NZ239172A

NZ239172A - Bristled article with tuft cavities having a lower portion cross-sectional area less than the cross-sectional area of an upper portion

Info

Publication number: NZ239172A
Application number: NZ23917291A
Authority: NZ
Inventors: Albert C Chen; Peter Hrinko; Kevin G Yost; John R Kent
Original assignee: Johnson & Johnson Consumer
Priority date: 1990-08-16
Filing date: 1991-07-29
Publication date: 1995-05-26
Also published as: IE65340B1; GB2247400B; TW225984B; JPH04261605A; AU8248391A; GB2247400A; AU652769B2; IE912901A1; JP3193079B2; GB9117597D0; BR9103498A

Description

<div class="application article clearfix" id="description"> 239 172 Patents Form No. 5 Number PATENTS ACT 1953 Dated COMPLETE SPECIFICATION BRISTLED ARTICLE We, JOHNSON & JOHNSON CONSUMER PRODUCTS. INC. of Grandview Road, Skillman, New Jersey 08558, United States of America, a corporation organized under the laws of the State of New Jersey, United States of America do hereby declare the invention for which I/we pray that a Patent may be granted to me/us, and the method by which it is to be performed, to be particularly described in and by the following statement: - 1 - (Followed by page la) 239172 -1 a- The present invention relates to an improved bristled article and more particularly to an improved toothbrush. The bristled article has a tuft cavity wherein the 10 cross-sectional area of the tuft cavity decreases such that the tuft cavity is broadest at a surface contiguous to an open top end of the cavity and narrows toward a bottom closed end of the tuft cavity. With all other components left unchanged, this decrease of the breadth of 15 the tuft cavity results in a greater packing factor and therefore better bristle retention in the smaller closed bottom end portion of the cavity. The bristled articles embodied in this invention include toothbrushes, hairbrushes, clothes brushes, industrial brushes, brooms, 20 copier brushes, mascara applicators and the like. Description of the Related Art Bristled articles of the related art may be produced by 25 injecting a thermoplastic material into a mold to form an article base, and subsequently mechanically anchoring the article base with tufts of bristles. A potential problem with bristled articles of the related 30 art described above is that the bristles may loosen or fall out of their tuft cavities. The effectiveness of the bristled article is thereby decreased. Loss of bristles from a tuft cavity reduces the number of exposed bristle ends and available effective surface. Further, loss of 35 bristles in a tuft cavity reduces how tightly and securely 239172 -2- the remaining bristles are retained in the cavity. In addition to lowering efficacy of these articles, loss of bristles reduces the convenience with which such bristled articles can be used. Understandably, users prefer not to use articles which leave stray bristles behind after use. Some types of toothbrush bristles historically have greater tendency for bristle fall out and therefore need increased bristle packing to improve bristle retention. 10 Different diameters of bristles are used by those skilled in the art to achieve a range of textures in toothbrushes. Toothbrushes have bristles ranging from 0.003 inch to 0.012 inch in diameter, more commonly from 0.005 inch to 0.012 inch. Individual bristle fallout is 15 more likely to occur in toothbrushes with small diameter bristles or an insufficient number of bristles in a tuft. Attempts to reduce the incidence of loose bristles in the brushes of the related art have not been wholly 20 successful. One such approach involves the insertion of increased numbers of bristles into each tuft cavity of the bristled article. A serious attendant problem with this approach is that splaying of the bristles occurs when too many bristles are crowded into a tuft cavity creating an 25 undesirable "bushy" appearance conveying a perception of a defective or worn brush. It is an object of the invention to provide such a bristled article having a tuft cavity configuration that 30 increases retention of the anchored bristles without attendant splay. With the above and other objects in view, the present invention comprises the combination and arrangement of 35 parts hereinafter more fully described, illustrated in the JDC-187 239172 m -3- accompanying drawings and more particularly pointed out in the appended claims, it being understood that changes may be made in the form, size, proportions, and details of construction without departing from the spirit or 5 advantages of the invention. Summary of the Invention In accordance with the present invention a bristled 10 article is provided comprising a plurality of bristles or filaments that are folded into tufts, and having at least one or more tuft cavities in a base that has a surface contiguous to an open top end of each tuft cavity. When filaments are inserted into the tuft cavity they form 15 approximately U-shaped bristles having two free ends and a portion in between the two ends that is placed inside the tuft cavity. An anchoring means holds the tufted bristles together inside the tuft cavity. The free ends of the tufted bristles remain