JP2009506837A - Variable diameter filament - Google Patents

Abstract

  The present invention discloses a filament having a varying diameter along its length. This change in diameter along the length of the filament improves both the interdental cleaning and the scrubbing effect of the toothbrush when assembled in the toothbrush bristle bundle.

Description

  The present invention relates to a filament that can be used in a toothbrush. More particularly, the present invention relates to a toothbrush having a filament having a variable diameter along its length.

(Cross-reference of related applications)
This application claims the benefit of US patent application Ser. No. 11 / 219,414, filed Sep. 2, 2005.

  Toothbrush filaments, or bristles, are usually made from constant diameter filaments made from thermoplastic polymers. Constant diameter filaments have a consistent diameter and cross-sectional area along the length of the filament that varies from 5 to 10% or less. There is a constant need to improve the cleaning performance of such toothbrushes made with these filaments. Cleaning performance is a combination of interdental cleaning between adjacent teeth and between teeth and gums and a scrubbing action that cleans the surfaces of the teeth and gums. While smaller diameter filaments tend to improve interdental cleaning, larger diameter and stiffer filaments are known to provide better scrubbing and plaque removal.

  The following disclosure may relate to various aspects of the present invention and may be briefly summarized as follows.

  There are a number of patents dealing with the use of constant diameter filaments with cut ends in toothbrushes. The following patents that can be related are: US Patent Publication (Patent Document 1), US Patent Publication (Patent Document 2), US Patent Publication (Patent Document 3), and (Patent Document 4). However, all of these patents relate to constant diameter filaments that are chemically cut or mechanically cut. This type of end cutting is accomplished by a secondary operation after the constant diameter filament has been manufactured. Since these filaments are cut off before being inserted into the toothbrush bristles, special care must be taken to insert the bristles at the appropriate height. This is important because any trimming performed on the toothbrush after bundling will change the tip, leading to reduced cleaning effectiveness. In some cases, special hair binding machines and / or processes are required to produce the desired brush. Furthermore, although these end cut filaments provide excellent interdental cleaning, they are not scrubbing because the tip diameter is very small. When the tip diameter is increased to improve the scrub, the interdental efficiency is reduced.

  Accordingly, it is desirable to have a filament that can provide interdental cleaning of smaller diameter filaments and scrubbing and plaque removal of larger diameter and stiffer filaments.

US Pat. No. 6,090,488 US Pat. No. 5,500,955 US Pat. No. 5,533,227 JP20000279230A U.S. Pat. No. 2,418,492

  Variations along their length, briefly described and according to one aspect of the present invention, bundled together with a handle and a toothbrush head at the end of the handle to form a bristle bundle attached to the toothbrush head A toothbrush is provided that includes a plurality of synthetic monofilaments having a diameter, each of the synthetic monofilaments differing from one or more synthetic monofilaments of the hair bundle in varying diameters along its length.

  According to another aspect of the present invention, there is provided a bristle bundle for use in a toothbrush comprising a plurality of synthetic monofilaments having varying diameters along their lengths that are bundled together to form a bristle bundle, the synthetic monofilament Each may differ from one or more synthetic monofilaments of the hair bundle in varying diameters along its length.

  The invention will be more fully understood from the following detailed description, taken in conjunction with the accompanying drawings, in which:

  These figures show the variable tip diameter achieved using the filaments of the present invention.

  While the invention will be described in conjunction with the preferred embodiments thereof, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, the intent is to cover all alternatives, modifications, and equivalents that may be included within the spirit and scope of the invention as defined by the appended claims.

  The filaments of the present invention are unique because they can provide a variety of different diameters for the same hair bundle. Filaments are not constant diameter filaments that are cut at both ends, but are filaments whose diameter varies along their length. The filaments of the present invention provide several advantages over existing constant diameter filaments because they provide toothbrushes with improved cleaning. The filaments of the present invention are very easy to process and do not require secondary operations after manufacture and prior to hair bundling to form variable diameter tips, so the existing ends have been cut Offers advantages over filaments. Filaments are grouped together in a manner similar to current constant diameter filaments, and variable diameter filaments can be bundled using standard manufacturing processes. Furthermore, the filaments of the present invention provide a combination of hair bundle diameters to provide both excellent interdental and surface cleaning of teeth and gums. The assembled toothbrush filaments may also be cut or rounded at the ends as part of a normal toothbrush (TB) manufacturing process. Examples of rounding the ends of the variable diameter filaments of the present invention are shown in FIGS.

