U.S. patent application number 10/363216 was filed with the patent office on 2003-09-25 for method for producing bristle products.
Invention is credited to Weihrauch, Georg.
Application Number | 20030178885 10/363216 |
Document ID | / |
Family ID | 7656924 |
Filed Date | 2003-09-25 |
United States Patent
Application |
20030178885 |
Kind Code |
A1 |
Weihrauch, Georg |
September 25, 2003 |
Method for producing bristle products
Abstract
In a method for producing brushware, individual bristles of
plastic material or bristles combined into groups in a
predetermined arrangement are mounted onto a support, thereby
forming the desired bristle stock, and at least one part of the
bristles in the predetermined arrangement or on the mounted bristle
stock is provided with a preferably regular structure in a
contact-free fashion using laser radiation. The invention also
proposes contact-free cutting of the free ends of the bristles
through laser radiation thereby producing, in a reproducible
fashion, structures on the outside and on top of the bristle stock
to support the cleaning action.
Inventors: |
Weihrauch, Georg;
(Wald-Michelbach, DE) |
Correspondence
Address: |
Lichti Lempert & Lasch
Bergwaldstr 1
Karlsruhe
D-76227
DE
|
Family ID: |
7656924 |
Appl. No.: |
10/363216 |
Filed: |
March 6, 2003 |
PCT Filed: |
September 5, 2001 |
PCT NO: |
PCT/EP01/10218 |
Current U.S.
Class: |
300/21 |
Current CPC
Class: |
A46B 9/045 20130101;
A46D 9/02 20130101; A46B 2200/1066 20130101 |
Class at
Publication: |
300/21 |
International
Class: |
A46D 001/08 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 19, 2000 |
DE |
100 46 536.6 |
Claims
1. Method for producing brushware (1) through mounting individual
bristles (3) or bristles (3) combined into groups (9) in a
predetermined arrangement on a support (2), thereby forming the
desired bristle stock, wherein the envelope of at least part of the
bristles of the bristle stock is structured through treatment,
characterized in that, in the predetermined arrangement or on the
mounted bristle stock (4), at least part of the bristles (3) are
structured in a contact-free fashion using laser radiation.
2. Method according to claim 1, characterized in that the bristles
have a regular structure.
3. Method for producing brushware through mounting individual
bristles or bristles combined into groups in a predetermined
arrangement on a support, thereby forming the desired bristle
stock, wherein the free ends of at least part of the bristles are
cut through treatment, in particular according to claim 1,
characterized in that, in the predetermined arrangement or on the
mounted bristle stock, the free ends of the bristles (3) are cut in
a contact-free fashion using laser radiation.
4. Method according to claim 3, characterized in that the free ends
of the bristles (3) are rounded through thermal loading via the
laser treatment.
5. Method according to any one of the claims 1 through 4,
characterized in that the envelope of the bristles (3) is profiled
or the free ends thereof are shortened through material abrasion
due to thermal decomposition of the plastic material.
6. Method according to any one of the claims 1 through 5,
characterized in that the envelope of the bristles (3) is
structured through foaming of the plastic material.
7. Method according to any one of the claims 1 through 6,
characterized in that, with two-component bristles having at least
one core and an envelope concentrically surrounding same, only the
envelope is structured via the laser radiation.
8. Method according to claim 7, characterized in that the envelope
is structured down to the core through local removal of the
envelope material.
9. Method according to any one of the claims 1 through 8,
characterized in that the structure of the bristle envelope extends
to a depth of approximately 10% of the bristle cross-section.
10. Method according to any one of the claims 1 through 9,
characterized by shortening the free ends of bristles (3) disposed
substantially along lines (7,8,9,13,14,15) in the surface of the
predetermined arrangement or of the mounted bristle stock.
11. Method according to any one of the claims 1 through 10,
characterized in that the free ends of neighboring bristles (3) are
shortened thereby forming a stepped envelope surface (6) of the
bristle ends.
12. Method according to any one of the claims 1 through 11,
characterized in that the free ends of individual groups (6) of
bristles (3) are shortened.
13. Method according to any one of the claims 1 through 12,
characterized in that the free ends of the bristles (3) of an
individual group (10,11) of bristles (3) are shortened thereby
forming a non-planar envelope surface.
