Materials

EPDM (ethylene propylene diene monomer) is a versatile synthetic rubber composed of ethylene, propylene, and diene monomers. Its unique molecular structure, featuring a chemically saturated single bond backbone, grants it exceptional resistance to the elements. This robustness stems from its resilience to ozone and UV rays, which are less likely to degrade EPDM compared to rubbers with double bonds.

Another standout feature of EPDM is its unparalleled weatherproofing capabilities. It has impressive resistance to abrasion, UV rays, ozone, aging, and various weather conditions, making it the premier choice for waterproof applications. EPDM also has good steam resistance, maintaining integrity at temperatures up to 150°C. It combines resilience, low electrical conductivity, and strong adhesion to metals. It has good elongation of up to 600% and a tensile range of 500-2500 psi, performing well across a temperature spectrum from     -45°C to 150°C.

Additionally, EPDM serves as an insulator and noise reducer, contributing to its widespread use in the automotive sector.

EPDM is often selected as a cost-effective substitute for silicone rubber, especially for components exposed to the outdoors or moisture, or for electrical insulation purposes. It is also employed in roofing and liner applications. EPDM’s versatility is commonly used across four primary sectors:

• Automotive: EPDM’s most prevalent use is in the automotive industry, where its flexibility, durability, and resistance to weather conditions are highly valued. It is commonly found in weather stripping, seals, sealants, wire and cable harnesses, and brake systems. Additionally, EPDM is mixed with other materials to create fender extensions, rub strips, and car bumpers.
• Industrial: In industrial settings, EPDM’s electrical insulation and waterproof properties are put to good use. It is incorporated into components like water system O-rings, hoses, gaskets, electrical insulators, and connectors for wire and cable. EPDM is also fashioned into accumulator bladders, diaphragms, grommets, and belts.
• Construction: The construction industry benefits from EPDM’s insulating, weatherproof, and waterproof qualities, particularly in roofing. It is also utilised in sealants, expansion joints, garage door seals, pool and tank liners, and as a waterproof coating for bitumen roofs. EPDM is even applied to RV roofs.
• HVAC: EPDM’s resistance to weather and temperature variations makes it ideal for HVAC applications, where it is used in grommets, tubing, gaskets, seals, and insulation.

Natural rubber, a marvel of nature, is composed of isoprene polymer chains that exhibit remarkable elasticity due to their ability to reconnect after being stretched. Unlike synthetic rubbers derived from petrochemicals, natural rubber is sourced from the latex sap of rubber trees, which are the primary producers of latex, contributing to 99% of the world’s natural rubber supply.

Natural rubber is celebrated for its flexibility and strength, despite the presence of natural impurities and sensitivity to environmental factors and hydrocarbons. It stands out among rubbers for its exceptional pliability and resistance to water and a range of chemicals. Its resilience against cutting, tearing, wear, fatigue, and abrasion is excellent, and it maintains its integrity within a temperature spectrum of -50C to +100C. The tensile strength of natural rubber is impressive, and it bonds seamlessly with various materials.

The journey of natural rubber begins with the tapping of a rubber tree, where the sap is collected and then refined through chemical and heat treatments for manufacturing purposes. Initially, the latex is a mix of one-third rubber and one-third water. The refining process involves adding formic acid to coagulate the rubber into curds, which are then cleansed and formed into blocks or sheets, followed by smoking.

Subsequently, the rubber undergoes mastication to enhance its workability and is combined with other chemicals and fillers to complete the final compound make up. The rubber is then shaped through calendaring or extrusion and undergoes vulcanization. This process, which typically occurs at around 160 deg C, involves heating the rubber with sulphur to increase its durability, elasticity, and resilience. Vulcanisation creates cross-links between polyisoprene molecular chains, enhancing strength and chemical resistance while eliminating the tackiness of raw rubber. Despite the advent of synthetic rubber in the 1930s, natural rubber remains a significant player in the market, accounting for nearly half of it.

Natural rubber excels in scenarios that demand superior wear. Its robustness and compressibility make it ideal for engineering applications such as anti-vibration mounts, drive couplings, springs, bearings, rubber bands, and adhesives. A significant portion (50%) of natural rubber is utilised in the production of high-performance tires for vehicles like race cars, buses, and aircraft, owing to its durability and thermal resistance. It also finds use in hoses, automotive components, foam mattresses, and battery containers. Natural rubber continues to be an indispensable material, valued for its unique properties and wide range of uses.