  These filaments have been developed for toothbrush applications and improve brush cleaning performance when used in place of constant diameter filaments. The filaments of the present invention provide a variable diameter filament that improves both interdental cleaning and scrubbing effects of the toothbrush when assembled into a toothbrush bristle bundle.

  An embodiment of the invention is a variable diameter synthetic monofilament made using a thermoplastic polymer. Preferred polymers have a molecular weight (MW) greater than 10,000, polyamides (nylon 612, 610, 6, 1010, 66, blends and copolymers thereof), polyesters (polybutylene terephthalate, polyethylene terephthalate, and the two Most likely it consists of a blend) and a polyolefin (polypropylene).

  Variable diameter filaments have a minimum diameter of 0.003 inches to 0.015 inches and a maximum diameter of 0.005 inches to 0.020 inches and are manufactured using a typical monofilament manufacturing process for filaments. . This process involves melting a polymer or combination of polymers from the above list using a single or twin screw extruder, extruding the molten polymer blend through a spinneret plate to produce a filament, and quenching the filament. Performing the steps of: stretching the filament; annealing the filament; and assembling the filament into hanks (eg, a bundle of filaments having a diameter of about 2 inches). The filaments are drawn at a draw ratio of 3.75 to 4.25, producing filaments having a flexural modulus of 400,000 to 700,000 psi depending on the polymer used. Filaments may be made in any color by blending in different colorants or color concentrates. Also, different cross-sectional shapes such as hollow, trilobal, tetralocular and quadrilobal may be produced by extrusion through different capillary shapes. In addition, the filaments of the present invention contain various additives including but not limited to clay, Teflon (R) fine powder, metal powder, abrasive coarse particles, metal particles, and antimicrobial components. May be manufactured as follows.

  For a detailed description of the present invention, reference is now made to the drawings. After the filaments are grouped into hanks, the hanks are cut into specific length pieces. The cut pieces are then assembled into a toothbrush using a standard hair bundling process. Since the filaments in the hank vary in diameter along their length, the cutting process of the cut piece forms a variable filament tip diameter at the surface of the cut piece. Reference is now made to FIG. 1, which shows this altered filament tip diameter.

  Reference is now made to FIG. 2, which shows another embodiment of filament diameter variability. The tip diameter may range in size from 0.003 inch to 0.020 inch. When filaments are bundled on a toothbrush using a standard bristle binding machine, the tips of the filaments in the bundle also change in size from 0.003 to 0.020 inches before final processing.

(Example 1)
A blend of nylon 612 (manufactured by the applicant as Zytel®) was loaded into the hopper of a single screw extruder. A spinneret plate with round capillaries was placed in the die head and the polymer was extruded at 240 ° C. and quenched in water at 25 ° C. located about 1 inch below the spinneret plate. The filament diameter obtained was varied using a rubber pinch roll operated at a periodically varying surface speed as described in US Pat. Resulting in varying strand thickness. The minimum to minimum diameter was repeated in 4 inch increments. The filament was drawn at a draw ratio of 3.75: 1 resulting in a variable strand diameter of about 5-9 mils. The filament was heat set by passing through a furnace at 170 ° C to 180 ° C. After spinning, drawing, and heat setting, the filaments were wound on a large spool and made into hanks about 98 inches long with an average diameter of 2 inches. The hank was then wrapped in paper and cut to a final length of about 96 inches. The 96 inch hank was then cut into 34 mm long pieces. The surface of the cut piece contains 0.005 "to 0.009" variable diameter filaments and is similar to Figs. The cut pieces were assembled into a toothbrush using a typical toothbrush bristle binding machine. The toothbrush bristles were then examined and showed the same variable diameter at the tip. Reference is now made to FIG. 3, which shows a typical hair bundle produced by this product. FIG. 3 shows a hair bundle having a variable diameter ranging from 0.005 inches to 0.009 inches.

