Extrusion Machines Key Terms
Understand the ABCs of extrusion machines to make smarter business choices
By Howard Robertson
Extrusion is the process of forcing a raw material through a die under extreme pressure to get the desired shape. Manufacturers of extrusion products can produce various profiles using the same extrusion machine. Commonly extruded materials include aluminum, copper, plastic and even ceramic. Extrusion products have applications in various industries, including automotive, food processing and construction.
If you want to use extrusion machines for your applications, you will need to be conversant with the technical terms of extrusion machines. This guide intends to familiarize you with the key terms for extrusion machines, such as extrusion die, extruder barrels, extrusion speed and screw and ram extruders.
Extrusion dies
An extrusion die, an integral part of an extrusion machine, has one or more machined openings to produce the desired extruded parts or sections.
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AACOA, a supplier of extrusion products, offers a glossary technical terms that explains extrusion dies and their types. For information about extrusion dies, their design features and characteristics, you can browse through the website of Uddeholm (PDF), a manufacturer of tool steel.
Extruder barrels
An extruder barrel is the portion of the extruder (extrusion machine) that surrounds the screw or plunger.
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For information about extruder barrels, you can browse through the Extruded Profile website, a business-to-business (B2B) marketplace for extrusion products.
Screw extruders
A screw extruder forces the material out through the barrel and die, using a screw mechanism.
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For information about screw extruders, their types and advantages, you can browse through Tangram Technology Ltd.’s website, a service provider for the plastics products and window industries.
Ram extruders
A ram extruder moves the raw material through a barrel and die, using a plunger (commonly known as a ram) rather than the usual screw mechanism.
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Ceramic Industry, a magazine for manufacturers of advanced ceramic products, explains more about screw extruders and ram extruders.
Purging
Purging is the process of cleaning one type of material or color from an extruder by forcing it out with a new material or color.
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You can read through the basics of purging at Xaloy Inc. (PDF), a supplier of industrial machinery components for the plastics industry.
Extrusion speed
Extrusion speed is an important specification of any extrusion process. Before selecting an extrusion machine, you must evaluate the required extrusion speed.
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Burak Aluminium offers a glossary of technical terms, including extrusion speed.
Direct or indirect extrusion
In direct extrusion process, a preheated billet, placed in a heavy walled container, is pushed through the die by ram pressure. The metal flows in the same direction that the ram has traveled. In indirect extrusion process, the die is at the ram end of the billet, and the product travels through the hollow ram in the opposite direction.
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For information about direct and indirect extrusion, you can read through the glossary of technical terms at Capital Aluminium Extrusions Ltd.
Hot or cold extrusion
Hot extrusion is carried out at high temperatures. At higher temperatures, the yield strength of a metal or alloy is less than its value at room temperature. Unlike hot extrusion, the cold extrusion process is carried out at room temperature. While selecting extrusion machinery, you will need to determine the type of extrusion process, as the machinery differs according to the process.
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eFunda, an informative website for engineering fundamentals, explains more about the hot and cold extrusion processes.
