Extrusion
tures and colours, with a beneficial nutritional profile. Elsewhere, Baker Perkins development of new, modular dies has led to the introduction of a range of products with a distinctive surface texture. These consist of a number of individual strands, with a sweet centre. Downstream, coating with sugar can provide additional options for added-value product development. These dies can be retrofitted to virtually any make of extruder.
Shaping products Products are shaped by being forced through the die, and Baker Perkins’ ‘library’ of shapes is continually being expanded; it ranges from rings or squares to stars and letters of the alphabet. Retrofitting new dies during the mid-life cycle of an extruder can freshen a product portfolio with new and attractive brands.
14 | September - October 2010
SBX twin-screw extruder The latest generation of twin-screw extruders can produce standard, direct expanded cereals such as fruit rings, corn puffs, alphabet letters, rings, cocoa curls, oat loops and crisp rice with no further processing, except sugar coating and drying. The SBX extruder can respond to market demand for rapid changeover between products and has the inbuilt flexibility to bring new products to market quickly. The modular barrel of the SBX Master enables the length of each machine to be matched precisely to the customer’s process application, and enables extension later as production needs change. To further increase flexibility, the range of end products that can be made has been increased by incorporating a motor and gearbox able to handle twice as much torque as the previous generation of extruder. The flexible Baker Perkins die design and segmented agitator configuration - allowing quick product change-over with few change parts - has been retained, together with the high free volume agitator geometry that enables high outputs to be achieved, even on low density materials such as bran and fine milled flours. A new, high output model has been introduced, to give a capacity range from 225 2000kg/hour of direct expanded product. Cost of ownership is driven
Feature
down by design features that cut maintenance. An AC drive system is virtually maintenance free, and innovative open-frame design maximises access for cleaning and maintenance. The newly introduced splined shafts and high torque capacity of the gearbox are designed for optimum reliability and durability. Processes that require a face cutter benefit from a new design of this unit. Changing the cutter blade can be achieved in 15 minutes without stopping production. The SBX extruder is particularly easy to use, with PLC touch-screen control, and timesaving automatic start and stop sequences as standard.
Co-extrusion equipment Co-extrusion is a recent Baker Perkins innovation for the cereal industry, and provides a simple, cost-effective means of extending a product range beyond standard direct expanded cereals. It involves the simultaneous extrusion of a cereal outer shell and a filling, and extends capability through the ability to make addedvalue products with contrasting textures and colours, with innovative flavours and fillings, and with out of the ordinary shapes that catch the eye. The Baker Perkins co-extrusion system can be added to an existing twin-screw line supplied by virtually any manufacturer. The essential elements of the system are a die, pillow crimper and cream feed system. The fillings can be of virtually any colour or flavour – creams, fruit pastes or chocolate praline are typical. The product range is limited only by the imagination.
Co-extrusion die Die design is crucial in controlling shape, expansion and shell structure, and providing end products of differing formulations and shapes from a single extruder. Baker Perkins has a modular die format, which allows shapes to be altered easily and cost-effectively by changing a product-specific insert.
Pilllow-crimper The pillow-crimper provides co-extruded pillow cereals in attractive new patterns such as hexagons, ‘cats face’, chevrons and waves. ‘Standard’ shapes such as squares can also be
&feed milling technology
Grain