U.S. patent application number 13/656064 was filed with the patent office on 2013-05-02 for process for winding dental tape.
This patent application is currently assigned to McNeil-PPC, Inc.. The applicant listed for this patent is McNeil-PPC, Inc.. Invention is credited to Curt Binner, Harold Ochs.
Application Number | 20130104928 13/656064 |
Document ID | / |
Family ID | 41304029 |
Filed Date | 2013-05-02 |
United States Patent
Application |
20130104928 |
Kind Code |
A1 |
Ochs; Harold ; et
al. |
May 2, 2013 |
Process for Winding Dental Tape
Abstract
This present invention relates to a process for winding tape to
prevent or reduce telescoping of the tape (e.g., dental tape) as it
is wound onto a bobbin spool. Dispensers comprising such bobbins
are also discussed herein.
Inventors: |
Ochs; Harold; (Flemington,
NJ) ; Binner; Curt; (Furlong, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
McNeil-PPC, Inc.; |
Skillman |
NJ |
US |
|
|
Assignee: |
McNeil-PPC, Inc.
Skillman
NJ
|
Family ID: |
41304029 |
Appl. No.: |
13/656064 |
Filed: |
October 19, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12185354 |
Aug 4, 2008 |
8316865 |
|
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13656064 |
|
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61085305 |
Jul 31, 2008 |
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Current U.S.
Class: |
132/325 ;
242/413.9; 427/2.29 |
Current CPC
Class: |
B65H 49/205 20130101;
B65H 54/74 20130101; B65H 54/2812 20130101; B65H 55/04 20130101;
A61C 15/041 20130101; B65H 2701/319 20130101; A61C 15/043
20130101 |
Class at
Publication: |
132/325 ;
427/2.29; 242/413.9 |
International
Class: |
A61C 15/04 20060101
A61C015/04 |
Claims
1. A process for winding elastomeric tape, comprising the steps of:
a. providing a powered rewinding mechanism for rewinding the tape
onto a take-up spool having a core, the spool having a longitudinal
axis and a constant circumference C along the length of the
longitudinal axis, the rewinding mechanism comprising; i. a
traverse barrel cam providing a cam advance and ii. pulleys in
driving communication with and sequentially ordered from the
take-up spool to the traverse barrel cam such that the product of
the pulley ratios is a Ratio A, where; Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.z-1/P.sub.z
where Z is the number of pulleys used to drivingly connect the
traverse barrel cam to the take-up spool and P.sub.1 to P.sub.Z are
the sizes of the pulleys as sequentially ordered from the take-up
spool to the traverse barrel cam, the traverse barrel cam and the
pulley sizes selected such that the product of the cam advance and
Ratio A when divided by the circumference C produces a Ratio B,
where Ratio B=(cam advance.times.Ratio A)/Circumference C and where
Ratio B provides a Helix Angle .theta. of from about 3.5 degrees to
about 5 degrees, when determined by formula: sin.sup.-1(Helix Angle
.theta.)=Ratio B b. optionally, providing a sensing mechanism
coupled to the powered unwinding mechanism for maintaining the
speed of the tape such that the tension is less than 250
grams-force just prior to the rewinding of the tape onto the
take-up spool; and c. winding no more than 6 pounds of the
elastomeric tape onto the take-up spool.
2. A bobbin of elastomeric tape formed by winding onto a bobbin
spool the tape unwound from the take-up spool produced according to
the process of claim 1.
3. A process for coating and winding elastomeric tape, comprising
the steps of: a. providing a powered unwinding mechanism for
unwinding a spool of elastomeric tape having a first side and a
second side, the first side being opposite the second side; b.
providing a line speed for the tape of greater than about 1000 feet
per minute; c. providing a die coating mechanism comprising a
coating die adapted to receive or orientate the elastomeric tape
such that the first and second sides are at a vertical orientation
and comprising coating outlet ports for delivering coating to the
first and second sides of the elastomeric tape; d. providing a
powered rewinding mechanism for rewinding the tape onto a take-up
spool having a core, the spool having a longitudinal axis and a
constant circumference C along the length of the longitudinal axis,
the rewinding mechanism comprising; i. a traverse barrel cam
providing a cam advance and ii. pulleys in driving communication
with and sequentially ordered from the take-up spool to the
traverse barrel cam such that the product of the pulley ratios is a
Ratio A, where; Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.z-1/P.sub.z
where Z is the number of pulleys used to drivingly connect the
traverse barrel cam to the take-up spool and P.sub.1 to P.sub.Z are
the sizes of the pulleys as sequentially ordered from the take-up
spool to the traverse barrel cam, the traverse barrel cam and the
pulley sizes selected such that the product of the cam advance and
Ratio A when divided by the circumference C produces a Ratio B,
where Ratio B=(cam advance.times.Ratio A)/Circumference C and where
Ratio B provides a Helix Angle .theta. of from about 3.5 degrees to
about 5 degrees, when determined by formula: sin.sup.-1(Helix Angle
.theta.)=Ratio B e. optionally, providing a sensing mechanism
coupled to the powered unwinding mechanism for maintaining the
speed of the tape such that the tension is less than 250
grams-force just prior to the rewinding of the tape onto the
take-up spool; and f. winding no more than 6 pounds of the
elastomeric tape onto the take-up spool.
4. A bobbin of elastomeric tape formed by winding onto a bobbin
spool that tape unwound from the take-up spool produced according
to the process of claim 3.
5-10. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application is a utility application claiming
the benefit of the earlier filing date of U.S. patent application
61/085,305, filed Jul. 31, 2008, the entirety of which applications
are hereby incorporated as if fully set forth herein
FIELD OF THE INVENTION
[0002] This present invention relates to a process for winding tape
to prevent or reduce telescoping of the tape (e.g., dental tape) as
it is wound onto a bobbin spool. Dispensers comprising such bobbins
are also discussed herein.
BACKGROUND OF THE INVENTION
[0003] Dental floss has been in use for more than 100 years for
removing plaque and entrapped food particles from between teeth, as
well as providing a clean feeling in the mouth. The reduction of
bacteria in the mouth is important because bacteria can cause
cavities and gum disease. Dental flossing has been shown to remove
bacteria in the interproximal as well as in the subgingival regions
of the mouth.
[0004] The original floss consisted of twisted silk placed in a
jar. Since then, many improvements have been made to dental floss
to make flossing more convenient and less problematic. Most
improvements have been aimed at solving the negative aspects of
flossing. These include reducing fraying and breakage, providing
easier insertion between teeth and providing a softer, more gum and
hand friendly floss. Nylon, a high tenacity fray-resistant yarn,
was first used to replace the silk, providing more fray resistance.
The addition of wax to twisted multifilament yarn helped anchor
fibers together, while providing a lubricious coating for easier
insertion. Low friction monofilament PTFE yarn coated with wax
provides good ease of insertion, depending upon the thickness and
lack of twists or folds, as well as improved fray resistance.
Unfortunately, PTFE monofilaments do not clean well, nor do they
easily remove food particles from the space between teeth due to
the low coefficient of friction of PTFE.
[0005] Further improvements to flosses were made by providing
monofilament tapes made of elastomeric materials which neck down
when passing into the interdental space and then expand upon
relieving tension. Monofilament dental tapes made of elastomeric
materials have been found to be difficult to process. One problem
encountered with elastomeric dental tape products of the type
described is called "telescoping." In a roll of dental tape or
bobbin of dental tape which suffers from telescoping, successive
layers of the tape wound upon the core are displaced axially. Thus,
the bobbin of tape takes on a generally conical shape rather than
the cylindrical shape of a tape product not suffering from
telescoping. A bobbin of dental tape suffering from a severe case
of telescoping often cannot be mounted on or into a dispenser.
[0006] Telescoping may be the result of the elastomeric properties
of the material comprising the dental tape. Bobbins of elastomeric
tape formed under high tension from supply rolls are more likely to
suffer telescoping since the increased tension increases the stress
on the bobbin. High tension during the bobbin forming process
generally stems from high tape tension during the supply roll
forming process. High tension during the supply roll forming
process can result from non-uniformities in the velocity or tension
(i.e, accelerations and decelerations) on the tape as it is being
processed or from additional tape processing such as from the
coating process. During the coating process the tape is typically
stretched and relaxed as it moves through coating apparatuses, thus
further contributing to increased tension. Without being limited by
theory, the present inventers have discovered that by lowering the
tension at which the supply rolls are formed, the tension is
proportionately lowered during the bobbin forming process.
