摘要 |
<p>For injection molding of tooth brushes a mold with two relatively movable mold parts (10, 12) defining a mold cavity (14) is used. One of the mold parts (10) has tuft insertion holes (16) therein. After tufts of bristles (18) have been introduced into the tuft insertion holes (16) so that they have an end projecting into the cavity portion (14a), the projecting bristle ends are exposed to heat to form individual knobs of molten bristle material at the end of each tuft. The mold is closed and plasticized molding material is injected into the cavity and around the knobs of molten bristle material. To prevent the bristles of thus embedded tufts from spreading open, the tufts with the knobs formed on their inner ends are pushed deeper into the molded material, simultaneously preventing plasticized molding material from leaking out of the cavity. <IMAGE></p> |