KR100334375B1 - Brush head composition for toothbrush - Google Patents

Abstract

A toothbrush is provided with a first set of discrete tufts (31) that are generally rectangular in the cross section perpendicular to the tuft axis with the larger dimension running parallel to the side of the brush head (1). A second set of tufts (32) is provided at the end of the head (1) remote from the handle, this set of tufts, or single tuft, having a cross section perpendicular to the tuft axis that is either 'C' or 'U' shaped or rounded. The arrangement of bristle tufts described provides a lower brushing stiffness in a direction transverse to the longitudinal axis of the brush.

Description

Bristle Compositions for Toothbrushes

The present invention relates to a novel device which is a toothbrush.

Toothbrushes are well known products and include a handle having bristles-containing heads all aligned along a longitudinal toothbrush axis at one end. The bristles on these heads are typically placed in the sockets at the bristle surface of the head and are generally aligned in a pattern of discrete tufts extending perpendicular to the bristle surface. In known toothbrushes, these tufts are actually circular in cross section and are actually placed in a circular cross section socket at the head.

Toothbrushes having bristles aligned in isolation "mats" which actually comprise the entire part of the bristle surface are known, for example, from US4646381, which also contains a larger portion of the individual bristles comprising a substantial portion of the bristle surface. Toothbrushes are described that have a combination of a circular cross section tuft, an oval cross section and a rectangular cross section located within the middle portion of the mat.

US4268933 describes a toothbrush with bristles aligned with a large tuft of rectangular shape, with long dimensions actually aligned across the width of the toothbrush head. US2209173 describes a toothbrush having an elongated rectangular tuft of bristles with long dimensions aligned substantially parallel to the toothbrush axis, alternating with a rectangular tuft tilted together, wherein the bristles in the tuft have sharp edges. It is fixed to the tuft of.

A bristle tuft, which actually has a circular cross section, is in fact perpendicular to the longitudinal axis of the bristles in the tuft ("tuft axis"), whether the direction is parallel to the toothbrush axis or perpendicular to the toothbrush axis, ie across the width of the toothbrush. Have the same rigidity for bending. This is especially true when the head moves in the direction of the toothbrush axis that crosses the teeth parallel to the gums, such as when the head moves in a direction that is generally perpendicular to the toothbrush axis that sweeps the teeth up and down across the gums. It has the disadvantage of having. If the toothbrush is brushed across the gum to prevent damage to the gum, it is desirable to have a softer, ie less rigid against bending.

The inventors have invented a toothbrush having a tuft pattern of bristle elongated mats with round tufts of bristles at the ends of the heads away from the handle.

Accordingly, the present invention provides a toothbrush having a handle and a bristle-containing head at the distal end of the handle, wherein the bristles on the head protrude from the surface of all the toothbrush heads ("brush brim surface") in a direction generally perpendicular to the toothbrush axis. Which is aligned in a pattern of multiple discrete tufts, in combination with one or more tufts ("second tufts") at the distal end of the tuft pattern away from the handle, in a direction generally perpendicular to the toothbrush shaft. At least one tuft ("first tuft") having a cross section perpendicular to the tuft axis having a larger dimension in a direction generally parallel to the second tuft (i) generally circular Or a pattern of discontinuous tufts arranged in a polygonal pattern, or (ii) a single tuft of generally round cross-section perpendicular to the bristle surface, or (iii) generally on a longitudinal toothbrush axis. Generally "C" perpendicular to the bristle surface with a rounded bend of "C" or "U" facing the distal end of the bristle surface with one or more "C" or "U" protrusions aligned in parallel Or a tuft of cross-section having a "U" shape.

The term "generally parallel to the longitudinal toothbrush axis" includes all directions between absolutely parallel to the longitudinal axis and parallel to the longitudinal plane of the head of the toothbrush. The term “generally circular” includes ovals.

Typically, these first tufts each represent 25% or less of the area of the bristle surface of the head, for example 20% or less, suitably 10% or less, preferably less than 5%, for example 1 of the area of the bristle surface. To 2%. Typically, such tufts have a constant dimension (ie, in a direction generally parallel to the toothbrush axis of at least 1.5: 1, suitably 2: 1 or more, for example 2.5: 1 or more, for example 2.5 to 3.5: 1). "Length dimension") to a dimension that is generally in a direction perpendicular to the toothbrush axis (ie, "width dimension").

