after ignition,

2) specific travel of the flame base, or

3) a specific heat output.

Due to different tendencies of fabrics to burn downwards, as well as sidewards, initiation of tilt at an equal

area of involvement was not practical. This work is currently being expanded to include other modes of investigation; among them is starting movement at a given heat

transfer to any one of four Sensors distributed over the

semicylinder surface.

Figure 3 shows the heat transfer patterns for different

weights of woven cotton fabrics where the tilt was initiated

(a) immediately after ignition of the fabric (when the paper

tab was consumed, roughly less than one second after ignition) , and (b) when the base of the flame reached 23.2 cm (9

in) abovq the point of ignition. Increasing shading of the

bars in this and subsequent figures indicates increasing

amounts of heat received during the total duration of the

burn. Thus a bar with a' relatively long unshaded portion

indicates no or low heat transfer to a relatively large

area, and' thus a low injury potential of the fabric in the

accident situations simulated by the present experiments.

It can be seen that the "area receiving more than 8.4 J/cm^

(potential second degree burn) [11] increased with increasing

fabric weight for tilts initiated at 23.2 cm burn distance.

However when tilt was initiated immediately after ignition

of the fabric, area of involvement decreased with fabric

weight because of the flower flame spread rate on the heavier

cotton fabrics. Tilting when the flame base reached 23.2 cm

was used throughout the experiments described in the body of

this report.

A few experiments were conducted in which the tilting

rate was varied, from 1 to 3 seconds duration of tilt.

There was no major effect of this variable on the heat

transfer pattern, and a tilt duration of 1.1 seconds was

used in all subsequent experiments.

3.1.2. Free-Hanging Burns

Several fabrics were also tested without tilting during

the burn/ i.e., suspended in the frame but with air supply

to both sides of the fabric. In order to choose a standard

8
fixed position for these burns, a cursory examination of the

angle of forward inclination (figure 1) of the semicylinder

was conducted. Figure 4 shows the percent surface area at

various heat levels which were obtained when 65 g/m^ (1.9

oz/yd2) and 235 g/m^ (6.9 oz/yd^), woven cotton fabrics were

allowed to burn at fixed positions of a 10® inclination of

the semicylinder and a 20° inclination. Also shown are the

results for ignition of the fabric while in contact with the

surface (-4° inclination) . As expected, ignition did not

occur when the fabric was in contact with the surface. It is

also interesting that the two fabrics used were not consumed

in their entirety, even without tilting. The fixed position

of 10° forward was chosen for the "free-hanging," no-tilt

experiments

3.2. Comparison of Free-Hanging Burns and Burns

with Contact Due to Tilting

Figure 5 compares heat distribution patterns for freehanging burns (no tilting) and burns in which as intimate as

possible contact between the semicylinder and the burning

fabric was established due to tilting. Heat distribution

patterns in other situations, such as partial contact, could

be assumed to lie between these two extremes.

Tilting greatly reduced the area receiving 8.4 J/cm^ or

more in the case of two woven cotton fabrics and one woven

65/35 polyester/rayon fabric because the flame extinguished

soon after contact. However, the effect of tilting was much

less in the case of a cotton terry towel fabric. The loops

protruding from the fabric apparently prevented intimate

contact with the semicylinder, and the fabric continued

burning for a considerable time after tilting. Similarly,

tilting had relatively little effect on the heat transfer

pattern from the acetate satin fabric which tended to curl

away from the semicylinder and continued to burn. The

acrylic fabric also tended to curl and shrink away from the

semicylinder, formed a thick char and continued to burn.

3.3. Total Heat Transfer in Tilting Experiments

The heat transfer patterns of 40 fabrics, some commercial, some experimental were investigated. The tilting

mechanism was started when the flame base reached 23.2 cm

(9 in) and the fabrics were permitted to burn until they

extinguished by themselves. The eight fabrics listed below

transferred only insignificant amounts of heat to any of the

sensors on the semicylinder surface:

9
Fabrics with Low Injury Potential

Fiber Content Weight Description

g/m2 oz/sq yd

Polyester 72 2.2 woven

210 6.1 pile

r 235 6.9 napped sleepwear knit

245 7.2 knit

Nylon 95 2.8 woven

Wool 220 6.5 twill

310 9.1 knit

Modacrylic 310 9.1 knit

The heat transfer patterns of the other fabrics are

shown in figure 6. The bars are arranged in order of de- - creasing length of the unshaded portion, i.e., in decreasing

order of area of the semicylinder receiving less than 8.4

J/cm2.

The major effect on the size of this area was fiber

content of the fabrics. Most fabrics which contained cellulose in some form (cotton or rayon, alone or in blends with

polyester) are in the upper portion of the graph, i.e.,

transferred potentially injurious heat (above 8.4 J/cm2) to

less than half of the available area. Five fabrics containing cellulose transferred more than 8.4 J/cm2 to a

larger, area: a polyester/rayon woven fabric, a heavy cotton

denim, a heavy rayon knit, and two terry towel fabrics. The

other fabrics, with more than half the area receiving more

than 8.4 J/cm2 , contained acetate, or acrylic, with the

latter generally on the upper end of the scale. The reasons

for the relatively high heat transfer from these fabrics

became obvious from observation of the burns. The acetate

tended to curl away from the semicylinder surface, and

continued to burn at the curled edges. The acrylics also

puckered and curled away at the edges; in addition they

formed rather thick chars which continued to burn even when

in contact with the semicylinder.

