Hollow tips for ball point paste dispensers - fabricated from thin-wall polyolefin shells to reduce moulding costs

摘要

The spherical tip of a container for dispensing a liq. or paste material, such as a deodorant compsn., comprises a hollow body assembled from two prefabricated hemispherical thermoplastic shells. Pref. the shells are made of polypropylene or polyethylene and are assembled by ultrasonic welding of rims which feature complementary tapered tongue-and-groove surface profiles. Esp. claimed for dispensers using a ball tip of 15-30 mm. dia., where the wall thickness is 1/10-1/6th of the dia. of the ball. More economic than use of solid balls, becaus less raw material is used and the moulding (cooling) cycles are significantly less for the thin-wall shells, despite the need for welding and polishing of the joint between the shells.