[0007] There is a continuing need for coated monofilament tapes
that do not have telescoping issues, as well as methods of
processing these dental tapes.
SUMMARY OF THE INVENTION
[0008] This present invention relates to a process for winding tape
to prevent or reduce telescoping of the tape as it is wound onto a
bobbin spool. Dispensers comprising such bobbins are also discussed
herein.
[0009] In one embodiment, the present invention relates to a
process for winding elastomeric tape, comprising the steps of:
[0010] a. providing a powered rewinding mechanism for rewinding the
tape onto a take-up spool having a core, the spool having a
longitudinal axis and a constant circumference C along the length
of the longitudinal axis, the rewinding mechanism comprising;
[0011] i. a traverse barrel cam providing a cam advance and [0012]
ii. pulleys in driving communication with and sequentially ordered
from the take-up spool to the traverse barrel cam such that the
product of the pulley ratios is a Ratio A, where;
[0012] Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.Z-1/P.sub.Z
where Z is the number of pulleys used to drivingly connect the
traverse barrel cam to the take-up spool and P.sub.1 to P.sub.Z are
the sizes of the pulleys as sequentially ordered from the take-up
spool to the traverse barrel cam, the traverse barrel cam and the
pulley sizes selected such that the product of the cam advance and
Ratio A when divided by the circumference C produces a Ratio B,
where
Ratio B=(cam advance.times.Ratio A)/Circumference C and where Ratio
B provides a Helix Angle .theta. of from about 3.5 degrees to about
5 degrees, when determined by formula:
sin.sup.-1(Helix Angle .theta.)=Ratio B [0013] b. optionally,
providing a sensing mechanism coupled to the powered unwinding
mechanism for maintaining the speed of the tape such that the
tension is less than 250 grams-force just prior to the rewinding of
the tape onto the take-up spool; and [0014] c. winding no more than
6 pounds of the elastomeric tape onto the take-up spool.
[0015] In another embodiment, the present invention relates to a
process for coating and winding elastomeric tape, comprising the
steps of: [0016] a. providing a powered unwinding mechanism for
unwinding a spool of elastomeric tape having a first side and a
second side, the first side being opposite the second side; [0017]
b. providing a line speed for the tape of greater than about 1000
feet per minute; [0018] c. providing a die coating mechanism
comprising a coating die adapted to receive or orientate the
elastomeric tape such that the first and second sides are at a
vertical orientation and comprising coating outlet ports for
delivering coating to the first and second sides of the elastomeric
tape; [0019] d. providing a powered rewinding mechanism for
rewinding the tape onto a take-up spool having a core, the spool
having a longitudinal axis and a constant circumference C along the
length of the longitudinal axis, the rewinding mechanism
comprising; [0020] i. a traverse barrel cam providing a cam advance
and [0021] ii. pulleys in driving communication with and
sequentially ordered from the take-up spool to the traverse barrel
cam such that the product of the pulley ratios is a Ratio A,
where;
[0021] Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.Z-i/P.sub.Z
where Z is the number of pulleys used to drivingly connect the
traverse barrel cam to the take-up spool and P.sub.1 to P.sub.Z are
the sizes of the pulleys as sequentially ordered from the take-up
spool to the traverse barrel cam, the traverse barrel cam and the
pulley sizes selected such that the product of the cam advance and
Ratio A when divided by the circumference C produces a Ratio B,
where
Ratio B=(cam advance.times.Ratio A)/Circumference C and where Ratio
B provides a Helix Angle .theta. of from about 3.5 degrees to about
5 degrees, when determined by formula:
sin.sup.-1(Helix Angle .theta.)=Ratio B [0022] e. optionally,
providing a sensing mechanism coupled to the powered unwinding
mechanism for maintaining the speed of the tape such that the
tension is less than 250 grams-force just prior to the rewinding of
the tape onto the take-up spool; and [0023] f. winding no more than
6 pounds of the elastomeric tape onto the take-up spool.
[0024] In a further embodiment, the present invention relates to a
bobbin of elastomeric tape, comprising: [0025] a. a spool having a
width; and [0026] b. an elastomeric yarn wound onto the spool such
that it forms a width, wherein the percent at which the width
formed by the elastomeric yarn exceeds the width of the spool by no
more than 10 percent of the width of the spool.
[0027] In a still further embodiment, the present invention relates
to a dental tape dispenser comprising [0028] a. a housing; [0029]
b. a bobbin movably connected within the housing, the bobbin
comprising: [0030] i. a spool having a width; and [0031] ii. an
elastomeric yarn wound onto the spool such that it forms a width,
wherein the percent at the which width formed by the elastomeric
yarn exceeds the width of the spool by no more than 10 percent of
the width of the spool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 is a schematic illustration of one embodiment of the
manufacturing line for unwinding, coating and rewinding the dental
tape of the present invention.
[0033] FIG. 2 is a schematic illustration of one embodiment of the
rewind mechanism of the present invention.
[0034] FIG. 3 is a perspective view of a roller coating die
according to an exemplary embodiment of the present invention.
[0035] FIG. 4 is an exploded perspective view of a roller coating
die according to an exemplary embodiment of the present
invention.
[0036] FIG. 5 is a perspective view showing movement of a
monofilament tape through entrance and exit blocks and rollers of a
roller coating die according to an exemplary embodiment of the
present invention.
[0037] FIG. 6 is a top plan view of a roller coating die according
to an exemplary embodiment of the present invention.
[0038] FIG. 7 is a cross-sectional view of a roller coating die
according to the exemplary embodiment of FIG. 6 along the plane
7-7.
[0039] FIG. 8 is a cross-sectional view of a roller assembly of a
coating die according to the exemplary embodiment of FIG. 6 along
the plane 8-8.
[0040] FIG. 9 is a bottom plan view of a coating die according to
an exemplary embodiment of the present invention.
[0041] FIG. 10 is a top plan view of an entrance block of a coating
die according to an exemplary embodiment of the present
invention.
[0042] FIG. 11 is a right side elevational view of an entrance
block of a coating die according to an exemplary embodiment of the
present invention.
[0043] FIG. 12 is a bottom plan view of an entrance block of a
coating die according to an exemplary embodiment of the present
invention.
[0044] FIG. 13 is a front elevational view of an entrance block of
a coating die according to an exemplary embodiment of the present
invention.
[0045] FIG. 14 is a cross-sectional view of an entrance block pool
and coating bores of a coating die according to the exemplary
embodiment of FIG. 10 along the plane 14-14.
[0046] FIG. 15 is a top plan view of an exit block of a coating die
according to an exemplary embodiment of the present invention.
[0047] FIG. 16 is a right side elevational view of an exit block of
a coating die according to an exemplary embodiment of the present
invention.
[0048] FIG. 17 is a bottom plan view of an exit block of a coating
die according to an exemplary embodiment of the present
invention.
[0049] FIG. 18 is a rear elevational view of an exit block of a
coating die according to an exemplary embodiment of the present
invention.
[0050] FIG. 19 is a 3 dimentional schematic illustration of one
embodiment of coated roll of dental tape showing the helix angle
.theta. formed by the strands of dental tape and the plane r.PHI.
perpendicular to the spool's longitudinal axis z.
[0051] FIG. 20 is a 2 dimentional schematic illustration of one
embodiment of coated roll of dental tape showing the helix angle
.theta. formed by the strands of dental tape and side r of plane
r.PHI. and the spacing between the individual strands of dental
tape in each layer of dental tape.
[0052] FIG. 21 is a perspective view of a bobbin spool core.
[0053] FIG. 22a is right side elevational view of a tape bobbin
with tape wound around the bobbin spool core.
[0054] FIG. 22b is a front elevational view of a tape bobbin with
tape wound around the bobbin spool core showing the bobbin spool
core width relative to the bobbin tape width.