outside of the tuft cavity wherein 20 the cross-sectional area of the tuft cavity decreases in such a way that the tuft cavity is broadest at the surface contiguous to the open top end of the cavity and narrows in a step towards a closed bottom end of the cavity at a point in the tuft cavity that will effectively prevent 25 splaying of the free ends of the tufted bristles. In a preferred embodiment of the bristled article, the tuft cavity narrows in step at a point 20% to 65% of the depth of the cavity. The cross-sectional area of the tuft 30 cavity remains constant above the step and remains constant at a smaller value below the step. In a more preferred embodiment of the bristled article the cross-sectional area of the top one-third of the depth of 35 the tuft cavity remains constant and the cross-sectional JDC-187 239172 -4- area of the remaining two-thirds of the tuft cavity decreases in a step so that the cross-sectional area of a closed bottom end portion of the cavity is less than the cross-sectional area of an open top end portion of the 5 remaining two-thirds of the cavity. The bristled article of a preferred embodiment is a toothbrush that has a base that has a long handle. Also the mechanical means of securing the bristles in the 10 cylindrical tuft cavity is an anchor, and the diameter of the closed end portion of the tuft cavity decreases in a step by about 2 to 20%. In another preferred embodiment the cross-sectional area of the tuft cavity decreases by 2% to 20% by tapering over a portion that is from 0% to 15 30% of the depth of the cavity. In a preferred embodiment the packing factor in the narrower portion of the tuft cavity is greater than that of the upper wider portion. Packing factor is defined as the sum total cross-sectional areas of the bristles in the tuft cavity divided by the 20 tuft cavity cross-sectional area, excluding the area of the anchoring means. As embodied and described herein the invention further comprises a method for making a toothbrush with a 25 plurality of bristles anchored in a toothbrush head, with improved bristle and tuft retention comprising the steps of: tufting a plurality of bristles; dispersing the tufted bristles in a tuft cavity in the toothbrush head; and anchoring the tufted bristles by anchoring means that 30 hold the plurality of tufted bristles together inside the tuft cavity while the free ends of the tufted bristles remain outside of the tuft cavity. The bristle and tuft retention of the toothbrush is improved by narrowing the cross-sectional area of said tuft cavity so that said tuft 35 cavity is broadest at the surface contiguous to the open JDC-187 239172 10 -5- top end of said cavity and narrows toward a closed bottom end of said cavity. Furthermore/ the narrowing of the cross-sectional area of said tuft cavity is effective to minimize splaying of the free ends of the tufted bristles. Brief Description of the Drawings FIGURE 1 is a perspective view of a toothbrush which is an embodiment of this invention; FIGURE 2 is a fragmentary perspective view of one group of bristles in a preferred embodiment of this invention; FIGURE 3 is an exploded perspective view showing the 15 bristles and base prior to insertion of the bristles; FIGURE 4 is an enlarged cross-sectional view taken along line 4-4 of FIGURE 2 and perpendicular to the anchor showing the straight sided open end portion of the tuft 20 cavity connected to a straight sided closed end portion by a step; FIGURE 5 is an enlarged cross-sectional view taken along line 5-5 of FIGURE 2 parallel to the anchor and 25 perpendicular to the bristles passing under it showing the same type of cavity as Figure 4; FIGURE 6 is a top plan view of the tuft cavity of the preferred embodiment depicted in FIGURE 3 - without the 30 bristles shown; FIGURES 7 through 11 show alternative embodiments of the tuft cavity which can be employed by the principles of this invention; 35 JDC-187 239172 10 -6- FIGURE 7 is a square configuration; FIGURE 8 is a rectangular configuration; FIGURE 9 is a hexagonal configuration; FIGURE 10 is an oval configuration; and FIGURE 11 is a rhomboidal configuration; FIGURES 12 through 15 show alternative cross-sectional tuft cavity shapes; FIGURE 12 shows a straight sided open end portion of the 15 tuft cavity and a tapered closed end portion; FIGURE 13 shows a straight sided open end portion of the tuft cavity joined to a tapered closed end portion by a step; 20 FIGURE 14 shows a straight sided open end portion of the tuft cavity joined to a tapered closed end portion by another tapered portion; and 25 FIGURE 15 shows a straight sided open end portion of the tuft cavity joined to a straight sided closed end portion by a tapered portion. Detailed Description of the 30 Preferred Embodiments of the Invention Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the following Examples section. The 35 preferred embodiments are conveniently described by JDC-187 239172 -7- reference to the accompanying FIGURES 1-15. The step in all of the figures is exaggerated for purposes of clarity. FIG. 1 illustrates a toothbrush 10 of an embodiment of 5 this invention. Handle 12 (which may be composed of various plastic polymers including polypropylene, cellulosics, polyesters, and acrylics, or wood and other suitable substances) is attached to the toothbrush head 14 which preferably has a plurality of tuft cavities 20. 