{"id":3462,"date":"2012-10-11T05:06:58","date_gmt":"2012-10-11T05:06:58","guid":{"rendered":"https:\/\/www.insta-pro.com\/?p=699"},"modified":"2025-12-18T10:22:23","modified_gmt":"2025-12-18T16:22:23","slug":"extruder-screw-design-and-purpose","status":"publish","type":"post","link":"https:\/\/instapro.spinuhost.com\/en\/blog\/engineeringandmaintenance\/extruder-screw-design-and-purpose\/","title":{"rendered":"Extruder Screw Design and Purpose"},"content":{"rendered":"

At its core, the extruder is a very simple machine. The various configurations of shaft speed, number of chambers and types of screws\/steamlocks enables the operator to create a multitude of products. Different products usually require different configurations and run parameters. An important parameter to consider is retention time in the barrel. Depending on what your product requires, you may have to increase or decrease the amount of time product stays in the barrel. A common way to do this is vary the screws inside each chamber.<\/p>\n

Definitions<\/span><\/strong>
\nThe screws inside each chamber serve two purposes:
\n1) Convey product through the barrel
\n2) Create shear and heat to perform necessary treatment to the product<\/p>\n

There are two main factors that affect how the screw performs: pitch and flighting (see diagram).<\/p>\n

Pitch<\/span>: The distance between adjacent flights
\nFlights<\/span>: Raised, helical sections of the screw (similar to threads on a machine bolt)<\/p>\n

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\"DesignPurposeofExtruderScrew\"<\/a><\/p>\n

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Flights<\/strong><\/span>
\nFlights can vary in design and are commonly either single or double (triple and quadruple are possible, but not very common). In the picture of the two screws, the one on the left is a single flight while the one on the right is double. Notice how the double appears to have two lobes on the end while the single only has one.<\/p>\n