Thermal insulation values of wool and acrylic blankets before

80 Pages·2014·1.76 MB·English

by  Rohde, Rosalyn Opal

AN ABSTRACT OF THE THESIS OF
Rosalyn Opal Rohde for the M. S. in Clothing, Textiles and
(Name) (Degree) Related Arts
(Major)
Date thesis is presented
Title THERMAL INSULATION VALUES OF WOOL AND ACRYLIC
BLANKETS BEFORE AND AFTER LAUNDERING
Abstract approved
(Major professor)
Twelve Acrilan acrylic, twelve Orlon acrylic, and twelve wool
blankets were studied to determine the effect of laundering on ther-
mal insulation value. The thirty -six blankets used in this study
were selected and purchased by Florence Petzel for use in the study
of the effects of maintenance on wool and acrylic blankets.
Specified sections of each of the blankets were laundered zero,
one, five or ten times using a soak wash method. Cutting diagrams
were then developed for each blanket section. Seven hundred twenty
warmth tests specimens, each measuring five inches square, were
prepared at the time of Petzel's study. They were kept under con-
stant temperature before the testing began and throughout the
testing procedures. The laboratory tests included a thickness read-
ing on the Compressometer and a warmth determination using the
Cenco -Fitch instrument.
The data from the warmth study is discussed in two parts.
The thickness measurements and thermal conductivity values for
each laundry interval are noted first. This is followed by a dis-
cussion of the significance of the relationship of thickness to
warmth. The findings show a loss in the thickness of the Orlon
acrylic and Acrilan acrylic blankets during laundering caused by
matting and /or a loss of fibers. Conversely, the wool blankets
gained continuously in thickness due to shrinkage. The thickest
blankets had the lowest thermal conductivity values and were the
best insulators; the thinnest blankets had the largest thermal con-
ductivity values and had the least insulation value. This emphasizes
the importance of the retention of thickness for the maintenance of
warmth.
There was not a significant difference in the amount of heat
that was transmitted by the Orlon acrylic, Acrilan acrylic or wool
blankets. This implies that warmth is dependent upon the thickness
of a blanket and the retention of that thickness rather than upon the
fiber content. An increase in insulation value was generally fol-
lowed by a decrease in insulation value if the blanket lost thickness.
The insulation value improved if the blanket shrank and became
more compact. However, there is a point at which compactness
is detrimental to warmth because of the reduction of vital air
spaces.
It was concluded that the warmth of a blanket is controlled
by the thickness of the blanket and its ability to retain that thickness
with laundering. It was further concluded that a thickness reading
which is interpreted along with data on dimensional stability, yarn
count, weight, and breaking strength would be sufficient to predict
warmth for consumer purposes and information. It was recommend-
ed that subjective testing wi;:h individuals be included in future evalu-
ations for more meaningful information. The best guide for the
selection of a blanket still appears to be the brand name of a repu-
table manufacturer and a business firm to which the blanket may be
returned if its performance is not satisfactory. One could expect
to find warm blankets made from any fiber material provided
the blanket is suitably woven and sufficiently thick.
THERMAL INSULATION VALUES OF WOOL AND
ACRYLIC BLANKETS BEFORE AND AFTER LAUNDERING
by
ROSALYN OPAL ROHDE
A THESIS
submitted to
OREGON STATE UNIVERSITY
in partial fulfillment of
the requirements for the
degree of
MASTER OF SCIENCE
June 1965
APPROVED:
Assistant Professor of Clothing, Textiles, and
Related Arts
In Charge of Major
Head of Department Clothing, Textiles, and
Related Arts
Dean of Graduate School
Date thesis is presented
Typed by Muriel Davis
ACKNOWLEDGMENT
The author expresses appreciation to the many persons who
have contributed assistance in this study. Special gratitude is ex-
.
pressed to Miss Elaine K. Carlson, Assistant Professor of Clothing,
Textiles and Related Arts, for her valued advice, criticism, and
encouragement.
