Rubber moulding and extrusions are two common methods used in the manufacturing industry to produce a wide range of products. These techniques involve shaping rubber materials into various forms, such as seals, gaskets, hoses, and more.
Rubber extrusion is the process of forcing heated rubber through a die to create continuous lengths of tubing or profiles with various cross-sections. Rubber moulding involves pressing uncured rubber into a mould where the material is then vulcanised to form a permanent shape.
The type of rubber used in these processes can vary depending on the needs of the application. Some common types include natural rubber, synthetic rubber, silicone rubber, EPDM (ethylene propylene diene monomer) rubber and neoprene. Each has unique properties that make it suitable for specific applications. Understanding the different types of rubber used in moulding and extrusions is crucial for manufacturers who require high-quality products that meet their specific requirements.
To follow, we investigate each type in a bit more detail:
Natural rubber is a type of rubber that is produced from the sap of the rubber tree, Hevea Brasiliensis. This type of rubber has unique properties that make it ideal for use in moulding and extrusions. Natural rubber has excellent elasticity, high tensile strength, and good resistance to abrasion and tearing. It also has good heat resistance and can withstand temperatures of up to 80°C.
One of the main advantages of natural rubber is its ability to be easily processed into different shapes, making it ideal for use in manufacturing various products such as tyres, seals, gaskets, hoses and conveyor belts. Additionally, natural rubber is biodegradable which makes it an eco-friendly choice compared to synthetic rubbers. However, natural rubber does have some limitations such as poor resistance to oils and solvents which can cause it to degrade over time.
Synthetic rubber is a man-made polymer that mimics the properties of natural rubber. It is produced through a process called polymerization, where various chemical compounds are mixed and heated to form long chains of molecules. The resulting material has several advantages over natural rubber, including greater durability, resistance to heat and chemicals, and better tensile strength. The most widely used types of synthetic rubber are:
One of the most common types of synthetic rubber used in moulding and extrusions is styrene-butadiene rubber (SBR).
SBR is a cost-effective option that offers good abrasion resistance and flexibility. It is a widely used general-purpose synthetic rubber, produced from a copolymer of styrene and butadiene. The physical properties of SBR are almost as good as natural rubber while being a more cost-efficient alternative. SBR is used across a broad range of applications, spanning everything from car tyres, shoe soles and heels, SBR drive couplings, automotive parts and mechanical rubber goods.
Neoprene is known for its resistance to oil, flame, and weathering. Neoprene (also known as Polychloroprene) is part of a family of synthetic rubbers that are produced by polymerization of chloroprene. Neoprene rubber is self-extinguishing so offers excellent resistance to flame. The compound has good resistance to oils, ozone and sunlight but poor resistance to fuels. The most common commercial use of neoprene is in rubber belts, gaskets, refrigerant seals, and door strips.
EPDM (ethylene propylene diene monomer) is a type of synthetic rubber that is widely used in moulding and extrusions. It has excellent weathering resistance, which makes it ideal for outdoor applications. EPDM rubber has good chemical resistance, making it suitable for use in harsh environments. It also has a low compression set, meaning it can maintain its shape even after being compressed for long periods of time.
EPDM rubber is commonly used in the automotive industry for seals and gaskets due to its excellent sealing properties and durability. It is also used in the construction industry as a roofing material because of its weathering resistance and UV stability. EPDM rubber can also be found in the manufacturing of electrical insulation, garden hoses, and even sports equipment.
Overall, EPDM rubber’s versatility makes it a popular choice for many applications due to its ability to withstand various environmental factors while maintaining its shape and sealing properties over time.
Silicone rubber is a widely used elastomer in moulding and extrusion processes. This type of rubber has a wide range of physical properties. It is known for its excellent temperature resistance, which makes it ideal for high-temperature applications. Additionally, silicone rubber has superior electrical insulation properties and is highly resistant to weathering, ozone, and UV radiation.
Another advantage of silicone rubber is its exceptional flexibility and durability. It can withstand repeated cycles of compression and stretching without losing its shape or mechanical properties. Silicone rubber also has a low compression set, meaning that it can maintain its original shape even after prolonged periods of compression.
Moreover, silicone rubber is biocompatible and does not react with most chemicals or solvents. As a result, it finds extensive use in the medical industry for making devices like implants, tubing, gaskets, and seals.
Overall, silicone rubber’s unique combination of physical properties detailed above makes it an excellent choice for various industrial applications where performance under extreme temperatures or challenging environments is essential. These applications include: seals and gaskets, electrical insulation, automotive components, medical devices and aerospace components.
Nitrile rubber, also known as NBR or Buna-N, is a synthetic rubber that is highly resistant to oils and fuels. This type of rubber is commonly used in applications where there is exposure to oil or other petroleum-based fluids. Nitrile rubber has excellent resistance to abrasion, tear and compression set, making it an ideal material for sealing and gasket applications.
It can be easily moulded into various shapes and sizes using different manufacturing processes such as injection moulding, compression moulding or extrusion moulding. One of the key advantages of nitrile rubber is its ability to maintain its properties even at high temperatures. It can withstand temperatures ranging from -40°C to 120°C without losing its elasticity or durability. Additionally, nitrile rubber has good resistance to chemicals such as acids and alkalis.
Choosing the Right Type of Rubber for your Application
Choosing the right type of rubber for your application is crucial to ensuring optimal performance and longevity of your product. Different types of rubber have varying properties that make them suitable for specific applications. For instance, natural rubber is ideal for applications that require high elasticity and tear strength, while neoprene rubber is perfect for applications that require resistance to oils, chemicals and extreme temperatures.
When choosing the right type of rubber, it’s important to consider factors such as temperature range, chemical resistance, hardness, and compression set. For example, if your application involves exposure to extreme heat or cold temperatures, you’ll need a type of rubber that can withstand these conditions without losing its properties.
Additionally, consider the environment in which your product will be used. Will it be exposed to water or other liquids? If so, you’ll need a type of rubber with good water resistance.
Overall, selecting the appropriate type of rubber will ensure reliable performance and durability for your product.
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