Note: Descriptions are shown in the official language in which they were submitted.
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CANDLE WITH CONTROLLED WICK PLACEMENT
[00011
TECHNICAL FIELD
[0002] This invention relates to the controlled placement of wicks in a candle
product.
The invention specifically relates to the placement of a candle wick a
sufficient distance
from the bottom of a candle product in order to create a product in which a
burning wick
will be extinguished by the molten solid fuel pool when the wick is expended.
By
quenching the burning wick with molten solid fuel, burn through of
freestanding candles
placed on a combustible surface is minimized. In a preferred embodiment of the
invention, this invention relates to a process for manufacturing a compression
molded
candle product having a contour in the bottom of the candle form that allows
for the
controlled placement and sealing of wicks in free-standing candles.
BACKGROUND OF THE INVENTION
[0003] Candles have become a very popular form of air freshening for the home
in
2o recent years. Candles are offered that appeal to the olfactory as well as
the visual sense,
and come in a variety of forms and shapes and combination of both decorative
and
fragrances. A popular form of candles offered are in the form of freestanding,
or pillar
candles.
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[0004] A common manufacturing practice for insertion of wicks on freestanding
candles is during the formation of the candle. Specifically, wicks are place
into die molds,
then a fuel source, such as paraffin wax is poured into the mold and allowed
to cool, or
prilled wax is poured into a mold and compressed to form a candle shape and a
wick is
then inserted. It is common practice that the bottom of the wick be in contact
with the
bottom of the candle shape. The result is a wick that extends the full length
of the candle.
[0005] The recent increase in candle sales also resulted in an increase of
accidents by
candle fires in consumer's home. A closer study of the cause of fires can be
attributed to
candles that are allowed to burn until the flames bum through bottom and cause
surface
damage from heat or worse combustion of near by flammables. More commonly,
freestanding candles can present fire issues when left unattended and allowed
to bum to
the bottom of the candle and thus cause surface damage or worse ignition of
near-by
combustibles, or become tipped over allowing the flame to extend beyond the
sidewall or
bottom of the candle resulting the same effect of ignition of near-by
combustibles.
[0006] Another manufacturing practice is to form a freestanding candles in
molds and
insert the wicks afterwards. The practice is to insert the wick and secure to
the candle
from the bottom, but has drawbacks and limitations. Wicks are inserted into
the candles
for positioning away from the bottom, there is no assurance of controlled
placement. To
be accurate, and to control the problems mentioned above, careful wick
placement is
required. If the bottom of the wick is placed too high in a candle, this will
limit the
enjoyment obtained by the consumer in burning the candle, and a large portion
of the
candle will be wasted. Conversely, if the bottom of the wick is placed too
close to the
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bottom of the candle bum through, and combustion of the surface on which the
candle is
placed can occur.
[0007] For purposes of commercial-scale manufacture, there can be an economic
advantage in utilizing a design to the bottom of a freestanding candle that
allows for the
controlled placement and securing of wicks by means of forming the candles in
molds.
[0008] The description of the present invention includes the advantages of
inserting
wicks to a specified depth from the bottom of the candle as a way to address
any issues of
bum through, as well as economic advantages to manufacturing by providing a
contour to
the candle which allows for the reclamation of scrap materials.
[0009] A fiu-ther advantage, with respect to the production of multilayer,
multicolored
candles is the ability to dispose of place scrap wax in the bottom cavity.
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THE INVENTION
[00010] Wright et al, U.S, patent application no 0010030195 describes the
dangers of
flash-over from candles allowed to bum to a shallow pool which can ignite if
the
temperature of the wax reaches its ignition points. Moreover, this invention
describes the
phenomenon associated with candles in metal containers.
[00011] Candle compositions comprised of mineral oil and various polymeric
additives
are known to develop the phenomenon of flashover due to the inherent nature of
these
compositions to build up heat in the melt pools which can reach the ignition
point.
Flashover can occur any time during the combustion of these compositions, so
placement
of the wicks away from the bottom can offer only limited benefits.
[00012] Candle compositions comprised of wax and respective additives and
molded
into the form of freestanding candles can only exhibit flashover when the
pools are
contaminated with objects intentionally, and when contained in some form of a
container.
A more common observation associated with freestanding candles is the loss of
sidewalls
from other means such as improper selection of wicks, or contamination of
pools.
