Note: Descriptions are shown in the official language in which they were submitted.
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ARTIFICIAL SNOW AND METHOD FOR MAKING SAME
Technical Field
[0001] This invention relates to artificial snow which may be
used,
for example, for seasonal decoration, to adorn sets for theater and
movie productions, and the like. The invention also relates to a method
for making artificial snow.
Background
[0002] Artificial snow is used for seasonal decoration of homes
and businesses as well as for standing-in for real snow in theater
productions, movie sets, and the like. Artificial snow may also be used
in the production of advertisements and other commercial artwork. A
good artificial snow resembles natural snow in texture. Where the
artificial snow will be dropped from above or blown to simulate falling
snow, it should drift in air relatively slowly in a manner that resembles
the falling of natural snow. Artificial snow should ideally drift and lie
on the ground in a way that closely resembles real snow.
[0003] Artificial snow is often displayed in places accessible to
children and other members of the public, for example, in seasonal
displays in businesses, homes and the like. The inventors have
determined that there is a problem with some materials which have been
used previously for artificial snow because these materials can be toxic,
if ingested, and can also disturb the environment. In addition, some
artificial snow products have yellowish tinges that can make them
unsuitable for use in film production.
[0004] The inventors have identified that there is a need for a
high-quality artificial snow which is environmentally benign and non-
toxic.
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Summary
[0005] Aspects of this invention provide artificial snow and
methods for making artificial snow. Embodiments of the artificial snow
are non-toxic, biodegradable, not charged with static electricity and/or
colored in any of a range of colors.
[0006] One aspect of the invention provides a non-toxic,
environmentally benign artificial snow comprising fine fragments of a
material extruded from a mixture comprising starch 80% to 90% by
volume; polyvinyl alcohol 10% to 15% by volume; talc 0% to 21/2 %
by volume; and colorant 0% to 5% by volume.
[0007] Another aspect of the invention provides a method for
making artificial snow. The method comprises extruding starch,
polyvinyl alcohol and talc to yield an extruded product; smashing the
extruded product into fragments; and sorting the fragments by size.
[0008] Further aspects of the invention and features of various
embodiments of the invention are set out below.
Brief Description of Drawings
[0009] In drawings which illustrate non-limiting embodiments of
the invention:
Figure 1 is a block diagram of a production line for artificial
snow according to an embodiment of the invention;
Figures 2A and 28 are respectively a partially schematic
elevation sectional view and a partially schematic plan sectional view of
a device for making artificial snow according to an embodiment of the
invention; and
Figure 3 is a cross-section through a bag for packaging artificial
snow.
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Description
[0010] The inventors have ascertained that a highly satisfactory
artificial snow product that is non-toxic and environmentally benign can
be made by combining the following ingredients (all percentages by
volume):
= starch 80% to 90% by volume;
= polyvinyl alcohol 10% to 15% by volume;
= talc 0% to 2 1/2 % by volume;
= hydrogenated soy flakes 0% to 2 1/2 % by volume; and
= colorant 0% to 5% by volume.
[0011] The starch may be provided in the form of vegetable starch
such as wheat starch, potato starch or corn starch.
[0012] The polyvinyl alcohol is preferably finely powdered.
[0013] The colorant, which is optional in some embodiments, may
be used to add a seasonal color to the artificial snow (for example, the
artificial snow may be made to be pink, blue, green or the like as well
as white). The colorant may also enhance the whiteness of the artificial
snow in some embodiments.
[0014] Figure 1 shows an example production line 10 for making
artificial snow according to one embodiment of the invention.
Production line 10 has a source of starch 11, polyvinyl alcohol 12, talc
13 and soy flakes 14. The soy flakes are optional and are not provided
in some embodiments. These materials are mixed, for example, in an
electric mixer 16, and fed into an extruder 18.
[0015] Water mixture 20 is added in extruder 18 to achieve
suitable extrusion of the starch mixture. In an example embodiment of
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the invention, the starch mixture is extruded with a water saturation of
up to 13% or 15%. In some examples, the extruded starch has a water
saturation in the range of 5% to 15%. In an example embodiment of the
invention, the extrusion is performed at a temperature in the range of
100 C to 200 C and 500 psi to 750 psi through a die.
[0016] The resulting extruded starch material has a crisp outer skin
and an internal cellular structure that is highly porous and irregular.
The extruded starch has a density of approximately 300 to 400 grams
per cubic foot (in some embodiments 340 to 380 grams per cubic foot).
In some embodiments, the extruded starch has the form of a somewhat
irregular cylindrical extrusion roughly 3/4 inch in diameter.
[0017] It is desirable to take steps to avoid the starch product
from
acquiring significant electrostatic charges from the time of extrusion.
Where the starch product is carried from one place to another by
entraining the starch product in a flow of air flow then the air flow
should preferably be maintained at a relatively low velocity to avoid
static buildup.
[0018] In some instances it is desirable to make colored artificial
snow. Colored artificial snow may be used to create special visual
images in theater or film productions. Colored artificial snow may also
be used for seasonal decorations of various kinds. For example, pink
or red snow could be used as part of Valentine's Day decorations; green
artificial snow may be used for St. Patrick's Day decorations; pink,
blue and yellow may be used for Easter-themed decorations; and so on.
