Sponge Viton® Sheet
Closed-cell cellular FKM fluoroelastomer sheet with integral skin on both faces. Combines two properties that no other sponge material offers simultaneously: the compressibility and lightness of a cellular material with the chemical resistance of Viton® to hydrocarbons, oils, fuels, chlorinated solvents, acids and ozone. For compressible seals in environments where silicone sponge or EPDM sponge fails due to chemical attack.
In many industrial applications, the seal requires a compressible material — a sponge that conforms to irregularities and seals with low closure force. Silicone sponge solves this perfectly in thermal and environmental settings. But when the seal is exposed to hydrocarbons (petrol, diesel, kerosene), engine oils, synthetic lubricants, chlorinated solvents or concentrated acids, silicone sponge swells, degrades and loses its sealing properties. EPDM sponge does not resist either: hydrocarbons destroy it rapidly.
Sponge Viton® sheet solves this blind spot. It is an expanded FKM fluoroelastomer with a closed-cell structure of non-interconnected cells, manufactured with a continuous integral skin on both faces. The closed cells prevent fluid passage — even if the surface is cut or punctured, the material does not absorb liquid. The integral skin increases tear resistance and provides a smooth sealing surface. And because the base is FKM, the material maintains its integrity against the full range of aggressive chemicals that would destroy any other sponge.
Available with custom cutting to drawing, high-temperature adhesive on one or both faces, and technical advice for selection of the appropriate thickness according to the application and service conditions.
When do you need sponge Viton® instead of silicone sponge?
The rule is simple: if the seal is exposed to hydrocarbons (fuels, mineral or synthetic oils, aromatic solvents), acids or chlorinated solvents, you need sponge Viton®. If the seal is only exposed to temperature, water, steam, ozone or weathering, silicone sponge is the better option (wider temperature range: –60 vs. –25 °C, and lower cost). Sponge Viton® is not a universal substitute for silicone sponge — it is the specific solution for when chemical resistance is the critical factor.
Sponge Viton®, solid Viton® or silicone sponge?
Locate your application and the recommended material.
| Requisito | Formulación | Serie | Proceso |
|---|---|---|---|
| Compressible seal + hydrocarbons | Sponge Viton® | 3–12 mm | Custom cut + adhesive |
| Compressible seal + engine oils | Sponge Viton® | 3–6 mm | Custom cut + adhesive |
| Compressible seal + acids | Sponge Viton® | 3–10 mm | Custom cut + adhesive |
| Compressible seal + temperature/weathering only | Silicone sponge | See sponge | — |
| Static seal + hydrocarbons (flange, bolt) | Solid Viton® | See Viton B | — |
| Compressible seal + food-grade | FDA silicone sponge | See sponge | — |
| Thermal insulation + chemical vapours | Sponge Viton® | 10–12 mm | Custom cut |
| Compressible seal + ketones (acetone) | Consult FFKM | — | On request |
Where conventional sponge does not survive
Engine compartment seals
Engine compartments combine high temperature (up to 200 °C near the exhaust), fuel vapours, engine oil, coolant and continuous vibration. Conventional sponge seals (EPDM, neoprene) degrade within months. Sponge Viton® resists all these aggressions simultaneously, and its cellular structure absorbs engine vibrations while maintaining the seal.
Gaskets in petrochemical equipment
In refineries, petrochemical plants and gas installations, seals on lids, access panels and enclosures are exposed to hydrocarbon vapours, acid condensates and elevated temperatures. Sponge Viton® provides compressible sealing without absorbing vapours or degrading from condensates.
Seals in chemical process equipment
Reactors, mixers, acid storage tanks, solvent lines. Any equipment where the compressible seal (door, lid, panel) is exposed to aggressive chemicals that would destroy a standard sponge.
Chemical-resistant thermal insulation
The cellular structure of sponge Viton® significantly reduces thermal conductivity compared to solid Viton®. In applications where thermal insulation AND chemical resistance are needed simultaneously — a rare combination — this material is the only viable option.