BRIEF DESCRIPTION OF THE DRAWINGS
[00013] Fig. 1 shows a freestanding candle;
[00014] Fig. 2 is a bottom perspective view of the freestanding candle of this
invention
showing the bottom cavity;
[00015] Fig. 3 is a cutaway view of a freestanding candle showing the cavity
and wick
placement;
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[000161 Fig. 4 is a bottom perspective view of the free standing candle of
this invention
showing the bottom cavity filled with a fuel source, optionally scrap wax.
DETAILED DESCRIPTION OF TI3E DRAWINGS
[00017] Fig. 1 shows a freestanding candle 2 having horizontal top 4, sides 6
and
bottom 8. Axially disposed wick 10 runs the length of candle 2 from the top 4
to the
bottom 8. The top 4, sides 6, and bottom 8 define a candle shape which can be
prepared
by a variety of methods. Among the methods that can be used are the pouring of
molten
solid fuel, generally a paraffin or vegetable wax into a mold defining the
desired candle
shape, such mold optionally containing, placed therein a wick material of
suitable
construction which will burn with the desired properties. Optionally, the wick
10 may be
placed into the candle shape after it has been removed from the mold by
forming a wick
channel or cavity, and then inserting the wick. The wick should extend a flame
sustaining
distance, generally 1/ to 1 inch above the top 4 of candle 2 and more
preferably generally
at least 1/2 inch above the top of the bottom cavity.. Wicks longer than 1
inch may bend
over and create undesirable wax pools when the candle is burnt. Wicks shorter
than 1/4
inch are difficult to light, and are sometimes difficult to sustain a flame
since they can be
quenched by the capillary action of the solid fuel source, generally a
vegetable or paraffin
wax.
[00018] Another method of forming candles is by compression. In this method
prill or
powder is formed from the wax, inserted into the mold, and then the wax is
compressed in
the mold to form the candle shape. The shape is removed from the mold, a wick
cavity
created, and a wick inserted. The fuel for either poured or compression molded
candles
may contain colorants, volatile active ingredients such as fragrances, insect
control
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chemicals, sanitizers, deodorants, or the like. In addition the fuel may
contain
microcrystalline wax to provide improved candle properties, and C14 C20 fatty
acids to also
enhance the properties of the particular wax fuel employed. Sometimes
synthetic wax
crystal modifiers such as ethylene-alpha-olefin copolymers such as those sold
under the
trademark Vybar may be added to the mixture as well. It is not within the
scope of this
specification, or this invention to specify particular wax or fuel
formulations used for
candles, and the method of this invention will perform with any candle made in
accordance with the teachings herein. Likewise, it is not within the scope of
this
specification to discuss the choice of proper candle wicks, and those skilled
in the art of
candlemaking will readily appreciate the various wick materials that are
available for
particular uses. It is not important in the function of this invention that
the candle contain
a volatile active material, this invention having applicability to candles
providing light
only. Likewise, the invention is applicable to any candle shape, for example
the common
cylindrical shape, square shapes, parallelogram shapes, triangles, etc.. so
long as the candle
2 has a relatively flat surface for balancing on a surface without falling
over.
[00019] With specific reference to the drawings, this invention is directed to
a meltable
solid fuel candle 2 having a substantially horizontal top surface 4, a
substantially
horizontal bottom surface 8, one or more side surfaces 6 communicating with
the top 4 and
bottom 8 surfaces to define a shape, and one or more vertical wick cavities 40
running
substantially vertically from the top surface 4 to the bottom surface 8 of
said shape, each
vertical wick cavity 40 having disposed therein a combustible wick 10 having
an upper
wick end 11 and a lower wick end 9 to form the shaped candle 2, the upper wick
end 11
extending above the candle top surface a flame sustaining distance, and which
upper wick
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end when ignited can sustain a flame with the solid fuel, the flame generating
sufficient
heat to melt at least a portion of the solid fuel below the upper wick end to
form a pooi of
the molten solid fuel immediately below the upper wick end, and to cause the
molten solid
fuel to move up a portion of the wick 10 by capillary action to the upper wick
end 11 to be
consumed by the flame, the lower wick end 9 of each wick 10 being located
substantially
near the bottom horizontal surface of the candle 8, the improvement comprising
placing
the lower wick end 9 a flame extinguishing distance 22 above the bottom
horizontal
surface of the candle whereby the pool of molten solid fuel formed by the
flame heating
the solid fuel extinguishes the flame upon the consumption of each wick 10 and
prior to
any contact of the flame or the molten solid fuel with a surface communicating
with the
bottom surface.
