Note: Descriptions are shown in the official language in which they were submitted.
~6~30~
BACKGROUND OF THE INVENTION
Description of the Prior Art
The employment of fabric-conditioning articles
to impart softening, antistatic, lubricating,
5 bacteriostatic mildew-proofing or other desirable fabric-
conditioning effects has been described in the art. For
example, U.S. Patent No. 3,442,692 to Gaiser ~May 6, 1969)
describes the conditioning of fabrics in a laundry dryer
by cotumbling the fabrics with a flexible substrate
10 carrying a conditioning agent. The conditioning agent is
removed to the tumbling fabrics to provide a ~abric
conditioning which otherwise might only inconveniently be
effected by treatment -- for example, during the rinsing
cycle of a laundering operation. Similarly, U.S. Patent
No. 3,686,025, issued August 22l 1972 ~o Morton and
U.S. Patent No. 3,956,S56 issued May 11, 1968 and U.S.
Patent No. 4,007,300 issued February 8, 1977 to McQueary,
describe an article for conditioning fabrics in a laundry
dryer. The articles comprise an absorptive substrate
impregnated with a fabric-softening agent for the
provision of fabric softening effects with minimal
staining tendencies.
U.S. Patent No. 3,956,556, issued May 11, 1976,
a~d the divisional thereof, U.S. Patent No. 4,00 7,300,
issued Februaxy 8, 1977, both to McQueary, addressed
themselves to a further problem in this partic;:ular art --
namely, the tendency of an absorbed fabric conditioner
substrate to adhere to the air outlet of the dryer which,
if not rapidly unblocked, caused excessive heat build-up
and possible burn-out o certain portions o the dryer.
Mc~2ueary addresses this problem by providing a plurality
of perforations in the substrate so as to permit at least
70~ of the normal air 10w through the dryer when the
coated subs~rate i~3 used therein. A similar approach to
~L26E~ Z
the same end is set forth in another McQueary patent,
U.S. Patent No. 3,944,694, wherein the flexible substrate
is provided with a plurality of slits in order to achieve
the desired volume of air flow.
It should be noted that in the known prior art,
which includes not only the above referenced patents but
also those cited therein, the substrate which is
preferably, but not solely, a non-woven material is coated
by a process of dipping the substrate in a solution or
dispersion of the conditioning agent. Indeed, McQueary,
as in U.S. Patent No. 3,956,55~, column 6, lin~ 45 et
seq, teaches that the manner of impregnating the substrate
is not considered to be an important part of her
invention~
The conditioning articles of the prior art,
including in particular those made in accordance with the
preferred or exemplified embodiments of the above
identified patent, while operative, have two disadvantages
which it would be desirable to avoid.
The coating technique employed covers the entire
substrate and, therefore, utilizes a great deal of fabric
conditioning agent, which agen-t constitutes a substantial
portion of the material cost of the article. It would,
therefore, be desirable to provide an operative articl2
utilizing a lesser amount of the conditionin~ agent.
The articles of the prior art have a tendency
to crumple. Indeed, this quality is stated at McQueary,
U.S. Patent No. 3~956/556~ column 7, lines 34 through 47,
as being a desirable quality. While the reasons for the
desirability of crumpling are understood, they carry with
them the concomitant disad~antage that an article which
has the tendency to crumple e~ually has a tendency to
fold, as is admitted in McQueary, and, thus, in the
~olded condition does not offer the same amount of surface
exposuxe to the clothlng which it is inten~ed to contact
as would a softer and more flexible material which did not
--3--
,
~2~i~3302
possess the crumpling properties.
It would, therefore, be desirable to pro~ide an
article which has, in addition to the desirable qualities
of the articles of prior art, the additional advantages of
lower conditioning agent requirement together with a
non-crumple quality while, at the same time, permitting
the clearly desired volume of air to continue to pass
through the dryer even under those conditions where the
conditioning article is held up against the air exit vent
of a dryer.
It should be noted that McQueary, U.S. Patent
No. 3,956,556, at column 7~ lines 66 th.rough 68, mentions
that the device disclosed and claimed in said patent
possesses perforations which need not necessarily be cut
into the substrate, but which could, it is alleged, be the
result of the porousity or air permeability of the
particular substrate material employed in its manufacture.
It should be noted, however, that the method o~
manufacture of the article disclosed therein is such as to
effectively negate the air permeability of the substrate
unless a perforation of substantial size, say 1/8" or
more~ was inserted into the substrate prior to coating.
