Conical Twins
Conical twin-screw barrels and screws for extrusion applications, engineered for maximum performance, thermal stability and extended service life.
PENA® conical twin-screw assemblies are manufactured to suit each specific application, optimising plasticising performance, process stability and dimensional accuracy. Thanks to our in-house Nitrex nitriding technology, we can apply double nitriding processes that increase the effective hardened layer and significantly extend component service life..
Conical Twin Barrels
Manufacturing & Standard Configurations
- Standard material: 1.8550 nitriding steel, selected for its superior hardenability in large diameters due to its nickel content.
- Optional segmented construction with replaceable inner liners.
- For liner configurations: 1.8550 nitrided outer body combined with a hardened 1.2379 inner liner.
Technical Specifications
- No maximum length limitations, depending on machine design.
- High rigidity and dimensional stability under operating conditions.
- Precision machining and grinding with full metrology control to guarantee perfect coaxiality.
Technical Advantages (Barrels)
- Flexible configurations, available as one-piece nitrided barrels or segmented assemblies with replaceable liners.
- Extended service life through double nitriding processes (nitriding, polishing and re-nitriding).
- Optimised repairability through interchangeable liner technology.
Conical Twin Screws
Typical Materials
- Nitriding steels: 1.8509 (F-174), 1.8519 (F-172) and 1.8515 (F-171).
- Nitrided finish providing high surface hardness and excellent wear resistance.
Technical Specifications
- No design-related length limitations.
- Nitrided surface engineered to minimise wear and seizure.
- Screw geometry adapted to the processed material, including PVC, compounds, recycled materials and mineral-filled formulations.
Bimetallic Screws Alloys
NITRIDED
67/70 HRC- Abrasion MEDIUM
- Corrosion LOW
An economical solution for standard applications with low wear requirements.
PENA 160
Ni–Cr · >1100 HV- Abrasion VERY HIGH+
- Corrosion MEDIUM
High hardness combined with excellent thermal stability and chemical resistance.
PENA 172
Aleación refinada · 58–60 HRC- Abrasion HIGH
- Corrosion VERY HIGH+
Excellent adhesion and oxidation resistance, ideal for humid and corrosive operating environments.
PENA 175
PTA con WC · >62 HRC- Abrasion MAXIMUM++
- Corrosion MAXIMUM++
Maximum protection against severe abrasion, mineral fillers and extreme wear conditions.
Technical Advantages Screws
- Extended flight life through application-specific hardfacing solutions.
- Compatible with both nitrided and bimetallic barrel technologies, depending on wear requirements.
- Complete refurbishment and rebuilding services available in-house.
Limits & Capabilities
- Conical twin-screw assemblies are manufactured without standard dimensional limitations and are fully customised according to machine design.
- In-house Nitrex nitriding technology, including double nitriding processes to increase the effective hardened layer and maximise service life.