[00020] With further reference to the drawings, Fig 2 shows a bottom
perspective view
of a candle 2 of this invention showing bottom cavity 20 of the invention.
Bottom cavity
has sides 22 and top 24 which define the cavity. Wick hole 26 extends through
top 24
15 into the cavity 20. Cavity 20 can be prepared by various means. It can be
molded into the
candle as it is poured, drilled out of a candle after pouring, or in
compression
manufacturing techniques, can be incorporated into either the bottom of the
compression
mold, or the ram which is utilized to compress the fuel source in the mold.
Bottom cavity
20 does not extend the entire width of the candle, leaving sides 6 and
shoulder 30 to
20 support the candle. The sides 22 of cavity 20 can extend from the bottom of
the candle
shoulde'r 30 to as high in the candle as it is desired to eventually
extinguish the flame on
wick 10. Normally, sides 22 should extend a minimum of about 1/ inch above the
bottom
of the candle.
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[00021] Fig. 3 shows a cross section view of candle 2. In this view the bottom
cavity
20 is shown along with sides 6, shoulder 30, cavity sides 22, and bottom
cavity top 24. In
this view, the wick cavity 40 is also shown. Wick cavity 40 shows a axially
disposed
vertically placed wick cavity adapted to receive an appropriate wick 10. In
practice, wick
10 would be placed within wick cavity 40 and extend about 1/4 to about 1 inch
above the
top 4 of candle 2. Likewise wick 10 would end at the top 24 of bottom cavity
20, or
slightly above top 24 where in practice it would be anchored with a molten wax
material.
The placement of wick 10 slightly above the top 24 of bottom cavity 20 helps
insure that
the flame when wick 10 is ignited will be extinguished with the wax pool
formed, and will
not be in a sufficient downward location to ignite a flammable surface onto
which free
standing candle 2 may be inadvertently placed. Wick 10 may be held in place by
a small
amount of molten fuel poured of the same or different composition as candle 2
provided
that the material used to anchor wick 10 should be compatible and adhere to
the material
used for candle 2. In a preferred practice, wick 10 is placed 1/8 th inch
below the surface
of the top 24 of cavity 20 which is 3/8 inch to give a total flame
extinguishing distance of
approximately 1/2 inch. In other words, the wick is slightly recessed into the
candle body
and does not extend into the cavity 20. This feature does not detract from the
utility of the
invention when the wick is flush with top 24 or even extends into cavity 20 so
long as the
wick is a flame extinguishing distance above the horizontal bottom 8 of the
candle. .When
a cavity is utilized, the wick should preferably extend substantially no
further than the top
surface of the bottom cavity.
[00022] Fig. 4 shows a bottom view of candle 2 showing bottom cavity 20,
bottom
cavity sides 22, bottom cavity top 24 and wick cavity 40. Also shown in dotted
line is
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wax fill 44 which is added to hold wick 10 in place and to provide a better
foundation
upon which candle 2 may rest, hopefully on a non-combustible surface. One of
the
surprising benefits of the flame extinguishing feature of this invention, is
that it provides
both economic and safety benefits.
[00023] Many times in the manufacture of candles different waxes are employed.
These waxes may contain different colorants or pigments, and thus, must be
carefully
sorted if they are to be reused, or the material, if commingled must be
disposed of as a
chemical waste. This is of special concern when the solid fuel being used
contains
different fragrance materials that may or may not be compatible to the
olfactory sense.
Previously, waste wax from broken or scrap candles was disposed of at great
economic
cost. If the solid fuel being comrningled contained different colorants, often
a gray or dark
unpleasing color would result if the scrap was melted down and reused. This
melted down
scrap was unsatisfactory for candle production since it did not provide proper
esthetics for
a commercially saleable product. We have found that when wax scrap is
collected and
melted, it may be used to fill the bottom cavity 20 to provide additional
support for candle
2 since the wax contained -in bottom cavity 20 is not consumed in the
combustion of the
candle. This scrap wax is thus contained in the candle and provides stability
and support
to the sides 4 and shoulder 30 of candle 2. The scrap wax may also help
maintain the wick
at a satisfactory location, preventing it from sliding down. When no sealing
wax is
utilized the wax placed into the cavity will help to maintain the wick in its
proper
location. We prefer to use sealing wax however to maintain the placement of
the
wick at a desired location.