SUMM~RY_OF THE INVENTION
The present invention, in its article aspects,
is directed to a fabric conditioning article comprising
a substrate having a fabric conditioning agent applied to
at least one surface thereof in a discontinuous or
substantially discontinuous manner. The term
"discontinuous" as used herein means that certain portions
o~ the subskrate are coated with the conditioning
agent and certain portions are not. Thus, if a line is
drawn at random across the article in any manner other
than along the axis of a straight line strip of
conditioning material as applied to the substrate, said
~l~6~3~3~
line will cross both coated and uncoated portlons of the
article.
There is thus provided an article comprising a
substrate partially coated with conditioning agents. The
substrate chosen i5 a material which, due to its normal
structure, permits a substantial flow of air therethrough.
Non-woven fabrics well known in the art are especially
suitable for this purpose. The conditioning agent is
applied to the substrate suitably by printing in a
pre-determined pattern, the sole criterion of the pattern
being that it shall leave enough unoccupied area on the
substrate to provide the necessary degree of air flow
therethrough in operation in a conventional laundry dryer,
In its method aspect, the invention provides,
in the conditioning of fabrics, the addition of softening
agents thereto in the step of co-mingling the fabrics to
be conditioned with a substrate carrying the conditioning
agent removable to the fabrics and having sufficient
inherent interstices therein to provide for a satisfactory
volume of air flowing therethrough.
The fabrlc~conditioning article comprises a
flexible web, such as paper or cloth, carrying a
conditioning agent, such as a fabric softening agent, and
is normally made up into a tubular roll or individual
sheets, A desired length of the treated web is torn off
the roll or a sheet remov~d from its package and placed
into the clothes dryer wherein the fabrics to be treated
have been loaded. The dryer is then operated in customary
fashion, and fabric conditioning occurs as the fabrics
directly contact the treated web, whereby the conditioning
agent is transferred from the web substrate to tha fabric,
Particularly when small fabric loads are tumbled and the
probability o~ a tumbling fabric-conditionin~ article of
making repeated, or prolonged, contact with a laundry
dryer exhaust outlet is enhanced, the perforations, or
openings, in the treated web advantageously minimize the
,
~z~o~
interruption of air flow through the dryer. This is
ef~ected by passage of air through the natural interstices
in the web on those portions of the web not coated with
the conditioning agent.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a side elevational view of the
article of the present invention (not to scale: verticle
scale substantially expanded).
Figure 2 is a plan view of the article of
Figure 1 viewed from 2-2.
Figure 3 is a plan view of a preferred
embodiment of the invention~
Figure 4 is a plan view of an embodiment of the
invention.
Figure 5 is a plan view of yet another
embodiment of the invention showing fabric conditioner
printed on both sides.
Figure 6 is a side elevational view of the
embodiment of Figure 5 viewed from 6-6 (not to scale:
substantially expanded vertically).
Figure 7 is a side elevational view showing two
sheets of Figure 1 sealed to each other at either end.
The drawings show samples of possible
embodiments of the invention. Three and four digit
numbers ending in a particular two digits signify the
same type o~ member as the members carrying said two
digits.
Figures 1 and 2 show a stripped embodiment where
strips of conditioner 14 are printed on one side only of
substrate 12. In the illustrated embodiments substrate 12
is an "open weave" non-woven fabric through which air may
readily pass at those portions not carrying aonditioner
1~ .
Figure 3 shows a substrate 112 carrying a
...
~ILZ683(~2
plurality of dots 114.
Figure 4 shows a substrate 312 carrying a
checker pattern 314.
Figure 5 shows a substrate 212 carrying wavy
pattern 214 on one side and wavy pattern 2214 on the
other.
Figure 7 shows two sheets 12 with strips 14 on
one surface ~ed together with heat seals 16 at either
end. An embodiment similar to this one, but using th~
dotted embodiment of Figure 3, is utilized in one of the
comparative test procedures set forth in the Examples.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The fabric conditioning articles of the
invention comprise a flexible web substrate carrying a
conditioning agent. Suitable suhstrate materials for
carrying the conditioning agent include a variety of
natural or synthetic substrate materials. Suitable
substrates are those which have the ability to retain a
fabric-conditioning agent in a form which is releaseable ;~
to fabrics tumbled therewith, and which h~ve a resistance
to shredding or other tearing failures when tumbled with
damp clothes in a dryer. Examples of suitable substrates
include paper towelling, swatches of woven and non-woven
cloth, papers/ sponges, plastics and felts. Fibrous
materials can be natural or synthetic but are preferably
cellulose. Foæm plastic web materials, such as the
polyurethanes, can also be employed.
