Rubber Coated Fabric

Metflex has designed and developed a unique purpose built rubber coating plant to produce un-vulcanised material for its in-house gas meter diaphragm manufacturing area.

However, this process lends itself perfectly to the manufacture of a wide combination of coated fabrics using a range of base substrates such as polyester, nomex®, cotton, etc, coated with an almost endless variety of rubbers including nitrile and viton® , to provide ideal products for varied customer applications.

Our manufacturing facilities fused with our process engineering and material development expertise means that coated materials can be designed to meet specific customer requirements.

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Compound Development

Metflex Products

Developing a new or modified compound is far more than alchemy. Although knowledge and experience will play an important part in developing a rubber formulation, arriving at the final compound will involve cooperation between the customer and manufacturer, and considerable participation of technologists, production, engineering, sales and logistics within Metflex.

At Metflex, we listen to the requirements of the customer and also take a proactive approach to help improve performance in the customers’ application.

Having agreed with our customers the optimum design criteria, we often develop several rubber prototype compounds for trial in situ. Having discussed the results in detail, we will then create up to three possible alternative formulations for the customer to evaluate. If they are happy with the quality and performance of the prototype components, we can run pre-production quantities for long term evaluation and approval. Internally, we will 100% control pre-production compounds and perform full lab evaluation to prove uniformity, using industry standard tests and statistical methods. This industrialisation data can then be made available to the customer, and agreed technical tolerances will be calculated for future production.

These methods are part of our commitment to BS EN ISO 9001:2008 standards. Metflex have WRC approved rubbers, and many grades approved to EN549 for the gas industry by DVGW.

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Rubber Approvals

Metflex Products

The sheer number of current materials standards throughout the world is extensive, but Metflex can develop the rubber materials and product to meet your needs. Typically, customers either produce their own specifications, make references to industry standards or provide copies / extracts for us to work to.

Metflex firstly develops the prototype rubber material, then works with the client to perfect the manufacturing process and gain subsequent approvals (if we do not already have a suitable material). We can often help our customers with design issues that in some cases result in improved equipment performance, reliability and safety.

At Metflex, we are continuously developing new materials and expanding our repertoire – we don’t just wait to be asked before developing something new and exciting. Currently, we are working on new material developments including Silicone, XNBR, HNBR, Fluorocarbon and Perfluoroelastomers as well as new composite materials and manufacturing methods. If you require something which has not been mentioned here we still might be able to help – to obtain more information please contact our sales department via the enquiry form.

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Rubber Types / Materials Key

Metflex Products

Metflex currently produce components in a wide range of rubber types, and we are constantly developing new formulations to widen the scope of applications for our customers, if there are other polymers which are not listed below and with which you currently have a working requirement for please do not hesitate to contact us. The list below is merely a guide to the most commonly used by Metflex within its processes.
Data sheets are available for our fully developed rubber types; please contact our sales team for information.


ISO designation; Rubber type. (Typical trade names)

Brief description
Optimum temperature of use
Best resistance
Typical applications.

NR / IR; Natural rubber / Polyisoprene. (Natsyn®, Cariflex®)
Natural rubber is considered the engineering polymer of choice. Why because it has very high tensile and tear strength.

-50 to +80ºC
Very good resistance to weathering and ozone, severe dynamic abrasion and vibration. High resilience and flex-fatigue resistance and hot tear.
Not widely resistant to most oils and chemicals. Combustible.
Used in tyres, drive couplings for example used in mass transit and boats, bridge bearings, civil engineering.

NBR / XNBR; Acrylonitrile Butadiene rubber. (Buna®, Nipol®, Europrene®)

The oil resistant material used in the gas and oil industry.

-40 to +110ºC
Dependant on level of acrylonitrile content; low gas permeability, good heat age and ozone resistance, resistance to aromatic hydrocarbons and oils. Can be modified with PVC for improved age, weather resistance and fire retardancy. Also can be carboxylated (XNBR) for greatly improved tensile / abrasion resistance and other physical characteristics with higher temperature resistance.

