Unveiling the Manufacturing Magic and Endless Applications of Nitrile Butadiene Rubber

Get ready for the detailed journey into the captivating sphere of Nitrile Butadiene Rubber (NBR) manufacturing! NBR or Nitrile Rubber is a synthetic rubber copolymer of Acrylonitrile and Butadiene. It is appreciated for its outstanding tolerance to oils, fuels and other chemicals, therefore is used extensively in the automotive, aeronautical and industrial sectors.

In this blog post, we shall reveal the process of manufacturing of NBR to ensure that you have an all-inclusive understanding of this versatile material. Starting from the polymerization step to the final bales ready for shipment, we will dissect the production line and present each phase through a process flow chart.

Please follow us as we take you through the various steps of NBR production and explain how the various complex processes and advanced tools used make this rubber an essential material in various industries. No matter if you are an expert in the field of the chemical industry, a chemist, or a layman who is interested in the processes that occur in the production of various materials, this article will be useful for you to understand the basics of synthetic rubber production. Let’s dive in!

Introduction

Nitrile rubber, also known as NBR, is a synthetic rubber made from the copolymerization of Acrylonitrile (ACN) and butadiene. Chemically, it is referred to as Acrylonitrile-butadiene copolymer. This type of synthetic rubber is highly valued for its exceptional resistance to aliphatic hydrocarbon oils and fuels, making it an important material in various industrial applications.

Some of the properties of NBR are:

1. Excellent Abrasion Resistance

Nitrile Butadiene Rubber is well-regarded for its high resistance to abrasion, making it ideal for applications where wear and tear are significant concerns. This property allows NBR to withstand rough surfaces and repetitive friction, which is essential for parts like seals, hoses, and footwear, ensuring longer service life and durability.

1. Good Rebound, Tear Resistance, and Non-Polar Solvent Resistance

NBRexhibits good rebound properties, meaning it can return to its original shape after being stretched or compressed. This resilience is crucial in dynamic applications such as gaskets and seals. Additionally, its tear resistance ensures that it can handle mechanical stresses without ripping. NBR is also resistant to non-polar solvents like oils, fuels, and various hydrocarbons, which makes it suitable for use in automotive and industrial environments where such substances are prevalent.

1. Good Water and Oil Resistance

Nitrile Butadiene Rubber is highly resistant to water and oil, making it an excellent material for seals, gaskets, and hoses used in hydraulic systems and other environments where exposure to these substances is common. This resistance ensures that NBR maintains its integrity and performance even when in prolonged contact with water or oil.

1. Good Resistance to Gas Permeability

NBR has low gas permeability, meaning it is effective at preventing gases from passing through it. This property is crucial for applications requiring airtight seals, such as in the manufacture of O-rings, diaphragms, and fuel system components. It helps in maintaining pressure and preventing leaks, enhancing the safety and efficiency of the systems it is used in.

1. Good Elongation Properties and Excellent Compression Set Resistance

NBR can stretch significantly (good elongation properties) without breaking, which is beneficial for applications that require flexibility and movement. Additionally, it has excellent compression set resistance, meaning it can return to its original thickness after being compressed. This is important for maintaining the seal and cushioning properties over time, especially in applications like gaskets and vibration dampers.

1. Adequate Resilience and Tensile Strength

Nitrile Butadiene Rubber offers sufficient resilience, meaning it can absorb and release energy efficiently, which is important for applications involving repeated stress and deformation. Its tensile strength, the maximum stress it can withstand while being stretched before breaking, is adequate for many industrial applications, ensuring reliable performance under mechanical load.

1. Good Resistance to Aliphatic Hydrocarbons

NBR shows excellent resistance to aliphatic hydrocarbons, which are organic compounds consisting of carbon and hydrogen in straight or branched chains (e.g., propane, butane). This resistance is particularly useful in the petrochemical industry and automotive applications, where such hydrocarbons are frequently encountered.

1. Excellent Adhesion to Metal and Rigid Materials

NBR adheres well to metals and other rigid materials, which is advantageous for creating composite materials and components that require a strong bond between rubber and a non-rubber substrate. This property is essential for manufacturing rubber-metal bonded parts, such as engine mounts and vibration isolators, where durability and reliability are critical.

Manufacturing Process

• Nitrile Butadiene Rubber (NBR) is produced through an emulsion polymerization process, which involves a complex system where water, an emulsifier or soap, monomers such as butadiene and Acrylonitrile, a radical-generating activator, and other necessary ingredients are mixed together in polymerization vessels.

• In this emulsion system, the monomers are dispersed in water with the help of emulsifiers, forming micelles that facilitate the polymerization reaction. The initiator, or radical generating activator, triggers the polymerization by breaking the double bonds in the monomers, allowing them to link together to form long chains of NBR.

• This process results in the creation of a polymer latex, a milky liquid containing the rubber particles suspended in water. To convert this latex into a solid form, coagulation agents such as calcium chloride or aluminum sulfate are added.

• These agents cause the rubber particles to clump together, forming what is known as crumb rubber. The crumb rubber is then dried to remove any remaining water and compressed into bales for easier handling and storage.

• Some specialty NBR products are sold in their crumb form rather than being compressed into bales.