Standard thicknesses with integral skin on both faces
Sponge Viton® is manufactured by moulding with integral skin on both faces — not by block cutting. This means each thickness has its own intact sealing surfaces. The available thicknesses are those manufactured directly in the mould.
3 mm (1/8")
3 mm ±0.5The thinnest available gauge. For low-section seals where space is limited (engine compartments, electrical enclosures in process zones). Good compressibility at this thickness.
- Thickness
- 3 mm (±0.5 mm)
- Skin
- Integral both faces
- Format
- Sheet ~760 × 1,420 mm
Availability: With or without adhesive.
6 mm (1/4")
6 mm ±0.8The most versatile thickness. Good compressibility with sufficient mechanical resistance for door and lid seals. The reference thickness for most compressible sealing applications with chemical requirements.
- Thickness
- 6 mm (±0.8 mm)
- Skin
- Integral both faces
- Format
- Sheet ~760 × 1,420 mm
Availability: With or without adhesive.
10 mm (3/8")
10 mm ±1.0For seals with wide tolerances or very irregular surfaces where greater compression travel is needed. Also suitable for thermal insulation with chemical resistance.
- Thickness
- 10 mm (±1.0 mm)
- Skin
- Integral both faces
- Format
- Sheet ~760 × 1,420 mm
Availability: With or without adhesive.
12 mm (1/2")
12 mm ±1.3The maximum thickness with integral skin. For heavy-section seals, high-performance thermal insulation and applications where the required compression exceeds 50% of the thickness.
- Thickness
- 12 mm (±1.3 mm)
- Skin
- Integral both faces
- Format
- Sheet ~760 × 1,420 mm
Availability: With or without adhesive.
Standard sheet format: approximately 760 × 1,420 mm (30" × 56"). The moulding process with integral skin limits available sizes. For larger surfaces: adhesive bonding of adjacent pieces. Tolerances per ISO 3302 class E3 (E2 and E1 on request).
Properties of cellular FKM fluoroelastomer
FKM sponge — closed cells with integral skin
Expanded FKM fluoroelastomer with a closed-cell structure of non-interconnected cells. Continuous integral skin on both faces formed during the moulding process — not block-cut. The skin makes the sheet more tear-resistant and provides a smooth, impermeable sealing surface. Even if the surface is punctured or cut, the closed cells prevent fluid from penetrating the material.
Petrochemical, refineries, chemical industry, automotive (engine compartment), energy, aerospace, any compressible seal exposed to hydrocarbons or acids.
| Property | Value | Notes |
|---|---|---|
| Apparent hardness | ~15 Shore A | Cellular material — hardness much lower than solid Viton® |
| Service temperature | –25 °C to +204 °C | High-temperature compression reduces resilience |
| Cellular structure | Closed cells with skin | Does not absorb fluids |
| Water absorption | < 5% | ASTM D1056 |
| Colour | Black | — |
The mechanical properties (tensile, elongation) of a sponge are significantly lower than those of solid Viton® — this is inherent to the cellular structure. The advantage is compressibility: it seals with very low closure forces.
Chemical resistance — what it resists and what it does not
Like all FKM fluoroelastomers, sponge Viton® has exceptional chemical resistance to the majority of aggressive industrial products. But it has specific limitations that the engineer must be aware of before specifying.
Chemical compatibility reference for material selection.
| Category | Resistance | Examples |
|---|---|---|
| Aliphatic hydrocarbons | Excellent | Petrol, diesel, kerosene, hexane |
| Aromatic hydrocarbons | Excellent | Toluene, xylene, benzene |
| Mineral and synthetic oils | Excellent | Engine oil, hydraulic oil, lubricants |
| Fuels | Excellent | Petrol, JP-8, biodiesel |
| Chlorinated solvents | Good | Dichloromethane, trichloroethylene |
| Dilute and concentrated acids | Good | Sulphuric, nitric, hydrochloric acid |
| Ozone, UV, weathering | Excellent | Outdoor, open installations |
| Hot water and steam | Good | Up to 200 °C |
| Ketones (acetone) | Not resistant | Acetone, MEK — use another material |
| Organic acids | Limited | Concentrated acetic acid |
| Amines, strong bases | Consult | Depends on concentration and temperature |
Always verify compatibility with the specific fluid of the application. Resistance may vary depending on concentration, temperature and duration of exposure.
