A STUDY OF THE EFFECT OF THE OILY
PORHON OF SO“. ON THE SOILING AND

SOEL RETENTION PROPERYIES OF A
FILAMENT NYLON TRECOT FABRIC

The“: for the Dogma of M. A.
MICHEGAN STRTE UNEVERSE'FY
Anna Jenifer .‘Echnson

1962

75:29:55

¥

LIBRARY

Michigan State
University

ABSTRACT

A STUDY OF THE EFFECT OF THE OILY PORTION OF SOIL
ON 9H3 BOILING AND SOIL RETENTION PROPERTIES
OF A FILAHENT NYLON TRICOT FABRIC

by Anna Jenifer Johnson

The purpose of this investigation was to study the
effect of the oily portion of soil upon the soiling and soil
retention properties of a nylon tricot fabric. Specific
objectives were: to compare the effect of three soiling
compounds containing different amOunts of an unsaturated oil
on the seiling and soil retention properties of the fabric
and to compare the effect of the soiling compounds on the
fabric upon successive soilings and launderingse

The test fabric used in this study was a filament
nylon tricot of double—bar construction. The artificial
soils used to treat the fabric were composed of a neutral
carbon, a saturated oil (mineral oil), and an unsaturated
oil (olive oil). All the soiling ingredients were held
constant for the three soiling compounds with the exceptiOn
of the unsaturated oil. 5011 I contained no unsaturated
oil: Soil II contained five grams and Soil III contained
fifteen grams of the unsaturated oil. A light duty, unbuilt
soap and a water conditioner were used in the laundering

procedure.

Anna Jenifer Johnson

Bach soil was used to treat one group of fabric
samples. The samples were alternately soiled and laundered
a total of ten times in an Atlas Launder-OIeter under con-
trolled conditions. The amount of soil take-up and soil
retention was measured by reflectance_values obtained from
the samples before treatment and after the first. fifth. and
tenth soilings and launderings. Lower reflectance values.
indicated greater soil take-up and soil retention. .an
analysis of variance was carried out on the reflectance data.
reporting as significant those differences between means
which met or exceeded the 95% level of confidence. .

. All the samples tested showed a large initial soil
take-up and a high degree of soil removal after the first
laundering. The samples which had been treated with soiling
compounds containing unsaturated oil (Soil II and 8011 III)
exhibited more soil take-up and retention than samples
treated with a compound containing only saturated oil (Soil I).

i At the fifth soiling and laundering. samples treated
with Boil II and Soil III decreased in both soil take-up and
retention. Soil III. which contained the greateramount of
unsaturated oil. showed the greater change. Samples
treated with Soil I continued to increase in take-up and
retention. with successive treatments.

All samples showed increased accumulation through
the tenth soiling and laundering.“ However. samples treated
'with soils containing unsaturated oil retained the least soil.

Anna Jenifer Johnson

The presence of unsaturated oil in the soiling com-
pound seemed to aid in the removal of soil from the fabric.
Generally. fabric samples treated with soiling compounds
containing a greater amount of unsaturated oil exhibited a
greater degree of soil removal. The decrease in soil take-
up and soil retention at the fifth soiling and laundering.
followed by an increase at the tenth. was apparently due to
a difference in the rates of soil removal and soil accumu-
lation. However. further investigation is necessary before

any conclusion can be drawn.

A STUDY OF THE EFFECT OF THE OILY PORTION OF SOIL
ON THE BOILING AND SOIL RETENTION PROPERTIES
OF A EILAHENT NYLON TRICOT FABRIC

BY

Anna Jenifer Johnson

A THESIS

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

MASTER OF ARTS

Department of Textiles. Clothing and Related Arts
1962

C7 .2 2 9.1? ”I;

/Jy@afl22

ACKNOWLEDGMENTS

The writer wishes to express her sincere
appreciation to: Mrs. Barbara S. Stowe for her guidance
and assistance in the selection and supervision of this
studyx‘Dr. Mary Gephart for her help and encouragement in
the writing of the study: Dr. H. J. Raphael. Associate
Professor of the School of Packaging for his assistance
in running the Gardner Tri-Stimulus Reflectometer and for
its use: Mr. P.J. Pynn. Director. Research Laboratory.

J. C. Penney Company. Incorporated. and.nr. Robert Hall.
J. c. Penney Company. Lansing. Michigan for their aid in
obtaining the test fabric and the fabric specifications

for this study.

11"

TABLE OF CONTENTS

Chapter Page
I. INTRODUCTION . . . . . . . . . . . . . . . . . 1

II. REVIEW OF LITERATURE

A. Introduction . . . . . . . . . . . . . . 5
B. Soiling
1. Nature of soil . . . . . . . . . 6
2. Mechanisms of soil impingement
and soil retention . . . . . . . 7

3. soiling methods . . . . . . . . . 13

C. Laundering

1. Theory of detergency . . . . . . 15
2. Effectiveness of detergent
solutions . . . . . . . . . . . . 18

3. Laundering method . . . . . . . 20
D. Reflectance . . . . . . . . . . . . . . . 21

III. EXPERIMENTAL PROCEDURES

A. Fabric Selection . . . . . . . . . . . . 24
B. Verification Tests . . . . . . . . . . . 24
1. Fiber content . . . . . . . . . . 25
2. Filament count . . . . . . . . . 25
3. Course and wale count . . . . . . 26
4. Fabric thickness . . . . . . . . 26
5. ‘Weight per square yard . . . . . 26
6. Moisture regain . . . . . . . . . 27
C. Preparation of Samples for Treatment . . 27
D. Soiling Procedure . . . . . . . . . . . . 29
E. Laundering Procedure . . . . . . . . . . 31
F. method of Measurement and Analysis . . . 33

111

TABLE OF CONTENTS - Continued

Chapter Page

IV. DISCUSSION OF RESUDTS

A. Verification Tests . . . . . . . . . . 35
B. Analysis of Soiling Effects . . . . . . 37
C. Analysis of Laundering Effects . . . . 42

D. Summary of Soiling and Laundering
Effects . . . . . . . . . . . . . . . . 46
3. Comparison with the Burgess Study . . . 48
V. SUMMARY AND CONCLUSIONS . . . . . . . . . . 51
LITERATURE CITED . . . . . . . . . . . . . . . . 54
APPENDIX . . . . . . . . . . . . . . . . . . . . 59

iv

LIST OF TABLES

Table Page

1. Comparison of physical characteristics of
nylon tricot test fabrics . . . .7. . . . . . 36

2. F-values from analysis of variance showing
differences in reflectance data at the first,
fifth. and tenth soilings and launderings . . 40

3. Percentage reflectance before and after
specified treatment with three soiling
compounds and subsequent launderings . . . 6O

4. Percentage reflectance for Fabric I of the
Burgess study before treatment and at the
first. fifth. tenth. fifteenth. and twentieth
soilings and launderings . . . . . . . . . . 62

5. Percentage reflectance comparable to Fabric I
of the Burgess study before treatment and at
the first. fifth. tenth. fifteenth. and
twentieth sailings and launderings . . . . 63

LIST OF FIGURES

Figure Page

1. Average reflectance readings for a nylon
tricot fabric before treatment and at
the first. fifth. and tenth sailings . . . 39

2. Average reflectance readingsfar a nylon
tricot fabric before treatment and at
the first. fifth. and tenth launderings . . 44

3. Average reflectance readings for a nylon
tricot fabric before treatment and at
the first. fifth. and tenth sailings
and launderings . . . . . . . . . . . . . . 47

4. Average reflectance readings for unextracted
fabric (Burgess study) and for benzene
extracted fabric (present study) before
treatment and at the first. fifth. tenth.
fifteenth and twentieth sailings and
launderings . . . . . . . . . . . . . . . . 50

vi

CHAPTER I

INTRODUCTION

Many of the basic factors involved in the sailing
and cleaning of textile fibers and fabrics are not completely
recognised nor satisfactorily understood (36). The majority
of the studies of soil acquisition and sail retention have
been made on cotton and a few on wool. Recently some com-
parisons have been made among several fibers. However.
little intensive study has been devoted to nylon despite.its
wide acceptance on the consumer market.

For the consumer. changes in the appearance of
fabrics due to repeated sailing and cleaning often determine
the useful life of an article (14). Clark and Holland (5)
found that nylon greyed with use more than other fibers
tested. According to Weatherburn and Bayley (42). fibers
with a smooth cross-section. devoid of pits or striations,
should be relatively soil resistant. However. they found
that reflectance readings showed nylon to be highly sailed
in comparison with other fibers. although the actual soil
content of the nylon.was lower.

Kaswell (20) stated that soil deposited on hydrophobic

fibers should be easily removed. Therefore. it would seem

that nylon. which is hydrophobic and has a smooth cross-
section. should be easily cleaned.

One of the major factors in the sailing of fabrics
is the adhesion of dust and other solid particles to the
fabric by means of an oily or greasy film. Cleaning is often
considered to be simply a matter of breaking the oil-fabric
bonds to remove the oil-coated soil particles (29). However,
Getchell (14) stated, and Snell. Snell. and Reich agreed (34),
that it was unlikely that fiber surfaces were ever completely-
free from an oily film and that the usual cleaning processes
did not remove all traces of oil or grease. Getchell (14)
also suggested that finely divided soil particles and the
oils which helped to bind them were the cause of the cumu-
lative dulling and discoloration of fabrics regardless of
the frequency of cleaning.

In the present study. the oily portion of the soil
was examined to determine the extent of the effect of oil
upon the sailing and soil retention of a nylon tricot fabric.
The specific objectives of the study were:

1. To determine the amount of soil take-up and soil
retention by a nylon fabric.

2. To compare the effect of three soil compounds
having different oil contents on the sailing properties of
the nylon fabric.

