How to Choose Rubber Sheeting for Oil, Heat, Water or Outdoor Exposure

Selecting the correct elastomeric material for an industrial, commercial, or domestic application can be a surprisingly complex task. Rubber is not a single, universal material; rather, it represents a vast family of distinct polymers, each engineered with unique chemical properties. Using the wrong type of rubber in an environment it was not formulated to handle can lead to rapid material swelling, cracking, structural degradation, or catastrophic joint failure.

Whether you are cutting custom gaskets, sealing pipework, lining chemical tanks, or fabricating outdoor weather strips, understanding the environmental stressors of your application is critical. By analyzing how different compounds react to oils, high temperatures, water submersion, and atmospheric ozone, you can make an informed choice that ensures safety, durability, and long-term performance.

The Chemistry of Rubber Degradation

When an elastomer fails, it is usually due to a chemical reaction between the polymer chains and the surrounding environment. For example, when non-resistant rubbers come into contact with petroleum-based oils, the hydrocarbons penetrate the rubber matrix. This causes the sheet to swell, lose its tensile strength, and eventually turn into a soft, sticky gel.

Conversely, when rubber is exposed to high heat or outdoor weathering, the degradation process is often characterized by hardening and cracking. Ultraviolet light and atmospheric ozone break down the molecular bonds of the polymer, stripping away its elasticity. To prevent these failures, engineers must match the environmental exposure to the specific synthetic or natural polymer designed to resist those exact degradation pathways.

Selecting Materials for Challenging Environments

Different applications demand highly specialized defenses against chemical and physical breakdown. Understanding these environments helps narrow down the ideal material choices.

1. High Resistance to Oils and Fuel

If your project involves contact with lubricating oils, grease, petroleum, or diesel, you must specify nitrile (NBR) rubber. Nitrile is a synthetic copolymer of acrylonitrile and butadiene. The acrylonitrile content provides exceptional resistance to petroleum-based fluids, making it the industry standard for automotive gaskets, hydraulic seals, and fuel line diaphragms. For extreme applications involving aggressive solvents or acids alongside oils, fluorocarbon (FKM or Viton) offers the absolute highest chemical resistance, albeit at a higher cost.

2. Extreme Heat and Thermal Insulation

For environments where temperatures regularly exceed 100 degrees Celsius, standard rubbers will rapidly bake and become brittle. Silicone rubber is the premier choice for extreme thermal demands, capable of maintaining its flexibility and sealing properties in temperatures ranging from -60 degrees Celsius up to 230 degrees Celsius. It is also chemically inert, making it ideal for food-grade, medical, and pharmaceutical applications. For heavy-duty industrial heat protection where high mechanical strength is also required, EPDM or high-temperature neoprene can be utilized for moderate thermal ranges.

3. Water Submersion and Outdoor Exposure

For general outdoor applications, marine seals, and water transport systems, the combination of moisture, sunlight, and ozone will quickly destroy natural rubber. EPDM (Ethylene Propylene Diene Monomer) is widely regarded as the ultimate outdoor rubber. It features outstanding resistance to UV radiation, weathering, and ozone, while remaining completely stable when permanently submerged in water. Neoprene (polychloroprene) is another highly versatile alternative, offering a balanced combination of water resistance, moderate oil resistance, and physical toughness.

Comparing Common Rubber Compounds

To help simplify your material selection process, the table below highlights the performance profiles of the most widely used industrial rubber sheets across key environmental factors.

Specification Factors Beyond the Polymer

Selecting the correct polymer is only the first step. To ensure your selected sheet performs correctly in its physical application, you must also specify its structural dimensions and hardness rating.

Shore A Hardness (Durometer)

Rubber sheeting is classified by its hardness, typically measured on the Shore A scale. A lower number indicates a softer, more compressible material, while a higher number indicates a harder, more rigid sheet.

• 40 Shore A: Soft and highly compressible. Ideal for low-pressure seals where flanges might be lightweight or uneven.

• 60 to 70 Shore A: The medium industrial standard. Offers an optimal balance of compressibility and structural resistance to extrusion under pressure.