[0055] FIG. 23a right side elevational view of a tape bobbin
movably positioned within a dispenser (phantom lined).
[0056] FIG. 23b is a front elevational view of a tape bobbin
movably positioned within a dispenser (phantom lined) depicting the
relative bobbin spool core, bobbin tape and dispenser widths.
DETAILED DESCRIPTION OF THE INVENTION
[0057] Dental tapes of the present invention are in the form of a
single monofilament. As used herein, the terms "tape", "yarn" and
floss are interchangeable. The tapes may be, for example, circular
or rectangular in cross-section with a smooth surface. A
monofilament tape in rectangular form typically has a width ranging
from about 1.0 mm to 2.0 mm, a thickness ranging from about 0.03 mm
to about 0.09 mm, and a denier ranging from about 600 to about
1800. In a specific example, a rectangular monofilament substrate
has a width of about 1.8 mm, a thickness of about 0.05 mm, and a
denier of about 940.
[0058] Alternatively, the monofilament dental tape of the present
invention maybe a high surface area tape or have a substantially
higher surface area than the tapes with smooth or non-textured
surfaces discussed above. A high surface area tape or a tape of a
substantially higher surface area is defined as a tape in which the
surface area is 15% (or about 15%), or optionally 20% (or about
20%), or optionally 25% (or about 25%) greater than the surface
area of a flat, smooth or non-textured tape of equivalent surface
dimensions of length, width and height. By "non-textured", it is
meant that the surface has no raised and depressed areas that (1)
are capable of being felt by a human hand and/or (2) form contours
that are discernible by a human eye without magnification. For
example, a millimeter of monofilament tape A of 1.8 mm wide and
0.05 mm thick has a surface area of 3.7 mm.sup.2. A millimeter of
tape B of the present invention would have the same monofilament
tape dimensions of 1.8 mm wide and 0.05 mm thick, but also has
surface protrusions and/or indentations (e.g., ribs) such that tape
B has a higher surface area than tape A. If there are 11 ribs added
onto each side of tape A and each rib is 0.04 mm high and 0.04 mm
wide, the surface area of the new tape (i.e., tape B) is increased
to 5.46 mm.sup.2 or 48%. These tapes have the capacity to anchor a
surface coating that may be required to provide the dental tape
with functions other than those of interdental cleaning, such as
flavoring, bactericide, abrasive, sensate, sialagogue, coloring,
aromatizing, therapeutical, etc., in relation to the same
characteristics of smooth monofilament tapes.
[0059] In one embodiment, dental tapes may comprise a core body
having a first external face and a second external face opposite
the first external face, wherein at least one of the first and
second external faces comprises a plurality of indentations
protruding into the core body of the dental tape. The indentations
may be provided in from about 5% to about 95% of the total area of
the at least one of the first and second external faces, and may
have a depth within the core body, in relation to the at least one
of the first and second external faces comprising the plurality of
indentations, corresponding to from about 0.1% to about 50% of the
thickness of the core body, taken transversally to the at least one
of the first and second external faces comprising the plurality of
indentations. Tapes such as these are disclosed in U.S. patent
application Ser. No. 12/026,839, which is incorporated by reference
herein.
[0060] In another embodiment, monofilament dental tapes according
to the present invention may comprise a core body having first and
second opposing cleaning surfaces, where at least one of the
cleaning surfaces comprise a plurality of ribs disposed along the
length thereof. As used herein, the term "rib" means a structural
element integral with and protruding from the core body of the
dental tape, which element has a configuration and dimension
effective to provide for removal of plaque and/or food debris from
interdental spaces of a mammal. Ribs may protrude substantially
perpendicularly from the core body of the dental tape or at an
angle. Tapes such as these are disclosed in U.S. patent application
Ser. No. 11/937,025, which is incorporated by reference herein.
[0061] In certain embodiments, the tape is made using an
elastomeric material. Elastomeric materials provide a high degree
of compressibility when extruded in the cross-sectional
configurations of this invention, allowing it to slip through the
tight spaces between teeth. Once in the cavity between teeth and
into the interdental space, the tape substantially recovers from
compression, providing cleaning surfaces that act as scrapers to
remove plaque and food particles from between the teeth.
Elastomeric materials that may be used to form the multi-ribbed
monofilament dental tape of the present invention include, but are
not limited to polyamide-polyether block copolymers sold under the
tradename PEBAX (Ato Chimie, Hauts-de-Seine France), such as PEBAX
7033, 5533 MX1205, 4033, 3533, and 2533; polyester-polyether block
copolymers and polyester-polyester block copolymers sold under the
tradename HYTREL (E. I. du Pont de Nemours & Co., Wilmington,
Del.), such as HYTREL 7246, 5556, and 4056; aliphatic thermoplastic
polyurethane elastomers sold under the tradename TECOFLEX (Lubrizol
Advanced Materials, Inc., Cleveland Ohio); aromatic thermoplastic
polyurethane elastomers sold under the tradename PELLETHANE (Dow
Chemical Co., Midland, Mich.); and thermoplastic polyolefin
elastomer sold under the name MULTI-FLEX (Dow Chemical Co.,
Midland, Mich.). A more detailed discussion regarding such
elastomeric materials and their use in manufacturing dental tape
can be found in U.S. Pat. No. 6,591,844 to Barlow et al. filed Aug.
23, 2001 and U.S. Pat. No. 6,029,678 to Tsao et al. filed Jan. 21,
1998, both of which are herein incorporated by reference in their
entirety.
[0062] The dental tape of the invention may also be made from a
substrate referred to as a pseudo-monofilament yarn.
Pseudo-monofilament tapes are made by extruding bicomponent fibers
typically having a core of one polymer and a sheath of a different
polymer, then either partially or totally melting the sheaths of
the fibers to bond or fuse the fibers, resulting in a monofilament
appearance and feel.
[0063] In preferred embodiments of the present invention, coatings
can be placed on the first and/or second cleaning surface of the
dental tape. Coating compositions for use in the present invention
must reliably adhere to the surface of elastomeric monofilament
dental tape as well as non-elastomeric tapes, whether the tape is a
monofilament or pseudo-monofilament yarn. By "reliably" as used
herein is meant that the coating composition must have sufficient
adherence to keep about 95%, optionally about 90%, optionally about
85% of the coating on the surface of the tape during coating,
winding, shipping and unwinding of the tape. By
"pseudo-monofilament" is meant tapes made by extruding multi-
and/or bi-component fibers typically comprising a core of one
polymer and a sheath of a different polymer and, then, either
partially or totally melting the sheaths of the fibers to bond
and/or fuse the fibers resulting in a monofilament appearance
and/or feel.
[0064] Suitable insoluble coatings include, but are not limited to,
microcrystalline wax, beeswax, paraffin waxes, low molecular weight
polyethylenes, silicone oils, essential oils, and mineral oil.
Typically, the insoluble wax coatings have melting temperatures
ranging from about 25.degree. C. to about 100.degree. C.,
optionally from about 35.degree. C. to about 80.degree. C. The
waxes may be combined with water insoluble colorants that are
FD&C approved for use in the mouth. Suitable colorants include,
but are not limited to, synthetically derived colorants such as
FD&C Blue #1 Lake, FD&C Blue #2 Lake, FD&C Red #40
Lake, Erythrosin Lake, Amaranth Lake, Ponceau 4R Lake, Carmoisosine
Lake, Carmine Lake and colorants generated by converting a
naturally derived dye to an aluminum or calcium based salt. Natural
colorants such as titanium dioxide and the like may also be
used.
[0065] The coating composition applied to the dental tape may be a
soluble coating, i.e., the coating is such that it tends to
dissolve or disperse in saliva present in the oral cavity. Such
soluble coatings include soluble waxes or the like, which include,
but are not limited to, low molecular weight polyethylene glycols
("PEGs"), such as PEG 1000 and PEG 1450. Combinations of higher
molecular weight PEGs and lower molecular weight PEGs, such as a
mixture of PEG 3350 and PEG 1000 may be used. Blends of liquid
PEG's with high molecular weight PEG's may also be used.