[0019] Within a method for making artificial snow according to
the invention, it is possible to add a colorant 22 to cause the artificial
snow to be colored. Food coloring is a suitable non-toxic colorant. A
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extruder 18 during the extrusion process to cause the extruded starch product
to be
colored. The amount of food coloring or other colorant 22 added can be
selected to
achieve a desired intensity of color. The amount should not be so great as to
affect
adversely the texture and quality of the extruded starch product.
[0020] In some embodiments, the extruded starch product, as extruded, is
approximately 3/4 of an inch in diameter. The material is cut into small
pieces in a cutter
26. Cutter 26 may be integrated with extruder 18. The cut material is conveyed
to a
storage hopper 30 (this may be done by carrying the cut extruded material in a
stream
of air while avoiding excessive air flow velocities to reduce the buildup of
static
electricity). The extruded starch product is allowed to cool to ambient
temperature.
[0021] The extruded starch product is then processed to make artificial
snow. This
may be done by smashing the extruded products in smasher 32 and then sorting
the
resulting fragments by size in a size sorter 34. FIGS. 2A and 2B are views of
apparatus
40 that combines the functions of a smasher 32 and a size sorter 34.
[0022] In apparatus 40, the extruded starch product is dropped into
hopper 42.
The extruded starch product is allowed to fall past a blunt-edged blade 46 of
approximately 6 to 8 inches in diameter rotating at a speed in the range of,
for example,
6,000 to 10,000 rpm. Control arm 48 allows adjustments to be made of blade
rotation.
As the extruded starch pieces fall past the rotating blade 46 they are smashed
into
small fragments. The fragments fall through a screen 50. The size of the
apertures in
screen 50 may be selected depending upon how coarse or fine it is desired to
make the
artificial snow. Larger apertures result in coarser artificial snow flakes.
Smaller apertures
result in finer artificial snow flakes. The screen 50 may, for example, have
apertures
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extruder 18 during the extrusion process to cause the extruded starch product
to be
colored. The amount of food coloring or other colorant 22 added can be
selected to
achieve a desired intensity of color. The amount should not be so great as to
affect
adversely the texture and quality of the extruded starch product.
[0020] In some embodiments, the extruded starch product, as extruded, is
approximately 3/4 of an inch in diameter. The material is cut into small
pieces in a cutter
26. Cutter 26 may be integrated with extruder 18. The cut material is conveyed
to a
storage hopper 30 (this may be done by carrying the cut extruded material in a
stream
of air while avoiding excessive air flow velocities to reduce the buildup of
static
electricity). The extruded starch product is allowed to cool to ambient
temperature.
[0021] The extruded starch product is then processed to make artificial
snow. This
may be done by smashing the extruded products in smasher 32 and then sorting
the
resulting fragments by size in a size sorter 34. FIGS. 2A and 2B are views of
apparatus
40 that combines the functions of a smasher 32 and a size sorter 34.
[0022] In apparatus 40, the extruded starch product is dropped into
hopper 42.
The extruded starch product is allowed to fall past a blunt-edged blade 46 of
approximately 6 to 8 inches in diameter rotating at a speed in the range of,
for example,
6,000 to 10,000 rpm. Control arm 48 allows adjustments to be made of blade
rotation.
As the extruded starch pieces fall past the rotating blade 46 they are smashed
into
small fragments. The fragments fall through a screen 50. The size of the
apertures in
screen 50 may be selected depending upon how coarse or fine it is desired to
make the
artificial snow. Larger apertures result in coarser artificial snow flakes.
Smaller apertures
result in finer artificial snow flakes. The screen 50 may, for example, have
apertures
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presence of any surfaces that can acquire a static electric charge. The
conveyors and other apparatus in production line 10 are preferably
made of metal, wood, or other materials that do not tend to acquire
static charges. Metal components are preferably grounded. Air flows
are preferably kept at relatively low velocities relative to any entrained
artificial snow, extruded starch, or other artificial snow precursors to
minimize the buildup of static electricity in the artificial snow or its
precursors.
[0027] It has been found that a non-static artificial snow can be
made by taking steps to minimize the buildup of static electricity
throughout the processes described herein. Advantageously, preferred
embodiments of such artificial snow can be displayed in displays in a
way that appears natural and it can also fall, blow and move in air in a
manner very similar to the way that natural snow falls, blows and
moves in air.
[0028] Further, it is desirable to package artificial snow in
suitable
non-static bags. One type of bag suitable for packaging artificial snow
is shown in Figure 3. Bag 70 is a laminated bag having an outer layer
71 of protective polypropylene, an inner layer 72 of polyethylene, and
an anti-static layer 73 which is electrically conductive and dissipates any
static charges which might otherwise attempt to collect on the bag.
[0029] 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 all such modifications,
permutations, additions and sub-combinations be considered to be part
of this invention. Accordingly, the scope of the invention is to be
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construed in accordance with the substance defined by the following
claims.
