A process for the injection molding of plastics moldings, where the moldings have at least one unoccupied space, and the process comprises the following steps: a) injection of plastics melt from an injection unit along a melt flow path, which is formed at least to some extent via a hot runner system, into the cavity of an injection mold (1, 1'), until the cavity has been completely filled, b) injection of a fluid from an injector into the plastics melt located in the cavity, so that a portion of said plastics melt is forced onto the wall of the cavity, and an excess portion of the plastics melt is forced back into the space in front of the screw of the injection unit, c) permitting the plastic remaining in the cavity to solidify, until this becomes self-supporting and forms the molding, d) removal of the fluid by way of the injector, e) demolding of the molding from the cavity of the injection mold (1,1'), where the injection of plastics melt according to step a) takes place along a first melt flow path, which is formed at least to some extent via a first hot runner and the forcing of the excess portion of the plastics melt back into the space in front of the screw of the injection unit according to step b) takes place along a second melt flow path, which is formed via a second hot runner, wherein - the first melt flow path leads to the lower end of the cavity, so that the plastics melt injected according to step a) is charged to the cavity in a direction opposite to that of gravity, and - the injector leads to the lower end of the cavity, so that the fluid injected according to step b) displaces the excess portion of the plastics melt from the cavity in a direction opposite to that of gravity, and - the second melt flow path is conducted back to the space in front of the screw of the injection unit from the upper end of the cavity, and - the plastic is selected from polyethylene, polypropylene, polyvinyl chloride, polystyrene, impact-modified polystyrene (HIPS), acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene-acrylate copolymers, methacrylate-acrylonitrile-butadiene-styrene copolymers (MABS), styrenebutadiene block copolymers, polyamide, polyethylene terephthalate, polyethylene terephthalate glycol (PETG), polybutylene terephthalate, polyoxymethylene, polycarbonate, polymethyl methacrylate (PMMA), polysulfones or polyether sulfones, thermoplastically processible polyurethane, and polyphenylene oxide. a) injection of plastics melt from an injection unit along a melt flow path, which is formed at least to some extent via a hot runner system, into the cavity of an injection mold (1, 1'), until the cavity has been completely filled, b) injection of a fluid from an injector into the plastics melt located in the cavity, so that a portion of said plastics melt is forced onto the wall of the cavity, and an excess portion of the plastics melt is forced back into the space in front of the screw of the injection unit, c) permitting the plastic remaining in the cavity to solidify, until this becomes self-supporting and forms the molding, d) removal of the fluid by way of the injector, e) demolding of the molding from the cavity of the injection mold (1,1'), - the first melt flow path leads to the lower end of the cavity, so that the plastics melt injected according to step a) is charged to the cavity in a direction opposite to that of gravity, and - the injector leads to the lower end of the cavity, so that the fluid injected according to step b) displaces the excess portion of the plastics melt from the cavity in a direction opposite to that of gravity, and - the second melt flow path is conducted back to the space in front of the screw of the injection unit from the upper end of the cavity, and - the plastic is selected from polyethylene, polypropylene, polyvinyl chloride, polystyrene, impact-modified polystyrene (HIPS), acrylonitrile-butadiene-styrene copolymers, acrylonitrile-styrene-acrylate copolymers, methacrylate-acrylonitrile-butadiene-styrene copolymers (MABS), styrenebutadiene block copolymers, polyamide, polyethylene terephthalate, polyethylene terephthalate glycol (PETG), polybutylene terephthalate, polyoxymethylene, polycarbonate, polymethyl methacrylate (PMMA), polysulfones or polyether sulfones, thermoplastically processible polyurethane, and polyphenylene oxide.