The cross section of this first tuft may for example be generally rectangular in shape with respect to a substantial part of the cross-sectional area having a length dimension of the rectangle generally aligned parallel to the toothbrush axis. The term “generally rectangular” includes rectangles having in particular rounded corners, rhombus shapes (ie having two generally parallel long sides and two rounded ends), parallelogram shapes and trapezoidal rectangle shapes. .

Alternatively, the cross section of the at least one first tuft may be of another generally linear polygonal or round shape, eg a diamond shape or at least one pointed end, having a length dimension aligned generally parallel or actually parallel to the toothbrush axis. And the “L” shape is aligned with a first protrusion generally aligned parallel to the toothbrush axis, and at a constant angle with respect to the first protrusion, for example about 45 ° with respect to the first protrusion. Or have a second protrusion, or the "V" shape has one or both of the protrusions of "V" aligned at an angle that is less than about 45 ° with respect to the toothbrush axis.

The toothbrush may have a single first tuft or many first tufts, and the tufts may be of different cross-sectional shapes combined, for example rectangular or rhombus shapes combined with "L" shapes. Representatively, the toothbrush of the present invention may have 2 to 25 first tufts, all of which may generally have a rectangular or rhombus shape.

For example, the first sphere of the toothbrush of the present invention may have a pattern of first tufts, which may have a generally rectangular cross section perpendicular to the tuft axis aligned to the bristle surface, each of the first tufts It has a length dimension of about 0.1 to 0.9, for example 0.25 to 0.75, of the total length of the surface, and the width dimension is about 0.05 to 0.5, suitably about 0.1 to 0.5 of the width of the bristle surface. Typically, the pattern of the first tufts may consist of 5 to 20, for example 5 to 12, such tufts. This first tuft may consist of a pattern of elongate rectangular or rhombic tufts having a longitudinal axis aligned generally parallel to the bristle surface. These first tufts each have, for example, about 0.75 of this length dimension, for example the length of the bristle surface, each of which extends along the entire length of the bristle surface actually occupied by the first tuft. Alternatively, the length dimension of the individual such first tufts can be, for example, about 0.1 to 0.5 of the length of the bristle surface, wherein the first tufts are at least two, for example two, across the width of the toothbrush surface. To six side rows. The first tuft in the above first embodiment may be arranged symmetrically with respect to the longitudinal axis of the toothbrush.

Alternatively, for example, a second embodiment of the toothbrush of the present invention may include one or more straight lines allocated across the width of a generally bristle surface of a tuft (“third tuft”) having a generally circular cross section, or It may have a tuft pattern consisting of two or more straight or curved side rows assigned in combination across a width of the generally bristle surface of the first tuft, combined with a curved row, for example. The first and third tufts of the second embodiment may be arranged symmetrically with respect to the longitudinal axis of the toothbrush.

Typically, in such a toothbrush there may be two to five, for example four side rows of the first tuft in combination with one to four, for example three rows of the third tuft. In the rows of first tufts, there may be two to five, for example four rows, which run across the width of the bristle surface, and in the rows of the third tufts, two to five, for example four A third tuft of generally circular cross section, or one to three, e.g., two generally rectangular cross sections, of the longest dimension assigned across the width of the bristle surface side by side across the width of the bristle surface Tufts may be present.

Alternatively, for example, the fourth embodiment of the toothbrush of the present invention may have a pattern of a first tuft having a generally rectangular cross section perpendicular to the tuft axis assigned to the bristle surface, the first tuft Each having a length dimension of about 0.10 to 0.9, typically 0.25 to 0.5, of the total length of the bristle surface, and typically, the pattern of the first tufts is 2 to 20, for example 5 to 12 such first tufts. Wherein the first tuft is assigned a first protrusion generally assigned parallel to the toothbrush axis, and at an angle with respect to the first protrusion, for example at an angle of about 45 ° to the first protrusion. In combination with one or more first tufts that are “L” shaped with a second protrusion. This "L" shaped first tuft may be disposed at the end of the bristle surface closest to the handle. The first tuft of the second embodiment is disposed symmetrically about the longitudinal axis of the toothbrush, preferably the toothbrush of this embodiment is an even number of such "L" shaped first toughs arranged symmetrically on one side of the longitudinal axis of the toothbrush. It has

If the second tuft consists of a pattern of discontinuous tufts, generally assigned in a circular or polygonal pattern, this second tuft is generally circular, semicircular, which may consist of a pattern of individual tufts assigned around a central tuft Or may have a pattern of tufts of generally circular cross section assigned to a polygon (each corner of which corresponds to the center of one of its tufts). Typically, the central tuft is a regular pattern of such tufts symmetrically assigned, such that there is, for example, the same number of second tufts arranged on one side of the longitudinal axis of the toothbrush, for example three peripheral tufts, For example, it may be surrounded by a cube pattern. The diameter of such a pattern can typically be about 0.5 to 0.95 of the width of the toothbrush surface near the pattern.