• NBR producers employ different polymerization temperatures to create “hot” and “cold” polymers, each with distinct properties. By adjusting the ratios of Acrylonitrile (ACN) and butadiene (BD) in the polymer, manufacturers can tailor the rubber’s characteristics to meet specific requirements such as enhanced oil and fuel resistance or improved performance at low temperatures.

• For instance, a higher ACN content generally increases resistance to oils and fuels but may reduce flexibility at lower temperatures. In addition to the basic monomers, specialty NBR polymers may include a third monomer like divinyl benzene or methacrylic acid to achieve particular performance characteristics.

• Furthermore, some NBR elastomers undergo a hydrogenation process, which significantly reduces the chemical reactivity of the polymer chain. This hydrogenation greatly enhances the rubber’s resistance to heat and oxidative degradation, making it suitable for high-temperature applications. Each of these modifications—whether through varying the monomer ratios, introducing additional monomers, or hydrogenating the polymer—contributes to the development of NBR products with unique and desirable properties for a wide range of industrial and commercial applications.

• This versatility makes NBR a critical material in the manufacture of products that require specific resistances and performance capabilities, such as automotive seals, hoses, and gaskets, as well as various types of protective gear.

Applications of Nitrile Butadiene Rubber (NBR)

• Automotive

NBR, or nitrile butadiene rubber, is a hero behind the scenes in the automotive industry. Unlike regular rubber that would crumble under constant exposure to oil and fuel, NBR boasts exceptional resistance to these fluids. This makes it the prime choice for critical components like oil hoses, where it ensures smooth flow without succumbing to wear and tear. NBR’s strength extends to seals, forming a tight barrier to prevent leaks that could disrupt engine performance. It even finds its way into grommets, those small but crucial parts that safeguard wires from the harsh environment filled with oils and fuels. NBR’s resilience keeps these vital systems running smoothly, ensuring a safe and reliable ride.

• Aerospace

The benefits of NBR extend beyond the automotive industry. Its exceptional resistance to fuel, oil, and various chemicals makes it a highly suitable material for hoses, seals, grommets, and even fuel tanks in a wide range of applications. This versatility positions NBR as a reliable choice for designers and engineers working with equipment exposed to harsh liquids across numerous sectors.

• Medical Gloves

In the medical field, disposable nitrile gloves are the workhorse. They provide a crucial barrier during examinations and cleaning procedures, protecting both healthcare workers from patients’ fluids and vice versa. However, for the intense radiation environments of nuclear applications, a different kind of protection is needed. Here, heavy-duty, reusable gloves are used to safeguard wearers from the harmful effects of radiation exposure.

• Industrial

NBR, a versatile material due to its resistance to oils, fuels, and chemicals, isn’t just for cars. It shows up in disposable medical gloves, heavy-duty nuclear gloves, and various industrial applications like roll covers, hydraulic hoses, and conveyor belts. Its durability even makes it a good choice for graphic arts rollers and oil field packers, and its ability to form tight seals makes it a common choice in plumbing and appliances.

Market Outlook

The NBR market thrives due to its unmatched versatility. In the automotive industry, NBR remains a critical material for hoses, seals, and other components that constantly battle oil and fuel. This is especially true as the electric vehicle revolution unfolds, as these vehicles still depend on NBR for essential parts. Beyond cars, the ever-growing demand for disposable nitrile gloves in the medical field acts as a major driver. Rising concerns about hygiene and an aging population requiring more medical procedures fuel the need for these cost-effective and protective barriers. NBR’s strength and chemical resistance extend its reach into industrial applications as well. It’s a key component in conveyor belts, hydraulic hoses, and oil field packers, and this demand is expected to climb alongside increasing industrial activity and infrastructure development, particularly in emerging economies.  The future looks bright for NBR. The potential for innovation in NBR formulations presents exciting possibilities. Advancements could lead to the development of new variations with enhanced properties, further propelling its use across various sectors. This, coupled with the ongoing need for durable and cost-effective materials across industries, positions NBR with a strong and sustained presence in the global market.

Nitrile Butadiene Rubber (NBR) Major Global Players

Main players in the Global Nitrile Butadiene Rubber (NBR) market are Arlanxeo, LG Chem Ltd., Kumho Petrochemical Co. Ltd., Krasnoyarsk Synthetic Rubbers Plant JSC, Blue Star NBR, LLC, Zeon Corporation, Ningbo Shunze Rubber Co., Ltd., Dynasol/Shanxi Northern Xing’an Chemicals, ARLANXEO-TSRC (Nantong) Chemical Industrial Co. Ltd., and Others.

Conclusion:

From the cars we drive to the hospitals we visit, NBR plays a huge role in our daily life, yet it remains discreet. Due to its excellent resistance towards oils, fuels, and chemicals, it is a universal choice for various sectors. Despite the future of transportation being more inclined towards EVs, NBR will continue to play a significant role in the foreseeable future. But as the world is concerned with hygiene and dealing with an aging population, the use of NBR in disposable medical gloves is expected to only increase. Another advantage of the use of NBR is that there are opportunities for the development of new formulations of the material. So, the next time you visit a doctor, drive your car, or look at the rising skyscrapers, do remember that NBR might be behind it!