[0066] Other coatings include meltable surfactants such as
Polyoxamer 407; sialagogues; olfactory stimulants; sensates;
essential oils; actives, such as fluoride; cetyl pyridinim chloride
(CPC); tetra sodium pyrophosphate; whitening agents such as calcium
peroxide, hydrogen peroxide, carbamide peroxide and other peroxide
compounds capable of generating hydrogen peroxide in-situ;
antimicrobials; anti-virals and mixtures thereof.
[0067] Such ingredients may be employed as solids, liquids,
particles, gels, or the like, and may be encapsulated in
conventional polymeric materials by conventional encapsulation
techniques to form encapsulated materials having a polymeric shell
and a core comprising the ingredient in one of the noted forms, as
the case may be. Such ingredients also may be applied directly to
the dental tapes of the present invention without the need for a
coating carrier, where appropriate.
[0068] A coating comprising an insoluble wax may be applied,
wherein the coating contains encapsulated components such as spray
dried flavors, essential oils, or other ingredients protected and
released from soluble spheres within the insoluble wax, or a
soluble coating may be applied directly to the yarn or over the
insoluble coating. The soluble coating may contain ingredients that
are placed directly in the wax or through the use of spray dried or
other encapsulation technologies commonly practiced within the
art.
[0069] In certain embodiments, two insoluble coatings are applied
to the fiber substrate. In these embodiments, the second coating
composition should have a lower melting point than the first
coating composition.
[0070] A soluble coating can be used by itself or as a second
coating over an insoluble coating. One or both coatings can contain
colorants, flavors, sweeteners, abrasives, anti-tartar agents,
actives, such as fluoride salts, and like additives known in the
art.
[0071] Additional components can be added to coatings for various
benefits. These include flavor systems, such as spray dried
flavors, flavor enhancers, and sweeteners, such as sodium
saccharin. The amount of flavor added typically ranges from 10
percent to 25 percent, based on the total weight of the coating
composition. The amount of sweetener typically ranges from 0.1
percent to 1 percent, based on the total weight is of the coating
composition.
[0072] Other components can be added to coatings to assist in
cleaning the teeth. These include actives including abrasives such
as silica or di-calcium phosphate, and anti-tartar agents such as
tetra-sodium-pyrophosphate. Where two coatings are used, actives
are usually added in the second soluble coating to guarantee that a
high percentage of the active will be released from the floss
during use.
[0073] In formulating a coating, it is desirable to limit the
amount of solid additives in the coating composition below about
30% by weight. Coating a dental tape with a coating composition
having a solid additive content above this amount may cause
difficulty in achieving uniformity of coating and reduce the
ability of the coating to adhere to the tape surface. Coatings
containing high amounts of solid additives may tend to flake off
during processing and during use of the final product.
[0074] The dental tape coating may be anhydrous or hydrous. When
the coating is hydrous, the water is evaporated upon drying.
[0075] The coating may be applied as an add-on typically ranging
from about 10 percent to about 60 percent, optionally from about 20
percent to about 50 percent, based on the weight of the fiber
substrate.
[0076] In certain embodiments, the dental tape is manufactured
using equipment and processes capable of doing the following:
[0077] 1. Feeding monofilament tapes to the coating die at a
controlled speed and tension so as to avoid telescoping issues,
[0078] 2. Pumping the coating composition in a uniform fashion into
an application die, [0079] 3. Uniformly and simultaneously applying
the coating composition to both sides of the dental tape, and
[0080] 4. Providing a sufficient period of time during which the
coating composition is substantially undisturbed on the dental tape
until it is solidified intact.
[0081] By "uniform" or "substantially uniform," it is meant that,
when manually (without the aid of measuring instrumentation) or
visually (without the need for magnifying devices beyond corrective
eyewear) inspected, the coating should have an even (or relatively
[or, substantially] even) thickness and be free from (or
sufficiently [or substantially] free from) defects (such as
pinholes or voids) in the coated area. The above-mentioned process
for manufacturing the monofilament dental tape of the invention is
illustrated in FIG. 1. In the first step, the coating composition
5, typically a wax, is liquefied if necessary, as by heating, in a
mix tank 40. A high sheer mixer 42, such as a Rotostat High Sheer
Mixer Model #XPBL, made by Admix, can be used to keep coating
composition 5 homogeneous. Typically, a Rotosolver head blade is
used in the high sheer mixer 42 and is operated at, e.g., 1700
rpm.
[0082] The coating composition is then allowed to flow from mix
tank 40, via a first pipe 44 into a positive displacement pump 46
which, when driven at a given speed, delivers a constant amount of
coating, via a second pipe 48, to a coating die 50. The positive
displacement pump can be a vane type positive displacement pumps,
piston pumps, or similar type pumps. In certain embodiments, a Kerr
piston pump, supplied by Kerr Corp. Sulfur Ok., is used. Piston
pumps, generally, facilitate the evenness and uniformity of
coatings where the coating composition 5 contains solid
particulates such as abrasives. In certain embodiments, positive
displacement pumps are used since the passage bores, pipes,
channels or outlets used in such embodiments to deliver coating
composition 5 are generally positioned or oriented such that the
directional path or track of the passage bores, pipes, channels or
outlets points upwardly and toward or horizontally level with and
toward the position of the dental tape 10 to be coated such that
gravity has no effect or minimal effect on the flow of the coating
composition from mix tank 40 onto the dental tape 10.
[0083] In certain embodiments, the dental tape 10 is simultaneously
fed and pulled through the process by a combination of a powered
unwinding system 20 and a floss rewinding system 70. The dental
tape 10 is fed or unwound at a low tension and, in certain
embodiments, pulled perpendicularly from feed spool 22 across or
through sensing arm assembly 30. Sensing arm assembly 30 is
provided for monitoring the tension of the dental tape 10 as it
enters coating die 50. In certain embodiments, the sensing arm
assembly 30 has an arm 32, a pivot point 34, and rollers 36 over
which the dental tape 10 passes. Sensing arm assembly 30 is used to
maintain a substantially constant low feeding or unwinding tension
on dental tape 10 by adjusting the speed of power unwinding system
20 as it is simultaneously fed and pulled into the coating process
system. In certain embodiments, where the dental tape passes
through the coating process at line speed rates greater than about
1000 feet per minute (fpm), or optionally from about 1500 fpm to
about 2500 fpm, or optionally from about 2000 fpm, the constant low
unwinding tension is generally maintained at from about 50
grams-force to about 100, optionally at from about 60 grams-force
to about 100 grams-force, for dental tape 10 having denier of about
400 to about 1200.
[0084] After coating, dental tape 10 is collected on a take-up
spool 72. The speed at which take-up spool 72 operates is
controlled by an electronic controller system. The controller may
be a computer, a programmable logic controller or similar device.
In the embodiment shown in FIG. 1, a speed sensing roll 74 rides on
surface of the tape on take-up spool 72. Speed sensing roll 74
generates a signal which is fed to an electronic controller, such
as a Fenner M-drive. The controller controls the voltage of motor
80 (shown in FIG. 2) which drives the speed of take-up spool 72.
The use of the signal generated by speed sensing roll 74 in
controlling the speed of take-up spool 72 helps to maintain a
constant speed or velocity of the dental tape 10 through the
coating process, controlling and maintaining the tension on dental
tape 10 to less than 250 or (about 250) grams-force. The electronic
controller also controls the speed of positive displacement pump
46. Thus the velocity of dental tape 10 is maintained while a
constant amount of coating composition 5 is pumped into the coating
die 50.
[0085] In certain embodiments, not shown in FIG. 1, the coating die
50 contains at least two rollers around which dental tape 10 has at
least some wrap. In certain embodiments, the number of rollers can
range from 2, optionally 3, optionally 4 or greater rollers, or
optionally 2 to 7 rollers or, optionally, from 3 to 5 rollers.