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[00024] In the manufacture of candles by compression techniques, such as that
disclosed in my commonly assigned application filed of even date, the
compression candle
is molded upside down with a conipression ram, having the desired shape to
impart the
bottom cavity 20 incorporated into the ram. After conipression, the candle
shape is
removed from the mold, and still upside down, a wick of suitable material is
inserted.
This wick 10 is in the wick cavity 40, placed about 1/8 th inch beneath the
top 24 of candle
bottom 8. The wicks utilized may be of any conventional wick material
including but not
limited to cotton, cotton/paper, cotton/linen, or synthetic such as rayon. A
preferred wick
material is cotton with or without paper braid or a paper core.
[00025] In practice, we prefer iiot to use metallic wick clips as are commonly
used for
the support of wicks, in for instance votive candles because free standing
candles are often
placed upon stands having protrusions which engage the candle and steady the
candle.
Such protrusions would damage a wick clip, and hence, while this invention
will function,
we prefer not to use such devices. Another disadvantage of a conventional
metallic wick
clip in the practice of our invention is that the metal will conduct heat,
melting additional
wax, and perhaps causing the fuel around the wick clip to melt. This
additional melted
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wax may cause breakthrough of the wax to the bottom of the candle, exposing
molten wax
to the surface upon which the candle is to be placed.
[00026] The example presented below illustrates the preparation of a multiple
layered
compression molded candle product having the wick shut off feature, and the
scrap
disposal feature of the subject invention. As will be seen, while this
invention is
illustrated with a compression candle making technique, those skilled in the
art will readily
appreciate that the subject wick shut off invention will have applicability
with regard to
candles that are poured as well.
[00027] For each composition of a layer, a refined paraffin wax ( IGI Paraflex
1239 MP
60 C); is pre blended with an ethylene derived polymer (Vybar 103, MP 76 C)
until the
polymer is fully integrated into the refined paraffin wax. A fragrance/dye/UV
inhibitor
concentrate of IFF Stargazer 18 (available from International Flavors &
Fragrances),
Sandoplast Yellow 3G, Sandoplast Red 2G (both available from Clariant Gmbh,
Pigments
and Additives Division, Frankfurt) and Cyasorb UV 531 (available from Cytec
Industries,
Inc., West Patterson, New Jersey) is mixed until all components are dissolved.
[00028] The following four streams: wax/ polymer pre-blend and the
fragrance/dye/LTV
inhibitor concentrate, stearic acid (Emersol 150 MP 65.5 C available from
Henkel Corp.),
and microcrystalline wax (Bareco's Victory Lite Wax MP 80 C.) are metered
simultaneously to the formula (using a four stream metering system) and are
blended
through an in-line blending process.
[00029] Separately and simultaneously, additional compositions are prepared
using the
same method of mixing process. For the second layer, a refined paraffin wax
(IGI Paraflex
1239 MP 60 C); is pre blended with Vybar 103 until the polymer is fully
integrated into
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the refined paraffin wax. A fragrance/dye/UV inhibitor concentrate of IFF 1814
HBA,
Clariant Sandoplast yellow 3G and Cyasorb UV 531 is mixed until all components
are
dissolved. The wax/ polymer pre-blend and the fragrance/dye/UV inhibitor
concentrate are
further blended through an in-line blending process with the same stearic acid
and
microcrystalline wax used in layer mixture 1. A third layer using identical
ingredients,
except the fragrance/dye/UV inhibitor concentrate was IFF Moonblossom 47,
Clariant
Sandoplast Green 3G, Nitro Fast Blue 2B and Cyasorb UV 531 is mixed until all
components are dissolved. The wax/ polymer pre-blend and the fragrance/dye/LJV
inhibitor concentrate are further blended through an in-line blending process
as with the
other two layers.