10
High heat transfers are indicated by dense shading of

the bars. It can be seen that all acrylic fabrics produced

more than 168 J/cm^ over some areas of the semicylinder.

Other fabrics which produced such high heat transfer were

the cotton denim, the terry toweling, and an acetate satin.

The same fabrics also generally produced relatively large

areas receiving between 84 and 163 J/cm^. They could thus

be considered to present the highest burn injury potential

in the garment burn scenarios represented by the present

experiments which, however, do not consider other parameters

contributing to garment fire accidents such as ease of

ignition

Among 100% cellulosic fabrics, higher weight generally

produced higher heat transfer over larger areas. Exceptions

were the two cotton flannels and the two terry towels, i.e.,

fabrics with a distinct surface texture. They exhibited

relatively high heat transfer for their weight. Such fabrics

tend to continue to burn even after contact with the semicylinder, the flannel primarily in the nap, the terry towel

in both pile and body of the fabric. Apparently the extinguishment effect of heat sink and oxygen exclusion on one

side of the fabric is obviated when the fabric-semicylinder

contact is poor.

There was no consistent effect of weight in the case of

the polyester/cellulosic blend fabrics. One possible explanation is that the polyester melts ahead of the flames, the

fabrics become soft, and make good contact with the surface,

regardless of weight and thickness, while pure cellulose

fabrics form stiff chars and conform less with the semicylinder surface as they increase in weight and thickness.

Two heavy wool fabrics self-extinguished and transferred

but little heat to the semicylinder. A light wool fabric

transferred heat exceeding 8.4 J/cm2 to 25% of the semicylinder area. The acetate and acrylic fabrics showed no consistent effects of weight.

The woven acetate fabrics transferred considerably more

heat than the knitted ones. The latter were of more open

construction, and parts of the fabrics ablated during burning,

removing them from the areas scanned by the heat sensors.

The only other effect of fabric structure was the above

discussed relatively high heat transfer from the cotton

flannels and terry towel fabrics which did not extinguish

upon contact with the semicylinder as readily as other

cotton fabrics.

11
3.3.1. Heat Transfer Patterns 90 Seconds After Ignition

The previous section discussed the total heat transferred

before and after contact with the semicylinder, from ignition

to extinction. Only four fabrics had not completed transfering heat in 90 seconds. They are indicated in figure 6 by a

second bar below the one indicating total heat transfer, and

marked 90 seconds. It can be seen that at 90 seconds after

ignition, the two cotton terry cloths had transferred heat

to a much smaller area than at the point of extinguishment.

The denim, and especially the 175 g/m2 acetate satin, were

much closer to completion of heat transfer at that point.

Future investigations will emphasize heat transfer patterns

at various times from ignition.

3.4. Effect of Undergarments

The effect of an undergarment on heat transfer patterns

was investigated by covering the semicylinder tightly with a

cotton underwear jersey, 135 g/m^ (4.0 oz/sq yd). Three

woven outerwear fabrics were ignited as usual, and tilted

when the flame base reached 23 cm. Figure 7 compares the

results with and without the underwear layer on the semicylinder. In both the cases of the light cotton and polyester/cotton fabrics, the area receiving less than 8.4 J/cm2

was reduced by the presence of the underwear, presumably

because the burning fabric-semicylinder contact was less

efficient and the outer fabric may have continued burning

for a longer period than when no underwear was present. In

the case of the acrylic fabric, the opposite effect of the

under layer on the heat transfer pattern was observed. Since

this fabric tends to continue burning even while in contact

with the bare semicylinder, the underwear fabric apparently

had little effect on the burning, but may have provided

modest insulation from the heat.

4. CONCLUSIONS

This work has been the first attempt to measure detailed

heat transfer patterns from burning fabrics to a simulated

body, both in a situation where the body moves and when it

is stationary. It has indicated that where burning garments

contact the body due to movement, relatively deep burns may

occur over a limited area. But the fabrics often extinguish

upon contact, and the total area of the body burned may thus

be reduced as compared to a case when garments burn at a distance from the body. Whether and how fast such extinguishment occurs, depends on fabric construction and fiber content.

12
While the present results were obtained with a simulated

body differing in thermal characteristics from skin, similar

phenomena have been observed in animal experiments [3].

The lowest heat transfer in both modes, free-hanging

and upon contact, was found for 100 percent modacrylics,

nylon, polyester, and some wool fabrics. Light, opentextured (knit) acetates had a somewhat higher heat transfer,

followed roughly in order by cellulosics and cellulosiccontaining fabrics, woven acetates, cotton terry and acrylics.