Generally, dental tape 10 wraps around the rollers at from about
90.degree. to about 270.degree.. The rollers assist in applying
coating composition 5 to dental tape 10. Downstream of the rollers
there is typically a slot die region where coating composition 5 is
smoothed onto the surface of dental tape 10. In certain
embodiments, the slot die is in the form of a groove having
parallel sides or walls, the groove, optionally, having a radius at
its bottom for guiding the dental tape into a slot. In certain
embodiments, the slot is sized such that excess coating is removed
from dental tape 10 as it passes through the die (as shown at FIG.
8) while, at the same time, minimizing any additional tension on
dental tape 10 caused by the slot die as the tape 10 passes through
the die. As will be apparent to those skilled in the art, the
dimensions of the groove and slot will depend upon such factors as
the denier and type of dental tape 10 and the amount of coating
composition 5 being applied thereto.
[0086] In certain embodiments, a coating die useful in coating high
surface area dental tapes may be used. Such coating dies are
adapted to receive or orientate the dental tape 10 such that the
planar surface of the dental tape 10 is in a vertical position (or
oriented such that the width dimension of dental tape 10 is
perpendicular to horizontal plane of the coating die base) (as
described in FIG. 5). Without being limited by theory, it is
believed that such a vertical orientation better facilitates
evenness and uniformity of the coating across the sides of the
planar surface of the dental tape 10 than does movement of a
horizontally oriented tape through the coating die.
[0087] One embodiment of a coating die useful in coating high
surface area dental tapes is shown in FIGS. 3 to 18. FIG. 3 is a
perspective view of roller coating die 110, including roller die
base 120 and cover plate 140. Uncoated dental tape 250 enters
coating die 110 such that the planar surface of the dental tape 250
is vertically oriented or oriented such that its width dimension of
dental tape 250 is perpendicular to roller die base 120. Dental
tape 250 traverses vertically along cover plate die slot 144 and
roller assemblies 200, and exits as vertically oriented, coated
dental tape 252. FIG. 3 shows three sections of cover plate slot
144. Slot 144a traverses from the die entrance to entrance block
window 142. Slot 144b traverses from entrance block window 142 to
roller assemblies 200. Slot 144c traverses from roller assemblies
200 to the die exit.
[0088] Optionally, heaters can be incorporated into or associated
with the coating dies of the present invention. The heaters are
used to provide temperatures sufficient to keep the coating
composition, typically a waxy material, flowable or in a liquid
state. Such temperatures typically range from 180.degree. F. to
about 200.degree. F. FIG. 3 shows an exemplary embodiment of the
present invention having two cartridge heaters 134, which can be
used for heating the rollers and/or other components of coating die
50.
[0089] FIG. 4 is an exploded perspective view of roller coating die
110, showing more details of roller die base 120 and cover plate
140. In addition to the three sections of cover plate slot 144 and
cover plate window 142, five roller wheel windows 146, and four
cover plate attachment holes 152 are shown on cover plate 140.
Cover plate attachment holes 152 align with roller die base
attachment holes 132. Roller die base attachment holes 132 are
threaded. Threaded handle 154 is used to hold together roller die
base 120 and cover plate 140.
[0090] Roller die base 120 includes entrance block recess 122,
roller assembly recesses 126, exit block recess 128, roller die
base attachment holes 132, and entrance and exit block attachment
holes 136. FIG. 4 shows two sections of base slot 124. Base slot
124a traverses from entrance block recess 122 to roller assembly
recesses 126. Slot 124b traverses from roller assembly recesses 126
to exit block recess 128. Entrance and exit block attachment holes
136 are threaded.
[0091] FIG. 4 also shows entrance block 160, exit block 180, as
well as five rollers 202. Entrance block 160 and exit block 180 are
positioned between roller die base 120 and cover plate 140, and are
used to guide uncoated dental tape 250 from the entrance of coating
die 110 to roller assemblies 200, and coated dental tape 252 from
roller assemblies 200 to the exit of coating die 110.
[0092] FIG. 5 is a perspective view showing details of how roller
coating die 110 transforms uncoated dental tape 250 to coated
dental tape 252. FIG. 5 shows uncoated dental tape 250 proceeding
into entrance block 160 at a vertical orientation and travelling
along and between the walls (or opposite sides) of entrance block
slot 162. Entrance block slot 162 is sized wide enough to produce
minimal tension on the vertically oriented, uncoated dental tape
250, but narrow enough that gravity does not cause the lower
portion of the uncoated dental tape 250 to receive more coating
than the upper portion of the uncoated tape 250. Coating travels
vertically through base passage hole 138 to entrance block pool
172, and splits into two coating bores (or passages) 174. In one
embodiment, uncoated dental tape 250 is coated simultaneously on
both sides as it passes coating bores 174. Coated dental tape 252
then passes around rollers 202 with at least some wrap while
maintained in its vertical orientation. Generally, coated dental
tape 252 wraps around the rollers at from 90.degree. to
270.degree.. Rollers 202 assist in uniformly applying coating
composition to coated dental tape 252. Though FIG. 5 shows five
rollers, it is understood that coated dental tape 252 may pass
around as few as one roller, or as many as about twenty or more
rollers. Downstream of rollers 202 is exit block 180. Coated dental
tape 252 proceeds into exit block 180 still vertically oriented and
travels along exit block slot 182 which aid in maintaining the
vertical orientation of dental tape 252. As mentioned above, the
width 182a of exit block slot 182 is sized to provide coating
composition 5 an additional opportunity to be smoothed onto the
surface of coated dental tape 252 and also removes excess coating
composition 5 while at the same time minimizing any additional
tension caused by movement of dental tape 252 through exit block
180.
[0093] Note that all slots discussed above, including cover plate
slots (144a, 144b, 144c), base slots (124a, 124b), entrance block
slot 162, and exit block slot 182 may be in the form of a groove
having parallel sides or walls, the groove optionally having a
radius at its bottom. As will be apparent to those skilled in the
art, the dimensions of the groove will depend upon such factors as
the denier and type of uncoated dental tape 250 and the amount of
coating composition being applied thereto.
[0094] FIG. 6 is a top view of an embodiment of coating die 110
showing details of the cover plate 140 and the monofilament coating
path. FIG. 6 shows uncoated dental tape 250 proceeding into
entrance block 160 where it is coated. Coated dental tape 252
proceeds around roller assemblies 200 to exit block 180 and out of
a coating die 110. Entrance block 160 is partially hidden by cover
plate 140, but is visible through cover plate window 142. Roller
assemblies 200 can be seen through roller wheel windows 146. Exit
block 180 is hidden by cover plate 140, but coated dental tape 252
is visible through cover plate slot 144c. FIG. 6 also shows
threaded handle 154, which are used to hold cover plate 140 to
roller die base 120, as well as alignment holes 156 to align cover
plate 140 to roller die base 120 prior to attaching the two.
[0095] FIG. 7 is a cross-sectional view of the coat die 110
embodiment of FIG. 6 along plane 7-7. FIG. 7 shows uncoated dental
tape 250 proceeding into entrance block 160. Coating travels
vertically from second pipe 48 (or coating dispensing pipe
receiving coating from displacement pump 46) through base hole 138
to entrance block pool 172, and splits into two coating bores 174
(FIG. 7 shows one of the two bores). In one embodiment, uncoated
dental tape 250 is coated simultaneously on both sides as it passes
coating bores 174. FIG. 7 also shows coated dental tape 252
travelling through exit block 180 and out of a coating die 110.
Threaded handles 154, which are used to hold cover plate 140 to
roller die base 120, as well as cartridge heaters 134, which can be
used if needed to keep coating composition, in a liquid state, are
also shown in the figure.
[0096] FIG. 8 is a cross-sectional view of the embodiment of FIG. 6
along plane 8-8. FIG. 8 shows cover plate 140, roller die base 120,
cartridge heaters 134, as well as detailed view of roller assembly
200. Roller assembly 200 includes roller 202 which assist in
uniformly applying coating composition to coated dental tape 252.