• 80 Shore A: Hard and highly resistant to physical wear, designed for high-pressure industrial gaskets, machinery mounting pads, and heavy-duty wear strips.

Insertion Reinforcement

For applications subjected to high mechanical stress, pressure, or tearing forces, standard unsupported rubber may stretch or deform out of place. Specifying fabric-inserted rubber sheeting introduces an internal layer of polyester, nylon, or cotton mesh. This internal reinforcement increases the tensile strength of the sheet and prevents the rubber from tearing or creeping under heavy bolt loads.

If you are currently evaluating materials for a demanding engineering project or workshop installation, taking a moment to read our comprehensive guide on choosing rubber sheet materials will help you navigate the fine details of pressure ratings, chemical compatibility, and thickness tolerances.

At Rubber Fit Floors, we source and supply a diverse range of commercial-grade roll stocks designed to meet rigorous industrial standards. Matching your environmental demands to the correct elastomeric polymer ensure your seals remain tight, your machinery stays protected, and your systems operate safely for the long term.

Frequently Asked Questions

1. Can I use standard Neoprene sheeting for applications involving permanent contact with petrol or diesel? 

While neoprene has a moderate tolerance for general grease and oils, it is not designed for continuous contact with refined fuels like petrol or diesel. Exposure to these substances will cause neoprene to swell, soften, and break down over a relatively short period. For fuel-contact applications, you must use nitrile (NBR) rubber or Viton (FKM), as these polymers possess the chemical stability required to resist aromatic hydrocarbons without degrading.

2. Why is natural rubber sheeting preferred for high-abrasion applications if it has poor chemical resistance? 

Natural rubber possesses outstanding physical properties that synthetic rubbers struggle to match, including incredible elasticity, high tear strength, and exceptional abrasion resistance. When chemicals or oils are not present, natural rubber is the absolute best material for lining slurry chutes, concrete mixers, shotblast cabinets, and industrial scraper blades. Its natural springiness allows it to bounce back from heavy, abrasive impacts rather than wearing away.

3. What is the difference between commercial grade and BS2751 specification nitrile sheeting? 

Commercial-grade nitrile is a blended compound that contains a lower percentage of pure nitrile polymer mixed with filler materials, making it highly cost-effective for general-purpose gaskets. BS2751 Nitrile, however, is manufactured to a strict British Standard that guarantees a specific, high-percentage nitrile content. This certification ensures the rubber meets precise mechanical properties, fuel resistance, and temperature performance required for military, aerospace, and high-liability industrial projects.

4. How does ozone in the air affect rubber sheets, and which material resists it best? 

Ozone is a highly reactive gas present in the atmosphere, and it is also generated by electrical equipment and electric motors. When ozone attacks susceptible rubbers like natural rubber or nitrile under tension, it breaks the double bonds in the polymer chains, causing deep, perpendicular cracks to form on the surface, which quickly leads to seal failure. EPDM and silicone have saturated polymer backbones, making them completely immune to ozone cracking and ideal for electrical enclosures.

5. Can silicone rubber sheeting be used in applications that require high mechanical strength? 

No, silicone rubber is generally poor when it comes to physical toughness, tear strength, and abrasion resistance. While it excels in resisting extreme temperatures and remaining chemically inert, it can easily tear or puncture if subjected to sharp edges, heavy mechanical shearing, or sliding abrasion. If you need heat resistance combined with high mechanical toughness, you should consider using a high-specification EPDM or a reinforced fabric-inserted neoprene sheet instead.

6. How do I know if a rubber sheet is food-safe for food processing or drinking water applications? 

To be used safely in contact with food, beverages, or pharmaceuticals, the rubber sheet must be manufactured from FDA-approved ingredients (Food and Drug Administration) or hold WRAS (Water Regulations Advisory Scheme) approval for drinking water. These specialty sheets, usually made from white silicone, white nitrile, or white EPDM, are formulated with non-toxic, non-marking ingredients that do not leach harmful chemicals, odors, or tastes into the products they contact.