Your furnace seal failed at 3 AM. Production stopped. The gasket, which is made of a standard rubber sheet, had hardened and cracked. The catch? It was never rated above 150°C. Your furnace runs at 220°C. This is the most common and most avoidable failure in industrial thermal sealing.
The wrong rubber costs more than the seal itself. It costs you downtime, energy loss, and emergency maintenance.
Silicone rubber sheets for thermal insulation are the engineering answer. But not every grade works for every job. This guide tells you exactly what to specify, where, and why.
What most buyers get wrong: they treat silicone as a single material. It is not. Grade, hardness, thickness, and certification all vary. Getting even one wrong leads to the same 3 AM call.
Why Silicone Outperforms Other Rubbers for Thermal Insulation
Silicone is built on a silicon-oxygen backbone. Standard rubbers use carbon chains. That structural difference is why silicone stays flexible at −60°C and stable at +230°C . It is the temperature range where neoprene and EPDM have already failed.
A heat resistant silicone rubber sheet does not harden under sustained heat. It does not crack through thermal cycling. It does not off-gas harmful compounds. For sealed industrial systems, that means longer service intervals and fewer unplanned shutdowns.
It also functions as a silicone rubber sheet for gaskets and seals industrial applications Thus serving as structural sealing and thermal insulation in the same component. That matters when space and part count are constraints.
Silicone vs EPDM Rubber Sheet Thermal Insulation: Comparison Table
See the differences at a glance:
| Property | Silicone Rubber | EPDM Rubber |
| Continuous temp. range | −60°C to +230°C ✓ | −40°C to +150°C |
| Peak temp. (short-term) | Up to +300°C | ~180°C |
| Compression set | Low — retains sealing force | Moderate |
| UV / ozone resistance | Excellent | Excellent |
| Steam / moisture | Good | Very good |
| Flame retardancy | FR grades available | Limited |
| FDA / food grade | Available | Limited |
| Unit cost | Higher | Lower |
Bottom line: EPDM is cost-effective below 150°C. Above that, silicone is the correct and often only viable choice. The cost difference is negligible against one unplanned shutdown.
Key Applications of Silicone Rubber Sheets in Industrial Equipment
Here are 6 applications of silicone rubber sheets in industrial equipment:
1. Industrial Furnaces & Kilns ( Silicone Sheet Door Gasket Furnace)
A silicone sheet door gasket furnace cycles through thousands of open-close movements per year. The seal must recover its shape every single time. Low compression set is non-negotiable here.
Use sponge grades on rough or uneven door frames. Use solid grades like Duratuf Silico60 Pro on machined surfaces. Specify continuous ratings of at least 220°C. Confirm compression set values in the datasheet before ordering.
2. Boilers & Steam Equipment ( Silicone Seals for Boiler Equipment)
Silicone seals for boiler equipment must handle both elevated temperature and sustained moisture exposure. At flanged pipe joints, silicone pads act as thermal breaks. They also prevent metal-to-metal contact corrosion.
Use grades like Duratuf Silico60 X or Silico60 Pro rated for saturated steam service. Specify 3–6 mm solid sheets. Confirm both temperature and steam resistance in the compound datasheet before finalizing.
3. Industrial Ovens (Industrial Oven Seal Silicone Rubber)
Industrial oven seal silicone rubber is cycled hundreds of times per shift in conveyor and batch ovens. Shape recovery after each compression is the critical performance metric. Not just once; thousands of times.
Use sponge grades at conveyor apertures. Use solid grades at door perimeters and duct joints. Verify compression set at operating temperature, not room temperature.
4. Electrical & Power Equipment
Silicone combines dielectric strength with thermal stability. One material handles both insulation requirements. Transformer mounting pads and bus bar separators are the most common uses.
Flame-retardant grades are mandatory in all electrical enclosure applications. Specify UL94 V-0 as a minimum. Request the test certificate; not just a supplier declaration.
5. Automotive & Aerospace ( Fire Resistant Silicone Rubber Insulation)
Under-hood temperatures near exhausts exceed what standard rubbers handle. Standard neoprene fails fast here. Fire resistant silicone rubber insulation protects wiring, sensors, and brackets from radiant and conductive heat.
Turbocharger wraps and heat shields use thin silicone sheet laminates. Weight and temperature rating both matter. For aerospace, confirm FAR 25.853 compliance before use.
6. Food & Pharma Processing
Autoclaves and sterilisation chambers cycle seals through repeated steam and pressure combinations. The material must not absorb odours, leach compounds, or degrade under repeated cleaning protocols.