3. To compare the effect of the three soiling com-

pounds on the soil retention properties of the nylon fabric.

4. To determine the effect of the three soiling
compounds on the fabric after successive sailings and
launderings.

A study conducted by Katherine B. Burgess (4) at
Michigan State University investigated the sailing and soil
retention properties of three nylon tricot fabrics. The
findings from her study suggested the course and direction
for the present investigation. Therefore. in order that
the two studies might be related. the materials and methods
outlined by Burgess were adapted for use in the present
study.

The test fabric. a nylon. double-bar tricot desig—
nated as Fabric I by Burgess. was chosen for this experiment
because of its common usage in consumer goods. The same
ingredients were used in the formulation of the synthetic
soils for both studies. The soap used in the earlier study
was chosen rather than the synthetic detergent since
Burgess (4) and other investigators (6. 12. 46) have found
soap to be more effective than synthetic detergents in the
laundering of fabrics.

As it was desirable that the samples used for testing
be as completely free as possible of any oily substance. the
fabrics were extracted with benzene prior to testing.
Preliminary soiling tests showed the extracted samples took
up more sail than the unextracted samples used in the

Burgess (4) study.

In general. the procedures for the study closely
followed those outlined by Miss Burgess. Changes from her
procedures were as follows:

1. The amount of carbon was increased because the
benzene extracted fabric tended to deplete the carbon supply
in the sailing solution. In order to examine the effect of
oil upon the particulate matter. it was desirable to have
some particulate matter remaining in the solution after
soiling. thus insuring the maximum amount of soil take-up by
the fabric.

2. The length of time the samples were in contact
with the sailing solution was decreased. since a preliminary
test showed no significant difference between samples soiled

five minutes and those soiled three minutes.

CHAPTER II

REVIEW OF LITERATURE

A. Introduction

Many studies have been conducted investigating the
mechanisms of sailing. soil retention and soil removal.
However. much of the work has been qualitative and specu—
lative. Relatively little has been done to determine
quantitatively the nature of soil. what causes its adherence
to fabric. and what influence the nature of the fabric has
upon the sailing and laundering processes (34).

One of the problems in obtaining quantitative data
on the sailing and soil retention properties of fabrics is
the lack of standard materials and procedures. This bag
made the reproduction and correlation of results between
laboratories difficult. Some of the differences in results
obtained by different laboratories are due to differences in
sailing procedures. the types of soils used. and the optical
properties of the various fibers.(4l). The need for
standardization has been recognised by several investigators
(2. 9. 28) but. as yet. no set of procedures has been found
satisfactory. Schwarz and the Mew York Section of the

American Association of Textile Chemists and Colorists (28)

concluded that any one test method might not give satis-
factory results due to the differences between fabrics and
their uses. Thus variations must be introduced into each
study depending upon the area of investigation. Utermohlen
and‘Wallace (36) found that reproducible results might be
obtained within a study by careful attention to the
following: the preparation of the sailing mixture. the
storage of the fabric prior to testing. the temperature and
humidity of the atmosphere during treatment. and the
mechanical details of the testing procedures. Differences
in any of these conditions might cause misleading variations

in the data.

8. Sailing

1. Nature of soil

Masland (22) defined dirt as small. solid particles
which might be detected visually on the fabric: ink. wine,
and other liquid stains were not considered normal dirt.
Soil. a more inclusive term. is. according to Getchell (14).
a complex mixture which. in varying composition and degree.
is found everywhere. Generally it may be divided into two
portions: a fluid portion which is usually oil. wax or
grease. and a solid portion composed of small, more or less
inert particles. Snell (32. 34) stated that soil. regardless
of where it is found may be considered to be of much the

same composition. It consists of solid particles. water-

soluble materials. proteins. and oily matter. In addition
there may be stains which require special treatment apart
from the normal cleaning process. The solid matter consists
of particulate matter such as soot. dust. clay. carbon. sand.
and iron rust. These by themselves might be wholly or
partially removed by shaking or brushing the fabric. The
water soluble materials are generally food residues such as
sugars. salts. and starches which can be easily rinsed away
and therefore present no real cleaning problem. The proteins
such as blood. eggs. and other albuminous matter are usually
soluble in water except at high temperatures. These must be
wet. loosened and then removed by mechanical friction or
rubbing. The oily portion consists of greasy matter. food
oils. fats. and traces of fatty acids formed when sapanifiable
oils decompose. This oily matter is particularly difficult
to remove being more complex and more adherent. It also
..causes otherwise loosely held solids and sooty matter to

cling to the fabric.

2. Mechanisms of soil impingement and soil retention
According to Schwarz. 55 ‘31. (28). the mechanisms
of soil impingement and soil retention are separate and
independent of each other in that they do not both attract
soil and hold it. Generally soil retention is a function of
the fabric and the fibers, while impingement is a function
of the test conditions. The degree of sailing is dependent

upon both conditions.

The mechanisms of soil impingement are:
l. Diffusion of small particles from air.
2. Deposition of medium and large particles from air.
3. Direct transfer of particles from a soiled surface.
4. Interception of particles in an air stream.
5. Contact by inertial effect with particles in a
moving air stream.
6. Electrostatic attraction either from air or from
another surface.
Thus. soil particles may come in contact with the fabric by
diffusion or deposition from the air. by interception or
inertial effects from a moving air stream. by direct transfer
of dirt particles from a soiled surface and by electrostatic
attraction. .

The mechanisms of soil retention. according to Snell.
Snell. and Reich (34). are: mechanical forces. chemical forces.
electrical forces. and oil bonding.

,The mechanical forces involved in soil retention were
called by Compton and Hart (7. l7) mitro-occlusion and macro-
occlusion. Micro-occlusion is the entrapment of particles in
the irregularities of the fiber surface. The relationship is
primarily between soil and fiber. 'Weatherburn and Bayley (42)
stated that two independent fiber characteristics which ap-
peared to influence the degree of fiber soiling were the
presence of channels or striations which accept soil particles

and the presence of pits and crevices which accept the

smaller particles. Hart and Compton (15) found that few
fiber rugosities were larger than 50 millimicrons. There-
fore. only particles of less than 50 millimicrons in size
could be involved in micro-occlusion as the particle must
be smaller than the crevice if it is to be trapped.
Studies made on nylon indicated a smooth circular fiber
free of both pits and crevices (16) and channels and
striations (42). Therefore. the forces of micro-occlusion
appeared to have little effect upon nylon fibers.
Macro-occlusion is the entrapment of soil within the
yarn structure and fabric structure. Weatherburn and
Bayley (43) found that the degree of sailing increased as
the amount of yarn twist increased at low values of twist.
Further twist. however. rendered the interior of the yarn
inaccessible to soil particles and the soil holding sites
became limited to the surface of the yarn. Snell. Snell.
and Reich (34) stated that soil penetrated the inter-yarn
capillary system and was held by the nature of the fabric.
Open weaves held more soil than close weaves; textured
fabrics held more than smooth fabrics: resilient fibers,such
as wool,held more than less resilient-Eibers,such as cotton.
This soil was loosely held and much of it could be removed
by mechanical action. A typical run showed that 40% of the
brightness recovery was due to mechanical action and 60% due
to soap. However. Hart and Compton (l7) contended that much
of the difficulty in removing soil during laundering was due

to the macro-occlusion of soil particles within the fabric

10

structures. This contention was supported by Weatherburn
and Bayley (43) who found that particles entrapped in the
interior of the yarn were difficult to remove by external
means.

Hart and Compton (17) found that nylon fabrics
showed much lower reflectance values than nylon fibers.
Investigating further. they found that the actual ag-
glomerative.build-up of soil within the fabric structure
was greater than in the other fabrics tested. Weatherburn
and Bayley (41) found that the rate of sailing of nylon
yarns was very rapid initially and then leveled off with
only small increases after that. They suggested. as did
Utermohlen and Wallace (36» that once the soil holding sites
in the yarns and the interstices of the fabric were filled.
additional soil attached only to the surface of the fabric
and was limited in extent. Thus it would seem that for
nylon fabrics macro-occlusion is the more important of the
mechanical forces active in soil retention.

Chemical forces in soil retention are those in which
the soil becomes chemically attached to the fabric by ionic
or hydrogen bonding. This type of soil is particularly
difficult to remove because of the strong forces which must
be broken down. However. only a small amount of soil is
chemically held. This type of soil usually consists of
stains which are not generally considered a part of normal

soil (34).

11

The electrical forces are the forces of attraction
between charged particles. Snell, Snell, and Reich (34)
indicated that these forces were one of the most important
factors in direct adhesion of soil to fabric. Whereas,
Schwarz, 33 El- (28) stated that electrostatic effects did
not seem to be as important as formerly believed. According
to Kaswell (20), soil particles are not usually charged and
therefore are not drawn to fabrics by their own state.
Friction and other natural conditions could probably induce
charges of short duration on many soil particles which,
while charged, might become attached to fabrics. However,
unless other forces of retention acted upon these particles.
as soon as the charge is dissipated, the soil particles
could be easily dislodged. Fabrics which have become charged
themselves, might also attract and hold uncharged particles.

Oil bonding is the common term used to designate the
adhesion of soil particles to oily or greasy surfaces and it
is generally agreed that a large portion of normal soiling
may be ascribed to it (14). Schwarz, gt al. (28) stated that
the true nature of the mechanism is probably related to
surface-tension bonding by any type of liquid, oily or
greasy film. It has usually been considered that oil forms
a film on the particulate matter in the soil, thus binding
it to the surface of the fiber (39). Compton and Hart (6)
found that no major contour changes occurred in the fiber
when greases were adsorbed. This seemed to indicate that

grease was either deposited in a thin but uniform layer on

12

the fiber surface, forming a contour which closely corre-
sponded to the original fiber contour or was distributed
uniformly between the individual fibrils. Probably both
types of sorption occur. The generally accepted belief is
that dirt adheres to fabric by means of an oily film (25).