In one embodiment of the invention, a substrate
which i9 relatively impermeable to the fabric-conditioning
~0 agent is employed so as to dispose the fabric-conditioning
agent onto the substrate as a discrete surface coating.
Wet strength papers, regenerated cellulose, rayon, nylon,
polyester, polyacrylonitrile, polyole~in and other
synthetic woven or non-woven fibrous materials are
.~ .
lZ~3t:~
suitable for this purpose. Wet strength paper is suitably
employed and can be treated with a waterproo~ing or
sizing material such as a thermosetting resin, starch or
other impregnant, having the effect of reducing water
absorption by fibrous cellulosic products, and allowing
the formation of a coating of conditioning agent. Waxy
papers which carry coatings or impregnations of paraffin
or microcrystalline or synthetic wax can be used -- for
example, "butcher paper" or dry waxed paper -- to the
extent of reducing moisture absorption but permitting
adherent coating of the paper with conditioning agent.
Wet strength papers, such as Kraft or bond papex, can be
employed.
Preferred articles of the invention include
those formed from a substrate having an absorption
capacity in relation~ for example, to fabric softening
agents as to provide an impregnated article capa~le of
controllably releasing the softening agent to treated
fabrics. Improved softness or feel of the treated fabrics
is provided without overdosing or lo~alized concentration
of softener in the form of spots or stains. Suitable
absorbent substrate materials are described in
considerable detail in U.S. Patent No. 3,686,025, issued
August 22, 1972, to Morton.
While Morton teaches that an absorbant capacity
of 5.5 through 12, as defined therein, is desirable for
practicing the invention disclosed by him, it has been
our finding that, in the present invention, substra~es
having absorbencies substantially lower than 5.5 are
entirely satisfactory and, indeed, constitute the
pre~erred embodiment of the present invention.
While not limiting the invention thereto, the
reason for this finding is that, while in the prior art
it would appear that the conditioning agent is absorbed
into the fiber of the substrate and held therein and
~Z~i~3~
between the interstices between the fibers. In the
articles of the present invention the conditioning agent
is, in ef~ect, placed u~on the substrate; in that the use
of a finer denia fiber provides sufficient absorbency
before the interstices only so that a very minimal amount
of absorbency is adequate for the purposes of the present
invention.
Preferred ahsorbent substrates are cellulosic
materials such as multi-ply paper towel and non-woven
cloth substrates. Preferred paper towel materials and
their method of manufacture can be found in U.S. Patent
No. 3,414,459, issued December 3, 1968, to Wells.
Preferred non-woven cloth substrates can be
generally defined as adhesively-bonded fibrous
or filamentous products having a web structura, in
which the fibers or ~ilaments are distributed
haphazardly, as in the "wet lay" processes,
or with a degree of orientation, as in the "carding"
process. Such substrates exhibit desirable strength in
all directions and are rasistant to shredding or tearing
failures when tumbled with damp fabrics. The ~ibers or
rilaments of such non-woven cloth substrates can be
natural (for example, wool, silk, jute, hemp, cotton,
linen, sisal or ramie) or syn-thetic (~o~ example, rayon,
cellulose ester, polyvinyl derivatives, polyolefins,
polyamides or polyesters) and bonded together with a
polymetric binder resin such as polyvinyl acetate. While
the invention is in no way limited thereto, it has been
~ound that the most satisfactory results are obtained
using polyester ~ibers. ~hese ~ibers have the advantage,
in the context o~ the present invention, of being so~ter,
not as absorbent, and have the ability to be produced in
a whiter - i.e., more hygenic appearing -- form than
those materia1s which are dis~losed by t~e prior art and
are presently to be found in t~e channels o commerce.
The factor of softness is advantagaous as it
lZ683~2
tends to counter the crumpling and folding efects which
were presen~, and indeed believed to be desirable, in
the articles of the prior art. The softer touch, as well
as the whiter appearance of the polyester fiber, are
5 considered to be specific advantages in a product closely
related, in the mind of the consumer, with hygenic
matters. The preferred, though not critical, range of
absorbency of the materials used herein is between 100
and 500~. This lower absorbency has the advantage of
permitting the easier removal of the conditioning agent
to the fabric which it contacts in the dryer. This ratio
of removability contributes to the efficiency of the
present met~od since, inherently then, less material is
required. Such substrates will normally have a void
volume of from about 20% to about 80~ to provide desirable
air flow properties.
