U.S. patent application number 14/337787 was filed with the patent office on 2016-01-28 for molded cosmetic applicators with perforated bristles and mold therefor.
The applicant listed for this patent is ELC Management LLC. Invention is credited to Herve F. Bouix, Christophe Jacob.
Application Number | 20160022012 14/337787 |
Document ID | / |
Family ID | 55163548 |
Filed Date | 2016-01-28 |
United States Patent
Application |
20160022012 |
Kind Code |
A1 |
Jacob; Christophe ; et
al. |
January 28, 2016 |
Molded Cosmetic Applicators With Perforated Bristles And Mold
Therefor
Abstract
A molded cosmetic applicator head having a core that supports an
array of perforated bristles arranged in rows and columns. Each
perforated bristle comprises a textured lateral surface and a flat
lateral surface, such that the surfaces of the bristles assume
certain orientations. A mold for an injection molded applicator
head is also described.
Inventors: |
Jacob; Christophe;
(Franqueville-Saint-Pierre, FR) ; Bouix; Herve F.;
(New York, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ELC Management LLC |
Melville |
NY |
US |
|
|
Family ID: |
55163548 |
Appl. No.: |
14/337787 |
Filed: |
July 22, 2014 |
Current U.S.
Class: |
401/129 ;
425/577 |
Current CPC
Class: |
B29C 45/4005 20130101;
A45D 40/265 20130101; A46B 1/00 20130101; A45D 40/262 20130101;
B29C 45/00 20130101; A46B 2200/1053 20130101; A46D 1/0253 20130101;
A46D 1/0292 20130101; B29C 45/2626 20130101; A46D 1/0261 20130101;
B29L 2031/718 20130101; A46D 1/0276 20130101; A46D 1/0238 20130101;
B29C 45/2602 20130101; B29L 2031/42 20130101; A46D 1/0284 20130101;
A46B 3/005 20130101; B29C 45/2628 20130101 |
International
Class: |
A45D 40/26 20060101
A45D040/26; B29C 45/26 20060101 B29C045/26 |
Claims
1. A molded cosmetic applicator head comprising: a core having a
longitudinal axis, and an array of bristles projecting radially
from the core, arranged in rows and columns, wherein: each bristle
comprises a flat surface that extends the height of the bristle,
and a textured surface; within each column of bristles, all of the
flat surfaces lie in the same plane and are parallel to the
longitudinal axis of the core; within each row of bristles, the
flat surfaces of adjacent bristles are oriented to each other at an
angle .gamma.=360.degree./M degrees, where M is the number of
columns; and one or more perforations that pass completely through
at least some of the bristles.
2. The applicator head of claim 1 comprising from 5 to 50 rows
bristles.
3. The applicator head of claim 1 comprising from 2 to 12 columns
of bristles.
4. An applicator head according to claim 1 wherein all of the
perforations are bounded.
5. An applicator head according to claim 1 wherein all of the
perforations are unbounded.
6. A cosmetic applicator comprising a molded applicator head
according to claim 1 and a handle attached to the core of the
applicator head, the handle having a threaded engagement.
7. A mold for an injection molded applicator head comprising a
number, M, of separable mold sections, wherein: each mold section
fills an angle of 360.degree./M, and comprises an interior face, a
flat lateral face, and a sculpted lateral face; when assembled each
flat lateral face contacts the sculpted lateral face of an adjacent
mold section, while the interior faces define a core space that has
a longitudinal axis that extends along the length of the core
space; the sculpted lateral faces are flat except for a number of
bristle spaces cut into them; the bristle spaces are regularly
arranged in M columns that extend down the core space, parallel to
the longitudinal axis; at least some of the bristle spaces comprise
one or more protrusions that contact the flat lateral face of an
adjacent mold section, and that is fashioned with a draft angle on
the distal end of the protrusion.
8. The mold of claim 7 wherein each sculpted lateral face has from
5 to 50 bristle spaces.
9. The mold of claim 7 wherein M=2-12.
10. The mold of claim 7 wherein the core space is approximately
cylindrical.