If the second tuft consists of a single tuft of generally round, e.g., round, oval, semicircular or semi-oval cross section perpendicular to the bristle surface, the diameter of this tuft is typically between about 0.5 and 0.95 near the tuft. It may be the width of the bristle surface.

Round band of “C” or “U” shape facing the distal end of the bristle surface away from the handle, with the second tuft having a “C” or “U” shape protrusion generally assigned parallel to the longitudinal toothbrush axis. When the tufts generally have a "C" or "U" shaped cross section perpendicular to the bristle surface having a diameter, the diameter of the rounded portion of this tuft may typically be about 0.6 to 0.9 of the width of the bristle surface near the tufts. have. The longitudinal axis of the toothbrush may be representatively divided into "C" "U" shapes.

A tuft of circular cross section in general has a first dimension as described above having a cross section perpendicular to the tuft axis, which has a larger dimension in a direction generally parallel to the toothbrush axis than in a direction generally perpendicular to the toothbrush axis. It may be additionally or alternatively combined with the second and third tufts.

The bristles in the first, second and third tufts may all have substantially the same length so that the surface of the tufts is actually flat, or alternatively, the length of the bristles in the direction of the tuft axis is in the direction of the toothbrush shaft or The length can be varied at different points along the direction perpendicular to this axis. This variation is particularly applicable to toothbrushes of the invention with alternating rows of tufts of different cross sections as described above, as in the second and third embodiments, while individual rows are included in the toothbrush. The length of the brush head can be varied. For example, for toothbrush shafts, tufts are for example DE 34 33 763, WO 91/19437, EP0449653A, US 4672706, US 451911, US 4268933, US 3229318, US 3188673, US As described in 2797429, US 1943225, US 74,560, and the like, it may have an “ripple” or “tooth” profile of alternating peaks and valleys.

Suitably, the first tuft may consist of bristles of length shorter than the length in the second and third tufts, and the second and third tufts may have the same length.

The bristles for making tufts can be made of plastic materials such as nylon, which are customary in the field of toothbrush bristles. The bristles are generally linear pieces of toothbrush material having conventional structures, for example with round polished ends.

The handle and head can be made of plastic material customary in the field of toothbrush handles. The head and handle may have an overall shape customary in the field of toothbrushes, the handle comprising, for example, one or more "V" shaped corrugations to modify the availability of the handle as described for example in EP 0336641A. The handle also comprises one or more grip-enhancing parts, for example in the form of a rubbery grip mat, as also described, for example, in EP 0336641A.

Tufts and individual bristles can be essentially placed in the toothbrush head by conventional techniques. Preferably, the bristles fuse together the ends of the bristles ("fixed ends") in the tuft to be fixed into the head into a mass by heating, and heat the bristles or the mass and the head material to a softening point and connect them together. After fusion, it is placed in the toothbrush head by a method of fusing the mass with the toothbrush head material continuously or simultaneously by cooling until it solidifies and welding it into the head. Suitably, the head is preformed using one or more sockets corresponding to the position, number and size of the tuft (s), the tuft (s) being as described above by the head material around the socket (s). Can be fused together. For manufacture by this method, the bristles and head must be made of a thermoplastic material, for example a known thermoplastic material such as nylon currently used in toothbrush manufacturing. Suitable methods for producing toothbrushes in this manner are described, for example, in US 2664316 and WO 93/12690, which are incorporated herein by reference.

In an alternative method of manufacturing the toothbrush of the present invention, the bristles of the tufts can be fused into a thermoplastic block in the tuft pattern described above using, for example, the fusion method described above, which block is for example heat The welding may be inserted and secured into a cavity in the head of the toothbrush, or alternatively the head of the toothbrush may be molded around the block.

Alternative methods of making the toothbrush of the present invention will be apparent to those skilled in the art.

