Extrusion & Forming

BCH world-leading food and confectionery extruders are designed to handle a wide range of products including liquorice, starch gels, fruit twists, sugar pastes, food pastes and gels.

Side Flow Extruders

The extruders are manufactured with 75, 130, or 200mm diameter screws to achieve throughputs of between 50-1,500 kg/hr via a side flow die configuration. The side flow dies will extrude over widths from 300-1200mm at right angles to the screw axis. Side flow dies can be designed to extrude sheets, ropes and twisted ropes in solid, hollow or co-extruded form.

The side flow design provides a cost effective, high output system with good uniformity of product weight across the die width. This uniformity is achieved by careful design of the screw across the die mouth; regulating/throttling plates/ screws on the dies and for some products, a positive displacement pump on each rope. The extruders are usually mounted on rails to position the dies over a retracting nose piece on the BCH high performance cooling tunnels. For die changing and cleaning, the extruders can be wheeled offline. The main barrel of the extruder is water jacketed to minimise start up times, maximise extrusion efficiency and in the case of the twin screw mixer extruder, provide heat transfer.

Continuous or Batch Fed Extruders

The extruder is fitted with a small vacuum inlet hopper to receive liquorice directly from the continuous cooker (Viscotator). The vacuum hopper enables the extrusion of a cooler, drier and firmer liquorice product. When fitted with a larger feed hopper, batch fed product is possible

Twin Screw Mixer Extruder

This type of extruder enables the mixing of colours, flavours and acid into a cooked liquorice base. Using this type of extruder, colour and flavour contamination of the premix and cooking equipment is eliminated, enabling rapid colour changes, minimal loss of flavour, minimal sugar inversion and starch gel breakdown. The extruder is fitted with a screw extraction system for rapid and easy cleaning. This mixer extruder is an efficient continuous mixer for multiphase products, such as sugar paste, seeded chew syrups and cereal bar mixes.

Multi Colour Multi Flavour Extruders

Suitable for any viscous product:

  • Sugar paste • Caramel • Fudge • Chocolate • Nougat • Chew

The process begins with a neutral cooked product being fed into a high pressure, low shear extruder. The product is split into 6 channels, each of which can be individually coloured and flavoured. Up to 40 ropes can be extruded onto the BCH cooling/drying tunnel each of which contains the 6 colours in equal metered proportions. The flow control of each colour channel to each rope is automatic, and no manual regulation of the machine is required, leading to quick start-up and guaranteed rope weight control. Rope can be extruded in a huge variety of shapes and designs including twisted, straight, flat strap, squares and stars.

They can also have hollow or filled centres.

  • Labour saving with quick start-up • Unique CIP System reducing energy costs • Flexible and fast colour change


To complement the range of extrusion solutions, the addition of further equipment gives the flexibility of manufacturing co-extruded products. There are a large range of combinations such as liquorice/sugar paste and liquorice/pectin gel.

Co-Extrusion – Liquorice/Sugar Paste

BCH also offer a solution for the production of sugar paste which comprises of a sugar mucilage cooker and a Z-arm duplex trough mixer. The resultant sugar paste supplies the side flow extruder in order to produce the combination extrusion of sugar and liquorice paste. The mucilage cooker is a steam-jacketed vessel with an anchor type stirrer which can be complemented by a high shear mixer. The combination of these two mixers together with the steam heating, results in a fully homogenous syrup mix. The vessel is load cell mounted with microprocessor and recipe controls. The syrup is transferred to the Z-arm duplex trough mixer by a positive displacement pump and jacketed pipework. Icing sugar is fed into the mixer, and together with the sugar syrup the resultant mix produces a sugar paste. The Z-arm duplex trough mixer is robustly designed to give a thorough mixing action, prior to tipping into empty mobile bins. The mobile bins are transferred to the extruder and mechanically tipped into the feed hopper of the sugar paste extruder.

The addition of a specially designed die head is used for the production of liquorice and sugar paste in a number of combinations.

Co-Extrusion – Liquorice/Pectin Gel

The liquorice/pectin gel application is achieved through the addition of mixing and holding vessels combined with a local colour and flavour dosing station. There is a feed pump to the extrusion assembly which is configured in the same way as that of sugar paste.