11. The mold of claim 7 wherein M=12, and the one or more
protrusions have a minimum draft angle of 60.degree..
12. The mold of claim 7 wherein M=10, and the one or more
protrusions have a minimum draft angle of 54.degree..
13. The mold of claim 7 wherein M=8, and the one or more
protrusions have a minimum draft angle of 45.degree..
14. The mold of claim 7 wherein M=6, and the one or more
protrusions have a minimum draft angle of 30.degree..
Description
FIELD OF THE INVENTION
[0001] The invention is in the field of molded cosmetic applicators
with uniquely shaped bristles, especially for delivering a high
volume of product to the eyelashes, and for grooming the eyelashes
and eyebrows.
BACKGROUND
[0002] Cosmetic applicators having molded applicator heads are
known. Molded applicator heads typically comprise a core and
several rows (for example, 4-12) of plastic or elastomeric bristles
uniformly arranged around the core. The core may be formed as an
elongated rod that has a distal end where the bristles are located,
and a proximal end that is suitable for attaching to a handle.
Alternatively, the core may be formed as a sleeve that supports the
bristles, and that fits over an applicator rod.
[0003] The most common molded bristle has a cross section that is
circular or semi-circular along its entire height. This type of
bristle may be integrally molded simultaneously with the core, in
one molding cycle. Being able to form a complete applicator head in
one molding cycle is a significant advantage in time and cost. On
the other hand, when the bristle cross sections are more
complicated, then parts of the applicator head may have to be
formed in successive molding cycles. A particular problem occurs
when one tries to mold a complete applicator head (core and
bristles) in one molding cycle, wherein the bristles have one or
more perforations. One of the more significant problems is how to
demold this type of applicator head without damaging it. The
present invention addresses these concerns.
OBJECTS OF THE INVENTION
[0004] A main object of this invention is to create a molded
applicator head (core and bristles) for a cosmetic applicator, the
bristles having one or more perforations, wherein the core and
bristles are molded in a single molding cycle.
[0005] Another object of the invention is to provide a mold that is
suitable for molding cosmetic applicators with perforated bristles
in a single molding cycle.
SUMMARY
[0006] We disclose molded cosmetic applicator heads, each head
having a core that supports an array of bristles arranged in rows
and columns, such that the surfaces of the bristles assume certain
orientations, and wherein at least some of the bristles have at
least one perforation. The bristles and applicator core are
integrally molded in one injection molding cycle.
[0007] The perforations along the height of the bristles may grip
the hair for improved separation of hairs and better definition.
The perforations also act as reservoirs of product to provide a
huge volumizing effect. The disclosed applicator heads may be used
for eyelash makeup and treatment products, as well as eyebrow
makeup and treatment products.
DESCRIPTIONS OF THE FIGURES
[0008] FIG. 1 is a cross sectional view of an eight section mold
ready to be filed with molten material.
[0009] FIG. 2a depicts a four section mold.
[0010] FIG. 2b shows an applicator head being released from a four
section mold. Each mold section slides along a flat surface of a
bristle.
[0011] FIG. 3 depicts an applicator head being released from a six
section mold.
[0012] FIG. 4 depicts an applicator head being released from a
eight section mold.
[0013] FIG. 5 depicts an applicator head being released from a ten
section mold.
[0014] FIG. 6 depicts an applicator head being released from a
twelve section mold.
[0015] FIG. 7 shows one section of a four section mold that will
produce bristles having two perforations.
[0016] FIG. 8 shows one section of a six section mold that will
produce bristles having one perforation.
[0017] FIG. 9a shows one section of a six section mold that will
produce bristles having one perforation.
[0018] FIG. 9b depicts an enlarged portion of the mold section of
FIG. 9a.
[0019] FIG. 10 shows one section of an eight section mold that will
produce bristles having two perforations.
[0020] FIG. 11 shows one section of a ten section mold that will
produce bristles having two perforations.
[0021] FIG. 12 shows one section of a twelve section mold that will
produce bristles having two perforations.
[0022] FIGS. 13a-19b depict examples of perforated bristles.