14. Method according to any one of the claims 1 through 13,
characterized in that only the envelope of the outer bristles of
the predetermined arrangement or of the mounted bristle stock is
structured.
15. Method according to any one of the claims 1 through 14,
characterized in that inwardly disposed bristles of the
predetermined arrangement or of the mounted bristle stock are
exposed by separating and laterally deflecting the bristles, and
the envelope of these bristles is structured.
16. Method according to any one of the claims 1 through 15,
characterized in that bristles (3) having fillers which absorb
laser radiation are used for producing brushware.
17. Method according to any one of the claims 1 through 16,
characterized in that the structure (5) produced during laser
treatment is visualized through coloring of the plastic
material.
18. Method according to any one of the claims 1 through 16,
characterized in that the structure (5) produced during laser
treatment is visualized through fillers in the plastic material of
the bristles (3) which change color in response to laser radiation.
Description
[0001] The invention concerns a method for producing brushware by
mounting individual bristles or bristles combined into groups, in a
predetermined arrangement, on a support thereby forming the desired
bristle stock, wherein at least the envelope of part of the
bristles of the bristle stock is processed to receive a
structure.
[0002] The invention also concerns a method for producing brushware
by mounting individual bristles or bristles combined into groups,
in a predetermined arrangement, on a support thereby forming the
desired bristle stock, wherein the free ends of at least part of
the bristles are shortened.
[0003] Brushware usually consists of a more or less regular bristle
stock, wherein the bristles forming same have a smooth envelope
surface with the free bristle ends being disposed in a flat,
continuously, or discontinuously curved envelope surface. The
bristle ends have the primary purpose of cleaning, grinding or
polishing through mechanical action on the surface while the
envelope of the bristles primarily has a wiping effect. A plurality
of bristles must be provided within a bristle stock to
substantially ensure effective and principally planar cleaning.
Only the envelopes of the outer bristles of the bristle stock
should be substantially effective during brushing, with the inward
bristles merely supporting the bristles among themselves and
serving the additional function of retaining application media or
media required for the brushing effect in the narrow capillaries
between the bristles.
[0004] Many attempts have been made to also include the bristle
envelope in the cleaning, polishing or grinding process effected
during brushing by e.g. structuring the outer bristles of the
bristle stock through mechanical material abrasion after
manufacture of the brushware (U.S. Pat. No. 5,678,275). This type
of treatment does not provide satisfactory results. In particular,
uniquely localized and geometrically predetermined structures
cannot be produced, since the bristles deflect due to their
flexibility which, in turn, differs in dependence on the position
within the bristle stock and on the separation from the mounting
point on the support.
[0005] The applicant has also suggested (WO99/66111) structuring
the extruded monofilaments used for producing bristles through
laser treatment of the monofilament envelope. The monofilaments are
subsequently combined into strands and the bristles of the strand
are cut to the desired length. Since the monofilaments are axially
displaced with respect to one another when combining into the
strand, a locally defined structure cannot be generated on the
combined bristles of the bristle stock. In addition, the somewhat
rough, structured bristles cause problems during conventional
sorting into groups, e.g. bundles. This leads to large fluctuations
in the number of bristles in a bundle. This method also fails to
facilitate arrangement of the structured bristles in the outer
region of a bristle stock only, where they are most effective. The
inwardly disposed, structured bristles are less effective or even
ineffective relative thereto. Therefore, an unnecessary excessive
amount of material is structured and possibly also weakened by the
monofilament treatment. Moreover, the production process during
manufacture of the monofilaments is slowed down by the laser
treatment.
[0006] It has been known for some time that a planar bristle
surface (envelope surface of the free bristle ends) does not
facilitate sufficient cleaning in many applications, in particular
with tooth brushes. The bristles of such a tooth brush bristle
stock cannot properly follow the irregular curvatures of the teeth.
The interdental spaces also remain largely untreated. For this
reason, tooth brushes having greatly differing bristle stock
"topographies" have been proposed. These topographies are usually
generated through subsequent mechanical abrasion of the plastic
material on the bristle ends, e.g. through cutting of the bristles
(U.S. Pat. No. 2,227,126, DE 198 32 436, EP 0 736 270) and
therefore involve a relatively demanding mechanical grinding or
cutting treatment. Only limited variations are possible. Mutual
axial displacement of the bristles before mounting on the support
(EP 0 346 646) has led to better results and, theoretically, any
"topography" can be produced. This method requires an additional
treatment step before mounting the bristles on the support. The
topographical bristles must then be held in position and
subsequently connected to the bristle support.
