eli5 Extrusion process


I’m a recruiter for an employment agency so we deal with a multitude of different jobs. I don’t know a lot about the industrial aspects and I come across extrusion a lot and “racking extrusions” ….what the hell is extrusion?

In: 5

It is like pushing toothpaste out of a tube or if you’ve played with Play-doh, you squeeze it through a star or cross or round hole to make a long “noodle”.

Industrially, extrusions are used to make long objects with constant cross sections. Things like pipes and bars etc are usually extruded. And yes, extrusion is used to make long pasta strands and noodles too.

Did you ever have that Play-Doh set where you have that thing that you put some Play-Doh in and put a strip with a shape on the other side, and you push down on it and the Play-Doh comes out the other end in that shape? That’s an extrusion.

More examples are vinyl siding, gutters, round aluminum rods, PVC pipe, the list goes on and on. It’s just forcing product through a die or series of dies to make a continuous line of something of a certain shape.


The extrusion factory is basically a giant playdoh factory with hot metal. [Take somewhat soft material, ram it through a specific shape, get a really long version of that shape on the other side](https://www.cvs.com/bizcontent/merchandising/productimages/large/7693022730.jpg)

Aluminum extrusion is fairly common and can be used to make things like hollow aluminum tube assemblies and can also be used to make older style heatsinks (not the tiny fins, the thick fins). They use a large hydraulic press rated for hundreds of tons to ram the aluminum through a die to get it into the right shape

You can use extrusions to make items of pretty much any length, its a relatively fast process compared to forging so it can produce miles of product per week

I work with an aluminum extrusion company, so here ya go. Think of your generic play-doh spaghetti maker, except it’s the size of a school bus, and uses telephone pole size aluminum rods. They come out as 1000F lengths of whatever shape the die the customer wants. It cools, is cut to shorter lengths, and goes on for further processing.

As what you ask?

Car, truck, electrical parts. Picture frames, window frames, door frames, door parts. Office divider edges/connectors. Track lighting tracks, brackets, fixtures. The pull-out ramp floors and sides on box trucks. The top and bottom edges of box trucks and trailer sides. See that beer truck with the roll up sides? We make those. Ride the elevator? We make the threshold. Aluminum fencing? Ditto. Open the cooler door at the quick mart? We make that long, smooth handle.

Extruders make the stuff other people use to make stuff!