[0023] FIGS. 20a and 20b show two views of an applicator head with
8 columns of bristles symmetrically arranged.
[0024] FIGS. 21 and 22 show an applicator head with 8 columns of
bristles symmetrically arranged, and its assembly to a handle.
[0025] FIGS. 23a-e show draft angels for one particular design of
perforated bristle.
DEFINITIONS
[0026] Throughout the specification, "perforated bristle", and
similar phrases, shall refer to a channel that passes completely
through the bristle.
[0027] "Comprise" and its conjugates mean that a composite
structure is not limited to those elements that are explicitly
recited, but may include additional elements.
[0028] Throughout the specification, the proximal end of the
applicator head is the end nearer to the handle, as described
below. The distal end of the applicator head is the end farther
from the handle. The proximal end of a bristle is the end that
attaches to the core of the molded applicator head. The distal end
of the bristle is the free end of the bristle.
DETAILED DESCRIPTION
[0029] Mascara applicators typically comprise a handle, a rod or
core extending from the handle, and an array of bristles projecting
from the core. The present invention contemplates specific bristle
shapes integrally molded with the core, in one molding cycle. The
molded core and bristles may be referred to as the applicator head.
The handle may also be integrally molded with the applicator head,
or the applicator head may be attached to a handle at a later
time.
The Mold
[0030] FIG. 1 depicts an assembled mold (2) according to the
present invention that is suitable for forming bristles according
to the present invention. The assembled mold is right circular
cylindrical, and comprised of a number of mold sections that are
shaped as truncated cylindrical sectors. While the mold (2) of FIG.
1 comprises eight separable mold sections (2a), molds according to
the invention are not limited to eight sections. Regardless of the
number of mold sections, when assembled, the mold sections define a
mold cavity (1), into which plastic or elastomeric material will be
injected. The mold cavity comprises a core space (1a) and a number
of bristle spaces (1b). The core space has a longitudinal axis that
extends along the length of the core space. The number of bristle
spaces is equal to the number of bristles (10b) in a finished
applicator head (10) that is formed from the mold.
Mold Sections
[0031] FIGS. 2a and 2b depict a mold (2) comprising four mold
sections (2a). Each mold section is shaped as a truncated
cylindrical sectors, characterized by a sculpted lateral face (2b),
a flat lateral face (2c), and an interior face (2d). The sculpted
lateral face is flat except for bristle spaces (1b) cut into it.
Each bristle space opens up onto the sculpted lateral face. In
contrast, the flat lateral face is continuously flat, and has no
bristle spaces therein. Consequently, each bristle has a flat face
that corresponds to a flat lateral face of a mold section.
Generally, one or more sections of a mold may differ from each
other in overall size and shape, however, in preferred embodiments
of the invention, the mold sections are the same overall size and
shape. Also, in general, the bristles spaces in one or more mold
sections may differ from each other, so that a single molded brush
may have bristles of different shapes and sizes. Alternatively, all
of the bristles in an assembled mold may be of the same type.
[0032] The sculpted lateral face (2b) and flat lateral face (2c)
have a relative orientation defined by a central angle, y. For
example, in FIG. 1, we show eight identical sections in a mold, so
that each mold section fills an angle of 360.degree./8=45.degree..
More generally, we define M as the number of mold sections. When
each mold section is the same size, then the central angle,
.gamma., of each mold section is given by 360.degree./M. For
example, when there are four, six, ten or twelve mold sections in a
mold, each mold section fills an angle of 90.degree., 60.degree.,
36.degree. and 30.degree., respectively.
[0033] In an assembled mold, the interior faces (2d) define the
core space (1a) and the shape of the core (10a) of the molded
article. In some preferred embodiments, the interior faces (2d) are
curved, such that the core of the molded article will have a
circular cross section. Preferably, the interior faces define a
core that is approximately cylindrical. Alternatively, if the
interior faces are straight, then the core would have a polygonal
cross section. Optionally, the interior faces may define a core
that has wider and narrower portions. In this case, the width,
.delta., (see FIG. 1) of one or more mold sections would vary along
the length of the mold section. For example, if the core of the
molded applicator head is to be wider in the middle and tapered
toward the distal (10f) and or proximal (10g) ends, then the mold
sections would be narrower in the middle, and wider at their distal
(2e) and proximal (2g) ends. FIGS. 10-12, for example, depict mold
sections that are wider toward their distal ends.