(Example 2)
Using the same process described in Example 1, filament cut pieces with tip diameters varying from 0.004 inches to 0.007 inches were produced. A 0.004 inch to 0.007 inch variable diameter material was produced by the extrusion process described in Example 1. The resulting extruded filament had a variable diameter of 0.008 to 0.014 inch. These were stretched at 3.75: 1 and heat set to produce filaments with variable diameters of 0.004 to 0.007 inches. The minimum to minimum diameter repeat cycle was 4 inches. Filaments were assembled in hanks, wrapped in paper, and cut into 34 mm pieces. The cut pieces are assembled into a toothbrush, resulting in a bristle bundle having a filament having a tip diameter that varies from 0.004 inch to 0.007 inch. The photograph of FIG. 4 shows an actual hair bundle.

  Toothbrushes with 0.004-0.007 inch variable diameter filaments were sent to the University of Pennsylvania for testing in their dental laboratory. The brush was tested for gingival access, gingival margin, interdental access efficiency (IAE), and deposit removal depth (DDR), and constant diameters of 0.005, 0.006, and 0.007 inches Compared to a toothbrush made of filament. The test results are shown in Table 1. As shown in the table, a variable diameter filament of about 0.004 to 0.007 inches had good interdental access, like a 0.005 inch constant diameter filament, but a 0.006 inch filament. As such, it has a higher DDR.

  Continuing to refer to FIG. 4, the brushes made with variable diameter filaments of about 0.004 to 0.007 inches and constant diameter filaments of about 0.006 inches and about 0.007 inches also show the rigidity of the toothbrush. Also measured. The results are shown in Table 2. As shown in the table, the stiffness of the variable diameter brush is lower than the 0.006 inch filament, making it a gentler treatment on the gingiva and softer by the user while providing the DDR that the stiffer 0.006 mil brush provides. It feels good.

  Thus, it is clear that the present invention provides a filament having a variable diameter that fully satisfies the objects and advantages set forth above. Although the invention has been described with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

Figure 2 shows a photographic cross-sectional view of a variable diameter 20x magnification of the present invention in a cross-sectional piece. FIG. 3 shows a photographic cross-sectional view at 50 × magnification of the variable diameter of the filament of the invention in a cross-sectional piece. FIG. 3 shows a photographic cross-sectional view at 50 × magnification of a filament of the present invention used to form a toothbrush bristle bundle having a variable diameter ranging from 0.005 to 0.009 inches. Figure 3 shows a photographic cross-sectional view at 50x magnification of a filament of the present invention used in a toothbrush having a tip diameter varying from 0.004 to 0.007 inches.

Claims (9)

a. A handle,
b. A toothbrush head at the end of the handle;
c. A plurality of synthetic monofilaments having varying diameters along their lengths that are bundled together to form a bristle bundle attached to the toothbrush head, wherein each of the synthetic monofilaments is Toothbrush, characterized in that it differs from one or more synthetic monofilaments of the hair bundle in a variable diameter along its length.   Each monofilament of the hair bundle has two ends, a first end and a second end opposite to the other end, and the first end is the first end in diameter. The toothbrush according to claim 1, wherein the toothbrush is different from two ends.   The toothbrush according to claim 1 or 2, wherein the variable diameter along the length of the monofilament of the bristles is in the range of about 0.003 inches to about 0.020 inches.   The monofilament of the hair bundle has a minimum diameter along the length of the monofilament, and the minimum diameter ranges from about 0.003 inches to about 0.015 inches. toothbrush.   The monofilament of the hair bundle has a maximum diameter along the length of the monofilament, and the maximum diameter ranges from about 0.005 inches to about 0.020 inches. toothbrush.   The toothbrush according to claim 1, wherein the monofilament material is selected from the group consisting of polyamide, polyester, polyolefin, blends, copolymers, or combinations thereof.   The toothbrush of claim 1 or 6, wherein the monofilament has a flexural modulus greater than about 10,000 psi.   The toothbrush according to claim 1 or 7, wherein the monofilament has a flexural modulus of about 400,000 psi to about 700,000 psi.   A hair bundle for use in a toothbrush comprising a plurality of synthetic monofilaments having varying diameters along their lengths that are bundled together to form a hair bundle, each said synthetic monofilament having its length A bristle bundle for use in a toothbrush, characterized in that it may differ from one or more synthetic monofilaments of the bristle bundle in a variable diameter along the line.

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