Toothbrushes with a conventional bristle arrangement comprising clusters of bristle filaments, e.g. made of polyamide (PA) or polyester (PBT), and additional flexible cleaning elements are known, for example, from WO-A-00/64307 and WO-A-01/21036. The conventional bristles here serve for customary teeth-cleaning purposes, while the flexible cleaning elements can perform different functions, e.g. massaging the gums, damping the cleaning movement, removing plaque or polishing the surface of the teeth. According to WO-A-00/64307, the flexible cleaning elements are rod-like, are of approximately the same length as the conventional clusters of bristles and are arranged on the periphery of the head part of the toothbrush. In the case of the embodiments disclosed in WO-A-01/21036, the elastic cleaning elements are of sheet-like, e.g. undulating, configuration and are arranged within the conventional bristle arrangement. According to WO-A-00/64307, a plurality of the flexible cleaning elements are connected to one another via a material bridge made of the same material. U.S. Pat. No. 5,628,082 describes a process for producing a toothbrush having conventional bristles and additional flexible cleaning elements.
In accordance with the production process described in U.S. Pat. No. 5,628,082, following the operation of covering the head part of the toothbrush with conventional bristles, the cleaning elements are produced by virtue of the head part being encapsulated by injection molding. The disadvantage here is that the bristle filaments have to be prepared for use, e.g. by virtue of the clusters of bristles being rounded or of a predetermined profiling being produced, before the flexible structure is produced. Renewed insertion into the injection mold is then necessary in order to produce the flexible cleaning element. It is possible for the clusters of bristles to be damaged or soiled during this subsequent machining operation.
USPTO Backgrounds
USPTO Backgrounds