Disclosed is an apparatus and a method for reducing flash in an injection mold (532 or 542,543) which molds a molded article between a first mold surface and a second mold surface. The apparatus includes an active material actuator (530 or 533a and 533b or 561a and 561b) configured to, in response to application or removal of an electrical actuation signal thereto, change dimension and urge the first mold surface relative to the second mold surface to reduce flash therebetween. The apparatus also includes a transmission structure (533) configured to provide in use, the electrical actuation signal to said active material actuator (530 or 533a and 533b or 561a and 561b) includes a set of active material actuators stacked one against the other to provide a varying sealing force to urge the first mold surface relative to the second mold surface.