[0007] It is the underlying purpose of the present invention to
propose a method for producing brushware which permits structuring
of the bristle envelopes before or after mounting on the bristle
support and in any reproducible fashion. The bristle ends should be
shortened to form any desired, reproducible bristle end envelope
surface.
[0008] The first part of the inventive object is achieved in that,
in the predetermined arrangement or on the mounted bristle stock,
at least one part of the bristles is structured without contact
using laser radiation.
[0009] Conventionally (DE 198 29 943), a finished bristle stock has
been marked using laser radiation to serve as an indication of
wear. Structuring is not involved since the bristle material itself
is not removed.
[0010] Modern laser technology permits accurate localization of the
action of the laser radiation and concentration of the effect on
the smallest of surfaces, such as individual points or lines. It
can moreover be adapted to the material to be treated and permits
exact adjustment of the depth in dependence on the material. The
inventive use of laser energy therefore permits generation of
defined and regular structures of preferably geometrical
arrangement on the envelope of the bristles of a bristle stock,
wherein the mechanical effect of the structures can also be
influenced through exact control of the depth of the laser
radiation. Since the method is carried out in a contact-free
fashion, reproducible structures can be generated irrespective of
the flexibility of the bristles. This is, in particular, the case
with plastic bristles even though the invention is not limited to
this material. Laser technology also permits adjustment of the type
and arrangement of the structures to the application at hand. The
structures improve the reception capacity for cleaning or
application media, which are delivered without complications due to
the smooth surfaces of the structures and which can be easily
rinsed out.
[0011] These structures also increase the massaging effect of tooth
and body brushes as well as the abrasive effect of the structured
edges of technical brushes, whose bristles contain abrasive
materials.
[0012] The inventive method can be used for forming bristle stock
"topographies" through contact-free cutting of the free ends of the
bristles using laser radiation.
[0013] This method in accordance with the invention permits
generation of the finest of structures, e.g. punctiform or linear
depressions in the surface of the bristle arrangement or of the
bristle stock, with the consequence that the envelope surface has
steps of any desired type to provide additional scraping or
scratching effects during brushing.
[0014] In a preferred embodiment, the laser source is controlled to
round the free ends of the bristles through thermal loading caused
by the laser treatment. While structuring is produced substantially
through evaporation or gasification of the plastic material by the
introduced laser energy, it has surprisingly turned out that, when
cutting the bristles at the free bristle end, the bristle end is
also advantageously rounded, like a dome. The reason therefor may
be that the molecules in the bristles, having a linear orientation
due to the monofilament production, are thermally loaded at the
location of action of the laser radiation thereby re-orientating
the molecules into their disordered, tangled state.
[0015] The laser source is also designed in dependence on the
respective material, preferably a plastic material, such that the
bristle envelopes are profiled through material removal in response
to thermal decomposition of the plastic material. Evaporation and
gasification processes also cause material removal. This has the
advantage, compared to all mechanical treatment methods, that the
structures do not fray. Fraying causes loss of material during use
of the brushware, which can cause problems, in particular for
hygiene brushes, especially tooth brushes. For the case of
application brushes, such fraying can lead to inclusions of foreign
matter resulting in irregularities in the application layer. During
mechanical treatment, removed material residues will always remain
on the bristles which require subsequent cleaning processes without
guaranteeing 100% success. The inventive method also obviates the
need for such cleaning.
[0016] In accordance with a further embodiment of the inventive
method, the bristle envelopes are structured through foaming of the
plastic material. Practical experiments have shown that the plastic
material bubbles in response to the laser treatment to form an
uneven bristle envelope surface. This foaming can be controlled
through fillers, laser guidance etc.
[0017] Two or multiple component brushes are known which consist of
a core and an envelope. They are used, in particular, for wear
indication, wherein the core and envelope have different colors.
The bristles, which initially have only one color, show a different
color with increasing wear at the bristle end to indicate the
degree of wear. One embodiment of the invention provides that, in
brushware having such bristles, only the envelope is structured by
the laser radiation. This permits structuring of the envelope up to
the core, through local removal of envelope material.