The conditioning agents employed herein include
any of a ~ariety of agents employed generally in textile
treating operations. Accordingly, fabric softening anti-
static, anti-mildew, germicidal, mothproofing and anti-
wrinkling agents, perfumes and the like can be employed.
The most universal preference, however, is for agents
which act to so~ten ~abrics or otherwise improve their
feel or hand. Softening agents which also have anti-
static properties and which reduce sta~ic charge or ~abxiccling are especially preferred.
Typically, the fabric softening agents that can
be employed are compounds having a relati~ely-long
hydrocarbon group serving to provide hydrophobicity or
lubricity. Among such groups axe alkyl groups containing
8 or more carbon atoms and preferably from 12 to 22 carbon
atoms. Suitable fabrlc softening agents include cationic,
anionic, nonionic, or zwitterionic compounds. Cationic
fabric-sotenlng agents include the cationic nitrogen-
containin~ compounds such as quaternary ammonium compoundsand amine which ha~e one or two straight-chain or~anic
--10--
.
~Z61~3~Z
groups of at least 8 carbon atoms. Preferably, they have
one or two such groups of ~rom 12 to 22 carbon atoms.
Preferred cation-active softener compounds include the
quaternary ammonium softener compounds corresponding to
the formula
G~X-,-'..
wherein R is hydrogen or an aliphatic group of from 12
to 22 carbon atoms; Rl is an aliphatic group having from
12 to 22 carbon atoms; R2 and R3 are each alkyl groups of
from 1 to 3 carbon atoms; and X is an anion selected from
halogen, acetate phosphate, nitrite and methyl sulfate
radicals.
Because of their excellent softening e~icacy
and ready availability, preferred cationic softener
compounds of the invention are the dialkyl dimethyl
ammonium chlorides, wherein the alkyl groups have rom 12
to 22 carbon atoms and are derived from long-chain fatty
acids such as hydrogenated tallow. As employed herein,
alkyl is intended as including unsakurated compounds such
as are present in alkyl groups derived from naturally
occurring fatty oils. The term "tallow" refers to fatty
alkyl groups derived from tallow fatty acids. Such fatty
acids give rise to quaternary softener compounds wherein
R and R~ have predominantly from 16 to 18 carbon atoms.
The term "coconut" refers to fatty acid groups ~rom
coconut oil fatty acids. The coconut-alkyl R and R
~2~i~33~;2
gxoups have from about 8 to about 18 carbon atoms and
predominate in C12 to C14 alkyl groups. Representative
examples of quaternary softeners of the invention include
tallow trimethyl ammonium chloride; ditallow dimethyl
ammonium chloride; ditallow dimethyl ammonium methyl
sulfate; dihexadecyl dimethyl ammonium chloride;
di(hydrogenated tallow)dimethyl ammonium chloride;
dioctadecyl dimethyl ammonium chloride; dieicosyl dimethyl
ammonium chloride; didocosyl dimethyl ammonium chloride;
di(hydrogenated tallow)dimethyl ammonium methyl sulfate;
dihexadecyl diethyl ammonium chloride; dihexadecyl
diethyl ammonium chloride; dihexadecyl dimethyl ammonium
acetate; ditallow dipropyl ammonium phosphate; ditallow
dimethyl ammonium nitrite; di(coconut-alkyl)dimethyl
ammonium chloride.
Suitable cation-active amine so~tener compounds
are the primary, secondary and tertiary amine compounds
having at least one straight-chain organic group of from
12 to 22 carbon atoms and 1,3-propylene diamine compounds
having a straight-chain organic group of from 12 to 22
carbon atoms. Examples of such softener actives include
primary tallow amine' primary hydrogenated-tallow amine;
tallow 1,3-prop~lene diamine; oleyl 1,3-propylene
diamine; coconut 1,3-propylene diamine; soya 1,3-propylene
diamine; and the like.