In certain embodiments, one end of stub shaft 210 is disposed in
center of roller 202, and attached to roller 202 by cap screw 204,
flat washer 206, and lock washer 208. The central portion of stub
shaft 210 is disposed in inner ring shield bearing 212. The
opposing end of stub shaft 210 is disposed in bearing retainer 220,
and attached to bearing retainer 220 by cap screw 204, flat washer
206, and lock washer 208. Bearing retainer 220 is attached to
roller die base 120 by bearing retainer cap screw 222 and bearing
retainer lock washer 224. In one embodiment, three sets of cap
screws 222 and lock washers 224 are used to attach bearing retainer
220 to roller die base 120. However, one skilled in the art could
use more or less screws to attach the two, or other means of
attachment known in the art. Finally, inner ring shield bearing 212
is kept approximately centered in roller assembly recess 126 and
roller wheel window 146, by outer race spacer 214.
[0097] FIG. 9 is a bottom view of an embodiment of a roller coating
die of the present invention. The FIG. 9 shows five roller
assemblies 200, base hole 138, cartridge heaters 134, and alignment
holes 156 on roller die base 120. An O-ring 139, is used to prevent
leakage of coating composition between positive displacement pump
and roller die base 120. Alignment holes 156 are used to align
cover plate 140 to roller die base 120 prior to attaching the
two.
[0098] FIGS. 10 through 14 show details of entrance block 160. The
FIG. 10 shows entrance block slot 162 and entrance block slot guide
164. Entrance block slot guide 164 is a V-shaped or tapered cut in
entrance block 160 to guide uncoated dental tape 250 into entrance
block slot 162. The entrance block slot 162 is sized at a width
162a such that it maintains the vertical orientation of uncoated
dental tape 250 through the entrance block 160, as well as
facilitate coating as mentioned above, with little to no additional
tension on the dental tape 250. Uncoated dental tape 250 travels
along entrance block slot 162 to where it is coated. Coating
travels vertically from entrance block pool 172 into two coating
bores 174. Uncoated dental tape 250 is coated simultaneously on
both sides as it passes coating bores 174. FIGS. 10 to 12 show two
optional entrance block holes 166 which may be used to attach
entrance block 160 to roller die base 120.
[0099] FIGS. 15 through 18 show details of exit block 180. FIG. 15
shows exit block slot 182 and entrance block slot guide 184.
Entrance block slot guide 184 is a V-shaped cut in exit block 180
to guide coated dental tape 252 into exit block slot 182. Exit
block slot 182 allows coating composition an additional opportunity
to be smoothed onto the surface of coated dental tape 252. The
width 182a of exit block slot 182 is sized to provide coating
composition 5 an additional opportunity to be smoothed onto the
surface of coated dental tape 252 and also removes excess coating
composition 5 while at the same time minimizing any additional
tension caused by movement of dental tape 252 through exit block
180. Coated dental tape 252 travels along exit block slot 182 until
it leaves roller coating die 110. FIGS. 15 to 17 show two optional
exit block holes 186 which may be used to attach exit block 180 to
roller die base 120.
[0100] While illustrated as separate components, it will be readily
understood by the skilled artisan that entrance block 160 and exit
block 180 (along with their distinct structural characteristics)
can be integral with roller die base 120 and/or cover plate 140
without changing the performance or function of coating die 110.
Maintaining entrance block 160 and exit block 180 as separate
components. however, provides the convenience of
interchangeability. For example, separate entrance block 160 and
exit block 180 components allow for the interchange of entrance
block 160 and/or exit block 180 with entrance and exit blocks of
differing slot (162, 182) and slot guide (164 and 184) widths.
[0101] Coating composition 5 once applied to dental tape 10 must be
solidified. Solidification can be accomplished by having a cooling
area 60. Cooling area 60 can be an open area where coating 5 cools
under ambient conditions. Alternatively, cooling area 60 can be a
chamber where refrigerated or room air is blown over dental tape 10
to increase the rate of cooling. In order to avoid undesirable
discontinuities in coating 5, dental tape 10 should not contact any
surfaces until coating 5 has solidified.
[0102] Once coating 5 is cooled sufficiently to prevent any
disruption of the outer surface, it is rewound on floss rewinding
system 70. Rewinding system 70, shown in FIG. 2, has take-up spool
72 and speed sensing roll 74 as described before, as well as a
drive motor 80, a series of timing belts (all labeled 84) and
timing belt pulleys (all labeled 82), and a traversing cam guide 76
disposed on a traverse barrel cam 86. For 6 pound rolls or less,
optionally 5 pounds or less, or optionally 4 pounds of less of
dental tape rolled onto spool 72, the tension of the dental tape 10
is monitored using conventional tension measuring devices (such as
Checkline, supplied by Electromatic Equipment Co., Cedarhurst,
N.Y.) prior to rewinding and the speed adjusted accordingly such
that the tension of the dental tape 10 during rewinding process is
less than 300 (or about 300) grams-force, optionally less than 250,
(or about 250) grams-force or optionally from about 190 grams-force
to about 200 grams-force. Traversing cam guide 76 and traverse
barrel cam 86 are disposed in a traversing cam guide housing 78
which has a traversing cam guide housing slot 79.
[0103] Rewinding system 70 is a traversing rewinder in that as
take-up spool 72 rotates, traversing cam guide 76 is traversed back
and forth along its length (see FIG. 2). The take-up spool 72 has a
longitudinal axis z; a plane r.PHI. which is perpendicular to
longitudinal axis z. and a circumference C (equal to the product of
the spool core diameter d.sub.s and .pi.) as shown in FIG. 19.
Rewinding system 70 functions as follows: spindle 81 of motor 80
rotates to drive timing belt pulley 82a, which, through timing belt
84a, drives timing belt pulleys 82b and 82c. Timing belt pulley 82b
drives timing belt pulley 82d, which, in turn, drives timing belt
pulley 82e via timing belt 84b. Timing belt pulley 82e is disposed
on the end of take-up spool 72, so as it rotates, take-up spool 72
rotates. Timing belt pulley 82c, via timing belt 84c, drives timing
belt pulleys 82f and 82g. Timing belt pulley 82g drives timing belt
pulley 82h via timing belt 84d. Timing belt pulley 82h is disposed
on the end of traverse barrel cam 86, so as pulley 82h rotates,
traverse barrel cam 86 rotates. Traversing cam guide 76 is disposed
on traverse barrel cam 86 such that when traverse barrel cam 86
rotates, traversing cam guide 76 traverses back and forth along its
length. Suitable traversing rewinders can be readily built or
purchased from companies such as Leesona Corporation.
[0104] In certain embodiments, the pulley sizes and traverse barrel
cam are selected for the rewinding system as described below:
[0105] a.) the pulleys are selected (or adjusted) such that the
product of the pulley ratios or Ratio A (which determines the
traversing movement of traversing cam guide (inches) per revolution
of Spool 72 (inches)) is as follows:
[0105] Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.Z-1/P.sub.Z
Where P.sub.1 through P.sub.Z are the pulley sizes of the
sequentially ordered pulleys from the pulley rotating the take-up
spool 72 or P.sub.1 to the pulley rotating traverse barrel cam 86
or P.sub.Z used in association with [0106] b.) the traverse barrel
cam 86, which is selected such that the product of the cam advance
(or, total length [end to end] traversed by traversing cam guide 76
divided by the turns of the traverse barrel cam 86 needed to
achieve the total traverse of traversing cam guide 76) and Ratio A
when divided by the circumference C of the core of take-up spool 72
(i.e., take-up spool 72 without tape 10) produces a Ratio B,
where
[0106] Ratio B=(cam advance.times.Ratio A)/Circumference C and
where Ratio B provides a helix angle .theta. of from about 3.5
degrees to about 5 degrees, where the helix angle .theta. is formed
by a strand of dental tape and plane r.PHI. of the spool 72 which
is perpendicular to the longitudinal axis z of the spool 72 as
shown in FIGS. 19 and 20 and is determined by formula:
sin.sup.-1(Helix Angle .theta.)=Ratio B
[0107] Without being limited by theory, it is believed that
obtaining a helix angle .theta. of about 3.5 degrees to about 5.5
degrees provides take-up spool rolls 72 of dental tape 10 such
that: [0108] i) in any given layer of the dental tape, the strands
of dental tape 10 forming that layer do not overlap, or,
optionally, do not touch or, optionally, have a space there between
t.sub.s of up to 1/32 (or about 1/32) of an inch and [0109] ii.)
the strands of dental tape 10 forming each layer of dental tape 10
overlap with the strands of dental tape 10 forming the preceding
layer of dental tape 10 to form intersection angles of about 7 to
about 11 degrees (or twice the helix angle .theta.)