[0018] To prevent unfavorable changes in the properties defined by
the bristle cross-section and the selected plastic material in
consequence of subsequent structuring, the invention provides that
the envelope structure of the bristles extends to a depth of not
more than .sup.10% of the bristle cross-section. The depth and
local arrangement of the structures within the bristle stock can be
selected such that the static properties of the individual bristle
and of the entire bristle stock are maintained to the desired
degree.
[0019] During production of the "topographies", the free ends of
the bristles can be shortened in a substantially linear pattern.
This linear pattern can be adapted to the directions of motion
which are normal for the respective brushware to obtain optimum
effects for the "topography".
[0020] The free ends of neighboring bristles can also be shortened,
thereby forming a stepped envelope surface.
[0021] The free ends of only individual groups of bristles can be
shortened by the laser radiation. The free ends of the bristles in
one individual bristle group can be shortened to thereby form a
non-planar envelope surface, e.g. conify the ends of a bundle.
[0022] As mentioned above, the inventive method can be carried out
on the prepared bristle arrangement or on the mounted bristle
stock. In this event, only the envelope of outwardly disposed
bristles can be structured. Instead or additionally, inwardly
disposed bristles can also be exposed through separation and
lateral deflection of bristles (DE 198 32 436, EP 0 763 270) to
permit structuring of their envelopes.
[0023] Although laser radiation can be used for controlled
structuring of the plurality of plastic materials which can be used
for bristles, it may be advantageous to use bristles with fillers
which absorb laser radiation, thereby providing easier and more
precise control of the structuring. The fillers may be provided
only in certain cross-sectional regions of the bristles, e.g. close
to the envelope, or, for bristles having a profiled cross-section,
in the outward profiled regions. This leads to particularly
intensive mechanical action during brushing, in particular, in
connection with the inventive structuring in the region of
polygonal edges of polygonal cross sections.
[0024] Finally, the structuring produced during laser treatment can
be visualized through simultaneous coloring of the plastic
material. Instead of or additionally, the structure produced during
the laser treatment can be visualized through fillers contained in
the plastic material of the bristles, which change their color in
response to the laser radiation.
[0025] The invention is described below with respect to some
embodiments shown in the drawing.
[0026] FIGS. 1 through 6 show a side view of a tooth brush head
with different structures on the bristle envelope;
[0027] FIGS. 7 and 8 show a side view of a tooth brush head with
structures on the bristle envelope and bristle end topography;
[0028] FIGS. 9 through 11 show a top view onto a tooth brush head
with different linear topographies;
[0029] FIGS. 12 through 14 show perspective views of a tooth brush
head with different structures or "topographies";
[0030] FIGS. 15 through 17 show a top view onto the bristle stock
of an exchangeable head for electric tooth brushes with different
"topographies";
[0031] FIG. 18 shows a representation of another embodiment
corresponding to FIGS. 13 and 14;
[0032] FIGS. 19 through 21 each show a representation of
modifications of the embodiments of FIGS. 1 through 8;
[0033] FIGS. 22 through 24 each show a view of a structured
individual bristle; and
[0034] FIG. 25 shows perspective views of a round brush.
[0035] The head 2 of the tooth brush 1, which is shown in sections
in the drawing, forms a support for bristles 3 which, in the
embodiments of FIGS. 1 through 12, are all mounted individually,
standing on the support 2, such that the bristle stock 4 consists
of a relatively dense bristle package defining intermediate, narrow
capillaries. In the embodiment of FIG. 1, structures 5 in the shape
of parallel lines have been formed via laser radiation through
removal of material from the bristle envelope. The structuring
according to FIG. 1 gives particularly good effects for the
so-called red-white cleaning method.
[0036] In the embodiment of FIG. 2, which also illustrates a
bristle stock 4 of individually, standing bristles 3, structures 5
in the form of wavy lines are provided through laser radiation,
which are narrower than those of FIG. 1.
[0037] In the embodiment of FIG. 3, the structures 5 at the outer
bristles of the bristle stock 4 are provided in the form of slanted
hatching and in the embodiment of FIG. 4 in the form of
cross-hatching. The embodiments of FIGS. 2 through 4 are suitable
for any tooth cleaning method.