Other suitable cation-active softener compounds
herein are the quaternary imidazolinium salts. Preferred
salts are those conforming to the formula
~f~ ~
~LZ683~;Z
wherein R6 is an alkyl containing from 1 to 4, preferably
from 1 to 2, carbon atoms; R7 is an alkyl containing from
1 to 4 carbon atoms or a hydrogen radical; R8 is an alkyl
containing from 8 to 22, preferably at least 15, carbon
atoms; R5 is hydrogen or an alkyl containing from 9 to 22,
preferably at least 15, carbon atoms; and X is an anion,
preferably methyl sulfate or chloride ions. Other
suitable anions include those disclosed with reference to
the cationic quaternary ammonium ~abric softeners
described hereinbefore. Particularly preferred are those
imidazolinium compounds in which both R5 and R8 are alkyls
of from 12 to 22 carbon atoms -- for example,
2-heptadecyl-1,1-methyl[(2-stearoylamide)ethyl]~
imidazolinium methyl sulfate.
Other cationic quaternary ammonium fabric
softeners which are useful herein includ~, for example,
alkyl(C12 to C22)-pyridinium chlorides, alkyl(C12 to C22)-
[Cl to C3)-morpholinium chlorides, and quaternary
derivatives of amino acids and amino esters.
The anionic conditioning agents can include any
of the various surface-active anionic fabric-softening
and anti-static agents such as alkali metal or ammonium
salts of higher ~atty alcohol sulates, higher a~ty
alcohol ether sulfates, higher fatty alcohol sul~onates,
the linear higher alkyl benzene sulfonates, the higher
fatty acyl taurides and isothionates. Generallyr the
cation of such compounds will be an alkali metal or other
water-solubilizing radical. The hydrophobic moiety of
such compounds will normally contain from 10 to 22 carbon
atoms. Alkali metal and ammonium soaps of fatty acids
of fxom 10 to 22 carbon atoms can also be employed and
include the sodium or potassium coconut or tallow soaps.
Suitable nonionic abric softeners and anti-
static agents that can be employed are the polyoxyalkylene
glycols, the higher fatty alcohol esters of
polyoxyalkylene glycols, the higher ~atty alcohol esters
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, .
:~Z6~30;Z
of polyoxyalkylene glycols. Also suitable are the
ethoxylates of long-chain alcohols of from B to 22 carbon
atoms such as the ethoxylates of tallow alcohol with, for
example, 10 to 40 moles of ethylene oxide. Other
nonionics include the amides such as the alkanolamides --
for example, the higher fatty amides and higher fatty acid
mono- and di-lower alkanolamides, wherein the long-chain
hydrophobic groups have from about 10 to 22 carbon atoms.
Other suitable softening agents include the
zwitterionic compounds of the formula
R'~ CH,--R"--CH,SO,-
1--
wherein Rg and RlO are each methyl, ethyl, n-propyl,
isopropyl, 2-hydroxyethyl or 2-hydroxypropyl; R8 is a 12
to 22 carbon atom alkyl or alkenyl and wherein said alkyl
or alkenyl contains from 0 to 2 hydroxyl substituents,
from 0 to 5 ether linkages, and from 0 to l amide linkage;
and Rll is an alkylene group containing ~rom 1 to 4 carbon
atoms with from 0 to l hydroxyl substituents; particularly
preferred are compounds wherein R3 is a carbon chain
containing from 14 to 18 caxbon atoms selected rom the
group consisting of alkyls and alkenyl and wherein said
alkyls and alkenyls contain 0 to 2 hydroxyl substituents.
Speci~ic examples of the particularly preferred compounds
of this class include the following: 3-(N-hexadecyl-N,N-
dimethylammonio)-2-hydroxypropane-1-sulfonate; and 3-(N-
25~ octadecyl-N,N-dimethylammonio)-propane-l sulfonate.
Other examples of conditioning agents suitable
or the articles herein are described in detail in U.S.
Patent No. 3,688,025 at column 5, line 51, to column 14,
-14-
~26~3302
line 6.
The amount of conditioning agent carried by the
substrate is an amount sufficient to provide the desired
conditioning effect without substantial excess. The
amount will vary in any given case and will depend, for
example, upon the nature of the particular conditioning
agent or substrate material and the type of conditioning
effect desired. When the conditioning agent is a fabric
softening agent, such agent will preferably be employed
in a weight ratio of agent to untreated substra~e from
0.5:1 to 4:1 or more. Generally, the amount of softener
will range from about 40 mg to about 1.2 grams per
centimeter length of a substrate no more than 28 cm wide,
with small amounts of softener being used on lightweight
su~strates, such as non-woven cloths, and large amounts
on heavy substrates, such as multi-ply paper.