Snell, Snell, and Reich (34) stated that oily soil
was able to penetrate the intra-fiber capillary system -
formed by closely grouped individual fibrils. These capil- .
laries, which are much smaller than the intra-yarn capillaries,
held the ingrained and, therefore, most difficult soil to
remove. The smaller the capillary, the greater time re-
quired for oil to migrate into it and the greater time re-
quired for the removal of the oil. Even though the amount
of oil applied is small, it will pass slowly into the small
capillaries since the smaller the capillary, the greater the
attractive force. Thus, very fine soil particles can be
carried into submicroscopic capillaries. This soil is
theoretically removable but the time required is beyond
practical limits.

There is some controversy in the literature concerning
the extent and importance of oil bonding as a soil retention
mechanism,particularly after cleaning. Masland (22) and
Fortress and Kip (8) agreed that oils or grease left after
processing promote the adhesion of soil. weatherburn and
Bayley (41) found that oily material, such as finishing oils,
when initially present on yarns was an important factor in

the soiling of textile fibers. The oil content of the soiling

13

mixture had little or no effect on the soil retention of
yarns. A study by Compton and Hart (6) indicated that the
retention of grease-free soil on greasy fibers was greater
than the retention of greasy soil on grease-free fibers.
This was attributed to the smaller particle dispersions
possible with the grease-free carbon than with the greasy
carbon. Snell, Snell, and Reich (34) stated that oily soil
should be more easily removed than non-oily soil because of
the emulsifying action of the detergent on oily soil. How-
ever, Utermohlen,‘§£_a;, (39)found that the removal of oily
soil and pigment soil were largely independent processes and
that the removal of pigment soil did not depend upon the
presence of an oil.

It is generally recognized that many natural soils
become more difficult to remove if left on the fabric for
any length of time (2). A study by Utermohlen and
Wallace (38) using synthetic soils showed that soiling
mixtures containing oils with the greatest degrees of un-
saturation produced the greatest change in the ease of soil
removal after storage. Some unsaturated oils oxidized during
storage and highly unsaturated oils polymerized. It was the
polymerization of unsaturated oils which chemically bound
the soil to the fabric, thus affecting the ease of soil

removal.

3. Soiling methods

In any study of soiling or soil retention properties.

14

the choice of a soil is of primary importance. Ideally a
natural soil would be chosen. However, although the general
components of all natural soils are similar (32), the ex-
treme variability of their specific ingredients discourage
analysis. Thus the standardization of experimental proce-
dures using a natural soil is hardly possible. Weatherburn
and Bayley (41) used vacuum sweepings which they found
similar to samples obtained in various cities throughout the
country. Most researchers use an artificial soil which
approximates the content of natural soil (34). The usual
soiling mixture consists of a pigment soil, usually carbon,
a mineral oil, and a vegetable oil. Bacon (2) considered
this mixture satisfactory for laboratory testing. For more
uniform soiling, Utermohlen and Wallace (36) recommended that
the soiling ingredients be dispersed in a volatile, inert,
water-insoluble solvent, such as carbon tetrachloride, ether,
or Stoddard Solvent. Powe (26) suggested the use of clay as
the pigment soil, since electron micrographs indicated that
clay minerals were the major particulate matter contributing
to soil build-up on textile fibers.

The most common method of soiling for laboratory
study is the tumbler method in which the test samples are
tumbled together with the soiling mixture in a tumble jar
or Launder-Ometer. Steel balls or rubber stoppers are used
to give greater agitation. Schwarz, gt 1;. (28) found that

although no one test method gave satisfactory results in all

15

cases, the tumbler method of soiling was the nearest to a
universal method, having the greatest potential for repro-
ducibility and stardardization. Other methods suggested were
floor soiling in which samples were exposed to foot traffic
until soiled and blower soiling in which air is drawn through
the test fabrics with resulting impingement of air suspended

particles.

C. Laundering

1. Theory of detergency

A detergent is defined as any cleansing agent such
as a soap or synthetic detergent which has the ability to
emulsify oils and hold dirt particles in suspension (44).
Common soaps are the sodium salts of fatty acids. Since
they are formed by the reaction of a strong base with a
weak acid, their water solutions are slightly alkaline.
Generally, their molecular structure is a long hydrocarbon
chain with a carboxylate group at one end (13). The hydro-
carbon chain is oil soluble while the carboxylate end of the
molecule is water soluble. Thus, when a soap is added to
water, the carboxylate ion dissolves to form a colloidal
solution with the water (25).

Investigators who study detergent problems agree that
most soil adheres to fabric by means of an oily film and
detergent action is largely the emulsifying action of the
soap solution upon the oily film (25, 27, 33, 45). Soil was

16

found by Williams, Brown, and Oakley (45) to be partly on
the surface and partly imbedded in the fabric. To remove
the soil the detergent solution has to wet all parts of the
soil and fabric, remove the oil and particulate matter by e-
mulsification, and hold the soil particles in suspension to
prevent their redeposition on the fabric.

In wetting the soil and fabric, the soap solution
must penetrate to the underlying surface to which the soil
is attached. Bacon and Smith (3) found that this wetting
action was accompanied by the adsorption of the detergent
which reduced the attractive forces between the fabric and
soil. According to Robinson (27) adsorption occurred with
the hydrocarbon chain of the soap molecule dissolving in
the oily surface, thus lowering the interfacial tension
between the fabric and oil. This lowering of interfacial
tension allowed the oil, which formed a comparatively even
layer on the surface of the fiber, to break up thus forming
globules. With agitation oil globules became detached from
the fiber. After leaving the individual fibers, the droplets
escaped from the interstices of the fabric. This could have
been aided by the formation of a fine emulsion or by
globules which were easily distorted. The ease of distortion
was dependent upon the viscosity of the oil, the very viscous
oil being less easily removed.

As the oil globules became detached from the surface

of the fabric, Sisley (29) found that emulsifying power of

17

the detergent diminished the size of the droplets which were
then dispersed in the detergent solution. The attraction of
the carboxylate ion for water helped to form the emulsion
and keep the oily soil particles suspended in the so-

lution (27). Noller (25) suggested very small dirt parti-
cles might be adsorbed by the colloidal solution. If the
attraction to the colloid was stronger than the attraction
of the fabric, the dirt particle would be removed.

According to Snell, Snell, and Reich (34), the
presence of oils during the process of detergency was
probably highly desirable as the oil-fabric bonds could be
broken by proper cleaning procedures. Oils also aided in
keeping soil particles suspended in the solution and pre-
venting them from redepositing on the fabric. Redeposited
soil was found to be more difficult to remove than ordinary
soil. Snell, Snell, and Reich (34) advanced the hypothesis
that this soil formed a direct soil-fiber bond while the fiber
was temporarily stripped of its protective oily film.

Fatty acids, formed by the decomposition of the oils.
were also found to be useful in the detergency process.
Williams, Brown, and Oakley (45) stated that not only were
fatty acids easily removed but they aided in the wetting of
the fabric by their affinity for the alkali in the soap
solution. Snell (32) found that alkaline salts, often used

as soap builders, reacted with the sapanifiable fats and

18

fatty acids to form soap. This soap, even though only a
trace, was found to be extremely effective in cleaning as

it was formed within the soil itself.

2. Effectiveness of detergent solutions

Williams, Brown, and Oakley (45) listed the
variables in detergent action as follows:

1. The nature of the detergent.

2. The nature of the fabric and fiber being cleaned.

3. The nature of the soil or dirt being removed.

4. The nature of the water (hardness) used in the

cleansing Operation.
They also stated that the effectiveness of the detergent
depended upon its chemical nature, its concentration in the
solution, the temperature of the solution, and the nature
of the agitation used in cleaning.

Several studies have been made to evaluate the ef-
fectiveness of various detergents. Some of the conclusions
from these studies are stated here. McKee and Roseberry (23)
rated soaps and non-ionic detergents as most effective for
nylon fabrics. Furry, McLendon,and Aler (12) found soaps to
be more effective in removing soil in distilled water than
synthetic detergents. This same effect was observed in hard
water when the soap concentration was 0.35% or more. Wolfrom
and Nuessle(46) found that ordinary soap was best for removing

oily carbon soil from cotton fabrics, and Compton and Hart (6)

19

agreed that soaps were as efficient as detergents in removing
greasy soil.

Bacon and Smith (3) found that the reduction of
interfacial tension between soil and fiber was increased by
greater concentrations of detergent until the adsorption of
detergent on soil particles reached a saturation point. At
higher concentrations, the excess detergent was useful only
if it improved the suspension of soil particles to reduce
redeposition. Vaughn, Vittone, and Bacon (40) stated that
0.1% soap concentration was used by most commercial
laundries. However, McKee and Roseberry (23) found a concen-
tration of 0.15% - 0.30% best, while Williams, Brown, and
Oakley (45) felt that optimummefficiency was found between
0.2% - 0.4%. The latter also stated.that at very high concen»
trations the efficiency might even decrease because of the
viscosity of the soap solution.

Little information was available on the optimum
temperature for detergent action. However, both the deter-
gent and the fiber used would be factors in determining the
correct temperature. McKee and Roseberry (23) found a
temperature of 120° - 130°F. to be best for soaps, with the
efficiency decreasing at 145°F. Johnson (19) suggested low
temperature laundering for nylon fabrics as high temperatures
promote the penetration of greasy soil into the fabric.

According to Bacon and Smith (3) wetting and ad-
sorption could occur without any mechanical action. However,

only in exceptional cases was water-insoluble soil removed

20

without some mechanical action. This view was supported by
Robinson (27) who felt that some agitation was necessary to re-
lease the oil droplets from the fiber and help them pass through
the fabric interstices. McKee and Roseberry (23) found that the
amount of soil removal increased with increased agitation. A
time of at least ten minutes was suggested. However, Frishman,
.55.;1. (9) stated that the major fraction of soil removal oc-
curred during the first minute and that after four minutes the
rate of soil removal was negligible.

