Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02794083 2012-10-31
WOOL DRYER BALL AND METHOD OF MANUFACTURING SAME
Technical Field
[0001] This invention relates to dryer balls. Particular embodiments relate to
a dryer ball
made from wool and a method of manufacturing the dryer ball.
Background
[0002] As an alternative to using chemical fabric softeners or dryer sheets,
dryer balls
may be placed in a clothes dryer along with the articles of clothing to be
dried. The dryer
balls are tossed around in the clothes dryer during the drying cycle and are
purported to
help fluff and soften clothing.
[0003] Some conventional dryer balls are made of heat-resistant plastic or
rubber and are
covered with outwardly extending knobs or spikes. Examples of such dryer balls
include
Nellie'STM dryer balls, Dryer MagicTM dryer balls, Dryer MaXTM dryer balls and
The
Original Dryer BaI1STM. Typically, such dryer balls are about 7.6 cm or 3
inches in
diameter, or are about the size of a tennis ball or smaller.
[0004] Other dryer balls are made from wool. For example, some dryer balls are
made
from wool yarn which has been twisted or wound into a ball and felted by
washing and
drying the ball several times in succession. Typically, wool dryer balls are
hard and
dense, and are similar in size to plastic dryer balls (e.g. about the size of
a tennis ball or
smaller). They are generally intended to emulate the function of plastic dryer
balls.
CA 02794083 2012-10-31
[0005] A main objective of conventional plastic or wool dryer balls is to
soften and fluff
clothing by beating the clothing as the balls are tumbled in the clothes dryer
along with
the clothing. The balls are typically quite heavy so that they can accomplish
this
objective.
[0006] In some cases, conventional plastic and wool dryer balls are purported
to also help
reduce drying time by separating the clothing as it dries. However, in
general,
conventional dryer balls have not been shown to reduce drying time by any
significant
amount.
[0007] There is a general desire for a dryer ball that addresses the
aforementioned
problems.
[0008] The foregoing examples of the related art and limitations related
thereto are
intended to be illustrative and not exclusive. Other limitations of the
related art will
become apparent to those of skill in the art upon a reading of the
specification and a study
of the drawings.
Summary
[0009] One aspect of the invention provides a method of making a wool dryer
ball. The
method includes providing a piece of wool material weighing in the range of 54
g to 60 g.
In some embodiments, the piece of wool material weighs about 57 g. The piece
of wool
material is folded into a substantially spherical wool ball having a
circumference in the
range of 43 cm to 53 cm. In some embodiments, the spherical wool ball has a
circumference of about 48 cm.
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[0010] Folding the piece of wool material may include taking a pair of
laterally opposed
sections of the piece and folding them over each other so that wool fibers of
each section
are oriented in substantially perpendicular directions to each other. Sections
of the piece
may be pulled and stretched and folded toward a middle portion of the piece.
[0011] After the piece of wool material has been folded into a ball, the ball
is placed in a
porous bag. The bag is sealed to contain the wool ball therein. The bag
containing the
wool ball is washed. In some embodiments the wool ball is washed in hot soapy
water,
then rinsed. The wool ball is removed from the bag and allowed to air dry.
[0012] According to some embodiments, a felting needle may be used to felt the
wool
ball after it has been formed and prior to washing. In some embodiments, a
felting needle
may be used to felt the wool ball after washing.
[0013] Another aspect of the invention provides a dryer ball for use in a
clothes dryer to
increase the dryer's efficiency. The dryer ball has a substantially spherical
wool body and
a substantially uniform distribution of wool fibers therethrough. The body has
a volume
in the range of about 600 cm3 to 900 cm3 and a weight in the range of 54 g to
60 g. In
particular embodiments, the body has a volume of approximately 760 cm3 and a
weight
of approximately 57 g. The density of the wool ball may be in the range of
0.06 g/cm3 to
0.09 g/cm3. In particular embodiments, the density of the wool ball is about
0.075 g/cm3.
A plurality of air pockets is substantially uniformly distributed throughout
the wool ball.
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[0014] In addition to the exemplary aspects and embodiments described above,
further
aspects and embodiments will become apparent by reference to the drawings and
by
study of the following detailed descriptions.
Brief Description of Drawings
[0015] Exemplary embodiments are illustrated in referenced figures of the
drawings. It is
intended that the embodiments and figures disclosed herein are to be
considered
illustrative rather than restrictive.
[0016] FIG. 1A illustrates a wool dryer ball according to an embodiment of the
invention.
[0017] FIG. 1B illustrates a cross-sectional view of the wool dryer ball of
FIG. IA taken
along line B-B.