[0110] If it is desired to apply a second coating to dental tape
10, this may be done by locating another coating line and cooling
chamber downstream of cooling area 60.
[0111] In certain embodiments, spool 72 dental tape 10 is then
removed for later processing into bobbins 90. Bobbins of tape as
shown in FIGS. 22a and 22b are formed from dental tape 10 unwound
from spool 72 onto bobbin spool cores 92 of selected width w.sub.c
as shown in FIG. 21 and packaged into dispensers 95 of selected
width w.sub.d for use by consumers as shown in FIGS. 23a and 23b.
In certain embodiments, the bobbin spool cores 92 have an aspect
ratio of greater than about 2:1, optionally about 3:1, where the
aspect ratio is the ratio of bobbin spool diameter to width. The
dental tape 10 winds from spool 72 onto the bobbin spool cores 92
to form tape bobbins where the wound tape widths w.sub.b such that
wound tape width w.sub.b exceeds the width of the bobbin spool core
w.sub.c by no more that 10% (or about 10%), optionally, 5% (or
about 5%), optionally 2.5% (or about 2.5%), optionally 1% (or about
1%). Hence, the inventive rewinding system 70 which produces helix
angles .theta. of from about 3.5 degrees to about 5.5 degrees
ensures that the wound tape widths w.sub.b of the finished tape
bobbins formed from spool 72 do not telescope so as to interfere
with the packaging of the finished tape bobbin into dispensers 95
specifically designed to movably accommodate bobbin spool cores 92
of widths w.sub.c. More generally, the inventive rewinding system
70 permits the use of narrower width dispensers particularly in
cases where the tape or floss is made of an elastomeric
material.
[0112] Several examples of the present invention are set forth
below to further illustrate the nature of the invention and the
manner of carrying it out. However, the invention should not be
considered as being limited to the details thereof.
[0113] In the following Examples, the mentioned percentages are
weight percentages.
Example 1
[0114] Dental tape spool rolls were formed in accordance with the
coating and winding processes of the present invention and using
the component sizes and/or type described below and summarized in
Table I.
TABLE-US-00001 TABLE I Component Type/Size Pulley 82e 14 Teeth
Pulley 82d 17 Teeth Pulley 82c 19 Teeth Pulley 82f 14 Teeth Pulley
82g 16 Teeth Pulley 82h 20 Teeth Traversing Cam 11.5 inches, 6
Guide Traverse turns end to end cam
[0115] Ordering the above pulley sizes sequentially (e.g., 82e is
connected to 82d which is connected 82c etc. as shown in FIG. 2)
and determining the product of the ratios of the sizes of the
sequentially ordered pulleys or Ratio A (as shown in I below)
Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.Z-1/P.sub.Z
I
Where P.sub.1 to P.sub.Z are the sizes of the pulleys sequentially
ordered from spool 72 and to the traverse barrel cam 86 of
rewinding system 70, results in the following ratio:
Ratio A=(Pulley 82e/Pulley 82d).times.(Pulley 82c/Pulley
82f).times.(Pulley 82g/Pulley
82h)=(14/17).times.(19/14).times.(16/20)=0.8941
[0116] A traverse barrel cam was selected to provide a traversing
cam guide traverse of 11.5 inches end to end for every 6
revolutions of spool 72. This results in a cam advance equal to the
following:
Cam Advance=Cam Guide Traverse/6 Revolutions of Traverse Barrel
Cam=11.5/6=1.9166 inches per Traverse Barrel Cam revolution
[0117] Ratio A indicates that for each revolution of the spool 72,
the traverse barrel cam 86 travels 0.8941 of the spool revolution.
This results in the following travel distance for the traversing
cam guide 76 per revolution of spool 72:
Travel Distance of traversing cam guide per revolution of spool=Cam
Pulley Ratio.times.Cam Advance=0.8941.times.1.9166=1.71 inches per
spool revolution
[0118] The core diameter d.sub.s of spool 72 was measured to be
6.21 inches, therefore, the distance traveled by any point on the
outer surface of the core of spool 72 after one revolution of spool
72 or circumference C can be calculated as follows:
Circumference C=6.21 inches.times..pi.=(6.21)3.1411=19.5 inches
[0119] The helix angle .theta. (the angle formed by a strand of
dental tape and plane r.PHI. of the spool which is perpendicular to
the longitudinal axis z of the spool as shown in FIG. 19) formed by
dental tape 10 as it is initially wound around the core of spool 72
can then be calculated as follows:
Travel Distance of traversing cam guide per spool
revolution/Circumference C=1.71/19.5
1.71/19.5=0.0876=sin.sup.-1.theta.(Helix Angle)
Where Helix Angle .theta.=5.03.degree.
[0120] As will be understood by the skilled artisan, as the spool
72 roll grows, the helix angle decreases. For example, as one inch
of dental tape is wound onto the core of spool 72, helix angle
.theta. decreases. This is exemplified as follows:
[0121] The diameter of spool after adding one inch layer of
tape=6.21 inches+2 inches (1 inch added layer results in diameter
increasing by 2 inches)=8.21 inches, hence:
Circumference of Spool with Tape=diameter of spool with
tape.times..pi.=(8.21)3.1411=25.7 inches
Travel distance of traversing cam guide per spool
revolution/Circumference of Spool with Tape=1.71/25.7
inches=0.066=sin-1.theta.'(Helix Angle)
[0122] Where Helix Angle .theta.'=3.8.degree.
[0123] Hence, as about an inch of material is wound around the
spool, the helix angle chances by about 1.degree.
(.theta.-.theta.'=5.03.degree.-3.8.degree.=1.5.degree.).
[0124] Using the above traverse barrel cam and pulley sizes, Rolls
1-7 (representative of spool 72 in FIG. 1) were formed and, then,
Rolls 1-7 were subsequently used to form separate tape bobbins
(representative bobbins formed on bobbin spool 90 in FIG. 1). The
parameters of the formed rolls and coating and rewinding process
are summarized in Tables II and III.
TABLE-US-00002 TABLE II (Wax Coating Formulation) Amount Ingredient
(%) Microcrystaline Wax.sup.1 82% Flavor 17% Sodium Saccharin 1%
.sup.1Multiwax-W445, supplied by Crompton Corp. Petrolia, Pa
TABLE-US-00003 TABLE III Process Parameters Roll 1 Roll 2 Roll 3
Roll 4 Roll 5 Roll 6 Roll 7 Line Speed (feet 1600 1600 1600 1600
1600 1600 1600 per min.) Tape Tension prior 190 190 200 205 205 200
210 to rewinding on rolls (grams-force) Tank Temp .degree. F. 200
200 200 200 200 200 200 Die Temp .degree. F. 200 200 200 200 200
200 200 Tape (yarn) Start Wt 3738 2907 3994 2998 2257 3804 2977
(grams). Tape (yarn) Finish 2907 2079 2998 2257 1364 2977 2131 Wt
(grams). Tape (yarn) Wt. 831 828 996 741 893 827 846 (grams) Coated
Tape and 2578 2661 2704 2637 2654 2704 2630 Core (grams) Core Tare
(grams) 1398 1462 1309 1367 1357 1474 1370 Coated Tape Wt. 1180
1199 1395 1270 1297 1230 1260 (grams) Wax Added.sup.1 (grams) 349
371 409 329 406 403 414 Wax Add-on %.sup.2 29.5 31.3 306 30.7 31.2
32.7 32.8 Wt. Roll.sup.3 (lbs.)t 2.60 2.65 2.94 2.35 2.86 2.71 2.77
.sup.1Wax Added = Tape Wt. - Coated Tape Wt. .sup.2Wax Add-on % =
(Waxed Added/Coated Tape Wt.) (100) .sup.3Wt. Roll = Coated Tape
Wt./454 grams/lb.