10 As can be seen in FIGS. 2 and 3 a cylindrical tuft cavity 20 contains a tuft 16 of a plurality of bristles 18 (which may be composed of various plastic materials including polyamides, polyolefins, polyesters or natural fiber 15 materials such as animal hair) . The tuft cavity has an open end 22 and a closed end 24. The tuft cavity is cylindrical and has a hemispherical closed bottom end in a preferred embodiment. The schematic diagrams of FIGS. 6 -11 illustrate some alternative embodiments of tuft 20 cavities. The product of this invention is in no way limited to the exemplary shapes illustrated. Other useful product shapes known to those skilled in the art may also be used in accordance with the present invention. For example, the shapes of the closed bottom end may be 25 hemispherical, chamfered, conical, flat, or flat with some texture or raised surface on it such as a crossed spline. FIG. 3 illustrates that the decrease in diameter between closed bottom end 24 and open top end 22 occurs in a step 30 26. The arrow entering open top end 22 shows how the bristles 18 are inserted into the tuft cavity 20. Likewise, the arrow touching the tuft 16 shows the direction in which an anchoring means 28 is inserted into the tuft cavity to press part of the individual bristles 35 18 toward the closed bottom end 24 of the tuft cavity so JDC-187 239172 -8- that the bristles 18 will be unlikely to be dislodged from the tuft cavity 20. Optimum anchoring, as known by those skilled in the art, requires careful control of anchor depth, diameters of portions of the hole, and the number 5 of bristles in the hole to achieve the desired packing factor previously described. Within the limits of good manufacturing, a high level of bristles in the tuft cavity, achieving a high packing factor, will increase the likelihood the bristles will not become loose and separate 10 from the tuft. The anchoring means 28 illustrated in FIG. 3 is a fastener that may consist of metal, plastic, wood, or any variety of synthetic or natural materials. Like the tuft cavity 15 there are many other alternate embodiments of the anchor that are encompassed by the product of this invention. Also, many different sizes of anchoring means 28 will be acceptable. 20 The splaying prevention feature of these products is accomplished by a step 26 in the cavity 24 that can be seen in the schematic diagrams in FIG. 4 and FIG. 5. In FIG. 4 the diameter D of the wider open top end 22 of the tuft cavity 20 is wider than the diameter of the closed 25 bottom end 24. The bristles 16 may expand into open top end portion 22 before their free ends are exposed beyond the surface contiguous to the open top end 22. The tuft cavity 20 is designed with a smaller 30 cross-sectional area at the closed bottom end 24 so the bristles 18 are optimally packed in the tuft cavity 20 and around the anchoring means 28. As a result, individual bristles 18 are unlikely to come loose from the closed bottom end 24 of the tuft cavity 20. A larger 35 cross-sectional area is provided at the top end 22 so that JDC-187 239172 -9- the tuft of bristles 18 does not have undesirable splay but remains together as a parallel and closely grouped aggregate. 5 The distance "x" does not have to be of equal length throughout the tuft cavity as it is in FIG. 4. In FIG. 7, for example, step 3 6 between the open top end 32 and closed bottom end 34 does not have to be the same for all four sides and may have up to four different lengths. 10 This applies to the embodiments in FIG.'s 8 through 11 as well. Similarly, in FIG. 9 step 56 between open top end 52 and closed bottom end 54 can be different along each respective side of the hexagon. Embodiments of tuft cavities with straight sides such as tuft cavities 30, 40, 15 50, and 70 may have as many different sizes of steps as they have sides along the open and closed ends. The steps do not have to be uniform in circular and elliptical embodiments either (i.e. FIG.'s 2, 3, 6, and 10) because the closed end may be positioned closer to one portion of 20 the wall of the open end. Referring to any of FIGS. 2-5, it is essential that the diameter of the open top end 22 be greater than the diameter of the closed bottom end 24. It is 25 inconsequential whether the step is symmetrically or asymmetrically juxtaposed between the "X" open top and closed bottom end. Preferably, the decrease in step width is about 2 to 20 percent of the diameter as illustrated in the preferred embodiments of FIGS. 4, 5 and 6. The step 30 does not necessarily have to fall within this preferred range, rather the step change in width should be of an amount effective to significantly increase packing factor and retention of bristles while minimizing any splaying effects herein. 