[0018] FIGS. 2A to 2D illustrate various stages of forming a piece of wool
material into a
ball according to one method of making a wool dryer ball.
[0019] FIG. 3 illustrates a needle felting step of a method of making a wool
dryer ball.
[0020] FIGS. 4A and 4B illustrate wet felting apparatus used in a method of
making a
wool dryer ball.
[0021] FIG. 5 is a flowchart illustrating a method of manufacturing a wool
dryer ball
according to an embodiment of the invention.
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Description
[0022] Throughout the following description, specific details are set forth in
order to
provide a more thorough understanding to persons skilled in the art. However,
well
known elements may not have been shown or described in detail to avoid
unnecessarily
obscuring the disclosure. Accordingly, the description and drawings are to be
regarded in
an illustrative, rather than a restrictive, sense.
[0023] FIG. 1A illustrates a dryer ball 10 according to one particular
embodiment. In the
illustrated embodiment, dryer ball 10 is substantially spherical in shape. In
particular
embodiments, dryer ball 10 is made entirely of wool. Wool fiber is naturally
hydrophilic
and can absorb up to about 30% of its own weight in moisture.
[0024] The inventors have found that fine, lightweight, soft or fluffy wools
are generally
suitable for making dryer ball 10. In particular embodiments, dryer ball 10
consists of
100% Merino sheep wool. Dryer ball 10 can be made from other types of sheep
wool,
such as for example Corriedale wool or Cotswold wool, or from wool obtained
from
other animals, such as for example alpacas, or any combination of wool
thereof.
[0025] The tendency is for conventional wool or plastic dryer balls to be hard
and dense
so that they are effective in beating and softening articles of clothing as
they are tumbled
in a clothes dryer. In addition, because there is concern that wool will
unravel after
repeated use in a clothes dryer, conventional wool dryer balls typically
consist of wool
which has been tightly felted into a highly compact, dense ball so as to
reduce the risk of
the wool unravelling. Generally, wool balls are laundered in hot water several
times to
repeatedly felt the wool so that it forms a hard, dense ball.
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[0026] However, the inventors have found that, for a certain mass of wool
material,
increasing the size of each wool dryer ball, or decreasing its density,
provides particular
advantages over conventional wool dryer balls. In particular, the inventors
have found
that reducing the density of a wool dryer ball reduces the time that it takes
to dry clothes
when the dryer ball is tumbled in the clothes dryer along with the clothes. A
less dense
dryer ball contains air pockets or gaps distributed through the ball. Such air
pockets in the
dryer ball help to trap heat in the dryer ball. This feature helps to
distribute the heat
generated by the dryer around the interior of the dryer (and hence, around the
clothes)
during a drying cycle. Such air pockets in the dryer ball also help to
increase the
absorbency of the dryer ball. The dryer ball absorbs some of the moisture away
from the
air and the clothes in the clothes dryer.
[0027] Accordingly, a dryer ball according to embodiments of the invention
described
herein is larger and less dense than conventional dryer balls. In addition,
the dryer ball is
manufactured in such a way that there is little danger of the wool unravelling
over use,
and without requiring the wool fibers to be tightly felted into a compact,
dense ball. The
method of manufacture is described below.
[0028] In particular embodiments, dryer ball 10 has a circumference of about
35.6 cm (14
inches) or a volume of about 760 cm3 and a weight of about 57 g (2 oz). The
density of
such dryer ball 10 is therefore about 0.075 g/cm3.
[0029] Dryer balls 10 may vary in weight and size. For example, in some
embodiments,
dryer ball 10 has a weight of 57 g 3 g (2 oz + 0.1 oz), and a circumference
of about
35.6 cm + 2.5 cm (14 inches + 1 inch) (i.e. the volume ranges from about 600
cm3 to 930
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CM3). However, other variations are possible. For example, in some
embodiments, dryer
ball 10 may have a weight in the range of 43 g to 85 g (1.5 oz to 3 oz), and a
corresponding circumference such that the density of the dryer ball 10 is
about
0.075 g/cm3 or within one of the ranges discussed below.
[0030] In some embodiments, the weight and size of dryer ball 10 are such that
the
density of the ball is less than 0.95 g/cm3. In particular embodiments, the
weight and size
of dryer ball 10 are such that the density of the ball is less than 0.85
g/cm3. In some
embodiments, the density of dryer ball 10 is in the range of 0.06 g/cm3 to
0.09 g/cm3. In
some embodiments, the density of dryer ball 10 is in the range of 0.06 g/cm3
to 0.08
g/cm3.