[0034] The more sections (2a) in a mold, the more flexibility there
is in designing cosmetic applicators of the present invention.
However, increasing the number of mold sections makes the mold more
difficult to operate in a commercial manufacturing environment.
Therefore, in preferred embodiments, M=2-12. Molds with 5, 6, 10 or
11 sections (i.e. .gamma.=72.degree., 60.degree., 36.degree. or
32.72.degree., respectively) are more preferred. Molds with 7
sections (.gamma.=51.43.degree.) or 9 sections (.gamma.=40.degree.)
are still more preferred, and exactly 8 sections
(.gamma.=45.degree.) is most preferred. Of course, when there are
relatively fewer columns of bristles (i.e. 4, 3 or 2;
.gamma.=90.degree., 120.degree., 180.degree.), then the applicator
performs more like a comb and less like a brush, but this is still
within the scope of the present invention.
[0035] In FIG. 2a, the mold sections (2a) are assembled, and the
mold cavity (1) has been filled with molten material to form an
applicator head (10). In FIG. 2b, the molded applicator head,
comprising a core (10a) and bristles (10b), is being released from
the mold (2) by moving each mold section parallel to its flat
lateral face (2c). FIGS. 3a and 3b are analogous to FIGS. 2a and 2b
for a six section mold. FIGS. 4a and 4b are analogous to FIGS. 2a
and 2b for an eight section mold. FIGS. 5a and 5b are analogous to
FIGS. 2a and 2b for a ten section mold. FIGS. 6a and 6b are
analogous to FIGS. 2a and 2b for a twelve section mold. In FIGS.
2a-6b, the shape of the molded bristles (10b) happens to be the
same, but bristle shape is not limited, except as explicitly
explained herein. Other bristle shapes are shown below.
Bristle Spaces
[0036] In some preferred embodiments, bristle spaces (1b) are
regularly arranged in columns that extend down the core space (1a),
parallel to the longitudinal axis of the core space. In an
assembled mold, a column of bristle spaces is defined by adjacent
mold sections (2a) that contact each other. The number of columns
in a mold equals the number of mold sections, M. This is because
each mold section has one column of bristle spaces (1b) cut into
its sculpted lateral face (2b). The number bristle spaces in a
column along the length of the core space will typically range from
5 to 50, preferably from 10 to 40, more preferably from 20 to 35
bristle spaces. For example, the mold section (2a) of FIG. 2c has
25 bristle spaces cut into it.
[0037] In some preferred embodiments, bristle spaces (1b) are
regularly arranged in rows, each row lying on a circumference of
the core space (1a), in a plane that is perpendicular to the
longitudinal axis of the core space. It may be appreciated that the
maximum number of bristle spaces in a row is equal to the number of
mold sections, M. This is because each mold section may contribute
only one bristle space or no bristle spaces to each row. In some
preferred embodiments, all rows have M bristle spaces that are
evenly spaced around a circumference of the core space.
[0038] In the most preferred embodiments, bristle spaces (1b) are
regularly arranged in columns and rows. The bristle spaces of the
mold typically extend radially from the core space (1a), so that in
a molded applicator head (10), the bristles (10b) extend radially
from the core (10a) of the applicator head. In terms of releasing
the finished part from the mold without damaging the bristles, A
row and column arrangement of radial bristle spaces is most
preferred, but may not be absolutely necessary in every
embodiment.
