70mm Nitrided Twin Screw Extruder Barrel for Stable Temperature Control

This 70mm twin screw extruder barrel is designed for extrusion lines that require accurate replacement dimensions, reliable bore performance and stable temperature control.

Manufactured from 38CrMoAlA nitrided steel, it is suitable for general plastic compounding, masterbatch production and other applications with moderate wear requirements.

The barrel bore, length, connection holes, heating holes, cooling channels and port configuration can be customized according to the original drawing, used barrel sample or measured dimensions.

It helps solve common replacement problems such as:

• Excessive barrel bore wear

• Reduced output caused by increased screw-to-barrel clearance

• Unstable material temperature

• Leakage between barrel sections

• Incorrect connection or hole positions

• Replacement barrels that do not fit the original machine

As the barrel bore wears, the clearance between the screw elements and barrel gradually increases.

This can reduce conveying efficiency, weaken mixing performance and cause unstable output.

A replacement barrel manufactured according to the original dimensions helps restore the correct working clearance and improve extrusion stability.

Critical dimensions include:

• Barrel bore diameter

• Center distance

• Overall length

• Positioning surfaces

• Bolt-hole pattern

• Connection dimensions

These dimensions must be confirmed before production rather than relying only on the nominal 70mm machine size.

Damaged or incorrectly positioned heating and cooling channels can cause uneven barrel temperature.

This may lead to unstable material viscosity, frequent process adjustments and inconsistent product quality.

Heating holes, cooling water channels and sensor holes can be reproduced according to the original barrel or customized for the required temperature-control layout.

The channel system can be checked for position, connection and sealing performance before shipment.

A barrel with the correct bore diameter may still fail to fit the machine if the flange, bolt holes, positioning surfaces or adjacent barrel connections are incorrect.

For OEM replacement projects, customers can provide:

• Original barrel drawing

• Used barrel sample

• Machine model

• Measured dimensions

• Installation photos

• Heating and cooling channel information

A used barrel can be measured as a manufacturing reference, but worn dimensions must be identified and corrected rather than copied directly.

The standard configuration uses 38CrMoAlA alloy steel with nitriding treatment.

The nitrided bore provides improved surface hardness and wear resistance compared with untreated alloy steel.

It is suitable for:

• General plastic compounding

• Color masterbatch

• Additive masterbatch

• Polyethylene and polypropylene processing

• Non-abrasive polymer blending

• Applications with moderate filler content

However, nitrided steel is not suitable for every operating condition.

For high glass-fiber, mineral-filled or highly corrosive materials, an upgraded material system may provide longer service life.

Optional solutions include:

• Tool-steel liner

• Bimetallic liner

• Nickel-based tungsten carbide liner

• Laser-clad wear-resistant bore

• Corrosion-resistant alloy liner

The material should be selected according to the processed formulation, filler percentage, corrosion level and operating temperature.

The barrel can be manufactured as different sections according to its position on the extrusion line.

Available configurations include:

• Closed barrel section

• Main feeding barrel

• Venting barrel

• Vacuum barrel

• Side-feeding barrel

The following features can be customized:

• Bore diameter

• Center distance

• Barrel length

• Connection dimensions

• Bolt-hole layout

• Feeding and venting ports

• Side-feeder opening

• Heating holes

• Cooling channels

• Temperature sensor holes

• Material and surface treatment

The replacement barrel should match the existing screws, shafts, adjacent barrel sections and machine frame.

Segmented twin screw barrels require accurate dimensions because multiple sections must be assembled together.

The following items can be inspected during manufacturing and before shipment:

• Inner bore dimensions

• Center distance

• Barrel length

• Parallelism

• Connection surfaces

• Positioning dimensions

• Bolt-hole locations

• Port dimensions

• Heating-hole positions

• Cooling-channel sealing

• Material and heat-treatment condition

Inspection records can be retained for dimensional traceability and future repeat orders.

A barrel replacement should be considered when:

• Extruder output decreases without a clear process-related cause

• Melt pressure or product quality becomes unstable

• Visible grooves or excessive wear appear inside the bore

• New screw elements do not restore machine performance

• Material leakage appears between barrel sections

• Heating or cooling performance becomes inconsistent

Barrel wear and screw-element wear should be evaluated together.

Installing new screw elements inside an excessively worn barrel may not restore the expected output or mixing performance.

Please provide as much of the following information as possible:

1.Extruder brand and model

2.Original barrel drawing

3.Used barrel sample

4.Bore diameter and center distance

5.Barrel length

6.Barrel section type

7.Port and connection dimensions

8.Heating and cooling configuration

9.Processing material and filler content

10.Existing wear or corrosion problem

11.Required quantity

Can you manufacture the barrel from a used sample?

Yes. A used barrel can be measured and used as a reference. Worn areas will be evaluated so that the damaged dimensions are not copied directly.

Is 38CrMoAlA suitable for glass-fiber-filled compounds?

It may be suitable for applications with limited abrasive content. For high glass-fiber or mineral-filled formulations, a tool-steel, bimetallic or laser-clad barrel is generally more appropriate.

Can only one worn barrel section be replaced?

Yes, provided that the adjacent barrel sections, connection dimensions and screw condition remain acceptable.

Can the heating and cooling channels be customized?

Yes. Channel positions, inlet and outlet arrangements, heating holes and sensor holes can be customized according to the original barrel or technical drawing.

Send us your barrel drawing, used sample information or measured dimensions.

We can help evaluate:

• Whether the barrel should be replaced

• Whether only one barrel section can be replaced

• Whether 38CrMoAlA nitrided steel is suitable

• Whether a wear-resistant material upgrade is required

• Whether the original temperature-control structure can be reproduced

Send Your Barrel Drawing for Technical Review