Extrusion

The extrusion is a forming process which is mainly used for thermoplastics. The plastic is pressed through a shaping opening as a viscous mass under high pressure and high temperature.
Extrusion is one of the most widely used processes in the plastics processing industry and, thanks to its wide range of advantages in terms of efficiency, has gained great importance in the production of plastic parts. An extruder is used for extrusion, which is also referred to as a screw press. In principle, a distinction is made between the single-screw extruder and the twin-screw extruder.

Find companies for Extrusion

Get started now

In the extrusion process, material is pressed under high pressure and high temperature in the viscous state through a shaping opening, the so-called nozzle. This results in a body of almost any length which has the same cross section as the nozzle and can be further processed subsequently to a finished end product.

Extrusion line with single-screw extruder

Technical basics of extrusion

Depending on how the pressure is built up in the extruder, a distinction is made between the piston extruder and the screw extruder. In the plastics industry, the screw extruder is of great importance, wherein a distinction is made between execution with one or two screws.

The single-screw extruder usually consists of the following main components:

Drive
Filling funnel
Cylinder
Snail
Temperature sensor
Heating tapes
Nozzle (mask)

In the first step, the plastic to be processed is introduced into the cylinder in the form of granules via a funnel. The plastic is continuously melted with the aid of heating belts and the resulting friction energy. The screw conveys and compresses the melting granulate and thereby sets it continuously under pressure.

Extrusion plant of SEM Plastomed GmbH

Pressure and temperature in extrusion vary depending on the type of plastic and the product being manufactured. Typically, screw extruders operate with pressures between 10 and 300 bar and temperatures between 60 °C and 300 °C. The efficiency of production primarily depends on the extruder's rotation speed. High-speed extruders, known as fast runners, can reach speeds of up to 1,500 revolutions per minute.
Following the actual extrusion, there is frequently a water-cooled calibration which closes the shaping by pressing against the calibration wall. The calibration is usually followed by a water bath for cooling the product.

Which materials are suitable for extrusion?

Extrusion is not only used in plastics processing, but also enjoys great popularity in other industries. The process convinces by a very large range of materials that can be extruded. These include, for example,:

Aluminium
Rubber and rubber
Composite materials (fiber reinforced plastics with glass fiber or carbon fiber)
Thermoplastic plastics such as PVC, PP, PE, PET, PA and other
Thermoplastic masses of corn starch and lignin
Tones and other ceramic materials
Dough-shaped food and feed mixtures

GUMMI FISCHER GMBH rubber profile

The extrusion of rubber marks the origin of the process and was already used in the 19th century. The success of rubber extrusion ultimately led to extrusion becoming firmly established in the plastics industry alongside injection molding.
In the extrusion of composite materials, such as fiber-reinforced plastics, it is primarily important to take into account the fiber length. Thus, short fibers with a length of up to 1 mm and long fibers with a length of up to 50 mm can still be processed in an extruder, long fibers frequently being admixed with thermosets or thermoplastics as fillers. Fiber-reinforced plastics are produced, for example, by inserting rovings or fabrics.

Which products are produced by extrusion?

Extrusion is a process that convinces with a very wide range of applications. A variety of products can be produced in series production for various purposes across the industry. The customers for extrusion products come from different areas from the automotive industry, plant engineering, air travel technology, medical technology and packaging technology to the construction industry, the agricultural industry and the food and food industry.

The most widely used products of extrusion include:

Semi-finished products (tubes and rods)
Profiles (frames, channels, seals, etc.)
Hoses
Covers
Films
Car tyre treads
Door seals
Bicycle rims
V- and toothed belts
Food (noodle pastry, biscuits, moulded meat)
Chemical fibres
heat sink

Aluminum extruded profiles from Çuhadaroğlu Metal San. ve Pazarlama A.S.

Plastic profiles of the company hama-plast Kunststofftechnik.

Find companies for extrusion

For Techpilot, Europe's largest platform for drawing parts, numerous Extrusion are registered. Techpilot brings buyers and businesses together and offers the opportunity to find new business partners and commission drawing parts.

Register as a buyer and use Techpilot completely free of charge. You upload your enquiries easily and receive offers from interested contract manufacturing companies. The offers compare for example price, quality and delivery time and thus save time and effort.

Techpilot's employees are well-known in the industrial sector and are available by phone at any time. Especially when creating your inquiries, you will receive support from our trained service staff.

This is how Techpilot works

Examples of jobs in the Techpilot marketplace

Distance block as plastic profile

Plastic profile - pipe

Plastic profile made of thermoplastics

More about extrusion

Find companies for

Techpilot is Europe’s largest platform for the manufacturing industry.

For over 25 years, we’ve been connecting buyers, suppliers, and manufacturers that are the perfect match – enabling accurate price discovery for custom-made parts. Covering the full spectrum of mechanical components and supporting more than 280 manufacturing technologies, Techpilot is the market leader in Europe.

Buyers gain instant access to qualified suppliers, full market transparency, and increased efficiency in their e-sourcing processes.

Suppliers benefit from high online visibility, extended media reach, and a profitable digital sales channel through Techpilot.