[0039] As noted above, each mold section (2a) has a sculpted
lateral face (2b) and a flat lateral face (2c). In the assembled
mold (2), a bristle space is defined by the sculpted lateral face
of one mold section contacting the flat lateral face of an adjacent
mold section. Thus, every bristle (10b) in the molded applicator
head (10) has at least one flat face (10c) that extends the length
of the bristle space. This flat face is free of features, such as
prominent protrusions and prominent depressions, and is a
characterizing feature of the bristle spaces of a mold according to
the present invention. The other sides of the bristle spaces (1b)
may comprise flat and/or rounded portions, and the horizontal cross
section of the bristle space is limited only by the ability to
machine the mold sections, and by demolding considerations.
[0040] In an assembled mold (2) of the present invention, at least
some of the bristle spaces (1b) have one or more protrusions (1d)
that contact the flat lateral face (2c) of an adjacent mold section
(2a). Such protrusions result in a perforated bristle (10b).
Bristle perforations may be bounded or unbounded. A bounded
perforation has an unbroken perimeter, which may include the core
of the applicator head. Examples of these are shown in FIGS. 13a
and 15a. An unbounded perforation has a break in its perimeter,
where the perforation opens up to the exterior of the bristle.
Examples of these are shown in FIG. 14a or 19a. Furthermore, the
mold section of FIG. 7 will produce bristles having two bounded
channels through each bristle. The mold section of FIG. 8 will
produce bristles having one open channel through each bristle,
while that of FIG. 9a will produce bristles having one bounded
channel through each bristle. The mold sections of FIGS. 10-12 will
produce bristles having one bounded and one open channel through
each bristle. A bristle space that produces a bristle with a
bounded perforation must be fashioned with a draft angle on the
distal end (1e) of the protrusion (1d) (see FIG. 9b). These draft
angles are important, and will be described more, below.
[0041] Furthermore, some or all of the bristle spaces (1b) may
feature additional protrusions that do not contact the flat lateral
face (2c) of an adjacent mold section (2a). Such protrusions result
in depressions in the molded bristle. Conversely, any depression
attached to the main part of a bristle space results in a
protrusion on the molded bristle (see FIG. 10, for example, and the
corresponding bristle in FIG. 16). These depressions and
protrusions are deliberately machined into the bristle space, and
do not arise as a result of random, macroscopic or microscopic
surface irregularities. Examples of various bristles of the present
invention are shown in FIGS. 13a-19b.
The Applicator Head
[0042] An applicator head (10) comprises core (10a) and an array of
bristles (10b) projecting from the core. The present invention
contemplates bristles having at least one perforation integrally
molded with the core, in one molding cycle.
The Core
[0043] Referring to FIG. 20a, the core (10a) of the applicator head
(10) is integrally molded with the bristles (10b). The core may be
of solid material or it may have a hollowed interior portion. A
hollowed interior portion would require an additional die in the
molding operation. Preferably, the core has a circular cross
section. In some embodiments, the core is approximately
cylindrical. Alternatively, the core may have wider and narrower
portions. For example, in FIG. 20a, the core tapers toward the
distal end (10f) of the applicator head.
[0044] In some embodiments, a stem portion (10h) which is free of
any bristles (10b) may depend from the proximal end (10g) of the
core (10a) of the applicator head (10). The stem portion may have a
diameter that is reduced compared to the diameter of the core. The
reduced diameter is designed to facilitate the attachment of a
handle. For example, referring to FIGS. 21 and 22, a typical handle
(4) may comprise a closure (4a) that is able to attach to a
reservoir of product. The handle may also comprises a rod (4b). The
stem of the applicator head (10) may be retained in a hollow
portion (4c) of the rod. Alternatively, the core (10a) of the
applicator head (10) may have a hollowed portion that opens onto
the proximal end (10g) of the core. This hollowed portion may be
designed to receive and retain the rod (4b) of a handle (4). In
general, the handle is of a type that is suitable for manipulating
an eyelash or eyebrow cosmetic applicator, as known in the art. A
typical handle may have a threaded engagement (4d) for attaching to
a reservoir of product.
