What Are Cold Resistant and Hot Resistant Rubber Sheets?

2025-12-18 09:16:03

　　Understanding the difference between cold-resistant and heat-resistant Rubber Sheets is crucial for selecting the right material for extreme temperature applications.In simple terms, they are specialized elastomer sheets engineered to maintain their critical physical properties—like flexibility, strength, and sealing force—at temperature extremes where standard rubber (like natural rubber or SBR) would fail.Here’s a detailed breakdown:

　　Heat-resistant Rubber Sheets

　　These sheets are designed to withstand high temperatures without degrading.

　　1. Key Characteristics:

　　Temperature Range: Typically perform from -30°C up to +250°C to +300°C+, depending on the polymer.

　　Primary Focus: Resisting thermal degradation (cracking, hardening), compression set loss, and chemical attack at elevated temperatures.

　　2. Common Polymers Used:

　　Silicone Rubber (VMQ): The most common general-purpose heat-resistant rubber. Excellent flexibility from -60°C to +225°C. Resists oxidation and weathering.

　　Fluorocarbon Rubber (FKM, Viton®): The king of high-temperature and chemical resistance. Used from -20°C to +250°C (short peaks higher). Exceptional against fuels, oils, and acids.

　　Ethylene Propylene Diene Monomer (EPDM): Excellent resistance to heat, steam, ozone, and weathering. Common in automotive cooling systems and HVAC (-50°C to +150°C).

　　Hydrogenated Nitrile Butadiene Rubber (HNBR): An upgraded Nitrile rubber with superior heat, oil, and chemical resistance (-40°C to +160°C, peaks higher).

　　3. Failure Mode if Overheated: Becomes hard and brittle, cracks (thermal oxidation), or in severe cases, chars and loses all elasticity.

　　4. Typical Applications:

　　Gaskets in engines, exhaust systems, and industrial ovens.

　　Seals in aerospace and automotive under-hood components.

　　Heat sealing jaws, conveyor belts in foundries, and baking processes.

　　Insulation and thermal padding.

　　Cold-Resistant Rubber Sheets

　　These sheets are designed to remain flexible and functional at very low temperatures.

　　1. Key Characteristics:

　　Temperature Range: Can remain functional down to -40°C, -60°C, or even below -100°C, while their upper limit is more modest.

　　Primary Focus: Preventing glass transition—where the rubber loses its rubbery properties and becomes hard, rigid, and glass-like.

　　2. Common Polymers Used:

　　Silicone Rubber (VMQ): Again, a top choice for a wide range, maintaining flexibility down to -60°C.

　　Fluorosilicone Rubber (FVMQ): Combines silicone's cold flexibility with better fuel and oil resistance (-60°C to +175°C).

　　Specialty EPDM Formulations: Can be compounded for good low-temperature performance.

　　Natural Rubber (NR): Has good inherent low-temperature flexibility but poor resistance to ozone, oil, and heat.

　　Low-Temperature Nitrile (LT-NBR) or Hydrogenated NBR: Formulated for better cold performance than standard NBR.

　　3. Failure Mode if Overcooled: Becomes stiff and inflexible, loses its sealing force, and can shatter or crack under stress.

　　4. Typical Applications:

　　Seals and gaskets in refrigeration, cryogenic systems, and cold storage.

　　Components for aerospace and polar exploration equipment.

　　Outdoor applications in Arctic climates.

　　Fluid handling systems for liquefied gases (like LNG).

　　The "All-Rounder" & Important Note

　　Silicone Rubber (VMQ) is often considered the best wide-temperature range compromise, performing reasonably well from -60°C to +225°C. For even tougher conditions, Fluorosilicone (FVMQ) offers a similar range with added fuel resistance.

　　Crucial Consideration: A single application often demands both properties. For example, an automotive gasket must withstand under-hood heat but also remain flexible in a winter cold start. This requires careful polymer selection and compounding.

　　It's Not Just the Polymer: The compounding ingredients (fillers, plasticizers, curing agents) are equally vital. A poor plasticizer can leach out at high temps or cause hardening at low temps.

　　Conclusion: Choosing between cold-resistant and heat-resistant rubber sheets requires analyzing the full operational temperature range and the medium (oils, chemicals, ozone) the sheet will contact. Always consult the manufacturer's datasheets for the specific compound's continuous service temperature range and key properties like compression set and brittle point.

　　The "All-Rounder" & Important Note

　　Silicone Rubber (VMQ) is often considered the best wide-temperature range compromise, performing reasonably well from -60°C to +225°C. For even tougher conditions, Fluorosilicone (FVMQ) offers a similar range with added fuel resistance.

　　Crucial Consideration: A single application often demands both properties. For example, an automotive gasket must withstand under-hood heat but also remain flexible in a winter cold start. This requires careful polymer selection and compounding.

　　It's Not Just the Polymer: The compounding ingredients (fillers, plasticizers, curing agents) are equally vital. A poor plasticizer can leach out at high temps or cause hardening at low temps.

　　Conclusion: Choosing between cold-resistant and heat-resistant rubber sheets requires analyzing the full operational temperature range and the medium (oils, chemicals, ozone) the sheet will contact. Always consult the manufacturer's datasheets for the specific compound's continuous service temperature range and key properties like compression set and brittle point.