In examining the rate of soil removal, Utermohlen and
‘Wallace (34) found that the laundering curves level off short
of complete soil removal even for lightly soiled fabrics. They
also stated that it was not possible to wash heavily soiled
fabrics to the same degree of cleanliness as lightly soiled
fabrics regardless of the number of launderings. Morris,
Mitchell, and Hoban (24) found a low initial drop in reflec-
tance values after the first soiling and laundering. The re-
flectance curve made a slight up-swing after the first laun—
dering with a gradual decline after successive soilings'and
launderings. Utermohlen and Wallace (37) found that soil re-
moval proceded at a slower rate in later washings than in the
first washing. There was evidence of a build-up of relatively
unremovable soil. A soil build-up was also reported by

Burgess (4) and by Frishman,;§§.§l. (9).

3. Laundering methods

Clark and Holland (5) quoted A. J. Kelly of Burkart-

21

Schier Chemical Co. as saying that the standard Launder-
Ometer was probably the most widely approved instrument for
the evaluation of detergents and came closest to offering
standardized results. Bacon and Smith (3) preferred the
Launder-Ometer because of the ease and convenience in
handling and the reproducibility of results. Loading and
unloading was simple and many samples could be tested at
one time. Mechanical action could be controlled by varying
the speed and by using various numbers and sizes of steel
balls. In the absence of steel balls, the Launder-Ometer
showed negligible mechanical action on fabric samples.

A comparison of fabrics washed in the Launder-Ometer
and in household washing machines was conducted by Furry,
e; 21. (10,11). The results of this study showed that for
similar cleaning solutions the order of brightness recovery
was the same for both methods when time, temperature, load-
to-solution ratio, and drying procedure were held constant.
Similar results were reported by McKee and Roseberry (23).
Thus the Launder-Ometer could be used to predict the

relative effectiveness of the laundering procedure.

B. Reflectance
The most commonly used method of determining the
amount of soil removal from fabric is reflectance meas-
urements with a photometer (35). There has been some
criticism of the use of reflectance as a measurement of soil

removal, however. Utermohlen and wallace (36) stated that

22

the relationship between reflectance values and the amount
of pigment soil was not linear to the quantity of the soil
present but to the logarithm of that quantity. Weatherburn
and Bayley (38) concurred that there was no linear rela-
tionship between reflectance values and the weight of the
retained soil. They also stated that the decrease in
reflectance was a visual measurement of the apparent
degree of soiling. It was dependent upon the amount of
soil added and the initial reflectance of the fibers prior
to soiling. Reflectance also measured an over-all effect
which was a combination of the physical characteristics of
the fiber, the characteristics of the soil,and the weight and
particle size of the soil retained.

Utermohlen and Wallace (36) found that for pigments
which could not be chemically analyzed, such as carbon and
lampblack, reflectance was the only method available for
evaluation. No satisfactory means of evaluating the removal
of oily soil, other than weight was found by Utermohlen and
Ryan (35) and this was satisfactory only when there was a
high weight percentage of oil. However,‘Weatherburn and
Bayley (41) felt that the weight of soil retained had little
value as a soiling criterion since the evaluation of soiling
is primarily a visual phenomenon. A good correlation was
found between reflectance readings and visual observation (42L
Snell, Snell, and Reich (34) concluded that for practical

purposes the amount of soiling was the extent to which fabric

23

was darkened. If the fabric was so lightly soiled or the soil
so light in color that no visible darkening was apparent. the

fabric might be considered clean.

CHAPTER III

EXPERIMENTAL paocsmmss

A. Fabric Selection

The test fabrics for this study were purchased from
the J. C. Penney Company, Incorporated. They consisted of
white nylon panties made of double-bar tricot. Ten garments
of the largest size available were obtained at a unit price
of $0.98. The garments had the same lot number as those
designated as Fabric I in an earlier study conducted by
Katherine E. Burgess (4).

Information obtained from the J. C. Penney Research
Laboratory stated that the fabric was knit of two ends of
twenty denier dull or semi-dull nylon. The fabric had been
pre-shrunk and given a plain Schreiner finish which flattened
the diameter of the yarns to reduce sheen and give a whiter
appearance to the fabric. No chemical finishing agent had

been used.

B. Verification Tests

The original fabric was analyzed for fiber content,
filament count, course and wale count, fabric thickness,

weight per square yard, and moisture regain. All tests were

24

25

conducted at standard conditions of temperature (709? 2°)
and relative humidity'(65%i2%) unless otherwise stated.
Standard procedures and instruments of the American Society

for Testing Materials (1) were used except where noted.

1. Fiber content

The fiber content of the fabric was ascertained by
burning tests, by microscopic examination, and by solubility
tests as recommended in a Technical Information Bulletin
published by E. I. DuPont de Nemours & Company (18). For the
solubility test, a sample of the test fabric was placed in
glacial acetic acid at 75°F. for five minutes, washed with
tap water and placed in a 20% solution of hydrochloric acid
for five minutes. In each case, the liquid-to-fiber ratio

was greater than 100:1.

2. Filament count

To determine the number of filaments in each yarn, a
one—inch length of yarn was unraveled and the number of
filaments counted as they were withdrawn from the yarn with
a pair of tweezers. The average count from five yarns was
reported as the filament count. (30)

Information on yarn denier was furnished by the
distributer. No attempt was made to verify the denier because
of the difficulty encountered in unraveling a yarn from the
fabric. In addition, Burgess (4) found that the accuracy of

the determination was questionable when an unraveled yarn

26

was used. The filament denier was determined by dividing

the average yarn.denier by the average filament count.

3. Course and wale count

Courses and wales were counted in five areas, two
inches square, in such a way as not to include the same set
of courses or wales in any two areas. The fabric was
placed flat on the surface of a light box without tension
and a Suter Mechanical Pick Counter was used to make the
counts. The average of five determinations was reported as

the course and wale count.

4. Fabric thickness

A Cenco Thickness Gauge was used to measure the fabric
thickness. The fabric was placed on the anvil of the gauge
without tension and the presser foot was lowered slowly on
the fabric to avoid sudden impact. A reading was taken after
a ten second interval. Five readings were taken so as not
to include the same set of courses or wales in any two
readings. The average of five readings was reported as fabric

thickness.

5. Weight per square yard

From the benzene extracted test fabric, five two-
inch squares were cut so that the same set of courses and
wales were not included in any two samples. The samples were

weighed under standard conditions and the weight per square

27

yard was calculated using the following formula:

Weight/square yard in ounces 8

total sample weight in gut x 1296 sq. in./sq. yd.

total sample area in sq. in. x 28.35 gut/62.

6. Moisture regain

Three weighing bottles were brought to constant
weight within 1 0.001 grams. A one-gram sample of extracted
fabric was placed in each weighing bottle and weighed to
obtain the air—dried weight. The samples were then placed
uncovered in an oven at 1050-110°C. for 18 hours. The
bottles were capped and placed in a desiccator to cool for
one hour: after which they were brought to constant weight
within 1 0.001 grams. The weights of the bottles were sub-
tracted from the total weights of fabric and bottles and
moisture regain was calculated by the following formula:

Percentage Moisture Regain = A - B x 100
B

where A a the air-dried weight of the sample.
B = the oven-dried weight of the sample.
The average of the three determinations was reported as the

moisture regain.

C. Preparation of Samples for Treatment

Twenty samples, measuring four inches by four inches,
were cut from each of five garments. The samples cut from
each garment were thoroughly mixed, keeping each garment

separate. The samples from all garments were then divided

 

28

randomly into five sets of twenty samples, so that each set
contained four samples from each garment. This procedure
was followed to minimize any minor differences between
garments, thus insuring greater control over the uniformity
of the sample. The five sets were treated as follows: Three
of the sets were alternately soiled and laundered a total of
ten times; a fourth group acted as a soap control, being
laundered only; the fifth group was used in a replication

of a portion of the Burgess study.

To remove any finishing oils which might have been
present on the fabric, the samples were extracted with
chemically pure benzene, using a soxhlet extracting apparatus.
Ten samples, weighing an approximate total of six grams,
were placed in each thimble and refluxed five hours. The
samples were removed and allowed to dry on a screen between
layers of cheesecloth.

Although the distributer stated that no chemical
finish had been applied to the fabric, the lowered reflectance
values of the soiled samples which had been extracted before
soiling made a further check desirable. An exhaustive
analysis of possible finishes was not attempted, however.
several tests were made.

A two gram sample of fabric was placed in a 400 ml.
beaker and covered with 50 ml. of carbon tetrachloride. A
200 ml. round-bottom flask filled with cold water was inserted

in the top of the beaker to provide a reflux action. The

29

fabric was refluxed for five minutes, the liquid decanted, and
the excess solvent evaporated.

A fresh portion of the soluble residue was covered
with a 0.05% solution of Calcomine Sky Blue F.F. ex..gggg.
for one minute at room temperature, then rinsed with water
of room temperature. Ethyl cellulose is indicated by a
dark blue stain.

The procedure was repeated using ethyl alcohol as
the extracting solvent. The residue was covered with hot
(Boo-90° C.) dye solution and maintained hot for one minute.
The excess stain was removed with several washes of hat water.
Methyl cellulose is indicated by a dark blue stain.

A portion of the residue obtained from the alcohol
extraction was covered with a 0.0l% solution of Calco Oil
Red N-l700 in 70%.ethyl alcohol. The residue was kept
covered for one minute at room temperature, then rinsed with

tap water. waxes and oils are indicated by a red stain (21).

