Disclosed herein is a toothbrush with tapered bristles and method of manufacturing such toothbrushes. The toothbrush is characterized in that the tapered end of each bristle is 0.02 mm or less of diameter. The bristle is tapered starting at a position of 3.5 mm or less from an end, and is made of polyethylene terephthalate or polybutylene terephthalate. The method of this invention consists of the steps of dipping 3.5 mm portions from ends of monofilaments for toothbrushes into erosive chemicals such as sulfuric acid or sodium hydroxide until the dipped portions of the monofilaments are completely eroded, neutralizing the shortened monofilaments prior to rinsing and drying them, and implanting the shortened monofilaments on a toothbrush. Thereafter, the shortened monofilaments are ground using a 240# mesh paper at 2600 to 2700 rpm for 3 to 10 sec, a 320# mesh paper at same speed for 3 to 10 sec, and a 400# mesh paper at same speed for 3 to 10 sec. The toothbrush of this invention enjoys advantages of proper flexibility and softness, improved feeling while brushing, and excellent scaling ability.
A toothbrush tufted with needle-shaped bristles. The bristles are formed of polyester resin. The bristles are 0.1 to 0.2 mm thick before tapering, 13 to 18 mm long, tapered 4 to 8 mm only on one end with a tapered tip thickness of 0.01 to 0.08 mm, and planted to be 7 to 13 mm high in the toothbrush.