[0031] FIG. 1B illustrates a cross-sectional view of dryer ball 10 taken along
line B-B of
FIG. 1A. As illustrated in FIG. 1B, dryer ball 10 has a plurality of air
pockets 12. The air
pockets 12 may be substantially uniformly distributed throughout the ball. As
discussed
above, air pockets 12 help to trap heat in the dryer ball 10. Air pockets 12
also increase
the absorbency of dryer ball 10.
[0032] FIGS. 2A to 2D illustrate various stages of forming a piece 16 of wool
material
into a ball according to a method of manufacturing a dryer ball 10. In FIG.
2A, the piece
of wool material comprises wool batting. A larger sheet of wool batting may be
cut,
separated or otherwise divided into individual wool pieces 16. According to
some
embodiments, each individual piece 16 weighs about 57 g. Other forms of wool,
such as
wool roving and wool roping, may be used instead of wool batting.
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[0033] In the illustrated embodiment of FIG. 2A, each piece 16 is a roughly
rectangular
sheet, having a pair of longitudinally opposed edges 17 and a pair of
laterally opposed
edges 19. Adjacent edges 17, 19 meet at their respective corners 18. It is not
necessary
that piece 16 have the shape as illustrated in FIG. 2A. In other embodiments,
piece 16
may be irregular in shape or have a non-rectangular shape.
[00341 To start rolling each wool piece 16 into a dryer ball 10, the wool at a
corner 18 at
one edge 17 is pulled to stretch out the wool material, then folded and/or
rolled toward a
middle portion 15 of piece 16 to begin forming a body 11 of the ball (see FIG.
2B). The
wool at opposite corner 18 of the same edge 17 is pulled to stretch out the
wool material,
and then folded and/or rolled around body 11 (see FIG. 2C).
100351 These steps of pulling and stretching, and folding and rolling, are
repeated for
opposed sections of piece 16 so as to build the body 11 of dryer ball 10. By
taking
laterally opposed sections of wool along edges 19 and folding or rolling them
around
body 11, a ball can be formed with fibers oriented in different directions.
For example, as
illustrated in FIG. 2D, one section 22 of wool having fibers oriented in one
direction 23
may be overlaid by another section 24 of wool having fibers oriented in a
direction 25
that is substantially perpendicular to direction 23. Wrapping and rolling the
wool so that
the wool fibers are oriented in different directions will facilitate the
felting or binding of
the wool fibers during the wet felting stage.
[0036] As seen in FIG. 2C, one or more peaks 20 may develop in the body 11 as
the wool
piece 16 is being folded into a ball. While body 11 is being built, pieces of
wool piece 16
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can be stretched and wrapped around or over peaks 20 that have developed in
body 11 to
smooth out such peaks and ensure a round shape to body 11.
[0037] To complete the building of body 11, the last sections of wool at the
two corners
18 of edge 17 may be pulled and stretched and then folded around body 11.
These wool
sections may be wrapped around body 11 in different directions.
[0038] Care should be taking during the stage of forming wool piece 16 into a
ball 10 to
ensure that the wool is not folded or wrapped too tightly, otherwise the
result may be an
overly dense wool ball that is not effective in reducing drying time. In
particular
embodiments, the result of the ball forming steps described above should be a
substantially spherical ball 10 having a circumference in the range of 43 cm
to 53 cm (17
inches to 21 inches). In particular embodiments, the dryer ball 10's
circumference is
about 48 cm (19 inches). Dryer ball 10 should feel soft and spongy.
[0039] FIG. 3 illustrates the needle felting step in a method of manufacturing
dryer ball
10. After the ball 10 has been formed by the steps described above with
reference to
FIGS. 2A to 2D, a felting needle 21 can optionally be used to weave loose wool
fibers
into body 11. The felting needle 21 can be used to pull fibers over or into
any visible
openings in body 11, or to pull and weave fibers into the ball which are not
flush against
body 11.
[0040] The dryer ball 10 is then inserted in a bag or sac 28. Bag 28 is made
of porous
material. Such material may comprise, for example, nylon material. In the
illustrated
embodiment of FIG. 4A, bag 28 is a nylon stocking having a closed end 26 and
an open
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end 27. Ball 10 is inserted in bag 28 through open end 27 and moved toward
closed end
26, working out any wrinkles or folds that may develop by stretching and
pulling the
nylon material over ball 10. Any loose fibers caught in the nylon material can
be pushed
or patted into place.
[0041] Once ball 10 is in the bag, open end 27 of bag 28 is closed. This can
be
accomplished by twisting and tying a knot 29 in the stocking as shown in FIG.
4B.
