Bi-Colour Barrel (BCB)
Overview
The Bi-Colour Barrel (BCB) is an upgrade for an existing twin-screw extruder that allows two distinct products to be produced continuously and simultaneously from the same machine. It adds new product capability without requiring a second extruder or a separate production line.
The process separates the material into two controlled flows within the final extruder barrel. These flows are then brought back together in the specialist die stack supplied with the BCB, creating a continuous two-colour or two-core product with clearly defined components.
Key Benefits
Two Colours from One Extruder
Key figure: Two simultaneous product streams
Produces two distinct colours continuously and at the same time from a single twin-screw extruder.
Flexible Product Formats
Key figure: Multiple two-product configurations
The specialist die stack can produce two sets of uniquely coloured kibble or treats, combine products side by side, or create an inner-and-outer core format.
Two Flavours from One Extruder
Key figure: Two independent recipes
Two different flavours can be produced independently on the same extruder, for example chicken and salmon kibble in one continuous process.
Late-Stage Product Additions
Key figure: Additional dosing at the final barrel
Provides the potential to introduce topical vitamins or other additions late in the extrusion process, closer to the final product-forming stage
Frazer-Nash injection head capable of injecting product at pressures up to 150 bar, including colour, vitamin or flavour additions.
Interchangeable dies allow the BCB to switch between different products, including treat ropes and two-stream kibble production.
Can run as a standard extrusion process without changing the equipment, or provide symmetric and asymmetric flows for either equal product streams or one main product with a smaller secondary product.
Only a small reduction in throughput compared with a typical twin-screw extrusion process.
Can be integrated with a Frazer-Nash Bayonet for fast, tool-less connection and changeover.
Can also be integrated into a Frazer-Nash Hood and combined with Frazer-Nash Guillotine or Crimper equipment to create a complete product-forming system.
Retrofittable Twin-Screw Upgrade
Flexible Two-Product Formats
Late-Stage Product Injection
Symmetric or Asymmetric Flows
The Bi-Colour Barrel can be retrofitted to an existing twin-screw extruder by replacing the final barrel and screw segments with the BCB barrel and matched segments.
This converts an installed twin-screw extruder to produce two controlled product streams without replacing the main machine.
The upgrade provides a practical route to two-colour production while retaining the existing extruder, drive and upstream process equipment.
The specialist die stack supports a range of two-product formats from the same Bi-Colour Barrel platform.
It can produce two separately coloured pieces of kibble, a single piece with two colours side by side, or an inner-and-outer core product with different colours.
Interchangeable dies allow these formats to be changed without replacing the complete BCB assembly.
Once the extrudate is divided into two distinct flow paths, each stream can receive its own additional ingredients.
Colours, coloured oils, different flavours or late-addition vitamins can be injected independently into either product stream.
Introducing additions close to the final forming stage provides greater control over recipe differentiation and the finished product appearance.
The Bi-Colour Barrel can provide symmetric flow, with two equal product volumes travelling through the separate paths to the die.
An asymmetric arrangement can also use larger and smaller screw paths, allowing a greater volume of standard product to run alongside a smaller volume of a specialist product, such as a vitamin-enriched or coloured stream.
This is particularly suited to two-colour formats where a smaller internal product is contained within a larger external product, creating a clearly defined core-and-shell kibble.
How it Works
The Bi-Colour Barrel is an upgrade for an existing twin-screw extruder. It replaces the final extruder barrel with a specialist barrel that divides the original extrudate into two distinct flow paths.
Within each path, dedicated screw elements are arranged primarily for mixing rather than further cooking. At this stage, each stream can receive colour, flavour, vitamins or other late-stage additions independently.
Once the two streams have been separated and conditioned, they are delivered to the specialist die stack. At the die, the process can either:
- Keep the streams separate to produce two distinct products.
- Bring the streams back together to create a single two-part product with clearly defined components.
Technical Specifications
| Operating and injection pressure | 150 Bar |
| Number of injection points | 6, spaced along the length of the Bi-Colour Barrel |
| Extruder size compatibility | Small, medium and large twin-screw extruders |
| Die-plate output configuration | From 2 distinct output ropes up to the number required by the product |
| Additional extruder length | Up to 10% additional length |
Applications
- Bi-colour kibble production, including two separately coloured kibble pieces, a single side-by-side two-colour piece, or an inner-and-outer core product.
- Bi-colour treat production using two separately coloured or flavoured ropes, which can remain separate at the die or be combined into a single two-part rope.
- Late-stage topical injection of additional ingredients, including colour, flavour, oils or vitamins.
- Standard kibble production with no colour mixing, using the same extrusion equipment.
Related Products
SEV
The Sanitary Extruder Valve is an energy-management valve installed at the end of the extruder.
SEH
The Sanitary Extruder Hood (SEH) is used in the manufacture of dry, cereal based foods produced continuously on a cooker extruder, commonly known as kibble.
Co-Extrusion Head
The Co-Ex is designed to produce filled treats directly from the end of an extruder. It takes the main extruder flow and divides it evenly across a number of treat nozzles, allowing multiple product strands to be formed at the same time.
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