Not recommended for use with polar solvents (e.g. MEK). Weather and ozone resistance only moderate unless specially compounded.
Used in seals and gaskets, diaphragms, drive couplings, audio equipment, hoses in oil and gas industries, also some food contact applications.

HNBR; Hydrogenated nitrile rubber. (Therban®, Zetpol®)
Oil resistance and higher temperature performance.

-40 to +150ºC.
Greatly improved chemical and oil resistance to NBR, with higher temperature limit. Resistant to hot air and water, industrial lubricants, sour oil and gas, some corrosion inhibitors. Very high durability and abrasion resistance. Can be further modified with methacrylate for even higher physical and temperature applications.
The limitations are the same as NBR but the material has an extended temperature range.
Used in hoses, drive belts, seals, gaskets, diaphragms in the oil and gas industries; a good intermediate where fluorocarbon rubbers are too expensive.

CR; Polychloroprene rubber. (Neoprene®)
A good balance of age resistance and moderate chemical resistance.

-35 to +110ºC
Very good resistance to oxidising agents, some oils, ozone & weathering, and refrigerants. Self-extinguishing and good adhesion to metals.
Only moderate petroleum and water resistance unless modified with litharge cure compounds.
Used in belting, coated fabrics, cable jackets and domestic fridge door seals.

SBR; Styrene Butadiene rubber. (Ameripol®, Intol®)
The general workhorse material for the rubber industry.

-40 to +100ºC
Substitute for more expensive NR. Greater hysteresis loss gives better grip in passenger car tyres. Improved ageing over NR/IR.
Moderate weathering and low chemical / oil resistance. Combustible
Used in tyres, audio for example in speaker units for the hi-fi industry, drive coupling and general rubber applications.

EPR / EPDM; Ethlylene Propylene rubber copolymers and terpolymers. (Keltan®, Vistalon®)
The age resistant material.

-50 to +180ºC
Excellent general purpose rubber with very good resistance to weathering and ozone. Normally electrically resistant but can be compounded to be conductive. Excellent resistance to hot water and steam.
Not recommended in certain mineral and synthetic fluids, lubricants and fuels. Combustible and only moderate adhesion to metals.
Used in automotive door seals, cable insulations, hoses and weather proofing / water proofing. Can be compounded for potable water (WRC) goods, foodstuff contact and some biomedical applications.

IIR; Butyl rubber. (Polysar®, Exxon®)
The non-permeable rubber.

-50 to +100ºC
Very low air permeability, insulating. Resistant to ozone and weather, refrigerants and a range of organic and inorganic fluids. Can also be polymerised with chlorine and Bromine to improve chemical resistance and flexibility. High damping.
Limitations include low resilience and combustibility.
Used in seals and gaskets, linings and membranes, diaphragms and some pharmaceutical goods.

IR; Polysoprene (synthetic)
Synthetic natural rubber.

-50 to +80ºC
Advantages; high tensile strength and elongation. More uniform and lighter in colour than NR. Wide hardness range. Very good abrasion resistance to particle abrasion, particularly at lower end of hardness scale in 40-45 IRHD range. Excellent flexing properties. Easily processed. Good adhesion to metal. High resilience.
Disadvantages; moderate heat resistance. Prone to ozone cracking. Combustible. Tensile properties slightly inferior to NR.
Used within chemical and abrasion-resistant linings, hoses, seals and conveyor belting.

AU / EU; Polyurethane rubber. (Urepan®, Vibrathane®)
The abrasion resistant material.

-35 to +70ºC
Outstanding tensile and abrasion resistance properties, with very good resistance to ozone and high energy radiation. Often specified where high durability or abrasion resistance is required with use in hydraulic fluids.
Main limitations are in hot climates where hydrolysis and micro bacterial attack are likely.
Used in hydraulic seals and gaskets, diaphragms and hoses, skateboard wheels and specialised tyres.

ECO; Epichlorohydrin homopolymer, copolymers and terpolymers. (Hydrin®)
Oil resistance and high and low temperatures.