35 JDC-187 239172 -10- As illustrated below, as the packing factor in the closed bottom end of the tuft cavity is increased the bristle removal force is also increased. Greater bristle removal force means the bristles are more likely to be retained in the tuft cavity. Examples The invention will now be illustrated by Examples. The 10 Examples are not intended to be limiting of the scope of the present invention, but read in conjunction with the detailed and general description above, provide further understanding of the present invention, and an outline of a process for preparing the toothbrush and other bristled 15 articles of the invention. Toothbrushes in accordance with the invention are made by conventional molding processes of preparing bristled articles known in the art except they employ a distinctive 20 core pin shape that is broadest at the open top end portion of the pin and narrows in a step toward the closed bottom end portion of the pin to form the appropriate tuft cavity. 25 The handle material used may be any injection moldable polymer such as polypropylene or cellulose acetate propionate. The polymer is processed in an injection molding machine by heating (melting), injecting under pressure into a mold and then cooling until rigid. The 30 polymer is forced into the mold cavity or cavities which contain precisely formed core pins in a specific pattern. The cooled plastic handle or article replicates the cavity/core pin configuration. 35 JDC-187 239172 -11- When toothbrushes are being prepared, toothbrushes bristles are inserted into the molded polymer handle utilizing conventional bristling equipment (e.g. Boucherie, Zahoransky or Evans machines). Other types of mechanical anchoring-bristling equipment are also suitable and can be applied in compliance with conventional methods to produce toothbrushes in accordance with the invention. Examples below illustrate that bristled articles of this 10 invention have greater bristle retention force than known bristled articles. The tuft cavities of the following toothbrush samples are cylindrical and are 0.150 inches deep. 15 To determine bristle and tuft retention these examples were subjected to force of removal tests utilizing conventional force testing equipment, e.g. the Instron Universal Testing Machine. The test procedure is as follows: at one end an operator places the toothbrush in 20 the machine so that the toothbrush is held by a holding device such as a jig while a hemostat or other clamping means is positioned above the toothbrush so that it pulls a bristle until it is completely removed from the tuft cavity. The operator chooses an outer bristle to clamp in 25 the hemostat. As illustrated in FIG. 4, bristles that are closer to the anchoring means have a narrower closed end portion than bristles that are closer to the walls of the tuft cavity. Bristles that are closer to the tuft cavity walls than to the anchor (wide-bend bristles) have a wider 30 shaped U than bristles that are closer to the anchor (narrow-bend bristles). The operator chooses bristles farther from the anchor because they are more likely to become loose than the bristles closer to the anchor that have a tighter bend at the closed bottom end portion. 35 JDC-187 239 172 -12- Removing bristles with a wider bend requires less force and therefore these are the bristles of interest. After the operator chooses a bristle with a wider bend to 5 be clamped, the Instron machine pulls the bristle until it comes out of the tuft cavity. The operator records the data regarding that bristle. The test is performed on only one wide-bend bristle in each tuft cavity since as bristles are removed from the tuft cavity the packing 10 factor, and therefore the bristle removal force decreases. The bristle retention force discussed in the Examples refers to the single bristle removed from each tuft cavity. 15 Toothbrush bristles with diameters of 0.006, 0.007, and 0.010 inch were placed within tuft cavities 0.150 inch deep, and therefore required a bristle removal force in the range of about 150 to 200 grams to remove a bristle from each tuft cavity. The mean bristle retention forces 20 ranged from 74 ± 19 grams to over 356 ± 159 grams. In order to increase the packing factor in the closed bottom end portion of the tuft cavity and prevent splaying of the free ends of the bristles beyond the surface contiguous to the open top end portion, the diameter of the open top end 25 portion of the 0.150 inch deep tuft cavity was 0.073 inches while the diameter of the closed bottom end portion of the tuft cavity was 0.069 inches. The bristle retention forces are reported as the mean + 30 standard deviation for ten samples. The effect of packing factor in the current invention on bristle removal force is illustrated in the following examples. 35 JDC-187 239172 -13- Current Practice Example 1 These examples are presented to show the effect of current practice for comparison to the present invention. 