Use FDA-compliant silicone only- like FoodsafeSI60 Pro. Confirm FDA 21 CFR 177.2600 compliance. Platinum-cured grades offer the highest purity for direct food and drug contact. Do not substitute peroxide-cured grades in these applications.
Duratuf Silicone Rubber Sheet Types & Grades Silicone Rubber Sheet Types & Grades for Insulation
Not sure which grade fits your equipment? Here are the three most common choices by Duratuf and exactly when to use each.
1. Industrial Grade ( Silico60 Pro)
Model: RS-SLCO(X)-SI16060 | −20°C to +200°C | 60 Shore A | Red
The go-to sheet for high-temperature industrial sealing. Flexible, heat-resistant, and built for equipment that runs hard.
Use it for cabinet seals, control box gaskets, high-temperature equipment lining, and general industrial sealing tasks.
Limitation: Not for food, pharma, or heavy chemical contact.
2. Premium Grade (FoodSafeSI60 Pro)
Model: RS-SLCO(P)-SL13060 | −20°C to +180°C | 60 Shore A | Red Translucent
Stronger tensile strength than the standard grade. Handles acids, ozone, and outdoor moisture.
A step up for semi-critical sealing in pharma-adjacent or precision environments.
Use it for lab and pharma equipment seals, outdoor industrial enclosures, metal processing pads, and electrical enclosures in harsh conditions.
Limitation: Not for full food or pharma compliance applications.
3. Food-Grade ( High Purity Silicone)
Model: RS-FOSA(P)-SI13060 | −30°C to +180°C | 60 Shore A | White Translucent
The cleanest grade in the range. Inert, odour-free, and stable through repeated sterilisation. The only right choice is when your seals touch food, dairy, or pharmaceutical products.
Use it for baking and steaming oven seals, autoclave gaskets, dairy and pharma processing lines, and food vending equipment.
Limitation: Not for heavy mechanical loads or oil-rich environments.
How to Select the Right Silicone Sheet for Your Application
- Identify your temperature range Establish both continuous and short-term peak temperature. Go for the maximum range, not the average. This single step eliminates most specification errors.
- Determine hardness requirement Shore A 30-50 for low clamping-force flanges. Shore A 60–80 for high compression loads. Wrong hardness means either seal failure or surface damage.
- Choose thickness based on load and gap 0.5-2 mm for insulation pads and liners. 3–6 mm for uneven mating surfaces. Use the supplier’s compression load curves. Do not guess.
- Check chemical exposure requirements Silicone resists dilute acids, alkalis, oils, and ozone. It has limited resistance to concentrated solvents. Verify compatibility with your process media before finalising grade selection.
- Verify compliance grade needed Food, pharma, and aerospace require documented certifications such as FDA, NSF, UL94, or FAR 25.853. Confirm before ordering. Not after delivery.
- Standard vs custom cut sheets Standard sheets suit in-house cutting. Custom die-cut or water-jet profiles reduce fabrication time and material waste for repeat orders. Factor this into total cost, not just the unit price.
Procurement Checklist: Buying Silicone Rubber Sheets in Bulk
- Verify material grade & compound datasheet: Temperature range, hardness, tensile strength, elongation, and compression set values must all be documented.
- Confirm certifications: Obtain copies of FDA, RoHS, or industry approvals before purchase, not on delivery.
- Test batch consistency: For critical orders, request a sample batch. Cross-check hardness and thickness against the datasheet before full delivery.
- Confirm thickness & hardness tolerance: Acceptable limit is ±0.2 mm for thickness, ±5 Shore A for hardness. Get this in writing before order confirmation.
- Confirm MOQ and lead time: High-temp and FR grades carry longer lead times. Clarify before your maintenance window closes.
- Custom fabrication capability: If you need gaskets or strips, confirm die-cutting, slitting, or water-jet services are available from the same supplier.
- Technical support availability: A competent supplier helps with grade selection and compression load calculations, not just quantity and delivery date.
Conclusion
Silicone rubber sheets for thermal insulation are not interchangeable with general-purpose rubber. The grade, hardness, thickness, and certification must match the application precisely.
Whether you need a silicone rubber sheet for gaskets and seals in industrial equipment, a heat resistant silicone rubber sheet for a furnace door, or fire resistant silicone rubber insulation for an electrical enclosure, the specification process is the same. Match the material to the environment. Verify it before you order. Then maintain it on schedule.
That is how you avoid the 3 AM failure call.
