Plastic object for use in personal hygiene

#1. Field of Invention

#The invention relates to a plastic object for use in personal hygiene and to a method of producing the plastic object.

#2. Description of Related Art

#The invention is explained in more detail below with reference to the drawing, in which:

#FIG. 1 shows a first exemplary embodiment of a toothbrush comprising two molded parts in side view and partially in longitudinal section;

#FIG. 2 shows the toothbrush according to FIG. 1 in plan view;

#According to FIGS. 1 to 3, a toothbrush 1 has a first molded part 2, which bears a brush head 3 in its front region 2a. The first molded part 2, consisting of a plastic material A, is enclosed over a portion of its length, to be specific its rear handle region 2b, by a second molded part 4, consisting of a plastic material B, and is non-positively joined to the latter in the manner of a shrink fit. The plastic materials A and B are plastic materials of a kind which do not bond with one another during the injection-molding operation at the surfaces where they touch.

#For better illustration, the two molded parts 2, 4 are represented separately from one another in FIGS. 4 to 7. The two molded parts 2, 4 have—as described further below—in the region where they touch diametrically opposite projections and recesses engaging in one another, by means of which a positive fit of the two molded parts 2, 4 is realized in addition to the non-positive fit of the same. It goes without saying that this joint is only produced during the injection-molding operation, in which one of the molded parts is injection-molded in a first step and then the other molded part is injection-molded around or into the first part in a second step. With the different degree of shrinkage of the two molded parts 2, 4, that molded part which is to be produced from plastic material with a lower degree of shrinkage is advantageously injection-molded first. In the second step, injection-molding of the other molded part takes place from plastic material with a greater degree of shrinkage, whereby a natural pressure of the second plastic material pressing against the first plastic material is produced.

#The second molded part 4, represented individually in FIGS. 6 and 7 and essentially forming the toothbrush handle, is designed in the form of a sleeve, i.e. is provided with an internal longitudinal bore 7, which corresponds in its shape and diameter to the rear handle region 2b of the first molded part 2, represented individually in FIGS. 4 and 5. The sleeve-shaped molded part 4 has an outer surface 6.