D. Soiling Procedure

Three synthetic soils were compounded using Norit A.
a neutral carbon, as particulate matter: Nujol mineral oil,
a saturated hydrocarbon: and olive oil, an unsaturated oil.

Each mixture was dispersed in one liter of Stoddard Solvent.

30

1

The three soiling mixtures were formulated as follows:

Soil I. grams Norit A carbon
grams Nujol mineral oil
grams olive oil

liter Stoddard Solvent

Soil II. grams Norit A carbon
grams Nujol mineral oil
grams olive oil

liter Stoddard Solvent

Soil III. grams Norit A. carbon
grams Nujol mineral oil
grams olive oil

liter Stoddard Solvent

p..-
HU'IhO HUI->0 I-‘Oho
000001 OOMU' OCWU‘

The amount of each ingredient was held constant with
the exception of the olive oil. Any chemical bonding which
might occur between the oil and either fabric or particulate
matter would more likely occur with the olive oil since it is
an unsaturated oil and, therefore, more chemically reactive.

Each soil was used to treat one group of fabric
samples, and the soiling procedure was carried out in an
Atlas Launder-Ometer, Style 8-1 at a speed of 42 r.p.m. Into
each pint jar was placed 38 ml. of the soiling solution
(approximately 0.019 grams carbon and 0.163 grams mineral oil
in each jar, 0.190 grams olive oil in jars containing
Soil II, and 0.570 grams olive oil in jars containing
Soil III), 112 ml. Stoddard Solvent, fifteen k-inch steel
balls, and four fabric samples. The soiling solution was
stirred vigorously before and after each sample was added,

to prevent carbon from settling unevenly upon the fabric.

 

1These mixtures were not kept longer than five days

31

The jars were covered, positioned in the Launder-Ometer so
as to be balanced, and rotated for three minutes at room
temperature.

After soiling the samples were removed from the jars
and placed on a screen between layers of cheesecloth to pre-
vent air-borne soil from settling upon them. The screens
were positioned between two laboratory benches with one fan
above the screens and one below, thus reducing the drying
time to one-half hour.

One group of fabric samples was treated as a replicate
of a portion of the Burgess (4) study. The same soiling
mixture and soiling procedure outlined by Burgess were used,
the only difference being the use of extracted fabric in the
present study. The soiling procedure was as follows:

0.25 grams carbon, 4.3 grams mineral oil, and 3.0 grams olive
oil were dispersed in one liter Stoddard Solvent. To each
Launder-Ometer jar was added 38 ml. soiling mixture, 112 ml.
Stoddard Solvent, fifteen k—inch steel balls and four fabric
samples. The jars were rotated in the Launder-Ometer for
five minutes, then removed and dried on a screen between

layers of cheesecloth.

E. Laundering Procedure

The laundering of the samples was also done in the
Atlas Launder—Ometer. The procedure followed was the same as

that used in the Burgess (4) study» as this was found to be

32
satisfactory for the present study.

A light duty unbuilt soap1 to which no optical
brightners had been added, was chosen as the cleaning agent.
A soap, rather than a synthetic detergent, was decided upon
because several studies (12, 23, 46) have shown soap to be
more effective in cleaning fabrics than detergents, if the
effect of hard water is neutralized. Because of the hardness
of the tap water (18.2 grains per gallon), a water condi-

tioner1

was added to the soap solution and to the rinse water.
The amount of conditioner added was based upon the amount
recommended by the manufacturer.

A soap solution of four times the desired concen-
tration was prepared. Enough solution was mixed at one time
for the entire study. The concentrated solution consisted
of: 280.0 grams soap

242.8 grams water conditioner

20.0 liters tap water
For use in laundering, this concentrated solution was diluted
with three parts water to one part soap solution.

The samples were laundered by the following procedure:
To each jar was added fifteen fi-inch steel balls, four
samples, 75 ml. concentrated soap solution, and 225 ml. water
at 1100?. 3 2°. (300 m1. of 0.35% soap solution with 0.91
grams water conditioner per jar). The jars were rotated for

fifteen minutes with the Launder-Ometer one-half filled with

water at 110°F. :20 to maintain the correct temperature.

 

1See Appendix for brands used.

33

The samples and steel balls were then removed from
the jars: the jars were thoroughly rinsed and the samples
and steel balls replaced. To each jar was added 300 ml.
water in which 0.91 grams water conditioner had been dissolved.
The jars were replaced in the Launder-Ometer for a two minute
rinse. The water temperature was maintained at 110°F-.i 2°.
The above procedure was repeated for a second rinse
with the water temperature reduced to 75°F i 2°. The samples
were removed and dried on screens as described earlier for

approximately thirty minutes.

F. Method of Measurement and Analysis

A Gardner Tri-Stimulus Reflectometer was used to
measure the percentage of light reflected from the samples.

A preliminary test indicated that a stack of twenty samples
was required to give an accurate reading, otherwise light
reflected from the background,altering the reading. To
prevent light leakage around the edges of the samples, a
three pound circular ring with a three-inch inside diameter
was placed on top of the stack of samples when measurements
were being taken.

Readings were made with the blue filter only since
color deviations were not being studied. The green and amber
filters were used only for standardization of the reflecto-
meter. A preliminary test showed that a total of ten readings

could be made before restandardization.

34

The samples were allowed to condition for at least
one hour before any measurements were made and all readings
were taken within twenty-four hours after the samples were
treated. Measurements were made on the original samples,
after the first, fifth, and tenth soilings, and after the
first, fifth, and tenth launderings. A series of ten
readings was made for each set of samples at each level of
measurement.

An analysis of variance was carried out on the
reflectance data. Differences in means which met or exceeded

the 95% level of confidence were reported as significant.

CHAPTER IV

DISCUSSION OF RESULTS

A. Verification Tests

The nylon tricot used as test fabric was analyzed
for fiber content, filament count, course and wale count,
fabric thickness, weight per square yard, and moisture re-
gain. The results from these tests are summarized in
Table I. Test fabric used in the present study had the
same lot number as that designated as Fabric I in the
Burgess (4) study, therefore comparable data from that study
is also included in Table 1. Differences between the two
sets of data were found to be within the American Society for
Testing Materials (1) tolerances. Designations for thickness
and moisture regain were not available; however, the dif—
ferences were within 1 5% and thus were considered insignif-
icant.

All fabric samples were extracted with benzene prior
to the soiling treatments. The extracted samples exhibited
a much higher soil take-up than samples which were rinsed
with distilled water before treatment. This result indicated
the possible presence of a soil resistant finish, although

the distributor stated that no chemical finish had been

35

 

36

TABLE I. COmparison of physical characteristics of nylon

tricot test fabrics

Fiber Content

Yarn structure
Filament denier
Filaments per yarn

Yarn denier
(as purchased)

Fabric structure
Courses per inch
Wales per inch
Thickness in inches
Weight/square yard in ounces

Percentage moisture regain

Results of Tests

Present
Stgdy

100% nylon

2.86

20

70

62
0.0062
1.82
3.40%

Burgess

Study(4)

100% nylon

2.86

20

70

57
0.0066
1.95
3.53%

37

applied. Tests for some of the more common soil resistant
finishes were conducted. Negative results were obtained
from tests for methyl cellulose and ethyl cellulose. Only

finishing oil was identified in the extracted residue.

B. Analysis of Soiling Effects

The nylon tricot test fabric was divided into four
groups, each containing twenty samples. One group was
treated with a soiling compound containing 0.5 grams neutral
carbon and 4.3 grams mineral oil (Soil I): a second group
was treated with a soil containing 0.5 grams neutral carbon.
4.3 grams mineral oil, and 5.0 grams olive oil (Soil II): a
third group was treated with a soil containing 0.5 grams
neutral carbon, 4.3 grams mineral oil, and 15 grams olive
oil (Soil III): and a fourth group received no soiling
treatment. In further discussion, Soil I, Soil II, or Soil III
will be used to designate fabrics treated with these soils.

Reflectance readings were taken on all samples before
treatment and after the first, fifth, and tenth soilings.
Lower reflectance values were indicative of greater soil take-
up. An analysis of variance of the reflectance data was
carried out, reporting as significant those differences be-
tween means which met or exceeded the 95% level of confidence.
Samples treated with Soil II and Soil III could be compared
directly as shown by the application of Bartlett's (31) test

for homogeneity of variances. However, the variance of the

38

reflectance data from samples treated with Soil I was much
greater than the variances of data from samples treated with
Soil II and Soil III. Therefore, Cochran's (31) test was
used to compare Soil I with Soil II and Soil III.

Reflectance data collected on sets before treatment
indicated no differences among the sets. Fabric treated
with Soil I exhibited the lowest soil take-up initially
(Figure 1). There was no significant difference between
Soil II and Soil III. At the fifth soiling, fabric treated
with Soil II and Soil III showed a significant decrease in
the amount of soil take-up, while Soil I lowered reflectance
slightly. Soil III was found to be significantly higher in
reflectance than Soil I and Soil II. while no significant
difference was noted between Soil I and Soil II (Table 2).
The same relative position among soils was also found at the
tenth soiling, although all three soils accumulated.

An explanation for the decreased soil take-up after
the fifth treatment with Soil II and Soil III is not readily
apparent. Little information was available in the literature
on the effect of successive soilings. Burgess (4) found a
steady increase in soil take-up, while Morris, Mitchell, and
Hoban (24) found some fluctuation. However, the general
trend showed increased soil take-up with successive soilings.
Snell, Snell, and Reich (34) stated that a thin coating of
oil probably remained on the fibers even after laundering.

Oil which had migrated into the intra-fiber capillary system

39

FIGURE 1. Average reflectance readings for a nylon tricot
fabric before treatment and at the first, fifth,
and tenth soilings

100..
: ,__ Soil I
90 __ Soil II
Soil III

—-

Percentage Reflectance

 

50-—

 

Soiling Intervals

40

TABLE 2.

