Tube extrusion process pdf shape of the die determines the shape of the tube. The extrusion is then cooled and forms a solid shape. The tube may be printed upon, and cut at equal intervals. The pieces may be rolled for storage or packed together.
Shapes that can result from extrusion include T-sections, U-sections, square sections, I-sections, L-sections and circular sections. This page was last edited on 10 November 2016, at 13:26. It also forms parts with an excellent surface finish. This limits the amount of change which can be performed in one step, so it is limited to simpler shapes, and multiple stages are usually needed.
The extrusion process can be done with the material hot or cold. The products of extrusion are generally called “extrudates”. Also referred to as “hole flanging”, hollow cavities within extruded material cannot be produced using a simple flat extrusion die, because there would be no way to support the centre barrier of the die. Instead, the die assumes the shape of a block with depth, beginning first with a shape profile that supports the center section.
The die shape then internally changes along its length into the final shape, with the suspended center pieces supported from the back of the die. The material flows around the supports and fuses together to create the desired closed shape. The extrusion process in metals may also increase the strength of the material. Unsourced material may be challenged and removed. It involved preheating the metal and then forcing it through a die via a hand-driven plunger. At that time the process was called “squirting”. In 1894, Alexander Dick expanded the extrusion process to copper and brass alloys.