[00030] The separate layer mixture-candle wax compositions are held at a
temperature
of approximately 65 to 80 C. usually 75-80 C, and preferably about 77 C and
pumped
separately to respective surge tanks until the ingredient mixtures are
homogenous. The
candle wax compositions are then pumped to their respective separate wax
reservoirs in
Kurschner wax spray drum system and the compositions are held at a temperature
of 65 to
80 C. The spray drums are set to a speed of approximately 42 meters/min. The
spray
room temperature is held to about 15 C. and the relative humidity of
approximately 50%,
although this temperature parameter may vary depending on the composition
being dried,
the humidity, the rate of spraying, and the temperature of the material_being
sprayed. The
candle wax composition for each layer is pumped through a spray manifold
system from
the spray drum reservoir and sprayed to 15 centimeters above the drum from
nozzles. The
wax is sprayed into the air and semi-solidifies before contacting the drum
surface. The
spray drum is held to a temperature between about 7 and 24 C. The prilled
wax is
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collected on the spray drum and them scraped from the drum and transferred
into a
vibrating conveyer that leads inside the drum for each of the compositions for
further
cooling. The prilled wax is collected at the end of the drum and vacuum fed
into holding
separate hoppers. For consistent cavity mold filling and compression for
multiple layers in
a single mold, the prilled waxes are maintained at temperatures between about
17 and 32
C.
[00031] The target dimension for the candle directly from the press is 7.60 cm
by
10.16 centimeters in dimension. For a pillar candle of this dimension, the
total weight is
about 366 grams and the weight for each layer is about 122 grams. It should be
noted that
the candles are made on the basis of volume and weights are given for the
purpose of
illustration only.
[00032] The prilled candle waxes above are transferred from the spray drum to
three
separate stationary hoppers and maintained at a temperature between 20 and 32
C. The
prilled waxes are transferred from the stationary hoppers to feed tube matrix
of the
Progressive Automation compression mold pillar candle press.
[00033] The feed tube matrix consists of 3 rows each containing 6 cavities
which are
filled with prilled wax for each layer. The feed tube matrix passes over the a
stationary
table of the press and fills one of the two sets of 6 cavity head units with a
volume of 122
grams from the feed tube matrix for a layer per candle, until the cavity is
filled with a total
of 366 grams of prilled wax, thus representing three distinct layers of
prilled wax
composition in a single candle. The table then rotates one of the 6 head
cavity units filled
with the three prilled wax compositions, 180 degrees to a compression station,
where the
prilled wax is compressed in the cavity from the top down, forming a contour
pocket of
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approximately 40 millimeters by 9.5 millimeters in dimension to the bottom of
the candle.
The prilled waxes are compressed to a force between 2400 and 2800 pounds, for
a dwell
time of approximately 1-5 seconds to produce a candle that is of a density of
between 0.83
and 0.92 grams/ cubic centimeter, at which time, the cavity molds are heated
through the
use of a water jacket, to a temperature of between 10 and 40 C.
[00034] The compressed candles are then extracted from the cavity molds, then
placed
onto a pocketed indexing conveyer system, bottom side up to allow for a
clearance space
for the top of the candle, and transferred to a Progressive Automation wicking
machine
where cotton wicks, with or without paper braids or paper cores having a
length of from
about 9 to about 11.5 cm. from Technical Braiding Gmbh are inserted into the
candles
from the bottom to allow the wicks to be placed flush to the upper portion of
the pocket
and to a total depth of lh inch from the bottom of the candle. While the
candles are
inverted with the bottom up, the wicked candles are dosed with approximately
0.2 to 0.5
grams of paraffin wax at a temperature between 65 and 85 C. to seal the
wicks in place.
While microcrystalline wax can be advantageously used in this step, it is
preferred to
utilize a material having the same properties employed in the bottom layer so
that the wax
material is compatible with, and has the same melting point as the main
structure. The
candle is then transferred onto a second station where the cavity is filled
with between 8
and 10 grams of candle wax that has been reclaimed from scrap candles, and at
a
temperature between about 60 and about 80 C. and generally about 60-70 C. This
temperature range is not critical, and molten paraffin of a higher or lower
temperature can
be used so long as the temperature is not high enough to damage the structure,
or dislodge
the wick. The candles that have been filled with wax into the bottom cavity
are then
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passed through cooling tunnel at a temperature of from about 13 to about 25 C
for a
period of approximately 12 to 20 minutes. In the practice of this invention it
is necessary
that the selected wick extend out of the top of the candle a flame sustaining
distance. In
practice this distance ranges from about 1/ inch to about 1 inch.
[00035] The resultant candles were esthetically pleasing, had satisfactory
burn
characteristics and emitted fragrance as they burned. When the candles of the
subject
invention were utilized the wick was extinguished by the molten wax pool. Over
a series
of candles that were tested, burn though was virtually eliminated.