The toothbrush of the present invention can be used in a fundamentally conventional manner by the user, and the tuft pattern of the toothbrush of the present invention is believed to improve the cleaning effect of the toothbrush and is believed to help reduce gum damage. Lose.

The invention will be described by way of example only with reference to the accompanying drawings, which are intended to represent the general concepts of the invention and are not intended to be limiting.

1, 2, 3, 4 and 5 are perspective views of the head of the toothbrush of the present invention.

6, 7, 8 and 9 are plan views of tuft patterns of bristle surfaces of the head of the toothbrush of the present invention.

10 is a longitudinal section through the toothbrush of FIG.

1 to 5 show a toothbrush head 1. Each head 1 is connected to an integrated handle 2. The toothbrush shaft is indicated by the line A-A in FIG. 1, the tuft axis is indicated by the line B-B in FIG. 1, and the width direction of the head 91 is indicated by the line C-C in FIG.

In each of the heads 1 to 5, tufts (generally 3) are arranged which generally extend perpendicularly to the toothbrush surface 1A of the head 1 in the direction of the tuft axis B-B.

In FIG. 1, the first tuft 31 is rectangular in cross-section, ie rhombus, taken perpendicular to the tuft axis B-B with two round ends. The pattern of tufts consists of many tufts 31 having a length dimension of at least 0.5 of the length of the bristle surface 4, which is actually larger than the width dimension, the length dimension of the bristle surface distant from the handle 2. At the end, it has one large second tuft 32 of circular cross section that is substantially parallel to and assigned to the toothbrush axis and perpendicular to the tuft axis BB.

In FIG. 2, the first tuft 31 has a cross-sectional rhombus shape taken perpendicular to the tuft axis BB, and the first tuft 34 has a cross-sectional "L" shape taken perpendicular to the tuft axis BB, It has a first projection that is substantially rectangular in cross section with a long projection generally assigned parallel to the toothbrush axis, and a second projection 34A at an angle of about 45 ° to the first projection. The second tuft 32 is a "U" shape with two protrusions arranged substantially parallel to the toothbrush axis in a cross-sectional shape taken parallel to the tuft axis and rounded at the end of the head away from the handle 2. The floor is adjacent. The longitudinal axis A-A of the toothbrush bisects the "U" shape between its two protrusions.

In FIG. 3, the first tufts 31 are generally rectangular, ie rhombic, in cross-section taken perpendicular to the tuft axis BB, and each of the four tufts, generally aligned side by side across the width of the bristle surface 4. The first tufts 31 are arranged in a series of five curved side rows. At the distal end of the bristle surface 4 remote from the handle 2, there is a pattern of generally circular cross-sections of the second tufts 32 arranged in a symmetrical hexagonal pattern around the center tufts. The diameter of the second tuft 32 pattern is about 0.9 of the width of the bristle surface 4 taken through the center of the pattern.

In FIG. 4, the first tufts 31 are generally rectangular, ie rhombic, in cross-section taken perpendicular to the tuft axis BB, and each of the four tufts, generally aligned side by side across the width of the bristle surface 4. The first tufts 31 are arranged in a series of four straight side rows. Between the alternating rows of first tufts 31 is a straight row of third tufts 33 aligned generally across the width of the bristle surface of tufts 33 having a generally circular cross section. . At the distal end of the bristle surface 1A away from the handle 2, there is a pattern of generally circular cross-sections of the second tufts 32 arranged in a symmetrical hexagonal pattern around the center tufts. The second tuft 32 and the third tuft 33 are longer in the tuft axial B-B than the first tuft 31.

In FIG. 5, the first tufts 31 are generally rectangular, i.e. rhombic, in cross-section taken perpendicular to the tuft axis BB, and each of the four tufts 31 is generally aligned side by side across the width of the bristle surface 1A. The first tufts 31 are arranged in a series of four straight rows. Between the alternating rows of first tufts 31, they generally have a rectangular cross section, but have the longest dimension aligned across the width of the bristle surface 1A, and generally aligned across the width of the bristle surface. The straight row of the third tufts 33 is located. At the distal end of the bristle surface 1A away from the handle 2, there is a pattern of generally circular cross-sections of the second tufts 32 arranged in a symmetrical hexagonal pattern around the center tufts. The second tuft 32 and the third tuft 33 are longer in the tuft axial direction B-B than the first tuft 31.

