In plastic extrusion, the design of the extruder screw is paramount to achieving optimal performance and product quality. As the exclusive partner of Bausano in the UK, Ireland, and Scandinavia, Intelicare recognises the critical role that customised screw designs play in enhancing the efficiency and output of extrusion processes.
Understanding Screw Design in Extrusion
The screw within an extruder serves multiple functions: conveying raw material, melting it through heat generated by friction and external heaters, and homogenising the molten polymer before it passes through the die to form the final product. The geometry of the screw—including its length-to-diameter ratio (L/D ratio), flight depth, pitch, and helix angle—directly influences the quality of the extrudate and the efficiency of the process.
Tailoring Screw Geometry to Material Characteristics
Different polymers exhibit unique behaviours under thermal and mechanical stress. For instance, processing PVC requires careful temperature control to prevent degradation, while materials like polyethylene may necessitate designs that promote better mixing. Bausano’s approach involves analysing the rheological properties of the specific polymer and customising the screw design to ensure optimal melting, mixing, and pressure development. This bespoke design enhances product quality and reduces waste.
Advanced Screw Designs for Enhanced Performance
Bausano offers a range of screw designs tailored to various applications:
- Dual Flight Screws: Featuring two helix pitches with varying lengths, these screws improve the consistency of the melt and enhance material transport capacity
- Barrier Screws: Incorporating a barrier section, these designs provide better control over temperature and mixing during extrusion, ensuring uniform melt quality.
- Mixer Screws: Equipped with additional mixing elements, these screws ensure uniform distribution of colourants or additives within the molten material, crucial for consistent product appearance and properties.
- By employing advanced computational methods such as Computational Fluid Dynamics (CFD) and Finite Element Method (FEM), Bausano’s engineers meticulously design and test screw geometries to meet the specific requirements of each application.
The Bausano Advantage
Bausano’s commitment to in-house manufacturing ensures stringent quality control over every component of their extrusion lines. Screws are crafted from special nitriding steel, and when necessary, bimetallic barrels with inner sleeves made from special alloys are utilised to enhance durability and performance. This dedication to quality results in extruders that not only meet but exceed production expectations.
Conclusion
Customising screw designs is not merely an option but a necessity for achieving optimal extrusion performance. Through collaboration with Bausano, Intelicare provides tailored extrusion solutions that address the unique challenges of various materials and applications. By focusing on customised screw geometries, we ensure that our clients benefit from enhanced efficiency, superior product quality, and a competitive edge in the marketplace.
When you invest in a Bausano extruder, you are investing in more than 100 years of experience, alongside UK based project management and aftercare. Request a technical brochure below or email paul@intelicare.co.uk to start discussing your project. You can check out the full Bausano range, and don’t forget to follow Intelicare on LinkedIn.