[0042] Dryer ball 10 is now ready to undergo the wet felting stage. In this
stage, bags 28
containing dryer balls 10 are submerged in water and washed to lubricate and
stimulate
the wool fibers so that they bond with one another. In particular embodiments,
dryer balls
10 are washed in hot water to agitate the wool fibers so that they bond
together in a
process known as felting. For some embodiments, the water for washing the
balls may be
heated to a temperature in the range of 40 C to 60 C. In some embodiments, a
small
amount of soap, such as a laundry detergent, is added to the water in which
the balls are
submerged and washed to help lubricate the fibers and encourage the fibers to
move and
bond together.
[0043] A clothes washing machine or other suitable machine can be used for the
wet
felting stage. In some embodiments, a number of dryer balls 10 contained in
their
respective bags 28 may be wet felted at the same time. For example, where a
clothes
washing machine is used, thirty (30) dryer balls may be placed in the washing
machine at
once. In some embodiments, the wash cycle may last between about 30 minutes
and 60
minutes.
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[0044] Following a wash in hot soapy water, dryer balls 10 are rinsed with
cold water to
remove the soap and stop the felting process. Bags 28 are opened, and dryer
balls 10 are
removed from the bags and allowed to air dry. In some embodiments, dryer balls
10 are
allowed to dry for about 24 hours. The finished, dried dryer balls 10 have a
substantially
uniform distribution of wool fibers throughout. In addition, dryer balls 10
contain air
pockets 12, as shown in FIG. 1B.
[0045] Dryer balls 10 may be inspected after removal from the bags. Any loose
fibers or
sections requiring further felting may be needle felted. A few drops of
essential oil or
other fragrance may optionally be added to dryer ball 10 by the manufacturer
or the
consumer to freshen the laundry with a scent. Otherwise, dryer ball 10 can be
left
unscented.
[0046] In particular embodiments, dryer balls 10 are wet felted only once
(i.e. they
undergo only a single wash in hot soapy water, followed by a rinse in cold
water). In such
embodiments a single wet felting step is generally sufficient to cause the
wool fibers in
dryer ball 10 to matt together so that the ball keeps its shape while being
used in a clothes
dryer.
[0047] After a single wet felting step, dryer balls 10 will have typically
shrunk from their
pre-wetfelting size. For example, in particular embodiments, dryer balls 10
shrink from a
circumference of about 48 cm 5 cm (19 inches 2 inches) prior to wet
felting, to a
circumference of about 35.6 cm + 2.5 cm (14 inches + 1 inch) after wet
felting. In other
embodiments, dryer balls 10 shrink to a circumference of about 38 cm 2.5 cm
(15
inches 1 inch) after wet felting. After wet felting, dryer ball 10 should
still feel quite
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spongy and contain air pockets 12. It is important that dryer balls 10 are not
over-felted,
for example, by washing too long in the hot soapy water, or using too high a
temperature
for the water, so as to cause the wool to become compacted and overly dense.
Wet felting
a dryer ball 10 more than once may increase the density of the ball such that
the ball is no
longer as effective at reducing drying time. A dryer ball 10 need only be
sufficiently
felted so that the wool fibers in the ball are bonded together and the ball
keeps its shape
while tumbled in the dryer. The temperature of the hot water and duration of
the wash for
the wet felting stage may be controlled such that dryer balls 10 shrink to a
particular
circumference after wet felting, such as for example, a circumference of about
35.6 cm
(14 inches).
[0048] FIG. 5 illustrates a method 100 of manufacturing a dryer ball 10
according to an
embodiment of the invention. Method 100 begins by providing a piece of wool
material
at block 102. The piece is weighed at block 103 to ensure that it is the
desired weight. For
example, in particular embodiments, each piece should weigh about 57 g (2 oz).
[0049] At block 104, the piece is formed into a ball. One method for
implementing block
104 is described above with reference to FIGS. 2A to 2D. The formed ball is
optionally
measured at block 105 to ensure that it is of a desired circumference. A ball
that is too
tightly wrapped may be too dense to be effective in reducing drying time. In
some
embodiments, after it is formed at block 104 dryer ball 10 has a circumference
in the
range of 43 cm to 53 cm (17 inches to 21 inches). In particular embodiments,
the dryer
ball 10's circumference is about 48 cm (19 inches).
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[0050] Method 100 proceeds to block 106 by needle felting the ball where
needed (e.g. to
tuck in any loose fibers or fill in any visible openings in the ball). This
step is described
above with reference to FIG. 3. The step at block 106 is optional.
[0051] Method 100 then proceeds to the wet felting stage at block 108, by
placing the
ball in a bag and washing the ball while it is in the bag. This step is
described above with
reference to FIGS. 4A and 4B.