Neoprene rubber, a versatile synthetic material also known as Polychloroprene, is manufactured from polymerised chloroprene. This material boasts a unique composition of carbon, hydrogen, and chlorine polymers, which, when cross-linked, endow neoprene with remarkable properties. These include its chemical stability and resistance to heat, oil, water, and various solvents.

As part of the standard product process neoprene is vulcanised, a process that enhances its qualities. This involves the formation of sulphur bridges that link chloroprene chains, creating a robust, larger molecule. The quantity of these sulphur connections directly influences neoprene’s characteristics, allowing it to exhibit a wide spectrum of properties while maintaining its fundamental structure. This adaptability makes neoprene suitable for a multitude of uses.

• Neoprene Sheets: Ideal for the manufacture of safety apparel like wetsuits and gloves, these sheets also serve as landfill liners or covers for protective gear.
• Extruded Neoprene: Perfect for making tubing, window seals, and when sliced, it becomes useful gaskets, seals, or washers.
• Neoprene Foam: With its thick, spongy texture, neoprene foam provides excellent cushioning for sports equipment and insulation for industrial machinery, doubling as effective weather stripping.

Originally developed as an oil-resistant alternative to natural rubber, neoprene has since revealed a broader range of applications thanks to its additional properties.

• Heat Resistance: Neoprene outperforms natural rubber in gas permeation resistance and can operate at temperatures up to 135C without degrading. Its resistance to fire adds to its appeal for long-term, high-temperature applications.
• Cold Resistance: Remarkably, neoprene remains functional down to -45C, although it does stiffen at sub-zero temperatures.
• Material Compatibility: Neoprene can be engineered to bond with cotton and various metals, such as stainless steel, aluminium, brass, and copper, using a basic bonding agent. With certain additives, it can also adhere to glass and acrylic.
• Outdoor Durability: With a low oxidation rate and high resistance to sun and ozone, neoprene is durable in outdoor settings.
• Chemical Resistance: Chemically inert, neoprene withstands petroleum-based mixtures, alcohols, alkaline, mineral acids, and some salt solutions, making it highly valued in numerous industries.

Nitrile rubber, known in the industry as Buna-N or NBR, is a synthetic rubber copolymer composed of acrylonitrile and butadiene. Renowned for its versatility, it’s extensively utilised across various sectors, notably in automotive and aerospace applications.

Developed in the 1930s, nitrile rubber rose to prominence as a natural rubber alternative during World War II due to the scarcity of natural rubber. It has since secured its status as a preferred material for myriad uses, thanks to its remarkable oil and chemical resistance, superior tensile strength, and good abrasion resistance. The advantages of nitrile rubber are many:

Durability Nitrile rubber’s robustness enables it to endure severe environmental conditions, including exposure to chemicals and oils. Its wear-and-tear resistance qualifies it for applications demanding sustained performance.

Oil and Fuel Resistance With its exceptional resistance to oils and fuels, nitrile rubber is the material of choice for the automotive, oil and gas, and manufacturing industries. This resistance guarantees dependable performance, even in environments heavily exposed to these substances.

Water Resistance Nitrile rubber’s closed-cell structure acts as a formidable barrier against water absorption, making it highly water-resistant. This trait is essential for applications like gaskets, seals, and hoses that require water resistance.

High Temperature Resistance Capable of withstanding elevated temperatures, nitrile rubber is apt for high-temperature applications. It retains its form and properties under extreme heat, ensuring consistent performance over time.

Flexibility The high flexibility of nitrile rubber allows for easy moulding into various shapes and sizes, accommodating a broad spectrum of applications in the automotive, medical, and industrial fields.

Cost-Effectiveness As a cost-efficient material, nitrile rubber delivers multiple benefits and efficient solutions for diverse industrial applications. Its adaptability and longevity make it a sought-after option for manufacturers seeking economical yet high-quality solutions.

NBR with Higher ACN offers improved oil resistance, fuel resistance and tensile at break. While Hydrogenated Nitrile (HNBR) is a product family designed to overcome some of the deficiencies of nitriles. HNBR shows improved chemical resistance, higher service temperature, and lower brittle temperature than regular nitrile. HNBR polymers are reacted with hydrogen to hydrogenate a percentage of NBR’s unsaturation to improve chemical compatibility to certain media, such as sour gas, ozone and some additive packages.