[0038] The embodiment of FIG. 5 shows structures 5 on the outer
bristles in the form of circular, planar depressions, whereas FIG.
6 shows structures 5 of circular lines.
[0039] In the embodiment of FIG. 7, the bristles 3 of the bristle
stock 4 have differing lengths, i.e. they are longer in the region
of the front end of the brush head 2 than in the remaining region
of the bristle stock, thereby forming a "topography" with one step
in the front region. In a similar fashion as in FIG. 1, structures
5 are provided in the envelope of the outer bristles in this front
region only.
[0040] In the embodiment of FIG. 8, the bristle stock 4 has a
"topography", wherein the ends of a portion of the bristles 3 lie
in one plane, and the ends of the other portion of the bristles are
subdivided into individual groups 6 and lie in a higher plane,
relative to the bristle support 2. In this embodiment, only the
protruding bristles of the group 6 have linear structures.
[0041] FIGS. 9 through 11 each show a top view of a tooth brush
head 2 with bristle stock 4, viewing onto the free ends of the
bristles 3. The outer contour of the bristle stock 4 approximately
follows the contour of the tooth brush head 2. In the embodiment of
FIG. 9, the bristles are shortened only in the region of the front
end of the bristle head through laser radiation, i.e. along
concentric lines 7 of a polygon. In the embodiment of FIG. 10, the
bristles 3 are shortened in a regular crosshatched pattern, while
in the embodiment according to FIG. 11 they are shortened along the
line 9.
[0042] FIG. 12 shows a perspective view of a tooth brush head 2,
wherein the envelope of the external bristles has a structure 5 of
parallel lines. The bristles are also shortened in the region of
the front end of the head in a cross-hatched fashion.
[0043] In the embodiment of FIG. 13, the bristle stock 4 consists
of groups 9 of bristles formed as round bundles. The front region
of the bristle head 2 has groups 10 and 11, wherein the free
bristle ends have been cut to different lengths using laser
radiation such that the free ends of the groups 10 and 11 have
different conical taperings. It is also possible to structure the
envelope of the bristles disposed on the conical surface.
[0044] In the embodiment of FIG. 14, the bristle stock 1 again
consists of groups 9 of bristles in the form of cylindrical
bundles, while a group 12 of individually standing bristles is
disposed in the front region of the bristle head. In this
embodiment, only the bristles 3 of this group 12 have linear
structures 5 which extend parallel to one another.
[0045] FIGS. 15 through 17 show a top view onto the bristle stock 4
of brushes having a rounded head which are used, in particular, in
electrical tooth brushes. In accordance with FIG. 15, the bristles
3 are shortened along concentric rings 13, while in the embodiment
in accordance with FIG. 16, the bristles 3 are shortened to produce
a spiral topography. In the embodiment in accordance with FIG. 17,
the bristles are cut in a co-radial 15 fashion. The embodiments of
FIGS. 16 and 17 particularly enhance the action of the free bristle
ends when the bristle head rotates about its central axis.
[0046] FIG. 18 shows a tooth brush head 2 similar to that of FIGS.
13 and 14, whose bristle stock 4 comprises groups 9 of bristles
formed as round bundles, and with a bristle group 12 disposed at
the front end. The front bristle group 12 consists of individual
bristle strips which are disposed like a star, wherein the
individual strips have parallel structures 5 disposed substantially
perpendicular to the bristle axis.
[0047] In the embodiments according to FIGS. 19 through 21, the
individual structures 5 produced on the envelope of the outer
bristles of the bristle stock 4 by the laser radiation, are
irregular, but have a regularly disposed statistical distribution
across the entire side surface of the bristle stock.
[0048] The envelope of individually standing bristles, in
particular of those having a larger diameter, can be structured in
the same fashion as described above in connection with an entire
bristle stock or bristle groups of such a stock. In the embodiment
of FIG. 22, the envelope of the bristle 3 has inclined structures 5
whereas the embodiment of FIG. 23 has a zig-zag-shaped line
structure 5. The bristle 3 can be structured with cross-hatching as
shown in FIG. 24.
[0049] FIG. 25 shows a round brush having a cylindrical carrier 1
which can be e.g. the head of a hair brush, a technical brush or
the like. Ray-shaped, cylindrical bristle groups 16 are mounted on
the support 1 whose free ends have parallel structures 5.
* * * * *