EXTRUTEX EXCT-35 Co-Rotating Twin-Screw Extruder

35 mm Modular Co-Rotating Twin-Screw Extruder with Clamshell Barrel

The EXTRUTEX EXCT-35 is a compact and versatile co-rotating twin-screw extruder designed for polymer compounding, mixing, dispersion, homogenization, masterbatch production, material development and other thermoplastic processing applications.

With a 35 mm screw diameter, the EXCT-35 provides an effective balance between processing flexibility, production capacity and compact equipment dimensions. Its modular construction allows the screw configuration and processing zones to be adapted to different formulations and material requirements.

The EXCT-35 is equipped with a practical clamshell barrel design, allowing the barrel to be opened quickly for screw inspection, cleaning, maintenance, product changeover and process development.

This makes the EXCT-35 particularly suitable not only for continuous production but also for R&D, pilot production and flexible manufacturing environments where different materials and formulations may need to be processed on the same machine.

EXCT-35 Technical Specifications

Actual output depends on polymer type, formulation, screw configuration, feeding conditions, temperature profile and operating parameters.

Modular Co-Rotating Twin-Screw Technology

The EXCT-35 is based on a modular co-rotating twin-screw processing concept.

The two screws rotate in the same direction inside a modular barrel, creating a controlled combination of conveying, melting, mixing, kneading, dispersion and homogenization.

Instead of using one fixed screw arrangement for every application, the EXCT-35 can be configured according to the specific material and processing objective.

Different screw elements can be combined to create dedicated processing zones for:

• Material conveying

• Feeding

• Melting

• Plasticization

• Distributive mixing

• Dispersive mixing

• Kneading

• Homogenization

• Filler incorporation

• Additive dispersion

• Degassing

• Pressure building

• Melt filtration

• Discharge

This modular concept makes the EXCT-35 a flexible platform for manufacturers working with different formulations.

35 mm Screw Diameter

The 35 mm screw diameter gives the EXCT-35 a compact processing platform while maintaining sufficient flexibility for continuous compounding and material development.

The machine can be used where a manufacturer requires more production capability than a small laboratory extruder while still wanting a relatively compact machine for development, pilot production or specialized manufacturing.

The EXCT-35 can therefore be positioned between laboratory-scale equipment and larger industrial compounding systems.

Its 20–60 kg/h nominal production range allows it to be used for a variety of applications, depending on the material and formulation.

The actual throughput can vary according to:

• Polymer density

• Melt viscosity

• Filler concentration

• Additive concentration

• Screw configuration

• Screw speed

• Feeding system

• Processing temperature

• Residence time

• Required mixing intensity

300–500 RPM Screw Speed

The EXCT-35 can operate within a screw-speed range of approximately 300–500 rpm.

The appropriate screw speed depends on the material and required processing conditions.

Higher screw speeds can increase the mechanical energy introduced into the material and may be beneficial for certain intensive mixing and dispersion applications.

Lower operating speeds may be selected where longer residence time, gentler processing or reduced mechanical energy is required.

The combination of screw speed and modular screw configuration allows the process to be optimized according to the formulation.

28–48 L/D Configuration

The EXCT-35 is available with an L/D ratio from 28 to 48, providing flexibility in the effective processing length.

The selected L/D configuration can be matched to the required process.

A shorter configuration may be appropriate for simpler conveying, melting and mixing applications, while longer configurations provide additional space for multiple processing stages.

A longer processing configuration can accommodate dedicated zones for:

Feeding → Conveying → Melting → Mixing → Dispersion → Degassing → Homogenization → Pressure Building → Discharge

This is particularly useful for formulations requiring several sequential processing operations.

Clamshell Barrel Design

One of the key practical features of the EXCT-35 is its clamshell barrel.

The barrel can be opened to provide direct access to the twin screws and internal processing area.

This design simplifies routine operations such as:

• Screw inspection

• Cleaning

• Material removal

• Product changeover

• Screw-element replacement

• Maintenance

• Troubleshooting

• Process development

In conventional closed-barrel equipment, access to the screws can require more extensive disassembly.

The clamshell system provides operators with much more convenient access to the processing chamber.

This can be especially valuable when processing materials that require frequent cleaning or when different formulations are produced on the same machine.

Independently Controlled Processing Zones

The modular barrel of the EXCT-35 can be divided into independently controlled temperature zones.

Each zone can be adjusted according to its specific function within the process.

For example, the feeding section may require a different temperature from the melting zone, while intensive mixing sections may require controlled thermal conditions to maintain the required melt viscosity.

Downstream sections can also be configured for degassing and pressure stabilization.

The temperature profile can therefore be developed around the material rather than applying one uniform barrel temperature.

Depending on the application, the barrel system can incorporate controlled electrical heating and cooling.

This provides better control over:

• Polymer melting

• Melt viscosity

• Mixing behavior

• Thermal history

• Devolatilization

• Final melt temperature

Flexible Screw and Kneading Elements

The screw system is a central part of the EXCT-35 modular concept.

Different conveying, kneading and mixing elements can be selected and arranged according to the application.

The screw configuration can include:

Conveying Elements

Used to transport the polymer and additives through the processing sections.

Melting Elements

Designed to promote controlled polymer melting and plasticization.

Kneading Elements

Used to increase mixing intensity and promote effective dispersion.

Mixing Elements

Used for distributive and dispersive mixing of polymers, fillers, pigments and additives.

Homogenizing Elements

Used downstream to improve melt uniformity before discharge.

Degassing Configuration

Designed to create a suitable processing environment for the removal of moisture and volatile components.

Pressure-Building Elements

Used toward the discharge side to stabilize the melt and provide the pressure required for filtration or downstream equipment.

The screw configuration can therefore be optimized according to the formulation rather than using one universal arrangement.