Treatment

 

Before treatment

Soiling intervals
First
Fifth

Tenth

Laundering intervals
First
Fifth

Tenth

*Significant difference at the 95% level of confidence

F-values from analysis of variance showing
differences in reflectance data at the first.
fifth, and tenth soilings and launderings

Differences Between Soils

 

7-11

0.56

4.76*
0.46
1.14

3.54*

2.27*
1.04

I-III

+ 0.61

4.60*

+ 5.00*
+ 4.82*

4.54*

+ 6.24*

II

+

— I I

0.05

0.16
4.54*
5.96*

1.00

0.79
5.20*

41

was impractical to remove under normal laundering conditions
because of the time required. Weatherburn and Bayley (41),
as well as Utermohlen and Wallace (36), suggested that once
the soil holding sites in the interstices of the fabric were
filled, soil was retained only on the surface.

In view of these findings by other investigators, a
possible explanation for the decreased amount of soil take-
up exhibited by Soil II and Soil III is as follows: A coating
of oil remained on the fibers after laundering, which ac-
cumulated over a series of soilings and launderings, filling
many of the soil holding sites in the interstices of the
yarns and fabric. As more particulate matter was deposited.
it attached only to the surface of the oily residue and did
not penetrate into the interior of the fabric where it would
become more difficult to remove. The interstices of the
fabric in which the greatest amount of oil was present were
filled to the greatest extent and therefore accepted the
least amount of particulate matter into the interior of the
fabric. However, as more soil and agitation were applied,
particulate matter became more deeply imbedded in the fabric,
resulting in an increase in soil take-up by the tenth soiling.
Thus Soil III, containing the most oil, accumulated less
particulate matter than Soil II.

Another possible explanation for the apparent decrease
in soil take-up for Soil III and, to a lesser extent, Soil II
is that mineral oil has a tendency to flocculate the carbon

particles and cause uneven soiling (38). Flocculation of the

42

carbon particles was observed after the sixth soiling. The
flocculated carbon appeared to be deposited primarily on the
surface of the fabric and became progressively greater on
additional soilings. The greatest amount of flocculation was
noted on fabric treated with Soil I which contained mineral
oil alone as the oily portion of the soil. Less flocculation
was noticeable on fabric treated with Soil II, while Soil III
showed little surface deposition even after ten soilings. No
flocculation was visible on laundered samples. The uneven
soilings attributed to flocculation caused little variation
in the reflectance readings as each reading measured the
effect of all the samples in each set, thus minimizing the

differences between samples.

C. Analysis of Laundering Effects

All fabrics were laundered using an unbuilt soap and
a water conditioner following each soiling treatment. Re-
flectance measurements were taken after the first, fifth, and
tenth laundering. Lower reflectance indicated an increase
in soil retention as measured by the amount of soil not
removed from the fabric by laundering. A fourth group of
fabric samples was laundered a total of ten times but was
not soiled. Reflectance data collected on the unsoiled
control showed only slight changes at each laundering interval.
indicating that little of the change in reflectance was due

to the effect of the soap.

43

An analysis of variance of the reflectance data was
carried out, reporting as significant those differences in
means which met or exceeded the 95% level of confidence.
Samples treated with Soil II and Soil III could be compared
directly as shown by the application of Bartlett's (31) test
for homogeneity of variances. However, the variance of the
reflectance data from samples treated with Soil I was much
greater than the variances of data from samples treated with
Soil II and Soil III. Therefore, Cochran's (31) test was
used to compare Soil I with Soil II and Soil III.

The greatest differences in reflectance occurred
between the untreated fabric and the first laundering, thus
showing that in no case was the soap able to restore the
soiled fabric to its original condition (Figure 2). Samples
treated with Soil I exhibited the least amount of retained
soil, or soil not removed from the fabric by laundering,
while no significant difference was noted between samples
treated with Soil II and Soil III (Table 2).

At the fifth laundering a significant increase in
reflectance was found for both Soil II and Soil III, indicating
a decrease in the amount of retained soil. Both groups
exhibited significantly less retention than Soil 1.

An increase in the amount of soil retained was noted
for all groups at the tenth laundering. Samples treated with
Soil III showed significantly higher reflectance than samples
treated with Soil I and Soil II, while no significant differ-

ence was found between the latter two groups.

FIGURE 2.

Percentage Reflectance

44

Average reflectance readings for a nylon tricot
fabric before treatment and at the first, fifth,
and tenth launderings

100.—

 

 

 

» —————- Soil I
— ——-——— Soil II
60——
- __“___ 3011 III
_ __._._ Control (no soil)
50—-
i l L
0 1 5 10

Laundering Intervals

45

Most investigators studying detergent problems agree
that most soil is attached to fabric by means of an oily film
and cleaning is largely a matter of removing the oil covered
soil particles from the fabric and suspending them in the
soap solution (25, 27, 33, 45). Snell, Snell, and Reich (34)
found that fatty acids and saponifiable oils reacted with
alkaline salts used as soap builders to form a very effective
soap within the soil. Williams, Brown, and Oakley (45)
indicated that this type soap might also be formed by re-
action of the oil and fatty acids with the alkali in the soap
solution of an unbuilt soap.

In the present investigation, the decrease in the
amount of soil retained at the fifth laundering, indicated by
the increase in reflectance, for Soil II and Soil III might
be explained as follows: The emulsifying power of the deter-
gent, together with that of any soap formed within the soil,
was more effective in removing soil held by an oily film than
soil held by other mechanisms. Thus the soil containing the
greatest amount of oil was the most easily removed. The rate
of soil removal was apparently greatest during the early
launderings. The data suggested that as the rate of soil
removal diminished, a point was reached at which the rate of
soil removal equaled the rate of soil accumulation. Thereafter,
soil accumulation proceeded at a more rapid rate than soil

removal. As the soil build-up increased with additional

soilings and launderings, the degree of soil retention increased"

46
D. Summary of Soiling and Laundering Effects

No significant differences were found among fabric
groups originally. Soil I and Soil III were found to be
significantly different at each soiling and laundering
interval. However, Soil III exhibited more take-up and
retention than Soil I at the first soiling and laundering
and less at all other intervals. There were no significant
differences between Soil II and Soil III at the first soiling,
first laundering, and fifth laundering. No significant
differences were noted between Soil I and Soil II at the
fifth soiling, tenth soiling, and tenth laundering. The
relationship among soils is shown on Figure III where the
data have been grouped to eliminate insignificant differences.
thus making the relationship more easily seen.

The decrease in soil take-up and retention of Soil II
and Soil III at the fifth soiling and laundering seemed to
be caused by a difference in the rates of soil accumulation
and soil removal. Apparently the rate of soil removal was
more rapid initially than that of soil accumulation. With
additional soilings and launderings, however, the rate of
soil removal decreased. This agreed with the findings of
Utermohlen and Wallace (37) who stated that soil removal
proceeded at a slower rate in later launderings and that
there was evidence of a build-up of relatively unremovable
soil. Apparently, as the rate of soil removal approached a

constant, a point was reached at which the rate of soil

FIGURE 3.

47

Average reflectance readings for a nylon tricot‘
fabric before treatment and at the first,

fifth.

and tenth soiling and launderings (data grouped
to eliminate insignificant differences)

 

 

 

94-96 ————-— Soil I
91-93 Soil 11
as-90 . ___ Soil III
85.87' s - soiling
g 82'84'4 ‘w - laundering
U
E”, 79-81% ,\
'7: 76-78») / \ \\
3 t / \ ”\ \ /
" 7345+ \\ I/ \ '
5‘ \ / ‘\\ é/ \\ \\ l
3 70-72— ) / \\ / \ \ I,
3 ' \/ \‘ ’ \ \ '
3 67-69— V \ \\ /
V \ ,
64-66— \ \ /
\ I
61-63- \ V
‘ \
sa-eo— .
55-57_
52-54;
.1 44 1 I . 1 I
0 s1 wl s5 wS s10 w10

Soiling and

Laundering Intervals

48

removal was equal to that of soil accumulation. Thereafter.
soil accumulation proceeded at the more rapid rate, resulting
in a gradual increase in the degree of soil take—up and
retention. Data presented by Morris, Mitchell, and Hoban (24)
showed a similar interaction of soil removal and soil ac-
cumulation. The greatest change in the amount of soil retained
was noted at the first laundering. A decrease in retained

soil was found on launderings after the first, with a gradual
increase on successive soilings and launderings.

The effect of the oil level in the soiling compound
was shown by the relationship of Soil II with the other soils
(Figure 3). The reflectance data for Soil II followed a
pattern similar to that of Soil III. For the first soiling
and laundering, Soil II was the same as Soil III. After the
fifth treatment, Soil II exhibited greater soil acoumulation
than Soil III, although the soil take-up was less than that
noted at the first soiling. At the tenth soiling and laun-
dering, Soil II had increased in soil accumulation to the
level of Soil I. Thus the rate of soil accumulation appeared
to proceed more quickly when less unsaturated oil was present

on the fabric.

E. Comparison with the Burgess Study

A replication of a portion of the Burgess (4) study
vwas conducted to determine the effect of the benzene extraction

¢>n the soiling and soil retention properties of the fabric.

49

Samples were soiled and laundered a total of twenty times
using the same materials and procedures used in the earlier
study. Reflectance readings were taken on the samples be-
fore treatment and after the first, fifth, tenth. fifteenth.
and twentieth soilings and launderings. The reflectance
data were compared with data for Fabric I of the Burgess
study.