The manner of applying the fabric conditioning
agent to the substrate in such a manner as to provide a
discontinuous pattern in at least one direction, is not
critical. It has been found most convenient, however, to
apply the conditioning agent by a printing proces~ which
will permit a ready repetition of the pre-determined
discontinuous pattern, as well as a means for applying the
conditioning agent on one, or both, principal surfaces of
the substrate in a pre-determined amount.
The sole criterion of the pattern o fabric
conditioner applied is that it shall leave an adequate
amount of ree space upon the substrate, pre~erably upon
a non-woven substrate, to allow a sufficient amount of air
to pass through the substrate that the air outlet of a
typical domestic dryer should not be blocked thereby.
While the preferred embodiments of the present application
contemplate the use of non-woven fabrics which, because of
the nature of their construction, possess a substantial
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,
... . . .
33~1Z
number of interstices between the fibers thereof through
which air may pass, the scope of the invention does not
exclude the use of woven fabrics, or other flexible
substrates in which perforations have been placed in the
manner of McQueary, U.S. Patent No. 3,956,556. Provided
that the important criterion of air permeability is
maintained, the pattern carrying the fabric conditioner is
purely a matter of economic and aesthetic convenience. As
specifically exemplified herein, a pattern of dots has
1~ been employed. There may also be employed patterns
including strips running with the length of the substrate,
strips running diagonally across the width of the
substrate, and strips running straight across the width
of the substrate. The strips may be straight, they may
be curved, they may be sinusoidal, or they may be totally
random. There may be included checkerboard patterns,
aesthetic, repeating designs, printed text having meaning
and not having meaning, and so forth. It is also
contemplated within the scope of the invention to utilize
a fabric conditioner having a different color from the
substrate. Because of the need to be able to employ the
articles of the present invention with colored and
non-colored fabrics, it would be preferred -to utilize a
non-colored or white conditioner upon a substra~e of a
dif~erent shade or color.
This latter type o~ patterning goes solely to
the appearance of the goods rather than their basic
function which is to transfer fabric conditioner to
fabrics without the disadvantages possessed by certain
prior art fabric conditioning articles.
In order to comply with the principal criterion
of the pattern set forth above, however, the pattern,
selected should be one which does not involve large areas
of fabric conditioner located in one portion of the
-16-
126~33~)2
article since such large areas of conditioner tend to
block air flow and tend to permit adhesion of the article
to the air flow outlet. The more open the applied pattern
of fabric conditioner, the better.
The fabric conditioning articles of the present
invention are structured to be compatible with
conventional laundry dryer designs. While it is preferred
to employ the articles of the present invention in an
automatic laundry dryer, other equivalent machines can be
employed and, in some instances, heat and drying air may
be omitted for part or all of the cycle. Generally,
however, heated air will be employed and such air will be
circulated frequently in the dryer. Normally, there are
from about five to fifty volume changes of drying gas in
the dryer drum per minute and the air moves at about 125
to 175 cubic feet per minute. These changing volumes
of air create a drawing or suction effect which aan,
especially in small loads, cause a fabric, such as a sock,
handkerchief or the like, or a fabric-conditioning article,
to be disposed on the surface of the air outlet of the
dryer. A usual load of fabrics of from about four to
twelve pounds dry weight will fill from about 10% to 70%
of the volume of most dryers and will normally pose little
difficulty. A sufficient number of tumbling items will
normally be present to prevent any item from being drawn
to the exhaust outlet or to cause it to be removed from
the outlet.
Preferably, a fabric conditioning article of the
invention will contain a sufficient number of perforations
as to permit ~he passage of at least about 75% of the
normal volume of air flow of the laundry dryer. This
permits fabrics to be dried efficiently without
undesirable temperature build-up or alternate on/off
cycling of the heater and resulting rise and fall of dryer
temperature. Normal operating temperatures are adhered to
-17-
, .
~z~3302
and extended drying times are thereby avoided,
Preferabl~, an article will have a sufficient number of
perforations as to allow at least 85~ of the volume of air
to pass through the dryer.
The fabric conditioning articles of the
invention are simple to employ and normally will be
employed in a laundry dryer which is operated at a
temperature, for example, of from 75 F to 210 F and for
a drying period of from about five to sixty minutes. A
load of fabrics to be dried is placed into the dryer and a
sheet, such as may be detached by tearing from a
perforated roll, is simply added to the dryer which is
operated in usual fashion. The treated fabrics are then
removed and handled in customary fashion.