Silicone, also known as polysiloxane, occupies a unique position between rubbers and plastics. This synthetic elastomer combines the elasticity of rubber with the durability of plastic, making it an incredibly versatile material. While it’s often categorized as a rubber due to its elastic properties, silicone’s ability to take on various forms—from liquids to solid objects—adds to its complexity.

Silicone rubber is distinguished by its silicon-oxygen base, enhanced with organic groups like methyl for flexibility. This structure offers several variants tailored for specific uses:

• MQ: The foundational silicone rubbers, known for their simplicity and historical significance.
• VMQ: Methyl vinyl groups that enhance compression set properties, aiding in vulcanisation and making them a popular choice.
• MPQ/PVMQ: These groups enhance performance in colder environments.
• FVMQ: A combination of fluoro, vinyl, and methyl groups, offering increased resistance to chemicals like oil and solvents.

Depending on the processing method, silicone rubber can be categorised into:

• Liquid Silicone Rubber (LSR): Known for its low molecular weight and weather resistance, LSR is ideal for extrusion or injection moulding.
• Room Temperature Vulcanised (RTV) Silicone Rubber: Available in one or two-component systems, RTV silicone cures at room temperature and is commonly used for moulds, sealants, and encapsulations.
• High Temperature Vulcanised (HTV) Silicone Rubber: Featuring long-chain polymers, HTV silicone requires vulcanisation at high temperatures, similar to traditional rubber.

Silicone rubber excels in temperature resistance and flexibility, withstanding a range from -80C to 300C. It boasts impressive tensile strength, elongation, and rebound qualities, making it a reliable insulator and weather-resistant material. Its hypoallergenic nature and gas permeability also make it suitable for medical applications.

Silicone rubber’s adaptability has led to its widespread use in various sectors:

• Electronics: Highly purified silicone rubber is used for insulation, lubrication, and component housing.
• Aerospace: It’s incorporated into spacesuit fabrics, seals, and gaskets.
• Construction: Silicone serves as a durable adhesive and sealant.
• Automotive: It’s utilized for parts requiring resistance to extreme conditions.
• Medical: Silicone appears in tubing and adhesives.
• Consumer Goods: From kitchenware to personal care products, silicone’s non-stick and hypoallergenic properties are highly valued.

Viton Fluoroelastomer Rubber is globally recognized for its superior performance, especially in harsh environments where it excels due to its outstanding resistance to high temperatures, chemicals, and fluids. This material is the go-to choice for durable and reliable seals, gaskets, and O-rings. Originating from DuPont’s innovation in the 1950s, Viton is a member of the Fluoroelastomer (FKM) family, a group of synthetic rubbers derived from fluorocarbons, which can be modified with various co-agents to enhance their properties for specific uses.

For industries such as automotive, aerospace, chemical, pharmaceutical, or oil and gas, comprehending the characteristics, applications, and advantages of Viton Fluoroelastomer Rubber is crucial for selecting the most suitable material for your unique requirements.

Viton rubber, a Fluoroelastomer variant, boasts a highly specialised molecular structure and composition. It is produced from hexafluoropropylene (HFP) and vinylidene fluoride (VDF), resulting in a material that offers exceptional chemical resistance, high-temperature stability, and superior mechanical properties. Below are some key attributes of Viton Fluoroelastomer Rubber:

• High-Temperature Resistance: Capable of enduring continuous temperatures up to 204°C, and intermittent peaks up to 315°C, without deformation or degradation.
• Chemical Resistance: Exhibits excellent resistance to chemical corrosion, including oxidation, acids, oils, fuels, and petrochemicals.
• Low Compression Set: Demonstrates superb resilience, retaining its shape even after multiple compressions. With a low compression set of 62% at 70°C for 22 hours, it swiftly returns to its original form.
• Tensile Strength: Possesses a high tensile strength of 7 MPA, ensuring flexibility and the ability to endure stretching without tearing.
• Tear Resistance: With a tear resistance of 20 kg/cm, it is suitable for use in scenarios involving sharp edges or abrasive surfaces.
• Abrasion Resistance: Resists abrasion and friction effectively, maintaining integrity over extended periods of use.

The FKM’s are a complex family, there are many types based upon the monomers used to create the elastomer’s backbone. There are also three cure systems that offer different performance characteristics. These features define the product’s performance.