Stretchblåformning

Stretchblåformning is a manufacturing process that combines deep drawing and inflation to create hollow, complex parts. It is primarily used for producing metal components with intricate shapes, such as exhaust systems, fuel tanks, and certain automotive body parts. The process begins with a sheet metal blank that is deep-drawn into a preliminary shape, often a cup or a basic shell. This preform is then placed into a mold cavity. Once the mold is closed, the preform is internally pressurized with a fluid, typically water or a mixture of water and oil, or sometimes air. This internal pressure causes the metal to expand and conform precisely to the contours of the mold. The external pressure of the mold, combined with the internal fluid pressure, allows for the formation of thin-walled, complex geometries that would be difficult or impossible to achieve with conventional deep drawing or stamping alone. Key advantages of stretchblåformning include its ability to produce parts with uniform wall thickness, high dimensional accuracy, and intricate details, often in a single operation. It is particularly effective for metals with good ductility, such as stainless steel, aluminum, and certain alloys. The process requires specialized equipment capable of handling high internal pressures and precise mold control.