Pasta Extrusion Technology Explained
How a pasta extruder works — dosing, mixing, vacuum, the screw, pressure, the die and the cutter — and what affects output and quality.
By R.N. Editorial Team · · 1 min read
Extrusion is the heart of short-cut pasta production. Designs vary between manufacturers, but most machines follow the same principles.
Dosing and mixing
Semolina or flour and water are dosed in a fixed ratio and mixed until the water is absorbed evenly. Pasta dough is much drier than bread dough — at this stage it looks like damp crumbs.
Removing air
Many industrial extruders mix or convey the dough under vacuum. Air bubbles trapped in the dough would make the pasta paler and weaker.
The screw and pressure
A screw inside the barrel compresses the crumbs into a dense dough and builds the pressure needed to push it through the die. Friction generates heat, so barrels are often cooled to protect the dough.
The die
The die is where the shape is made. Its openings, inserts and surface finish decide the shape, size and texture of the pasta. Because the die is interchangeable, one extruder can make many shapes. Read more in Understanding Pasta Dies and Inserts.
Cutting
For short shapes, a rotating knife at the die face cuts the strands to length. Long goods such as spaghetti are hung on rods instead.
What affects output and quality
- Dough moisture and temperature
- Screw speed and die design
- Die wear and cleanliness
- Raw-material quality
Output in kg per hour also depends on the shape: two shapes on the same machine can run at different rates. That is why the profit calculator asks for rated capacity and a separate utilisation figure.
See the full production sequence on How Pasta Is Made.