No significant differences were found between the
samples before treatment. The greatest difference between
the two studies was noted at the first soiling (Figure 4).
The rates of soil take-up and soil removal had decreased for
both groups by the tenth soiling and laundering with only
small changes thereafter. Differences between the two sets
of data diminished gradually from the tenth soiling and
laundering until the groups reached approximately the same
level at the twentieth soiling and laundering. Thus the
effect of the benzene extraction upon the fabric had ap-

parently been dissipated at this point.

FIGURE
100
8
c 90
a
.u
o
o
H
H
m
n
u 80
a:
a
.p
c
o
o
:3
m 70
60
50

4.

[II

lTTII

[Illllflll

 

O

50

Average reflectance readings for unextracted
fabric (Burgess study) and for benzene ex-
tracted fabric (present study)'before treatment
and at the first, fifth, tenth, fifteenth, and
twentieth soilings and launderings

______ Burgess (4) study

/\’ Present study

\ / \ s - soiling

w- laundering

1 1 , J 1 1 1 J 1 1 n

s1 ‘wl s5 w5 le wlO s15 w15 s20 w20

Soiling and Laundering Intervals

CHAPTER V

SUMMARY AND CONCLUSIONS

The purpose of this investigation was to study the
effect of the oily portion of soil upon the soiling and soil
retention properties of a nylon tricot fabric. Specific
objectives were: to compare the effect of three soiling
compounds containing different amounts of an unsaturated oil
on the soiling and soil retention properties of the fabric
and to compare the effect of the soiling compounds on the
fabric after successive soilings and launderings.

Samples were alternately soiled and laundered a total
of ten times. The amount of soil take-up and soil retention
was measured by reflectance values obtained from the samples
before treatment and after the first, fifth, and tenth soilings
and launderings. Lower reflectance values indicated greater
soil take-up and soil retention.

All of the samples tested showed a large amount of
initial soil take-up and a high degree of soil removal after
laundering. The samples which had been treated with soiling
compounds containing relatively high amounts of unsaturated
oil (Soil II and Soil III) exhibited more soil take-up and
soil retention than samples treated with a compound containing
only saturated oil (Soil I.) At the fifth soiling and laun-
dering, fabric samples treated with Soil I increased in both

51

52

soil take-up and soil retention, while samples treated with
Soil II and Soil III decreased significantly. Fabric treated
with Soil III, containing the highest level of unsaturated
oil, displayed the greatest decrease in soil take-up and
retention. At the tenth soiling and laundering, all samples
showed increased soil accumulation. However, samples treated
with soil containing unsaturated oil accumulated the least
soil.

The data indicated that the presence of unsaturated
oil (olive oil) in the soiling compound aided in the removal
of soil from the fabric. Generally, fabric samples treated
with soiling compounds containing unsaturated oil exhibited
a greater degree of soil removal than those treated with soil
containing saturated oil only. The increase in reflectance
followed by a decrease in reflectance (Figure 3) for samples
treated with unsaturated oil was apparently due to a dif-
ference in the rates of soil removal and soil accumulation.
The rate of soil removal seemed to proceed rapidly at first
as indicated by the higher reflectance values at the fifth
soiling and laundering. The data suggested that, as the rate
of soil removal approached a constant, a point was reached
where the rate of soil removal equaled that of soil accumu-
lation. Thereafter, soil accumulated more rapidly than it
was removed and reflectance decreased.

The soiling and soil retention properties of fabrics,

as well as the mechanisms of the detergent process, require

53

further research. In examining the effect of soil upon nylon

fabrics, many possibilities are apparent. Some suggestions

for future study are:

1.

Study the rate of soil accumulation and soil removal,
taking reflectance readings after each soiling and
laundering, to ascertain if there is a point at which
the rate of soil removal is equal to that of soil
accumulation,

Study soil accumulation and soil removal independently
to determine the actual rates at which these occur.

Study further the synthetic detergents as cleaning
agents, since they are commonly used in laundering
nylon fabrics.

Compare the efficiency of an unbuilt soap with that
of a soap containing a builder on soils varying in
unsaturated oil content,

Use soil compounds containing various amounts of
unsaturated oil, eliminating the mineral oil to
minimize carbon flocculation,

Experiment with other forms of particulate matter.
i.e. clay, to devise a soil compound which more
nearly approximates normal soil.

The results of this study indicated that the type

and amount of oil present in the soiling compound affected

the rate of soiling and soil removal from the fabric. There-

fore,

further investigation of the effect of the oily portion

of soil on the soiling and soil retention properties of

fabrics would seem to be of value in understanding the

factors involved in fabric soiling and cleaning.

LITERATURE CITED

A.S.T.M. Standards on Textile Materials. Prepared by
the A.S.T.M. Committee D-13 on Textile Materials.
American Society for Testing Materials, Philadelphia.
1959.

Bacon, 0. C. "A Practical Laboratory Test For Evaluating
Scouring Agents For Cotton.“ Amepican destuf;
Reporter. Vol. 34, No. 27 (December 31, 1945),
pp. 556-561.

Bacon, Osborne C., and Smith, Edward J. "Detergent
Action: Mechanical Work As A Measure of Efficiency
of Surface Active Agents in Removing Soil."
Industrial and Engineeping Chemistry. Vol. 40,

No. 12 (December. 1948), pp. 2361-2370.

Burgess, Katherine E. A Study of The Soilinggand Soil
Retention Propeptieggof Three Selected Nylon Tricot
Fabrics. M. A. Thesis, Michigan State University.
1961.

Clark, J. R., and Holland, V. B. "Studies in Soiling and
Detergency." American Dyestugg Reporter. Vol. 36.
No. 25 (December 15. 1947), pp. 734—747.

Compton, Jack, and Hart, W. J. ”A Study of Soiling and
Soil Retention in Textile Fibers-«Grease - Carbon
Black Soil - Cotton Fiber Systems." Textile Research
Journal. Vol. 23, No. 3, (March, 1953), pp. 158-163.

Compton, Jack, and Hart, W. J. "Soiling and Soil
Retention in Textile Fibers." Industpial and Engi-
neering Chemistpy. Vol. 43, No. 7 (July, 1951),
pp. 1564-1569.

Fortress, Fred, and Kip, Charles E. "Factors Influencing
the Soiling of Acetate Carpets.“ Amepican Dyestuff
Reporter. Vol. 42, No. 12 (June 8, 1953), pp. 349—
359.

Frishman, Daniel, Furry, Margaret S., Davison, Suzanne,
Fulton, George P., and Getchell, Nelson F. "Soiling
of Fabrics in Contact with The Skin." American
Dyestuff Reporter. Vol. 43, No. 23 (November 8, 1954),
pp. 751-759.

54

10.

11.

12.

13.

14.

15.

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17.

18.

55

Furry, M. 8., Bensing, P. L., and Kirkley, J. L.
"Evaluating the Effectiveness of Flourescent
Whiteners and Oxidizing Bleaches on Cotton: Part I.
Unsoiled Swatches Washed in Launder-Ometer.“
American Dyestuff Reporter. V0. 48, No. 8
(April 20, 1959) pp. 59-67.

Furry, M. 8., Bensing, P. L., Taube, R. R., Poole, N. D.,
and Ross, E. S. "Evaluating the Effectiveness of
Flourescent Whiteners and Oxidizing Bleaches on
Cotton: Part II. Naturally Soiled Pillowcases
Washed and Dried in Household Equipment.” American
destufereporter. Vol. 48, No. 8 (April 20, 1959),
pp. 67-73.

Furry, Margaret S., McLendon, Verda 1., and Aler, Mary E.
"An Evaluation of Soaps and Synthetic Detergents.“

American Dyestuff Reporter. Vol. 37. No. 23
(November 15, 1948). PP. 751-759.

Fuson, Reynold C., and Snyder, H. R. Chapter 9:
”Carboxylic Acids and Their Derivatives." Organic
Chemistry. 2nd edition. John Wiley & Sons, Inc.,
New York. 1954. pp. 93-121.

Getchell, Nelson F. "Cotton Quality Study: III.
Resistance to Soiling." Textile Research Journal.
Vol. 25, No. 2 (February, 1955). PP. 150-194.

Hart, W; J., and Compton, Jack. ”Soiling and Soil
Retention in Textile Fibers - Primary Deposition of
Grease-Free Carbon Black On Chopped Fibers.”

Industrial and Engineering Chemistry. Vol. 44, No. 5
(May. 1952). pp. 1135-1141.

Hart, W. J., and Compton, Jack. "Primary Deposition of
Grease-Free Carbon Black Soil On Various Types of
Textile Fibers." Textile Research Journal. Vol. 23.
No. 3 (March, 1953), pp. 164-168.

Hart, W. J., and Compton, Jack. “ A Study of Soiling

' and Soil Retention in Textile Fibers - The Effect of
Yarn and Fabric Structure in Soil Retention."
Textile Research Journal. Vol. 23, No. 6 (June, 1953).
pp. 418-423.

Identification of Fibers in Texpile Materials. Technical
Information Bulletin x-156. .Textile Fibers Department.

E. I. DuPont de Nemours and Company, Inc., Wilmington.
December, 1961.

19.

20.

21.

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24.

25.

26.

27.

-28.

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56

Johnson, George H. ”Laundering Properties of the
Science Fibers." American Dyestuff Reporter. Vol. 43,
No. 8 (April 12, 1954). PP. 239-242.

Kaswell, E. R. Chapter 19: "Fabric Soiling, Soil
Removal, Laundering, and Dry Cleaning.” Textile
Fibers,V¥arn§and Fabrics. Reinhold Publishing
Corporation, New York. 1953. pp. 397-420.

Krammes, Ray, and Maresh, Charles. "Identification of
Textile Finishes.” American Dyestuff Repopter.
Vol. 42,'No. 11 (May 25, 1953). pp. 317-327.

Masland, C. H. "Soil Retention of Various Fibers."
Rayon Textile Monthly. Vol. 20, No. 10 (October, 1939).
pp. 573-574 and No. 11 (November, 1939). Pp. 654-656.