The following Examples illustrate certain
preferred embodiments of the invention and are not
intended as limiting the invention. The quaternary
ammonium fabric softening agent of Examples I - III was
di tallow dimethyl ammonium chloride. Other of the
various fabric conditioning agents described hereinbefore
in detail can be employed to advantage.
-18-
,
~LZ6i330Z
EXAMPI,E I
There is utilized as a substrate a non-woven
fabric cut to a desired size (7.6 x 22.8 centimeters).
The substrate consists of 100% airlaid polyester fiber
bonded with a hydrophobic binder, has a thickness of
280 microns, weighs 24 grams per square meter, and has an
absorbency of 4 (400%).
The fabric conditioning formulation consists of
100% Arquad 2HT-75 (a di tallow dimethyl ammonium
chloride manufactured by Armak Co., Chicago, Illinois.)
(Arquad is a registered trademark of the manufacturer.)
A nickel sheet, 127 microns in thickness,
perforated with dot shaped perforations at a rate of 26
perforations per square centimeter, each perforation having
a diameter of 0.7 millimeters diameter, is placed on top
of the substrate sheet. The soEtening formulation is
warmed to a temperature of approximately 40 C, and
squeegeed through the perforated sheet onto the substrate.
The foregoing procedure provides substrate application at
the rate of 30 grams per square meter.
EXAMPLE II
.
The procedure of Example I was repeated
utilizing, however, in place of the substrate of Example I,
a 100% rayon fiber non-woven substrate bonded with an
acrylic binder (Sterns & Foster, Style F-3387, a material
similar to that utilized in commercially available ~abric
softeners produced under the trademark Bounce, a product
of Proctor & Gamble.) The substrate has a thickness of
254 microns, weighs 24 grams per square meter, and has an
absorbency of 6.5 (650%)~
--lg--
~L26l~3~Z
EXAMPLE III
Comparison of Exam~le I and II Products
Four samples produced in accordance with each
of the foregoing Examples were, at separate times, placed
in a commercially available home-size clothes dryer
(Frigidaire Model LCT-120, manufactured by General Motors)
together with six spin dried but damp terrycloth towels,
and dried in the dryer for 120 minutes. Examination of
the samples after use showed that the substrates of
Example I (absorbency 4.0) released over 60~ of the
fabric conditioning agent and those of Example II
(absorbency 6.5) released less than 40% of the fabric
conditioning agent.
EXAMPLE IV
Pairs of sheets, produced in accordance with
Example I, are heat sealed together at two opposite ends
yielding a two-layer sample containing 38 grams of fabric
conditioning agent per square meter.
EXAMPLE V
Samples were prepared in accordance with the
procedure of Example ~ but, in place of utilizing a sheet
having 26 dots per s~uare centimeter of 0.7 millimeter
diameter, there is utilized a masking sheet having 15
dots per square centimeter of 1.4 millimeters in diameter.
2S The resulting sheets carry 38 grams of fabric conditioning
agent per square meter. The resultant sheets are then
joined together in accordance wi~h the procedure of
Example IV.
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3~
EXAMPLE VI
Comparl n of Example IV and V Products
The samples compared in accordance with
Examples IV and V were tested in accordance with the
test procedures utilized for the products of Examples I
and II and showed that the product of Example IV
released 20% more fabric conditioning agent than the
product of Example V.
EXAMPLE VII
Samples were prepared in accordance with
Example IV, except that the fabric conditioning
formulation utilized consisted of Arquad 2HT-75 and
Ethomeen T/12 (4:1). Ethomeen T/12 is a Bis-2-hydroxy-
etnyl tallow amine manufactured by Armak Co., Chicago,Illinois. (Ethomeen is the registered trademark of the
manufacturer.) The sheets utilized were 7.6 x 24.76
centimeters, and the weight of fabric softening agent is
57 grams per square meter.
EXAMPLE VIII
Comparison of Example VII Product with a Commercial Sheet
A sample of Example VII is evaluated in the
home dryers previously described. The dryer load
consisted of two cotton terrycloth dishclo~hes, four
cotton terrycloth dish towels, four blue polyester pillow
cases, and four velour terrycloth bath towels, all spin
dried but damp. The quantitative and qualitative results
are set forth below.
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.~ .
