Cold feed extrusion

Screw selection

The choice of the correct screw depends on three main factors: Temperature, appearance and output. Maximizing one always influences the other two.

We have developed screws that are specialized for certain tasks. For example our Deep Cut (DC) screw has a high output performance and is perfect for the use with compounds that aren’t homogenization critical. A comparison of the different models and a side-by-side output analysis of DC and our all-purpose combi screw is shown below .

Driven feed roll

• Feed roll bearings with life time lubrication
• Gears for the feed roll lubricated by an oil
• circulation system with pump and flow controller
• Exchangeable retainer rings
• Easy removal of feed roll assembly
• With a hardened surface
• Easily adjustable scraper made of special bronze
• Suitable for liquid heating/cooling
• Hinged parallel to the infeed section

Hot feed extrusion

The trend in the tire industry is headed towards using increasingly high viscous natural rubber compounds for special applications such as truck tread. Due to their limits concerning temperature and homogeneity, standard cold feed extruders cannot process these hard natural rubber compounds efficiently.

From an economic point of view, hot feed extruders can run these special applications more efficiently, even when taking initial investment costs for peripheral equipment and the higher operating costs into account.

Our hot feed portfolio is aimed at high output rates with these particularly high viscous compounds. We offer screw diameters of 200 mm and 250 mm.

New hot feed development

• Easier feeding through new hopper and inlet area design
• Limitation of extruder length for an optimum of compound processabilty
• Transfer of the successful modular concept for HF cold feed extruders to the hot feed design
• Screw redesign leads to high flow rate, while temperature build-up has been lowered for an extremely good
• output-temperature behaviour