6 to 9 show a plan view of the head 1 of the toothbrush of the invention as seen under the tuft axis B-B.

In the toothbrushes of FIGS. 6 and 7, a pattern of tufts 31, 32 is shown which is similar to the pattern of tufts in the toothbrush of FIG. 3. The pattern is a cross-sectional rhombus shape taken perpendicular to the tuft axis BB and consists of a first tuft 31 arranged in a series of lateral rows generally aligned across the width of the bristle surface 4, the rows being the first ones. In FIG. 6 it is a curve (as shown in FIG. 3) and in FIG. 7 it is a straight line. The longitudinal dimension of the first tuft 31 is such that the five first tufts occupy the length of the bristle surface 4 occupied by the first tuft 31. At the distal end of the bristle surface 4 away from the handle 2, there is a pattern of generally circular cross-sections of the second tufts 32 arranged in a symmetrical hexagonal pattern around the center tufts.

In the toothbrushes of FIGS. 8 and 9, patterns of tufts 31, 32 are shown, similar to the pattern of tufts in the toothbrushes of FIGS. 4 and 5, respectively. The pattern is a cross section rhombic shape taken perpendicular to the tuft axis B-B and consists of a first tuft 31 arranged in a series of straight side rows arranged generally across the width of the bristle surface 1A. Between the alternating rows of first tufts 31, the third tufts having the longest dimension, generally aligned across the width of the bristle surface 1A, and generally aligned across the width of the bristle surface, 33 are located respectively. In FIG. 8, the third tuft 33 generally has a circular cross section. In FIG. 9, the third tuft 33 has a generally rectangular cross section, ie a rhombus shape, with the longest dimension aligned across the width of the bristle surface 4. At the distal end of the bristle surface 4 away from the handle 2, there is a pattern of generally circular cross-sections of the second tufts 32 arranged in a symmetrical hexagonal pattern around the center tufts.

Regarding FIG. 10, the head of the toothbrush shown in FIG. 9 is shown in longitudinal section with respect to the inclined axis D-D shown in FIG. 9. The toothbrush consists of a head 1, a handle 2, and a first tuft 31, a second tuft 32 and a third tuft 33. The tufts 31, 32, 33 consist of individual bristles which are generally all aligned in the direction of the tuft axis B-B perpendicular to the bristle surface 4. The ends of the bristles in the tufts 31, 32, 33 are fixed into the head 1 by fusing them into agglomerates by heat and then cooling them. At the bristle surface 1A, a socket 6 is located at the head, each chunk 5 is located in the socket 6, and at a location therein fuses with the material of the toothbrush head 1, the head material and the bristle material Are both thermoplastic. The tufts 31, 32, 33 of the toothbrush of FIGS. 1 to 8 are fixed into the head 1 of each toothbrush in a manner similar to that shown in FIG. 10. The technique used to fuse the mass 5 and the socket 6 may be the technique of US 2664316 or WO 93/10639 or other known methods, and the tufts 31, 32, 33 into the head 1. ) Is merely representatively shown.

Claims (22)