Cotton and polyester/cotton fabrics were found to show

a large reduction in injury potential when brought into

contact with a simulated body. Heavy-weight acetates and

acrylics showed a smaller reduction in injury potential upon

contact. Cotton terry showed the least reduction in injury

potential

The degree of reduction in injury potential appears to

be related to the ability of the fabric to make contact with

the body. This degree of contact in turn is affected by

construction and fiber content.

5

. REFERENCES

[1] Braun, E., Cobble, V. B., Helzer, S., Krasny, J. F.,

Peacock, R. D. and Stratton, A. K. , Back-up Report for

the Proposed Standard for the Flammability of General

Wearing Apparel, NBSIR 76-1072 (June 1976).

[2] Bercaw, J. R. and Jordan, G. K. , Proceedings of the

Eighth Annual Meeting, Information Council on Fabric

Flammability, New York, N. Y. , 214-239 (Dec. 5, 1974).

[3] Krasny, J. F. and Fisher, A. L. , Textile Research J.,

Vol. 43, No. 5, 272-282 (May 1973).

[4] Arnold, G. B. , Fisher, A., and Frohnsdorff, G.

,

Hazards from Burning Garments, Final Report to the

Government-Industry Research Committee on Fabric

Flammability by Gillette Research Institute, Rockville,

Md., 20850 (March 1973).

[5] Finley, E. L. , Summers, T. A., Carter, W. H. , Cochran,

B. J. and Farthing, B. R. , Flammability Characteristics

of Multilayer Clothing, J. of Fire and Flammability,

Consumer Product Flammability Supplement, Vol. 2,

170-184 (June 1975)

13
[6] Apparel Flammability Testing Program, American Textile

Manufacturers Institute, Inc., Washington, D. C.

20036.

[7] Buchbinder, L. B., Human Activity Patterns and Injury

Severity in Fire Accidents Involving Apparel, J. Fire

and Flammability, Consumer Product Flammability

Supplement, Vol. 1, 4-18 (March 1974).

[8] Spivak, S. M..et al., Extinguishability as a Component

Measure of Flammability Hazard, University of Maryland,

Second Annual Report to NBS in preparation.

[9] Krasny, J. F. and Francis, J. G. , Ranking Extinguishability of Burning Fabrics, Textile Chem. and Colorist,

Vol. 6, 36-37 (June 1973).

[10] Tesoro, G. and Backer, S. (Massachusetts Institute of

Technology), Extinguishment in Apparel Textiles,

NBS-GCR 76-71 (July 1976).

[11] Stoll, A. M. and Ghianta, M. A., Heat Transfer through

Fabrics as Related to Thermal Injury, Trans. N.Y.

Acad. Science, Sec. II, Vol. 33, No. 7, 649-670 (1971).

14
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Figure 4. Effect of Angle of Semicylinder on Heat

Distribution Patterns (No Tilting)

18
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Various Fabrics

20
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NBS-1 14A (REV. 7-73)

U.S. DEPT. OF COMM. BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO.

77-1 236

2. Gov’t Accession

No.

3. Recipient’s Accession No.

4. TITLE AND SUBTITLE

The Measurement of Fabric Flairmability Paraireters in

Movement Simulation Experiments

5. Publication Date June 1977

6. Performing Organization Code

7. AUTHOR(S) E. A. Zawistowski, J. F. Krasny, E. Braun,

R. Peacock, and N. Williams

8. Performing Organ. Report No.

9. PERFOR.MING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

10. Project/Task/Work Unit No. 4922 372

11. Contract/Grant No.

12. Sponsoring Organization Name and Complete Address (Street, City, State, ZIP)

same as No. 9

13. Type of Report & Period Covered

Final Report

14. Sponsoring Agency Code

15. SUPPLEMENTARY NOTES

16. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey, mention it here.)

This paper describes results of experiments simulating the phenomena

occurring during burns of apparel items. Fabrics were burned near a semicylinder which was covered by 54 heat sensors. The areas which

received various heat loads (corresponding to various depth of burn

injury in real-life flammable garment accidents) were recorded. In

most cases, the semicylinder was moved during the burn, so that the

burning fabrics made contact with it, simulating movement by the

victim during a garment burn. This caused rapid extinguishment in some but not all fabrics. Results are reported for 40 fabrics varying

in fiber content, and fabric construction and weight.

17. KEY WORDS (six to twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name; separated by semicolons) Accident; apparel; bum injury; fabric flammability;

fabrics; fire; garments; heat transfer; injury hazard; simulation.

18. AVAILABILITY [3 Unlimited

For Official Distribution. Do Not Release to NTIS

[ I Order From Sup. of Doc., U.S. Government Printing Office Washington, D.C. 20402, SD Cat. No. Cl 3

I Xl Order From National Technical Information Service (NTIS)

Springfield, Virginia 22151

19. SECURITY CLASS 21. NO. OF PAGES

(THIS REPORT)

UNCL ASSIFIED 25

20. SECURITY CLASS 22. Price (THIS PAGE)

UNCLASSIFIED $ 3.50

USCOMM.DC 29042-P74
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