-50 to +130ºC
Resistant to a wide range of oils, water, acids and ozone, weathering and gases. Similar low gas permeability to nitriles but better low temperature flex-fatigue resistance.
Corrosive to metals, so not recommended in rubber to metal bonding. Not recommended in ketones, esters, alcohols and certain hydraulic fluids, oxidising agents and chlorine. Electrically non-insulating.
Used in seals and gaskets, diaphragms, belts and cable sleeves.

MQ and VMQ Silicone Rubber.
Extremely low and high temperature performance.

-50 to +200ºC
Silicone processes excellent long term performance with good resistance to heat ageing, and are useable at temperatures of 200ºc high strength is not exhibited at room temperatures, they do retain their properties at high temperatures to a greater level than other rubbers. Silicones do with prolonged exposure to steam at high pressure, and ageing in closed systems (oxygen essentially excluded) can result in degradation via a hydrolysis reaction, this can be accelerated if acidic peroxide remnants have not been driven off during post curing.

Advantages; high resistance to heat and cold, available in a liquid form. On exposure to flame, an insulating residue of silica is formed which is an insulator, thus cables insulated with silicone can function after short term exposure in a fire. Good physical properties at high temperatures and indeed very small change in dynamic characteristics over a wide range of temperatures.
Disadvantages; low tensile properties (except for high strength grades).
Used for seals, gaskets – for example heating ventilation and air conditioning (HVAC), hoses for food liquid applications.
There are in addition to MQ and VMQ four other variants as follows

1. Fluoro Methyl Silicone FMQ
2. Fluoro Vinyl Methyl Silicone FVMQ
3. Phenyl Methyl Silicone PMQ
4. Phenyl Vinyl Methyl Silicone PVMQ

The advantages of the above are a great increase in fluid resistance when compared with conventional silicone (VMQ) and also strength at high temperatures compared with other fluoroelastomers (FKM,FFKM)
Disadvantages of the four variants are very expensive and they give off vapours during vulcanisation and in the event of fire.
Applications include high temperature parts for aircraft, automotive, tubing, hoses, seals, o-rings and diaphragms.

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Large-Block Moulding Department to receive significant boost

The Large-Block Moulding Department will receive a significant boost to its capacity with the introduction of a new twin bed ‘Tung-Yu’ press.

Shot-Blasting Department is to be relocated to a new purpose-built installation within the main factory

The new press, which has two 900mm bed plates and a capability of 500 tonnes of pressure (per bed plate), will ensure that we can be more receptive and reactive to the ever increasing demands of our customers.

To accommodate this new press, the Shot-Blasting Department is to be relocated to a new purpose-built installation within the main factory.

These two new presses are expected to be fully operational by mid-November 2012, boosting our ability to provide a quick turnaround on rubber coupling manufacture.

Investment by Metflex enables us to be in a better position to service the Subsea and Rubber in Compression block markets. In addition the presses also result in being able to offer more Rubber to Metal bonded couplings, as capacity is opened up with this additional resource.

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18 Month refurbishment programme

Metflex have commenced an 18 month refurbishment programme across all its Compression Moulding Departments.

This is to ensure the quality and accuracy of products manufactured by Metflex is of the highest level, satisfying the ever increasing tighter tolerances and product specifications demanded by our customer base.

This 18 month programme is due to be completed by December 2013, and will enhance Great Harwood as a site for manufacture of rubber components. The press above is one of our unique designed cells for diaphragm manufacture.

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Metflex adopt the ‘FIVE WHY’ approach

As part of Metflex’s continual improvement process, every operation and method of working are questioned.

By adopting a “FIVE WHY” approach Metflex have been able to increase production efficiencies through the merger of two similar departments. This has maximised labour efficiencies and achieved economies of scale within the enlarged department.

The re-positioning of the two departments was completed on the 1st August 2012 and immediate improvements can be seen though an increase in our O.E.E (overall equipment effectiveness) for this area and improved service levels to our customers.

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