MFE 201 Lecture Notes - Lecture 5: Plastics Extrusion, Impact Extrusion, Extrusion

• School: Cal Poly Pomona
• Department: Manufacturing Engineering
• Course: MFE 201
• Professor: Ohkyusen

Document Summary

Principle: push material through cavity of desired shape. Long and uniform cross sections such as ladder sides, pipes, whiteboard trim, and eraser shelf. In direct extrusion, the most typical type of extrusion, the plastic material is pushed through a hole of the desired shape, and the material then assumes this shape. Typically the original material billet is coated with a lubricant to facilitate the process and minimize tool wear, except in the case of hollow products as will be explained later. Note that there is signi cant structural support in the form of the container body and die backer. The forces used in metal extrusion can be quite large, and the solid billet behaves somewhat hydrostatically and pushes against the sides of the container liner with great force. The use of the die backer allows for the production of a smaller tool that becomes much more inexpensive.