Co-Extrusion heads

HF extrusion heads offer a universal flow channel technology with our unique hammerhead locking system to ensure fast & safe changing of profiles in combination with a high degree of operational reliability and precision. Co-Extrusion heads are available with head openings of MW 500 mm and MW 800 mm. The Duplex is also available in MW 650. The available setup extends up to five extruders:

Duplex
Triplex
Quadruplex
Quintuplex

• Compact design/marginal deflection
• High-quality forged steel
• Optimised head weight and space required
• Good access for cleaning and maintenance
• Use of insert modules for profile adjustment
• Secure operation
• Effective location of hydraulic cylinders
• Floating hydraulic locking system
• Separate locking systems for upper/lower section
• No wear of contact surfaces
• No bleeding
• No lubrication required

Modular tooling

HF offers modular tooling for flexible head openings, fast profile changes and reduced changeover times. Basic flow channels are already milled into the large movable parts of the extrusion head. Lightweight insert pieces allow quick and easy change ensuring full flexibility, for example from sidewall to tread or single to dual cavity extrusion. The individual flow channel re-configuration delivers the following benefits:

• Increase of flexibility
• Low pressure reduces material temperature
• Short channels for minimum retention time
• Avoidance of no-flow zones
• Balanced compound distribution

Double tread
channel inserts for cap or base

Double tread
channel inserts for wing

Change from single to dual cavity

Flow Simulation

Special emphasis is placed on the design of the flow channels in the extrusion head. On the one hand, the smoothest possible transition from the circular cross section at the extruder outlet to the rectangular, flat geometry of the profile in the area of the die is desired. On the other hand, care is taken that in the flow channels pressure; temperature and speed of the mixture over the entire flow cross-section are as identical as possible. Consequently, HF applies state-of-the-art software to calculate three-dimensional flows in order to achieve optimal results.

Flow simulation: Calculation model flow channel

Flow simulation: Pressure distribution in flow channel

Flow simulation: Speed profile in flow channel

Temperature distribution in flow channel