If it is required to be of high quality:
co-rotating twin screws
The twin-screw technology offers decisive advantages.
It can handle large quantities and has an excellent mixing effect and degassing performance.
Ideal conditions for recycling and upcycling.
Excellent mixing effect
Twin-screw and single-screw compared:
Single-screw extruder technology conveys, compresses and homogenises the material axially in the direction of the extrusion tools and builds up the required pressure in the process. However, this design reaches its limits when it comes to (complex) mixing or incorporating additives such as fillers, reinforcing materials or colours.
The twin screw, on the other hand, is an open system. The material is moved in a "figure of eight" mould. The melt pools are continuously transferred from one screw to the other.
The result is an excellent mixing result. The homogeneity of the melt is perfect with optimum geometry.
Color, additives, fillers and reinforcing materials can therefore be incorporated perfectly.
The optimum distribution of colorants, reinforcing agents and additives can have a significant impact on raw material input costs while maintaining the same compound quality.
The compound's production costs are reduced.
Outstanding degassing performance
An efficient process saves processing steps.
This is possible with the twin-screw extruder.
In order to remove even small amounts of residual and odorous substances from the recycled material, water or another stripping agent (e.g. CO2) is fed into the extruder during the stripping process and then removed again together with the gaseous contaminants during degassing.
This means that processing steps such as pre-drying before extrusion or decontamination after extrusion can be significantly reduced or eliminated completely.
This reduces both operating and investment costs.
Remarkable energy efficiency
The co-rotating twin screw is 30 % more energy efficient than the single screw.
The melting energy is essentially supplied by the drive motor, which can be significantly smaller than with the single screw, especially for high output rates of approx. > 2 t/h. The open system of the co-rotating twin screw provides significantly more options for controlling the melt temperature with the processing unit.
Thanks to the modular system and process lengths of > 60 L/D, work steps can be realized in one production run.
The effect: more cost-effective, material-friendly reprocessing.
High flexibility
Twin-screw extrusion can be adapted very flexibly to a wide variety of plastics such as PP, PE, PA, POM etc. for recycling tasks.
It also has a high output capacity: twin-screw extruders have significantly higher output rates than single-screw extruders with the same screw diameter. This enables a compact modular machine concept.
For the highest demands in plastics processing: twin-screw extrusion with unbeatable flexibility and performance.
We are here to help you
Do you have any questions? Our contacts look forward to hearing from you and will be happy to help.
Roberto Freire Matteucci
Global Sales Director Recycling & Biopolymers
Leistritz Extrusionstechnik GmbH
T+49 911 4306-327