5 Toothbrushes produced according to current practice have tuft cavities with uniform diameters from the open top ends to the closed bottom ends. Tuft cavities of toothbrushes of this Example with uniform diameters of 0.073 inches and hemispherical closed bottom ends 10 containing bristles of 0.010 inch diameter have a packing factor of 0.68 and mean bristle removal force of 103 ± 18 grams. Current Practice Example 2 15 This example is produced according to the procedure of Current Practice Example 1 having tuft cavities of a uniform 0.073 inch diameter and hemispherical closed ends. Bristles with a diameter of 0.006 inch placed in 20 the tuft cavities to achieve a packing factor of 0.65 show bristle retention forces of 69 ± 36 grams. Bristles with diameters of 0.007 inch and a packing factor of 0.67 show measured bristle retention force to be 88 ± 45 grams. 25 Example 1 W The tuft cavities of Example 1 have hemispherical closed bottom ends with a 0.073 inch diameter over the top one-third of the cavities and a 0.069 inch diameter over 30 the remaining bottom two-thirds of the cavities. The packing factor of the open top end portion of the cavity is 0.68, however, the packing factor of the closed bottom end portion is 0.77 and the bristle removal force mean of the ten sampled 0.010 inch bristles is 272 ± 67 grams. 35 The difference between the bristle removal force mean of JDC-187 239 1 -14- this Example and of Current Practice Example 1 discussed previously is significant. Despite the larger bristle removal force of this example, splaying of the free ends of the tufted bristles was avoided. 5 Example 2 This Example as well as Example 3 is carried out according to the same general procedure of Example 1. Like Example 10 1, the diameter of the open top end portion is 0.073 inch and the diameter of the closed bottom end portion is 0.069 inch. Unlike Example 1 the closed bottom end shape is flat. While the packing factor of the closed bottom end portion of this configuration is the same (0.77) as the 15 one for Example 1, the bristle removal force mean (184 + 37 grams) is not as high, but still much larger than the bristle removal force mean of Current Practice Example 1, and again undesirable splaying was avoided. 20 Example 3 This Example is produced according to the procedure of Example 1. In order to calculate the mean bristle removal force for the 0.006 inch and 0.007 inch bristles, force 25 testing was performed on ten tuft cavities of each type of bristle. Wide-bend 0.006 inch bristles having a packing factor of 0.74 within a tuft cavity of 0.069 inch diameter along the 30 entire depth of the cavity (0.004 inch smaller than the diameter of the tuft cavity described previously) have a mean bristle removal force of 156 + 68 grams when the closed bottom end is hemispherical. Wide-bend 0.007 inch bristles inserted into a tuft cavity having a diameter of 35 0.069 inch along the entire depth of the cavity and JDC-187 239 1 7 -15- achieving a packing factor of 0.76 have a mean bristle removal force of 156 ± 77 grams. In comparing these values to those of Current Practice Example 2, the improvement in bristle retention force with increased packing factor is seen. Packing factor is increased in the Examples by narrowing the diameter of the closed bottom two-thirds of the tuft cavities in a step. The examples also show that smaller 10 diameter fibers characteristically have lower bristle retention forces. The improvement in bristle retention achieved by the present invention is observed by comparing the increase in 15 retention force for 0.010 inch bristles from 103 grams in the uniform diameter tuft cavities of Current Practice Example 1 and the 272 grams in the stepped tuft cavities of Example 1. A more important change is seen with the smaller diameter bristles of Current Practice Example 2 20 showing an increase in retention force from 69 grams and 88 grams to 156 grams in the stepped holes of Example 3. These show an increase to greater than 170% of the original bristle retention forces for these bristle sizes. These increases are achieved through an increased 25 packing factor allowed by the stepped hole design. Increasing the packing factor had more of an effect upon bristle retention force than did different shapes of the closed bottom end of the tuft cavity. For example, the 30 difference between the bristle retention force values of Example 1 (hemispherical closed bottom end) and those of Example 2 (flat closed bottom end) is not significant. By tapering the diameter from the broadest open top 35 portion to the narrower closed bottom end portion one JDC-187 239172 -16- increases packing factor. However, undesirable splaying is not prevented as well by a configuration of this sort as by one which has a step decrease in diameter from the open top end portion to the closed bottom end portion of 5 the tuft cavity. In toothbrushes, tapering the diameter from the broadest open top portion to the narrower closed bottom end portion is probably not desirable because of potential splaying, but for other applications it may be favored. For example, a broom containing bristles that 10 splay covers more floor space than a broom containing bristles that do not splay. In such cases, i.e. brooms, more area can be cleaned faster with a tool that has splayed bristles. FIGS. 12-15 illustrate some different tuft cavities that have tapered portions. 15 The scope of the present invention is not limited by the description, examples and suggested uses herein, and modifications can be made without departing from the spirit of the invention. For example, the stepped 20 cavities of the invention may be utilized for producing other bristled consumer items, e.g. hairbrushes, brooms, scrub brushes etc. and the above examples delineate a variety of closed bottom end shapes that are not meant to encompass all of the shapes that may also be used in 25 accordance with the present invention. Application of the methods of the present invention can be accomplished by any extruding, injection molding, anchoring, bristling and product forming methods and 30 techniques as are presently or prospectively known to those skilled in the art. Thus it is intended that the present application cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 35 JDC-187 </div>

