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Bell Plastics



Bell PlasticsBell manufactures highly specialised plastic mandrels used predominantly by the manufacturers of hydraulic and other industrial hoses in their own production processes - a mandrel is a critical consumable for the global rubber hose industry.  Hose mandrels are long, high-specification rods around which reinforced industrial rubber hoses are formed. 

Bell is one of very few companies in the world that can produce flexible hose mandrels and the only company in the UK to do so.  


Bell focuses on mandrels made from various types of plastic, but primarily nylon, using a proprietary highly automated extrusion process which results in superior mandrel properties and performance.  Bell uses a unique, specially-designed production technology that guarantees very low dimensional variability and a complete absence of internal voids or holes in its mandrels.  These defects are frequently present in lower-quality competing mandrels produced by conventional extrusion processes, and can lead to defects and inconsistencies in the customer’s finished hose.

Bell moved to new premises at the start of September 2009 as recent expansion in Bell’s flexible hose mandrel product line and integration of the Safetytread business meant that a larger facility was required.  The new site located in Poole, Dorset, provides room for growth for many years to come.


The customers for Bell’s mandrel and film products range from large multi-national rubber products companies to local/regional hose producers.  Almost all of its mandrel and film products are exported, predominantly to continental Europe, South Asia and the Far East.


Bell accounts for approximately 7% of Group sales.  Sales were £3.6m for the year ended 31 March 2016.



Hose mandrels are long, high-specification rods around which reinforced industrial rubber hoses are formed.  Examples of such mandrel-made hoses include hydraulic hoses, high-pressure water hoses, air-conditioning hoses and power steering hoses.

The mandrel determines the critical internal diameter of the hose, and supports the rubber of the hose as its steel wire or fabric reinforcements are applied during production.  Once the rubber hose has been formed and vulcanized, the mandrel is removed by high pressure water, and is re-used, typically for 10-20 cycles.

Dimensions of Bell mandrels vary from 3mm to 50mm in diameter, and up to 2km in length supplied in coils or on drums.

Bell has recently been working to expand its mandrel range to include other materials with advantages for certain hose-making applications (e.g. greater flexibility), and currently has products on trial at key customers.

Specialist Films

Bell manufactures two types of film, XLPE and UHMWPE, which are used as chemically-resistant inner linings and abrasion-resistant outer coverings of industrial hoses.

Bell’s customers use its XLPE (cross-linkable polyethylene) and UHMWPE (ultra-high molecular weight polyethylene) film to make continuous internal linings in their hoses, with exceptionally wide chemical resistance.  Typical applications include the internal lining of chemical transfer hoses, e.g. tanker discharge hoses.

Both films are highly abrasion-resistant and have low friction properties and are therefore also used by Bell’s customers to make wear-resistant coverings on industrial and high-pressure hoses, such as mining hoses and hydraulic hoses on diggers and earth-moving equipment.

Other products

Bell’s other products include:

  • Safetytread, a business specialised in manufacturing anti-slip stair treads, inserts and nosings for use in commercial and public buildings
  • Coating of wire and wire rope with a variety of plastics materials.  This activity was started to complement the range of nylon mandrels (the smallest diameters require wire for tensile reinforcement) but has developed into a significant business supplying the wire and cable industries

Competitive advantages

  • Exceptional quality of nylon mandrels used for spiral reinforced and large diameter braided hose
  • Leading range of technical solutions for hose mandrels
  • Technical service for hose manufacturers with mandrel needs
  • Most of Bell’s production equipment is designed and built by Bell to its own specifications, providing a substantial barrier to entry for would be competitors seeking to make mandrels of equivalent quality. 

Benefits of nylon mandrel

Mandrels can be made of steel, rubber, PP (polypropylene) and nylon (polyamide), as well as other materials.  The type of mandrel material used has a significant impact on the hose manufacturer’s production process, which is designed to suit the flexibility and other characteristics of the mandrel material.  This results in difficulties for hose producers to switch between mandrel materials.

Bell is a leader in the production of nylon mandrels, which have several benefits over other types of mandrel.

  • They are more flexible than metal and PP mandrels, giving the hose producer greater production efficiencies
  • They can typically be re-used more times than PP and rubber mandrels and are easier to join into long defect-free production lengths
  • They are easier to extract from the hose
  • They can be re-used more times than PP and rubber mandrels
  • These characteristics all help to reduce hose-makers costs and make nylon the mandrel of choice.


The market for industrial rubber hose is growing approximately in line with GDP in the relevant markets.  Bell estimates that there are approximately 300 hose plants worldwide of which approximately half use some form of mandrel for hose formation.
The estimated total market size is +£20m. 


There are no other significant specialist producers of nylon mandrel supplying the hose industry.  The key competition comes from in-house production of mandrels, from the rubber hose manufacturers or from local, non-specialist producers making plastic mandrel as part of a wide range of other extrusions. 

The type of mandrel material used has a significant impact on the hose manufacturer’s production process - this results in barriers to switching mandrel type and provider. 

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