Forming tool and method for forming a semi-finished product comprising reinforcement fibers and forming apparatus

A forming apparatus for forming a semi-finished product comprising reinforcement fibers, the forming apparatus comprising:

• a forming tool for forming a semi-finished product comprising reinforcement fibers and being conveyed to the forming tool in a continuous process;
• a forming element comprising a forming surface;
• and
• a conveying device for conveying the semi-finished product along a conveying direction, the forming tool comprising:
• at least one pressure bag configured to be pressurized during a forming step of the semi-finished product, during which forming step the semi-finished product is sandwiched between the forming surface of the forming element and the at least one pressurized pressure bag, such that the semi-finished product substantially takes on the shape of the forming surface, wherein a cross section of the forming element taken in a plane perpendicular to the conveying direction of the semi-finished product varies along the conveying direction;
• and
• at least one wrinkle reduction means comprising unidirectional structural reinforcements oriented parallel to a longitudinal axis of the at least one pressure bag configured to limit longitudinal stretch of the at least one pressure bag in the conveying direction wherein a structural configuration of the at least one pressurized bag limits a wrinkle formation in the semi-finished product,
• wherein the at least one pressure bag comprises a volume divided by membranes, wherein the unidirectional structural reinforcements comprise at least one of a thicker membrane portion and an additional material applied on at least one local portion of at least one of the membranes of the at least one pressurized bag pressure bag.