Claims

<div class="application article clearfix printTableText" id="claims"> -17- *9 172 WHAT WE CLAIM IS:

1. A bristled article comprising: a base having walls defining at least one tuft cavity extending into said base and having an open top end contiguous with a surface of said base, said tuft cavity having an upper portion and a lower portion; at least one plurality of bristles folded into a tuft, said tuft having a folded portion and free ends; said folded portion of said tuft being inserted into said tuft cavity and held therein with anchoring means with the free ends of said tuft extending out of said cavity; wherein the entire folded portion of said tuft is held inside the lower portion of said tuft cavity and the lower portion of said tuft cavity has a cross-sectional area which is less than the cross sectional area of the said upper portion of the cavity and wherein at least a portion of the bristles will splay outwardly so that the lowest part of said outwardly splayed bristles extend from said lower portion at an acute angle to the wall of the upper portion and the upper part of said splayed bristles are redirected by the constraint of the wall of the upper portion to extend substantially parallel to each other when exiting the tuft cavity.

2. The bristled article according to claim 1 wherein the depth of the upper portion of said tuft cavity comprises 20% - 65% of the depth of the tuft cavity and the cross-sectional area of the upper portion remains constant throughout its depth, and wherein the cross-sectional area of the lower portion of said tuft cavity decreases from said upper portion in a step.

3. The bristled article according to claim 2 wherein the cross-sectional area of the lower portion of said tuft cavity decreases by 2% to 20% from the cross-sectional area of the upper portion in a step or by tapering over a portion from 1% to 30% of the depth of the cavity and wherein the cross-sectional area of the portion of the tuft cavity below said step or taper remains constant or decreases in a taper. -18- 239172 The bristled article according to any one of the preceding claims wherein the upper portion comprises the top one-third of the cavity depth, and wherein the cross-sectional area of the upper portion remains constant throughout its depth, and wherein and the cross-sectional area of the lower portion decreases in a step. The bristled article according to any one of the preceding claims wherein the article is a toothbrush. The toothbrush of any one of the preceding claims wherein the tuft cavity is cylindrical. The toothbrush of claim 5 wherein the cross-sectional area of the top 20-65% of the depth of the cylindrical tuft cavity remains constant and the diameter of the remainder of the tuft cavity decreases in a step by substantially 2 to 20%. The toothbrush of claim 5 wherein the cross-sectional area of the top one-third of the depth of the cylindrical tuft cavity remains constant and the cross sectional area of the remaining two thirds of the tuft cavity decreases in a step. The bristled article of any one of the preceding claims wherein the base has a long handle. The toothbrush of claim 5 wherein the cross-sectional area of the tuft cavity occupied by the plurality of bristles as measured by the total cross-sectional area of the bristles in the tuft cavity divided by the cross-sectional tuft cavity area, excluding the anchoring means area, comprises a packing factor and the packing factor is greater in the lower portion than the upper portion of the tuft cavity. The toothbrush of claim 10 wherein the packing factor in the lower portion of the tuft cavity is greater than substantially 0.74. The toothbrush of claim 10 wherein the packing factor is in the rang^fgwb^tantially 0.74 - 0.77. 239172 The toothbrush of claim 5 wherein a bristle removal force comprises the necessary amount of force exerted upon a bristle to remove said bristle from the tuft cavity and the bristle removal force is greater than substantially 150 grams. The toothbrush of claim 13 wherein the bristle removal force is in the range of substantially 150-200 grams. The toothbrush of claim 5 wherein the diameter of the bottom two-thirds of the cylindrical tuft cavity is from substantially 2 to 20% less than the diameter of the top one-third of the tuft-hole. A bristled article substantially as herein described with reference to the accompanying drawings. WEST-VVALKEFT, McCABE gen . ATTORNEYS for the applicant ^5 £ N </div>