We shape the world!


The potential of cooking extrusion is far from exhausted. Since the company was founded, Schaaf has been continuously developing new processes, machines and shapes, using innovative, interesting raw materials, also on the initiative of customers. The motto is: Less theorising, more trying out new raw materials, recipes or shape ideas during practical tests with the extruder.

Schaaf's efforts in the area of research and development are entirely aimed at providing the customer with immediate and usable advantages. The customer benefits from this, through valuable support in the development of new product ideas, innovative formulations, adaptations to local raw material preferences or in the form of technical solutions for a wide range of extrudates.

The mid-range extruder available in Schaaf's pilot plant offers customers and clients the opportunity to try out new ideas in practice without blocking their own production capacities or contaminating them with problematic raw materials. Thus, high-quality and attractive products can be realised with little effort and in the shortest possible time.

Turbo Extrusion

The TURBO extrusion process developed by Schaaf works with turbines. In practice, we use the term TURBO rotors, which transport, mix and knead highly viscous doughs much more effectively than it is possible in conventional single or twin screw machines. The decisive factor in this process is the enormous pressure difference between the front and back of the turbine blades, caused by the high viscosity of the dough.

While fluid engineering in general tries to avoid cavitation, it produces enormous mixing and homogenizing effects, especially in food extrusion, and ensures optimum heat transfer within the dough.

It has been shown that in TURBO extrusion the mixing effect is of a quality that could not be achieved in the past even by much more complex twin screw extruders. In our processes, the classic "screw" is basically only a feed element.

Functional diagram TURBO process
Functional diagram TURBO process

Advantages of the TURBO process:

  • flexibility through dimensioning of turbo elements, pressure plates and number of turbo stages
  • very high throughputs with smaller extruder process part lengths
  • excellent process control capabilities
  • very easy handling of the parts
  • considerably greater freedom in recipe design with regard to fatty, sugary or fibrous materials
  • antibacterial effect: caused by the interaction between expansion and compression, the reduction of germs by far exceeds that of other extrusion processes
  • long service life and inexpensive wear parts
  • quick, easy and cost-saving cleaning and maintenance of the TURBO process parts

Illustrative example for temperature and compression ratio

The following illustration (in simplified form) is intended to show the relationship between temperature and pressure in the dough during compression and decompression in front of and behind the turbo rotor: One must imagine a cylinder in which different pressure ratios are generated by means of a piston:

Example sketch for temperature and compression ratio
Example sketch for temperature and compression ratio

In the extruder, the screw speed determines the number of compression and decompression cycles to which the dough is subjected during its passage through the processing zone, and thus the dough temperature. Energy is introduced into the dough during each compression cycle. As often as the dough is compressed and decompressed again, it tends to reach a high temperature.