Expanded FKM fluoroelastomer with a closed-cell structure of non-interconnected cells. Continuous integral skin on both faces formed during the moulding process — not block-cut. The skin makes the sheet more tear-resistant and provides a smooth, impermeable sealing surface. Even if the surface is punctured or cut, the closed cells prevent fluid from penetrating the material.
Petrochemical, refineries, chemical industry, automotive (engine compartment), energy, aerospace, any compressible seal exposed to hydrocarbons or acids.
| Property | Value | Notes |
|---|---|---|
| Apparent hardness | ~15 Shore A | Cellular material — hardness much lower than solid Viton® |
| Service temperature | –25 °C to +204 °C | High-temperature compression reduces resilience |
| Cellular structure | Closed cells with skin | Does not absorb fluids |
| Water absorption | < 5% | ASTM D1056 |
| Colour | Black | — |
The mechanical properties (tensile, elongation) of a sponge are significantly lower than those of solid Viton® — this is inherent to the cellular structure. The advantage is compressibility: it seals with very low closure forces.
Like all FKM fluoroelastomers, sponge Viton® has exceptional chemical resistance to the majority of aggressive industrial products. But it has specific limitations that the engineer must be aware of before specifying.
Chemical compatibility reference for material selection.
| Category | Resistance | Examples |
|---|---|---|
| Aliphatic hydrocarbons | Excellent | Petrol, diesel, kerosene, hexane |
| Aromatic hydrocarbons | Excellent | Toluene, xylene, benzene |
| Mineral and synthetic oils | Excellent | Engine oil, hydraulic oil, lubricants |
| Fuels | Excellent | Petrol, JP-8, biodiesel |
| Chlorinated solvents | Good | Dichloromethane, trichloroethylene |
| Dilute and concentrated acids | Good | Sulphuric, nitric, hydrochloric acid |
| Ozone, UV, weathering | Excellent | Outdoor, open installations |
| Hot water and steam | Good | Up to 200 °C |
| Ketones (acetone) | Not resistant | Acetone, MEK — use another material |
| Organic acids | Limited | Concentrated acetic acid |
| Amines, strong bases | Consult | Depends on concentration and temperature |
Always verify compatibility with the specific fluid of the application. Resistance may vary depending on concentration, temperature and duration of exposure.
From the sheet to your sponge Viton® part
We supply sheet as a full piece or custom-cut to size. High-temperature adhesive option on one face for direct mounting.
Application sectors
General Industry
Compressible seals in petrochemical, chemical and engine applications exposed to hydrocarbons and acids.
Aerospace
Sponge gaskets resistant to kerosene, hydraulic fluids and aviation oils.
Nuclear
Compressible FKM seals for equipment exposed to aggressive fluids in nuclear environments.
Rail
Engine compartment and hydraulic system seals on railway rolling stock.
Related products
Sponge Silicone Sheet
VMQ silicone sponge — when chemical resistance is not the critical factor.
Food-Grade Silicone Sheet
Solid FDA sheet for food applications without chemical aggression.
Fire-Retardant Silicone Sheet
Solid EN 45545-2 sheet for railway and transport.
Conductive Silicone Sheet
Carbon-loaded silicone sheet for ESD protection.
Need a compressible seal resistant to aggressive chemicals?
Tell us the fluid to which the seal will be exposed (type, concentration, temperature), the available closure force, the part dimensions and the quantity. We verify chemical compatibility and provide a quotation with the appropriate thickness and technical documentation.
Request quotation