Bristles
[0045] Each bristle space (1b) in the mold (2) will give rise to
one bristle (10b) in a molded applicator head (10). Thus, the
number of bristles in a finished applicator head is equal to the
number of bristles spaces in the mold. As noted above, every
bristle space (1b) in the mold is bordered by a flat lateral face
(2c). Consequently, every bristle in a molded applicator head will
have a flat surface (10c) that extends the full height, H, of the
bristle, and that is free of surface features such as protrusions
and depressions. The flat surface (10c) is a characterizing feature
of the bristles of the present invention. During demolding, a mold
section (2a) slides along this flat surface (10c) of the bristle.
In a column, C, of bristles, all of the flat surfaces lie in the
same plane and are parallel to the longitudinal axis, A, of the
applicator head (see FIG. 20a). In a row of bristles, the flat
surfaces of adjacent bristles are oriented to each other at an
angle, .gamma.=360.degree./M. For example, in FIG. 20b, M=8 and
.gamma.=45.degree.. These orientations are a characterizing feature
of the invention, and are important for allowing the molded
applicator head to be ejected from the mold easily, with no
damage.
[0046] Furthermore, at least some bristles of an applicator head
according to the invention have at least one perforation (10d). A
perforation is a channel that passes completely through the
bristle. Preferably, at least half of the bristles that make up an
applicator head have at least one perforation; more preferably at
least 75%; most preferably at least 99% of the bristle in an
applicator head have perforations. The perforations of the bristles
may be any suitable size or shape. From one bristle to the next,
the sizes and shapes of the perforations may be the same or
different. Also, a perforation may be bounded or unbounded. A
bounded perforation has an unbroken perimeter (see FIG. 13a or 15a,
for example). An unbounded perforation has a break in its
perimeter, where the perforation opens up to the exterior of the
bristle (see FIG. 14a or 19a, for example). The bristles depicted
in FIGS. 16a, 17a and 18a have one bounded perforation and one
unbounded perforation.
[0047] Within the limits herein described, the perforated bristles
(10b) in an applicator head (10) may have any size and spacing
suitable for its intended functions, e.g., application,
arrangement, and/or separation of human hairs, such as eyelashes.
For guidance, the height, H, of the bristles will range from about
0.1 mm to about 10 mm, preferably from 0.5 mm to 7 mm, and more
preferably from 0.8 mm to 5 mm. The average cross-sectional
diameter of the bristles ranges from about 0.1 mm to about 2 mm,
preferably from about 0.2 mm to about 1.5 mm, and more preferably
from about 0.3 mm to about 0.9 mm. Also, all the bristles in a
single applicator head may be same or different. For example, all
the bristles in a single applicator head may be same height, H, or
not. The height of a bristle is measured from where the bristle
rises from the core (10a) of the applicator head, to the free end
of the bristle. FIG. 20a shows an example where the height of the
bristles varies along the length of the core, being taller toward
the middle of each column, and shorter toward the ends of each
column. Optionally, within each row, the bristles may be the same
height or different. Optionally, the bristles in any one column may
be the same size and/or shape, or not. Optionally the shape of the
bristles in one column may be different from the shape of the
bristles in another column.
Material
[0048] Exemplary materials that can be used in the present
invention to mold cosmetic applicator heads include, but are not
limited to: silicone elastomers, thermoplastic elastomers (such as,
for example, styrene-ethylene-butylene-styrene block
copolymer--SEBS), vinyl elastomers (EVA), thermoplastic polyester
elastomers (Hytrel.RTM. from Dupont de Nemours), thermoplastic
polyurethane elastomers (Pellethane.RTM. from Dow Plastic),
Nitrile, and EPDM. Hardness of the chosen material preferably
ranges from about 35 MPa (35 shore D Hytrel.RTM. from Dupont de
Nemours) to about 1180 MPa (82 shore D Hytrel.RTM.). More
preferably the tensile modulus ranges from about 95 MPa (45 shore D
Hytrel.RTM.) to about 570 MPa (72 shore D Hytrel.RTM.). Most
preferably, tensile modulus ranges from about 200 MPa (55 shore D
Hytrel.RTM.) to about 280 MPa (63 shore D Hytrel.RTM.).