McKee, Barbara N., and Roseberry, Elizabeth D. "Soil
Removal From Nylon." Rayon and SynthetTc Textiles.
Vol. 32, No. 5 (May, 1951), pp. 62-64 and No. 6
(June, 1951). PP. 54-56.

Morris, Mary Ann, Mitchell, Barbara Wilsey, and Hoban,
Ann Day. "Effect of Two Cleaning Methods on A Wool
Knit Fabric." qupnal of Home Economicp. Vol. 52,
No. 3 (March, 1960), pp. 166-171.

Noller, Carl R. Chapter II: "Waxes, Fats and Oils."
Chemistpy of Organic Compounds. W. B. Saunders
Company, Philadelphia. 1951. pp. 177-191.

Powe,‘William C. "The Nature of Tenaciously Bound Soil
On Cotton." Textile Research Journal. Vol. 29,
No. 11 (November, 1959). pp. 879-884.

Robinson, Conmar. "The Mechanism of Detergent Action.“
Wetting and Detepgency. Chemical Publishing Company
of N. Y., Inc., New York. 1937. pp. 137-151.

Schwarz, E. W. K., Leonard, Edmond A. and the New York
Section, A.A.T.C.C. "Measurement of Fabric Soiling."
Amepicangpyestugg Reporter. Vol. 41, No. 11
(May 26. 1952). pp. 322-340.

Sisley, J. P. "Studies On Detergent Power." American
‘destuff Reportep. Vol. 36, No. 17 (August 25, 1947),
pp. 457-465.

Skinkle, John H. Textile Testing. 2nd edition revised.
Chemical Publishing Co., Inc., Brooklyn. 1949.

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Snedecor, George Waddel. Statistical Methods. 5th
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No. 10 (October, 1947), pp. 505-511.

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Utermohlen, William P., Jr., and Ryan, Mary E.
”Evaluation of Detergentsfor Textile Cleaning."
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(December, 1949). PP. 2881-2887.

Utermohlen, William P., Jr., and Wallace, Louise E.
”Detergency Studies: I. Soiling of Cloth and
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676.

Utermohlen, William P., Jr., and Wallace, Louise E.
"Detergency Studies: II. Washing Cloth of Various
Degrees of Initial Soiling." Textile Research Journal,
Vol. 17, No. 12 (December, 1947), pp. 676-681.

Utermohlen, William P., Jr., and Wallace Louise E.
"Detergency Studies: III. Influence of the Soiling
Mixture and of Storage Conditions on the Ease of
Washing of Soiled Cloth." Textile Research Joupnal.
Vol. 17, No.12 (December, 1947), pp. 682-688.

Utermohlen, William P., Jr., Fischer, Earl K., Ryan,
Mary E., and Campbell, Gordon H. “Detergency Studies:
IV. Influence of Oily Soil Upon the Removal of
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(August, 1941). pp. 1011-1019.

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58

Weatherburn, A. S., and Bayley, C. H. Part I: "The
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Weatherburn, A. S., and Bayley, C. H. "The Soiling
Characteristics of Textile Fibers: Part II. The
Influence of Fiber Geometry On Soil Retention."
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Characteristics of Textile Fibers: Part III. The
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pp. 753-762.

APPENDIX

The light duty, unbuilt soap used in this study was
Lux soap flakes, manufactured by Lever Brothers Company.
Calgon (a sodium hexametaphosphate) was used as the water
conditioner. The amount of Calgon placed in each jar (0.91
grams Calgon per 300 ml. water) was based on the Calgon
Company recommendation of 12.6 grams Calgon per gallon of
water of 20 grains per gallon hardness.

Use of these products does not constitute an
endorsement of the products by either the author or the
University, and the conclusions reached were based on limited

study under specified conditions.

59

 

60

Percentage reflectance before and after specified
treatment with three soiling compounds and subse-

quent launderings

TABLE 3.

 

 

 

 

Before Treatment First Soiling
Soil I SoiTTII Soil III Soil TTSoil II Soil III
92.0 92.0 91.8 63.4 64.3 62.2
91.1 92.7 93.2 62.2 61.4 58.7
91.1 91.2 92.7 67.0 56.4 58.0
91.5 92.6 91.6 64.4 61.8 65.2
91.8 92.4 91.8 67.3 59.8 61.0
91.3 91.6 92.3 68.0 ‘62.7 59.8
91.2 92.6 92.6 68.1 64.3 61.4
91.0 91.2 91.0 66.2 62.2 58.3
92.6 91.7 92.4 61.7 56.1 63.2
92.0 93.2 92.3 67.3 59.0 61.8
Average
91.6 92.1 92.2 65.6 60.8 61.0

 

 

 

 

 

 

 

Before Treatment First Laundering
Control Soil I Soil II Soil III Control,
91.7 81.5 78.7 75.6 90.5
92.3 82.0 79.1 78.5 90.2
91.3 81.5 77.1 78.0 89.6
91.8 81.7 76.9 76.7 89.3
91.8 82.4 77.9 77.7 90.0
92.0 80.7 76.9 77.1 90.7
93.2 80.0 77.0 75.9 91.2
92.7 80.2 76.8 75.7 90.3
92.1 81.2 78.0 76.1 89.5
91.6 81.0 78.4 75.5 90.3
Average
92.0 81.2 77.7 76.7 90.2

61

TABLE 3. Continued

 

 

 

 

 

Fifth Soiling Tenth Sailing
‘Soil I Soil II Soil III Soil I Soil II Soil III
65.1 63.1 68.3 58.3 59.8 62.4
65.5 62.2 68.7 56.5 57.8 64.6
64.7 65.2 68.1 59.3 57.2 62.1
62.0 67.6 70.3 58.4 56.5 61.7
62.3 67.1 70.2 58.7 57.1 64.0
64.7 63.6 68.8 57.4 54.5 62.8
62.7 63.2 67.9 58.3 53.6 65.1
65.7 66.5 71.1 57.4 54.3 59.6
66.6 62.2 67.6 57.6 56.9 63.1
62.3 65.5 70.6 56.5 59.3 61.2
64.2 64.6 69.2 57.8 56.7 62.7

 

 

 

Fifth Laundeging yTenth~Lagndering

Soil I Soil II Soil III Control Soil I Soil II Soil III Copppol
77.9 80.7 80.5 90.4 70.9 72.7 78.5 90.1
78.1 79.2 80.5 90.8 71.0 73.6 77.1 89.1
76.1 79.2 81.3 90.1 71.7 73.4 77.9 89.2
78.1 80.6 80.2 90.8 71.3 71.9 77.0 89.4
78.5 79.1 80.0 91.2 72.7 72.5 79.4 90.2
77.5 81.5 81.2 91.1 71.1 72.6 78.2 90.5
78.0 79.2 81.4 91.1 70.3 73.5 76.2 91.0
78.2 80.0 81.6 91.4 71.6 71.5 76.0 90.7
78.1 80.1 81.0 90.9 73.0 72.0 79.2 89.5
77.7 81.3 81.1 90.7 71.3 71.6 77.8 89.5
77.8 80.1 80.9 90.8 71.5 72.5 77.7 90.0

62

TABLE 4. Percentage reflectance for Fabric I of the
Burgess study (4) before treatment and at the
first, fifth, tenth, fifteenth, and twentieth
soilings and launderings

 

 

 

Before Soilings

Treatment _T§£ gpp T93p_ .T§__ 395p
’94.9 85.7 70.9 61.8 60.4 58.1
94.2 86.1 70.7 62.2 60.5 57.7
94.6 85.6 70.3 62.1 60.3 59.0
94.5 85.9 70.2 61.2 60.9 58.7
94.2 86.1 70.5 61.3 59.3 58.8

average
94.5 85.9 70.5 61.7 60.3 58.5

Launderings
£12.23; 111:2. 15229111.
93.4 82.4 74.7 74.4 67.0
92.7 82.3 75.0 74.6 66.9
92.8 82.8 75.2 73.8 67.4
93.0 82.9 75.0 74.3 67.1
93.2 82.8 74.4 73.5 67.8
average

93.0 82.6 74.9 74.1 67.2

63

 

 

 

 

TABLE 5. Percentage reflectance comparable to Fabric I
of the Burgess study before treatment and at the
first, fifth, tenth, fifteenth, and twentieth
soilings and launderings

Before SoTTinggfi
Treatment lst 5th 10th 15th 20th
92.7 65.3 54.2 54.2 53.0 57.0
93.9 67.7 53.0 55.9 51.8 57.1
93.4 66.1 54.1 55.5 55.2 56.0
92.8 63.9 54.8 55.4 53.2 54.6
93.3 64.2 55.0 55.5 53.7 56.5
93.1 65.8 57.0 54.3 51.3 55.8
92.8 62.9 52.4 56.4 51.1 55.3
92.5 63.1 55.1 55.6 54.2 57.0
93.7 64.1 53.6 54.6 53.8 57.0
93.8 63.9 53.5 57.2 53.4 54.8
average
93.2 64.7 54.3 55.5 53.1 56.1
Launderings
lst 5th 10th 15 20

76.4 65.7 62.8 68.5 66.9

77.7 67.5 66.2 67.2 66.0

74.5 68.0 63.3 67.5 67.3

77.1 68.6 65.2 69.3 67.8

76.8 68.4 63.7 69.1 67.6

73.3 67.7 64.5 68.2 66.4

77.4 68.8 62.9 68.3 66.7

78.3 67.3 64.5 66.8 66.8

79.2 67.7 66.0 68.1 65.7

78.3 68.0 64.0 69.9 67.4

average
76.9 67.8 64.3 68.3 66.9

 

 

MICHIGAN STATE UNIVERSITY LIB

R

293 03047 04J4

ARIES

 

1

3