~L~6~30~
Example #VII Commercial Sheet
Density 57 gm/sq. m. 32.45 gm/sq~ m.
applied weight 1.073 gram 2.072 gram
amount transferred 0.651 1.184
~ transferred 60.7% 57.2~
A panel of ten women judged the fabrics treated
with Example VII product to be superior in perceived
softness to similar goods treated using the commercial
material even though the actual amount of fabric
conditioning agent transferred to the fabric by the
commercial softener is almost twice the amount
transferred by the Example VII product.
EXAMPLE IX
Samples were prepared in accordance with
Example I with the following ~ariants. The samples were
28 x 22.8 centimeters in size (full commercial size).
The fabric conditioning agent utilized was Arquad 2HT-75
and Carbowax (9:1) (Carbowax is a polyethylene glycol,
molecular weight range 190 - 210, manufactured by
Union Carbide Corporation, New York, New York. Carbowax
is a registered trademark of the manufa~turer. The
conditioner is applied in various weight per unit area
ranges -- i.e., 29, 24, and 12 grams per square meter.
(Commercial sheet density is 39.5 grams per square
meter.)
E~AMPLE X
Comparison of Example IX Product with Commercial Sheet
The procedures relating to the evaluation o~
Example VII material (comparison No. 3) were repeated
utilizing samples prepared according to Example VIII with
commercial sheets. (Quantitative and Qualitative Tests)
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~2~33C~2
Quantitative Tests
Commercial Sheet
A B_ C
applied wt. 1.859 1.541 0.761 2.526
density 29 24 12 39.5
amount agent
transferred 1.044 0.970 O.S16 0.933
% transferred 56.2% 63% 67.8% 37%
Qualitative Tests
A panel of ten women judged the clothes being
treated for perceived softness. The women were asked to
evalute the treated clothing by rating each lot from 1
to 5 with 1 being the highest degree of softness and 5
being the least degree of softness. The results are
tabulated with the lowest score being rated as the
highest degree of softness. For purposes of the panel
test a control, Column E, was included. This control was
dryed under normal conditions and not treated with
softening agents. The panel test appears below.
Commercial
Sheet
A B C D E
Woman #1 1 5 2 3
Woman #2 2 I 3 4 5
Woman #3 3 1 2 4 5
Woman #4 1 2 4 3 5
Woman #5 2 1 4 3 5
Woman #6 1 2 4 3 s
Woman #7 3 2 1 5 4
Woman #8 1 2 4 3 5
Woman #9 2 1 3 4 5
Woman ~10 2 1 3 4 5
18 1830 36 48
The foregoing te~ts show that, utilizing
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~6~30;2
commercial size sheets, approximately twice as much
softening agent is released by products produced in
accordance with the present invention than from products
presently commercaill~ available. It is further shown
that the least satisfactory product produced in
accordance with the present invention compares favorably
with the commercial product, but requires a conditioning
agent load of approximately 1/3 of the amount utilized in
the commercial product.
EXAMPLE XI
400 grams of a softening formulation consisting
of 90 parts Arquad 2HT-75 , 10 parts polyethylene glycol
200, and 300 parts water was prepared by placi~g said
materials in a container and immersing the container in a
water bath heated at 44 C. A non-woven substrate of the
type described in Example I was prepared. The softening
agent was applied by immersing the substrate in the
softenincJ agent, completely saturating the substrate, and
removing the excess with a spatula. The polyester
material is dried in an oven for five minutes at 104 C to
remove excess moisture. A dried coating weight of
approximately 0.8 grams per 175 centimeters squared
sheet (i.e., 4.6 mg/cm2) is achieved.
EXAMPLE XII
Example XI is repeated but a non-woven substrate
of the type described in Example II is substituted. A
coating weight of 0.75 grams per 175 square centimeters
t4.3mg/cm ) is achieved,
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~L2~3302
EXAMPLE XIII
Evaluation of Samples from Examples XI and XII
_ _ _
The treated samples were evaluated by testing
them under actual drying conditions. Four samples from
5 Example XI were placed in a home dryer, Sears Model
Kenmore 77656100, along with six damp terry towels and
dried for thirty minutes.
It was found that Example XI using a fabric of
100% polyester fiber with an absorbency of 400%, there
10 was released over 60% of the softening agents.
It was noted that the finished coated polyester
material was stiff, waxy and had an objectionable feel and
hand.
Using a 100% rayon fiber fahric of Example XII
15 substrate with 650% absorbency, there was released under
7061 45% of the softening agent.
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