Release From the Mold
[0049] Applicator heads as described herein, are preferably made by
injection molding. When a set of mold sections (2a) are assembled,
a mold cavity (1) is defined. Access into the mold cavity is
through an opened end of the core space (1a). Molten material may
be injected into the mold cavity through the opened end. When a
molded applicator head is to be released from the assembled mold
(2), the flat faces (2c) of the mold sections (2a) are made to move
away from each other radially, and parallel to (or sliding along)
the flat faces (10c) of the bristles (10b). This is most easily
seen in FIGS. 2a-6. One or more sections of the mold may move
simultaneously to release the molded component. Preferably, all
sections of the mold move simultaneously to release the molded
component, as this would put the least amount of stress on the
molded bristles. For example, in a mold with eight sections, the
mold sections retreat from each other at 45.degree. increments (see
FIG. 4). For a mold with ten sections, the mold sections retreat
from each other at 36.degree. increments (see FIG. 5), and for a
mold with twelve sections, the mold sections retreat from each
other at 30.degree. increments (see FIG. 6), etc.
[0050] When a bristle comprises a bounded perforation, then the
distal end of the bounded perforation must formed with a minimum
draft angle that ensures that the bristle is not damaged during
de-molding. The distal end (10e) of a perforation is the end nearer
to the free end of the bristle. This draft angle, along with the
orientation of the flat and textured lateral surfaces described
above, make it more likely that the sculpted face (2b) of a mold
section will pull away from the molded applicator head without
subjecting the bristles to any appreciable stress, especially when
both of the mold sections that define a bristle separate
simultaneously. The minimum draft angle depends on the number of
dies in the mold. Examples follow.
EXAMPLE 1
A Brush With 4 Columns of Bristles
[0051] The mold comprises 4 dies. During de-molding, each die moves
parallel to its flat lateral surface (2c), at an angle of
360.degree./4=90.degree. relative to its sculpted lateral surface
(2b). In order for the bristles (10b) to freely de-mold from the
die, the distal ends (10e) of any bounded perforations (10d)
preferably have a draft of at least 1.degree.. See FIG. 23a.
EXAMPLE 2
A Brush With 6 Rows of Bristles
[0052] The mold comprises 6 dies. During de-molding, each die moves
parallel to its flat lateral surface (2c), at an angle of
360.degree./6=60.degree. relative to its sculpted lateral surface
(2b). In order for the bristles (10b) to freely de-mold from the
die, the distal ends (10e) of any bounded perforations (10d)
preferably have a draft of at least 30.degree.. See FIG. 23b.
EXAMPLE 3
A Brush With 8 Rows of Bristles
[0053] The mold comprises 8 dies. During de-molding, each die moves
parallel to its flat lateral surface (2c), at an angle of
360.degree./8=45.degree. relative to its sculpted lateral surface
(2b). In order for the bristles (10b) to freely de-mold from the
die, the distal ends (10e) of any bounded perforations (10d)
preferably have a draft of at least 45.degree.. See FIG. 23c.
EXAMPLE 4
A Brush With 10 Rows of Bristles
[0054] The mold comprises 10 dies. During de-molding, each die
moves parallel to its flat lateral surface (2c), at an angle of
360.degree./10=36.degree. relative to its sculpted lateral surface
(2b). In order for the bristles (10b) to freely de-mold from the
die, the distal ends (10e) of any bounded perforations (10d)
preferably have a draft of at least 54.degree.. See FIG. 23d.
EXAMPLE 5
A Brush With 12 Rows of Bristles
[0055] The mold comprises 12 dies. During de-molding, each die
moves parallel to its flat lateral surface (2c), at an angle of
360.degree./12=30.degree. relative to its sculpted lateral surface
(2b). In order for the bristles (10b) to freely de-mold from the
die, the distal ends (10e) of any bounded perforations (10d)
preferably have a draft of at least 60.degree.. See FIG. 23e.
[0056] In all cases, the proximal ends of the perforations may have
a draft angle of 0.degree., but a minimum of 0.5.degree. is
preferred practice. The draft of the bristle in its transverse
cross section will be 0.5.degree. minimum. For example, in FIGS.
23a-e, this draft angle is shown as 4.degree..
* * * * *