Mold for molding an article in two materials

Mold comprising:

• a first shell having a cavity of a shape and size compatible with a product to be manufactured;
• a second shell having a projection suitable for being coupled in the cavity of the first shell;
• and
• an intermediate shell having a projection suitable for being coupled in the cavity of the first shell and a cavity suitable for being coupled with the projection of the second shell;
• when the projection of the second shell is coupled in the cavity of the intermediate shell, a first bottom space and a first perimetral space around the first bottom space are generated;
• when the projection of the intermediate shell is coupled in the cavity of the first shell, a second bottom space and a second perimetral space are generated around the second bottom space;
• wherein said second shell comprises a first injection channel extending from an inlet hole in a side wall of said second shell to an outlet hole in the projection of the second shell in such a way to communicate with said first bottom space of said mold in order to inject a first plastic material into said first bottom space of the mold so as to obtain a first semi-manufactured part, and wherein said intermediate shell has a second injection channel extending from an inlet hole in a side wall of the intermediate shell to an outlet hole in the projection of the intermediate shell in such a way to communicate with said second bottom space of the mold, in order to inject a second plastic material of a different color from the first plastic material in said second bottom space of the mold so as to obtain a second semi-manufactured part;
• wherein said first injection channel is obtained only in the second shell and said second injection channel is obtained only in the intermediate shell;
• wherein said intermediate shell can be removed from the mold, leaving said first semi-manufactured part on the second shell with no portion of sprue and the second semi-manufactured part on the first shell with a portion of sprue;
• and
• wherein said first shell and second shell can be coupled to each other to join the first semi-manufactured part to the second semi-manufactured part so as to obtain an article made of materials of different colors;
• wherein when the projection of the second shell is coupled in the cavity of the intermediate shell, a first end space is generated in projecting position from the first perimetral space in such a way to form of a semi-burr of the first semi-manufactured part;
• wherein when the projection of the intermediate shell is coupled in the cavity of the first shell, a second end space is generated in projecting position from the second perimetral space in such a way to form a semi-burr of the second semi-manufactured part;
• and
• wherein when the first shell is coupled with the second shell, the semi-burrs of the first and of the second semi-manufactured part are melted together, forming a perimetral burr suitable for being removed.