A toothbrush having a handle and a bristle-containing head at the distal end of the handle, wherein the bristles are all on the head in a pattern of discrete tufts that protrude from the surface of the toothbrush head ("brush brim surface") in a direction perpendicular to the toothbrush axis. Aligned with a tuft axis having a greater dimension in a direction parallel to the toothbrush axis than in a direction perpendicular to the toothbrush axis with a tuft ("second tuft") at the end of the tuft pattern away from the handle. A tuft having a vertical cross section (“first tuft”) is provided, the second tuft comprising (i) a pattern of discrete tufts arranged in a circular or polygonal pattern, (ii) a round cross section perpendicular to the bristle surface. Single tuft, or (iii) with a round bend of "C" or "U" facing the distal end of the bristle surface away from the handle with protrusions of "C" or "U" aligned parallel to the longitudinal toothbrush axis. "C" perpendicular to the brush surface Is in the form of a tuft of "U" shaped cross section. 2. The toothbrush of claim 1 wherein each first tuft occupies between 1% and 25% of the bristle surface area of the head. 3. The toothbrush of claim 1 or 2, wherein the cross section of the first tuft has a rectangular shape with respect to the cross-sectional area having a rectangular length dimension aligned parallel to the toothbrush axis. 3. The toothbrush of claim 1 or 2, wherein the cross section of the first tuft has a linear polygonal or round shape with a length dimension aligned parallel or nearly parallel to the toothbrush axis. 5. The toothbrush of claim 4 wherein the cross section of the first tuft has a "L" shape with a first protrusion aligned parallel to the toothbrush axis and a second protrusion aligned at a non-zero angle to the first protrusion. . 10. The toothbrush of claim 1, wherein the toothbrush has 2 to 25 first tufts, all of which have a rectangular or rhombus shape. The bristles of claim 1 having a pattern of first tufts having a rectangular cross section perpendicular to the tuft axis, aligned on the bristle surface, wherein the first tufts have a 0.05 to 0.5 width dimension of the bristle surface's width and the bristles' surface. Toothbrush having a total length of 0.1 to 0.9 length dimension, and comprises 5 to 20 first tufts. 8. The toothbrush of claim 7, wherein each tuft has a length dimension extending along the entire length of the bristle surface each occupied by the first tuft. 8. A toothbrush as recited in claim 7, wherein the length dimension of each such first tuft is such that it aligns the first tufts in lateral rows across the width of the bristle surface. The straight or curved side of claim 1 aligned across the width of the bristle surface of the first tuft in combination with the straight or curved side rows aligned across the width of the bristle surface of the third tuft having a circular cross section. Toothbrush characterized in having a tufted pattern of heat. 2. The first tuft in combination with a straight or curved lateral row of claim 1, arranged across the width of the bristle surface of the third tuft having a rectangular cross-section with the longest dimension aligned across the width of the bristle surface. And a tuft pattern consisting of straight or curved side rows aligned across the width of the bristle surface of the toothbrush. 12. The toothbrush of claim 10 or 11, wherein two to five side rows of the first tuft are combined with one to four rows of the third tuft. 12. The toothbrush of claim 10 or 11, wherein two to five first tufts traverse the width of the bristle surface side by side. 12. The bristles according to claim 10 or 11, wherein two to three third tufts of circular cross section, or one to three third tufts of rectangular cross section having the longest dimension aligned across the width of the bristle surface. A toothbrush characterized by crossing the width of the surface side by side. The bristles of claim 1 having a pattern of first tufts arranged on the bristle surface, the first tufts having a length dimension of the entire length of the bristle surface of 0.10 to 0.9, each consisting of 2 to 20 such first tufts. Wherein said first tuft is combined with a first tuft of "L" shape having a first protrusion aligned at an angle with respect to the first protrusion. 2. A polygon according to claim 1, wherein when the second tuft consists of a pattern of discontinuous tufts arranged in a circular or polygonal pattern, the second tuft is a pattern of tufts of polygonal or circular cross section aligned in a circle, Or each corner of the circle corresponds to the center of one of the tufts that make up and is aligned around the center tuft. 17. The toothbrush of claim 16, wherein the central tuft is surrounded by a six-tuft symmetrically aligned hexagonal pattern, with three of the surrounding tufts lying on one side of the longitudinal axis of the toothbrush. 18. The toothbrush of claim 17, wherein the diameter of the six-sided pattern is between 0.5 and 0.95 of the width of the bristle surface in the vicinity of the pattern. 2. The toothbrush of claim 1, wherein the second tuft consists of a single tuft of round cross section perpendicular to the bristle surface, wherein the diameter of the tuft is 0.5 to 0.95 of the width of the bristle surface in the vicinity of the tuft. 2. The "C" or "U" of claim 1, wherein the second tuft has a "C" or "U" shaped protrusion aligned parallel to the longitudinal toothbrush axis and facing the end of the bristle surface away from the handle. In the case of tufts of generally "C" or "U" shaped cross-section perpendicular to the bristle surface with a "shaped round band, the diameter of the rounded portion of this tuft is 0.5 to 0.95 of the width of the bristle surface near the tuft. Toothbrush characterized in that. 2. The toothbrush of claim 1 wherein the first tuft consists of bristles of length shorter than the lengths in the second and third tufts, and the second tuft and the third tuft have the same length. . 2. The tufts of tufts fixed in the head are fused together into agglomerates by heating, and the bristles or the agglomerate and head material are heated to a softening point and brought into contact by fusing together to be solidified. A toothbrush characterized in that tufts and individual bristles are disposed within the toothbrush head by cooling until welding and welding into the head, either continuously or simultaneously with the lump to fuse the toothbrush head material.