The bobbins produced on bobbin spools of width 10.3 mm and percent
of bobbins rejected as exhibiting unsatisfactory telescoping are
summarized in Table IV.
TABLE-US-00004 TABLE IV # Bobbin Produced 236 240 261 213 259 296
251 # Rejects.sup.1 0 0 0 8 1 0 0 .sup.1Rejected bobbins rolls are
bobbin rolls in which the width of the wound tape on bobbin
exceeded the bobbin dispenser width of 11.2 mm.
[0125] Total Bobbins Produced=1711
[0126] Total Rejects=9%
[0127] % Rejects=0.5%
Example 2
[0128] Dental tape spool rolls are formed in accordance with the
coating and winding processes of the present invention and using
the component sizes and/or type described below and summarized in
Table V.
TABLE-US-00005 TABLE V Component Type/Size Pulley P.sub.1 14 Teeth
Pulley P.sub.2 14 Teeth Pulley P.sub.3 15 Teeth Pulley P.sub.4 19
Teeth Pulley P.sub.5 17 Teeth Pulley P.sub.6 20 Teeth Traversing
Cam 12 inches, 6 Guide Traverse turns end to end cam
[0129] The above pulley sizes should be ordered sequentially (as
illustrated FIG. 2, where 82e (which would be P.sub.1) is connected
to 82d (which would be P.sub.2) which is connected 82c (which would
be P.sub.3) etc.). The product of the ratios of the sizes of the
sequentially ordered pulleys or Ratio A can be determined as shown
in I below:
Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.Z-1/P.sub.Z
I
Using the size values from Table results in the following Ratio
A:
Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.5/P.sub.6)=(14-
/14).times.(15/19).times.(17/20)=0.671
[0130] A traverse barrel cam can be selected to provide a
traversing cam guide traverse of 12 inches end to end for every 6
revolutions of traverse barrel cam 86. This results in a cam
advance equal to the following:
Cam Advance=Traversing Cam Guide Traverse/6 Revolutions of Traverse
Barrel Cam=12/6=2 inches per Traverse Barrel Cam revolution
[0131] Ratio A indicates that for each revolution of the spool 72,
the traverse barrel cam 86 travels 0.671 of the spool revolution.
This results in the following travel distance for the traversing
cam guide 76 per revolution of spool 72:
Travel Distance of traversing cam guide per revolution of spool =
Cam Pulley Ratio .times. Cam Advance = 0.671 .times. 2 = 1.342
inches per spool revolution ##EQU00001##
[0132] A core diameter d.sub.s of spool 72 of 5 inches can be
selected such that the distance traveled by any point on the outer
surface of the core of spool 72 after one revolution of spool 72 or
circumference C can be calculated as follows:
Circumference C=5 inches.times..pi.=(5)3.14=15.7 inches
[0133] The helix angle .theta. (the angle formed by a strand of
dental tape and plane r.PHI. of the spool which is perpendicular to
the longitudinal axis z of the spool as shown in FIG. 19) which
forms by dental tape 10 as it is initially wound around the core of
spool 72 can then be calculated as follows:
Travel Distance of traversing cam guide per spool
revolution/Circumference C=1.342/15.7
1.342/15.7=0.0854=sin.sup.-1.theta.(Helix Angle)
Where Helix Angle .theta.=4.9.degree.
[0134] As one inch of dental tape is wound onto the core of spool
72, helix angle .theta. decreases. This can be calculated as
follows:
[0135] The diameter of spool after 1 adding one inch layer of
tape=5 inches+2 inches (1 inch added layer results in diameter
increasing by 2 inches)=7 inches, hence:
Circumference of Spool with Tape=diameter of spool with
tape.times..pi.=(7)3.14=21.98 inches
Travel distance of traversing cam guide per spool
revolution/Circumference of Spool with Tape=1.342/21.98
inches=0.061=sin-1.theta.'(Helix Angle)
[0136] Where Helix Angle .theta.'=3.5.degree.
[0137] Therefore, as about an inch of material is wound around the
spool, the helix angle chances by about 1.degree.
(.theta.-.theta.'=4.9.degree.-3.5.degree.=1.4.degree..
[0138] Using the above traverse barrel cam and pulley sizes, rolls
(representative of spool 72 in FIG. 1) can be formed, which rolls
can subsequently be used to form separate tape bobbins.
(representative bobbins formed on bobbin spool 90 in FIG. 1).
Example 3
[0139] Dental tape spool rolls are formed in accordance with the
coating and winding processes of the present invention and using
the component sizes and/or type described below and summarized in
Table VI.
TABLE-US-00006 TABLE VI Component Type/Size Pulley P.sub.1 14 Teeth
Pulley P.sub.2 14 Teeth Pulley P.sub.3 14 Teeth Pulley P.sub.4 14
Teeth Pulley P.sub.5 16 Teeth Pulley P.sub.6 20 Teeth Traversing
Cam 12 inches, 5 Guide Traverse turns end to end cam
[0140] The above pulley sizes should be ordered sequentially (as
illustrated FIG. 2, where 82e (which would be P.sub.1) is connected
to 82d (which would be P.sub.2) which is connected 82c (which would
be P.sub.3) etc.). The product of the ratios of the sizes of the
sequentially ordered pulleys or Ratio A can be determined as shown
in I below:
Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.Z-1/P.sub.Z
I
Using the size values from Table results in the following Ratio
A:
Ratio
A=P.sub.1/P.sub.2.times.P.sub.3/P.sub.4.times.P.sub.5/P.sub.6)=(14-
/14).times.(14/14).times.(16/20)=0.80
[0141] A traverse barrel cam can be selected to provide a
traversing cam guide traverse of 12 inches end to end for every 5
revolutions of traverse barrel cam 86. This results in a cam
advance equal to the following:
Cam Advance=Traversing Cam Guide Traverse/5 Revolutions of Traverse
Barrel Cam=12/5=2.4 inches per Traverse Barrel Cam revolution
[0142] Ratio A indicates that for each revolution of the spool 72,
the traverse barrel cam 86 travels 0.80 of the spool revolution.
This results in the following travel distance for the traversing
cam guide 76 per revolution of spool 72:
Travel Distance of traversing cam guide per revolution of spool=Cam
Pulley Ratio.times.Cam Advance=0.80.times.2.4=1.92 inches per spool
revolution
[0143] A core diameter d.sub.s of spool 72 of 7 inches can be
selected such that the distance traveled by any point on the outer
surface of the core of spool 72 after one revolution of spool 72 or
circumference C can be calculated as follows:
Circumference C=5 inches.times..pi.=(7)3.14=21.98 inches
[0144] The helix angle .theta. (the angle formed by a strand of
dental tape and plane of the spool r.PHI. which is perpendicular to
the longitudinal axis of the spool as shown in FIG. 19) which forms
by dental tape 10 as it is initially wound around the core of spool
72 can then be calculated as follows:
Travel Distance of traversing cam guide per spool
revolution/Circumference C=1.92/21.98
1.92/21.98=0.0873=sin.sup.-1.theta.(Helix Angle)
Where Helix Angle .theta.=5.01.degree.
[0145] As one inch of dental tape is wound onto the core of spool
72, helix angle .theta. decreases. This can be calculated as
follows:
[0146] The diameter of spool after 1 adding one inch layer of
tape=7 inches+2 inches (1 inch added layer results in diameter
increasing by 2 inches)=9 inches
Circumference of Spool with Tape=diameter of spool with
tape.times..pi.=(9)3.14=28.26 inches
Travel distance of traversing cam guide per spool
revolution/Circumference of Spool with Tape=1.92/28.26
inches=0.068=sin-1.theta.'(Helix Angle)
[0147] Where Helix Angle .theta.'=3.9.degree.
[0148] Therefore, as about an inch of material is wound around the
spool, the helix angle chances by about 1.degree.
(.theta.-.theta.'=5.01.degree.-3.9.degree.=1.11.degree.).
[0149] Using the above traverse barrel cam and pulley sizes, rolls
(representative of spool 72 in FIG. 1) can be formed, which rolls
can subsequently be used to form separate tape bobbins
(representative bobbins formed on bobbin spool 90 in FIG. 1).
* * * * *