Compounding Process Stages

The EXCT-35 can be configured to perform several important stages of polymer compounding.

1. Metering and Feeding

Accurate feeding is essential for maintaining formulation consistency.

The EXCT-35 can be integrated with suitable feeding systems for polymer pellets, powders, fillers, additives, pigments and other ingredients.

Depending on the formulation, multiple feeders can be used to introduce different components at selected positions along the extrusion process.

2. Conveying

The initial screw sections transport the material through the barrel.

The conveying configuration can be selected according to the required feed rate, filling level and residence time.

Controlled conveying is important for maintaining stable feeding and preventing unnecessary pressure or thermal loading.

3. Melting

The polymer is progressively heated and mechanically processed until a homogeneous melt is formed.

The combination of barrel temperature and screw configuration can be optimized for the selected polymer.

The EXCT-35 can be configured to provide controlled melting while avoiding unnecessary thermal stress.

4. Dispersion and Homogenization

Once the polymer has melted, fillers, pigments and additives can be dispersed into the polymer matrix.

The twin-screw configuration provides strong mixing capabilities and allows engineers to balance dispersive and distributive mixing.

This makes the EXCT-35 suitable for applications involving:

• Polymer blends

• Filled polymers

• Masterbatch

• Additive concentrates

• Reinforced polymers

• Recycled compounds

5. Degassing

Some materials require the removal of moisture, air or volatile components.

The EXCT-35 can incorporate a dedicated degassing section where required.

Vacuum-assisted devolatilization can be used for appropriate applications to improve the quality and stability of the final melt.

6. Pressure Building

After mixing and degassing, the material is transported toward the discharge section.

The downstream screw configuration can generate the pressure required for melt filtration, pelletizing or other downstream processes.

7. Screening and Filtration

The EXCT-35 can be integrated with melt filtration systems when the application requires removal of contaminants or unmelted particles.

This can be particularly useful for recycling and filled-compound applications.

8. Pelletizing or Semi-Finished Products

The final melt can be directed toward different downstream systems depending on the desired product.

The EXCT-35 can be integrated with suitable pelletizing or forming equipment for continuous production.

Possible downstream configurations can include:

• Strand pelletizing

• Water-based pelletizing

• Melt filtration

• Sheet production

• Profile production

• Specialized extrusion dies

The final configuration depends on the formulation and required product.

Applications of EXCT-35

The EXCT-35 can be configured for a broad range of polymer-processing applications.

Typical applications include:

• Polymer compounding

• Masterbatch production

• Color masterbatch

• Filler masterbatch

• Calcium carbonate compounds

• Mineral-filled compounds

• Polymer blending

• Additive dispersion

• Reinforced thermoplastics

• Recycled polymer compounds

• Specialty compounds

• Engineering plastics

• R&D and formulation development

• Pilot production

• Small and medium production batches

The modular design also makes the EXCT-35 suitable for companies producing multiple formulations on one processing platform.

R&D and Pilot Production

The EXCT-35 is particularly suitable for research and development and pilot-scale production.

The relatively compact 35 mm processing platform allows manufacturers and material developers to test formulations without immediately committing to a large industrial production system.

Different screw configurations can be evaluated to determine the appropriate combination of:

• Screw speed

• Mixing intensity

• Residence time

• Temperature profile

• Feeding rate

• Degassing conditions

• Pressure

• Throughput

Once the desired process has been established, the resulting processing knowledge can be used when designing a larger production line.

Wear-Resistant Construction

The screws, kneading elements and barrel components can be manufactured with material and surface-treatment options appropriate for the intended application.

Standard configurations can use suitable nitrided steel, while more demanding applications can be supplied with enhanced wear or corrosion resistance.

This is important when processing formulations containing abrasive components such as:

• Calcium carbonate

• Glass fiber

• Mineral fillers

• Wood fiber

• Ceramic fillers

• Recycled materials

• High filler concentrations

The appropriate material selection should be determined according to the formulation and operating conditions.

EXCT-35 Main Advantages

35 mm Co-Rotating Twin Screw

Compact processing platform for flexible compounding applications.

20–60 kg/h Production Capacity

Suitable for pilot production, specialized production and formulation development, depending on material and process conditions.

300–500 rpm Screw Speed

Provides flexibility for different mixing and processing requirements.

28–48 L/D

Multiple processing-length configurations allow the machine to be adapted to different process sequences.

11 / 22 kW Motor Options

Motor configuration can be selected according to the required processing conditions.

Clamshell Barrel

Fast and convenient access to the twin screws for cleaning, inspection and maintenance.

Modular Screw System

Flexible arrangement of conveying, melting, kneading, mixing, degassing and pressure-building elements.

Independent Temperature Zones

Individual barrel sections can be controlled according to the requirements of each processing stage.

Flexible Application Range

Suitable for compounding, masterbatch, recycling, polymer blending, filler incorporation and R&D.

EXTRUTEX EXCT-35

The EXTRUTEX EXCT-35 brings together a compact 35 mm co-rotating twin-screw platform, modular screw technology and a practical clamshell barrel system.

With 300–500 rpm screw speed, 28–48 L/D configurations, 11/22 kW motor options and a nominal capacity of 20–60 kg/h, the EXCT-35 provides a flexible processing platform for companies that require controlled compounding without the footprint of a large industrial extruder.

Its modular construction allows each processing zone to be developed around the material and formulation. Conveying, melting, kneading, mixing, dispersion, homogenization, degassing and pressure-building operations can be combined into a single continuous process.

The clamshell barrel further improves accessibility, making cleaning, maintenance, screw changes and formulation development faster and more convenient.

EXTRUTEX EXCT-35 — Compact in size, modular in configuration, and engineered for flexible polymer compounding.