extrude

Everyday

1. To extrude something is to push or squeeze it out through a small opening, often to give it a shape, like toothpaste from a tube. tree →
2. In industry and technology, to extrude plastic, metal or pasta is to force it through a shaped hole to make long pieces. tree →

In the lessons

In design and technology, plastic pipes, window frames and pasta are made by extrusion, and 3D printers extrude melted plastic in thin lines. In geography and science, volcanoes extrude lava onto the surface (extrusive rock). In maths, «extrude» is used in 3D drawing software to turn a 2D shape into a prism. Phrases: «extrude plastic», «extruded lava», «extrude a shape».

Examples

• The 3D printer extrudes hot plastic to build the model. tree →
• Pasta machines extrude dough into spaghetti. tree →
• The volcano extruded thick lava. tree →
• Squeeze the tube to extrude a line of glue. tree →
• In the drawing program, extrude a square to make a cube. tree →
• Factories extrude aluminium to make window frames. tree →

Note

Noun: extrusion. Adjective: extrusive (rocks formed from lava on the surface). Opposite idea: intrude (push in). In maths: extruding a 2D shape makes a prism with that shape as its cross-section.