[0052] After wet felting, the ball is removed from the bag and allowed to air
dry at block
110. The drying stage may take about 24 hours. For quality control purposes,
the ball is
optionally measured at block 111 to ensure that it is of a desired
circumference. In some
embodiments, for a 57 g (2 oz) dryer ball, the ball should have a
circumference of about
35.6 cm (14 inches) after wet felting. The ball is optionally finished by
needle felting
where needed at block 112.
[0053] Three dryer balls 10 made according to the method described herein may
be
placed inside a clothes dryer to reduce drying time. The inventors have found
that,
depending on the characteristics of the dryer and clothes being dried, three
dryer balls 10
placed in the dryer during the drying cycle may reduce drying time by as much
as 30% to
50% as compared to drying the same load in the dryer without dryer balls 10.
Dryer balls
10 in some cases work best in reducing drying time for clothes made from
natural fibers,
such as cotton, rather than non-natural fibers (like acrylic or polyester or
polyester
blends).
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[0054] While some suppliers of conventional wool dryer balls advise using as
many as 6
to 12 or more dryer balls for each load of laundry, it has been found that due
to the
particular properties of dryer balls 10 according to embodiments described
herein,
placing three dryer balls 10 in the dryer may be generally sufficient to
reduce drying time
by a noticeable amount (e.g. for certain laundry loads and dryers, the
inventors have
observed a 30% or greater reduction in drying time by using three dryer balls
10).
[0055] Dryer balls 10 may shrink in size after many uses to a point where they
are no
longer effective at reducing drying time. It has been found by the inventors
that for
maintaining adequate performance of the dryer balls, each dryer ball 10 should
be
replaced with a new ball after a certain number of uses. For example, dryer
balls 10 made
from Merino wool according to the methods described herein should be replaced
after
100 uses.
[0056] Wool has a number of properties which make it suitable for use as a
material for
dryer balls 10. For example, wool is:
= hydrophilic and can absorb up to 30% of its own weight in moisture;
= resistant to static electricity;
= fire resistant;
= elastic (which keeps the dryer ball durable and helps the ball to retain
its shape);
= dirt resistant due to the small scales on the surface of the fiber which
hold the dirt near
the surface of the fiber;
= odor repellant; and
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= able to felt due to the small scales on the surface of the wool fiber as
well as other
factors such as the waviness or crimp of the wool fiber.
[0057] As will be appreciated upon reading this description, the apparatus and
methods
described herein provide a number of benefits. For example, dryer balls 10 can
reduce
electricity consumption by reducing drying time. Dryer balls 10 can help to
dry clothes
more evenly and more efficiently since dryer balls 10 separate the clothing,
and absorb
moisture and distribute heat around the dryer as facilitated by the
distribution of air
pockets 12 in dryer balls 10 and the low density of dryer balls 10. In
addition, dryer balls
may help to reduce static build-up in the clothes. Dryer balls 10 may help to
reduce
10 wrinkles in the clothes. Since dryer balls 10 are made of natural
materials, namely wool
fibers, they can be used by those who are sensitive to chemicals.
[0058] Dryer ball 10 can be made from one or more types of wool. For example,
as
discussed above, particular embodiments of dryer ball 10 are made from Merino
sheep
wool. Other types of sheep wool or a wool blend or wool from other animals
(e.g.
alpacas) may be selected to make dryer ball 10. The inventors have found that
the
effectiveness of dryer ball 10 may vary based on the properties of the wool
material that
is selected. For example, the fineness or coarseness of the wool fiber varies
between
different types of wool and can affect the absorbency and density of dryer
ball 10. In
general, finer wool (such as Merino, which has a fiber diameter of between 17-
24
microns) may be formed into less dense and more absorbent balls than as
compared with
relatively coarser wool (such as Corriedale, which has a fiber diameter of
between 25-33
microns). Some finer wools may also felt gradually and are better able to
retain their
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. .
shape in the dryer than other kinds of wool which have a greater tendency to
felt and to
shrink with use in the dryer. For example, dryer balls 10 made from Corriedale
wool
according to the methods described herein have been found by the inventors to
reduce
drying time, but typically do not have a useful lifespan as long as dryer
balls made from
Merino wool given the aforementioned differences in the wool properties
causing the
Corriedale wool balls to continue felting and shrinking after fewer uses in
the dryer.
[0059] While a number of exemplary aspects and embodiments have been discussed
above, those of skill in the art will recognize certain modifications,
permutations,
additions and sub-combinations thereof. It is therefore intended that the
scope of the
following appended claims and claims hereafter introduced should not be
limited by the
embodiments set forth in the examples, but should be given the broadest
interpretation
consistent with the description as a whole.
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