Which manufacturing process is characterized by producing continuous lengths such as tubing or rods?

The manufacturing process that is characterized by producing continuous lengths such as tubing or rods is extrusion. This process involves forcing material, often in a softened state, through a die to create long shapes with a consistent cross-section. Extrusion is widely used for various materials, including metals, plastics, and rubber, enabling manufacturers to create a variety of products, from piping and structural components to films and sheets.

During extrusion, the material is heated until it reaches a pliable state, after which it is pushed through a specific die that determines the shape of the output. As the material emerges from the die, it can be cut to length or left in a continuous form, making it ideal for applications where uniform shape and size are crucial.

Other manufacturing processes listed in the options do not primarily focus on producing continuous lengths. Moulding typically forms items using a cavity or mold, calendering involves passing material through rollers to create sheets or films, and vulcanization is a chemical process used to harden rubber. None of these processes inherently creates long, continuous profiles in the same way that extrusion does.