A mold assembly includes a first mold part with a first mold opening and a second mold part with a second mold opening. The first mold part and the second mold part are separate parts. A rotating device rotates the second mold part from a position in which the second mold opening faces upwards to a position in which the second mold opening faces downwards. A moving device moves the first mold part and/or the second mold part relative to each other such that the second mold part is located above the first mold part. A closing device moves the first mold part and the second mold part towards each other with the first and second mold openings facing each other until the first and second mold parts engage. Further, a method of closing a mold assembly is provided.