Acknowledgment is also given to Dr. Lyle Calvin in the
Department of Statistics for his assistance, and to the Physics
Department for technical advice.
Special recognition is given to Dr. Florence E. Petzel,
Barbara Buckwalter and Margaret Hunter for the procuring and
processing of all the materials needed for this study.
TABLE OF CONTENTS
Page
INTRODUCTION
, 1
REVIEW OF LITERATURE
4
METHODS AND PROCEDURES 26
DATA AND DISCUSSION 35
Effects of Laundering Upon the Dimensional Change 35
Effects of Laundering Upon the Thickness 41
The Effect of Laundering Upon the Thermal
Conductivity Values 47
The Relationship of the Thickness and Thermal
Conductivity Values 50
SUMMARY AND RECOMMENDATIONS 60
BIBLIOGRAPHY
67
LIST OF FIGURES
Figure Page
I Percentage Warpwise and Fillingwise Dimensional
Change After Laundering According to Fiber Content 37
II Percentage Warpwise and Fillingwise Dimensional
Change in Wool Blankets After Laundering 39
. .
III Mean Weight Change After Laundering 40
.
IV Mean Thermal Conductivity Per 001 Inch Thickness
.
of Blankets 51
LIST OF TABLES
Table Page
I Fiber Content, Size, Price, Yarn Count. Weave
and Weight of Blankets 36
II Mean Thickness in Inches 42
.
III Mean Thermal Conductivity per 001 Inch Thick-
.
ness of Blankets and Means According to Fiber
Content 49
..
IV Thickness by Blanket Number and Fiber Content
For 0, 1, 5 and 10 Launderings 53
THERMAL INSULATION VALUES OF WOOL AND
ACRYLIC BLANKETS BEFORE AND AFTER LAUNDERING
INTRODUCTION
The development of man -made fibers by industry has served to
complicate the purchasing of textiles in apparel and home furnishings.
"There has been an over emphasis and an exaggeration on both the
national and local level of the virtues of fibers per se that tends to
provide a distorted picture regarding the end use" (57, p. 54). The
problem for industry is to efficiently, effectively, and creatively con-
vert the fiber properties into an end result,that will give the greatest
value to the consumer. One home furnishing item that is frequently
used by every consumer in this country is a blanket. The major rea-
son for purchasing a blanket is to provide warmth while the body is
inactive, and the blanket accomplishes this by slowing down the pas-
sage of heat from the body. The consumer formerly had a choice of
cotton or wool fiber content when purchasing a blanket. "The acrylic
blankets, however, have largely replaced the woolen ones on the mar-
ket" (53, p. 188). The laundering procedures for cotton and wool
blankets were generally known by the consumer. Whereas, the ef-
fects of the maintenance upon acrylic blankets have not been com-
pletely defined.
Blankets are classified as "broad woven goods" by the Bureau
of the Census (54, p. 199). Fourteen million linear yards of woolen
2
and worsted broad woven goods were produced during 1959 and
1960. During the same period, 118 million linear yards were
woven of man -made fibers. These fibers included rayon, acetate,
nylon, polyester, glass,and acrylics (54, p. 198). The shipments
of acrylic and modacrylic fiber within the United States have risen
from 65 million pounds in 1956 to 124 million pounds in 1961 (48,
p. 29). Blankets are one of the principal outlets for acrylics in
the United States (48, p. 30). Possibly an influencing factor in
this increased use of acrylics is the ease of care that is offered
by these fibers. Blankets that are made from acrylic fibers are
advertised as machine washable and dryable, shrink resistant,
moth and mildew resistant, non -allergenic, and as offering warmth
without weight (4, p. 56).
This study was initiated to provide information on the effects
of maintenance upon the thermal insulation values of wool and acry-
lic blankets. Ten launderings were chosen to represent approxi-
mately the total number of laundering treatments that would be
given to a blanket during its lifetime of use. The determination of
the effect that maintenance has upon the warmth of wool and acrylic
blankets made it necessary first to measure the change in the
thickness that was caused by laundering. A specific objective was
to determine whether or not the original blankets were comparable
in their warmth characteristics and if they retained their warmth