Co-extrusion system enhancements to improve control and performance

Baker Perkins has developed innovative technology to improve process control, performance and hygiene on all the units in Co-Ex Master co-extrusion systems, which creates products by adding a centre filling into a cereal outer.

Co-extrusion systems can be added to almost any new or existing food extrusion line to produce a variety of pillows, sticks, bites, tubes and bars, in different shapes and with filling of sweet and savoury flavours.

Visual appeal of the product has been enhanced by adding a rotary insert to each stream of the co-extrusion due where extrudate and filling are combined. This allows the position of the seam on the pillow to be adjusted so that the dark line, which features on products, is hidden.

On the cream feed system, the introduction of progressive cavity pumps transform control. Metering accuracy is precise; product conveying is gentler and back flow has been eliminated; a broad range of viscosities can be handled; and the pumps are designed for high pressure. There is also a temperature-controlled hopper with a recirculation system to maintain the filling in optimum condition, even if the line stops.

The unit is fully stainless, features hygiene design throughout, and the time required to carry out a full clean has been reduced with the introduction of an Assisted Cleaning system. The three-stage process uses an external boost pump to circulate water through the pumps and pipework at 1.5m/s to ensure thorough material removal. Operators are guided through the entire process by prompts on the human-machine interface (HMI). Cleaning may be carried out in situ or the unit can be wheeled away for washdown and cleaning off-line. Flowmeters have been added to the list of optional extras.

On the crimping unit, the introduction of servo control combines accuracy with operational simplicity. The crimping rolls are driven by independent servo motors, allowing them to be easily removed, replaced and synchorised while servo gap adjustment provides “accurate and repeatable” positioning with by-pass for set up. The precision of servo control allows operators to align the cutting blades for precision cutting.

Co-extruded products can be positioned as cereal, pet or infant foods as well as snacks. Bite-sized pieces and bars are being marketed as confectionery and count lines.

Fillings can be of virtually any colour of flavour – sweet and savoury creams, fruit pastes, cheese and chocolate praline are typical. Exotic flavours, plus glazings, frostings or chocolate coating, add even more appeal.

The outer shell can appear to be plain or stringy, with surface textures such as grooves and highlights. The product stream can be cut into appealing shapes such as chevrons, fish and faces.

Co-extruded products can be made in any lengths from 12-120mm.