Silicone Products Silicone Sponge Tubing

What Is Silicone Sponge Tubing?

Silicone sponge tubing is a hollow, closed-cell silicone extrusion used for sealing, cushioning, insulation, protective sleeving, and environmental protection. Its cellular construction provides greater compressibility than solid silicone tubing while maintaining the temperature stability, flexibility, and environmental resistance associated with silicone rubber.

Bellofram Elastomers manufactures custom silicone sponge tubing in virtually any combination of inner diameter (ID) and outer diameter (OD) up to a maximum 2.5” OD. Available in density grades ranging from soft to firm, tubing dimensions, density, color, and formulation can be tailored to meet specific application requirements.

Key Takeaways

• Silicone sponge tubing is a hollow, closed-cell extrusion used for sealing, cushioning, insulation, and protective applications.
• Available in custom inner diameter (ID) and outer diameter (OD) combinations up to 2.5” OD.
• Available in density grades ranging from soft to firm.
• Closed-cell construction provides compressibility and low water absorption.
• Designed for continuous operating temperatures up to +400°F.
• Resists compression set, weathering, moisture intrusion, and environmental degradation.
• Flame-retardant versions are available to meet UL 94 V-0 and UL HB requirements.
• FDA-compliant and NSF 51 certified options are available.
• Ideal for electronics, industrial equipment, food processing, medical devices, transportation, and environmental sealing applications.

Why Choose Silicone Sponge Tubing?

Silicone sponge tubing combines the flexibility of a hollow tube with the compressibility of closed-cell silicone sponge.

Because the tubing has both an inner and outer diameter, engineers can tailor wall thickness, compression behavior, and overall fit around the application. Softer density grades are well suited for cushioning and low closure-force sealing, while firmer sponge materials provide greater structural support and sealing resistance.

Benefits of Silicone Sponge Tubing

BENEFIT	WHY IT MATTERS
Custom ID and OD	Allows tubing dimensions and wall thickness to be tailored to specific sealing, cushioning, insulation, and installation requirements.
Closed-Cell Construction	Provides compressibility while helping minimize water absorption and moisture intrusion.
Low Closure Force	Sponge construction compresses more easily than solid silicone tubing, helping create a seal without excessive force.
Multiple Density Options	Soft through firm constructions allow compression resistance, cushioning, and structural support to be matched to the application.
Thermal Stability	Maintains reliable physical performance in continuous operating temperatures up to +400°F.
Environmental Resistance	Resists weathering, moisture intrusion, and environmental degradation in demanding indoor and outdoor applications.
Specialty Formulations	Flame-retardant, FDA-compliant, NSF 51 certified, and other application-specific formulations are available.

Silicone Sponge Tubing Size and Material Options

Bellofram Elastomers manufactures silicone sponge tubing in custom ID and OD combinations to support different sealing, cushioning, insulation, and protective applications.

Silicone Sponge Tubing Options

OPTION	AVAILABLE CAPABILITY
Profile	Hollow closed-cell silicone sponge tubing.
Inner Diameter (ID)	Custom ID dimensions available to match internal fit and application requirements.
Outer Diameter (OD)	Available in custom OD dimensions up to a maximum of 2.5".
Wall Thickness	Determined by the selected combination of inner and outer diameter.
Density	Available in density grades ranging from soft to firm.
Temperature Range	Designed for continuous operating temperatures up to +400°F.
Custom Formulations	Materials can be tailored to functional, environmental, flammability, or regulatory requirements.

Standards and Specialty Silicone Sponge Tubing

Bellofram Elastomers offers silicone sponge tubing formulations for applications requiring enhanced flammability performance or materials suitable for regulated environments.

Silicone Sponge Tubing Standards and Specialty Options

OPTIONS	TYPICAL APPLICATION
UL 94 V-0	Flame-sensitive applications requiring enhanced vertical-burn performance.
UL HB	Applications requiring horizontal-burn flammability performance.
NSF 51	Food and beverage equipment requiring appropriate certified and FDA compliant materials.
Custom Formulations	Application-specific silicone sponge compounds tailored to performance and environmental requirements.

Silicone Sponge Tubing vs. Solid Silicone Tubing

The primary difference between silicone sponge tubing and solid silicone tubing is material construction. Silicone sponge tubing has a closed-cell structure that provides lower density and greater compressibility, while solid silicone tubing uses dense, non-cellular silicone rubber for greater firmness and mechanical stability. Bellofram’s solid silicone tubing is available in 30–80 Shore A and custom ID/OD combinations up to 2.5” OD.

Silicone Sponge Tubing vs. Solid Silicone Tubing

FEATURE	SILICONE SPONGE TUBING	SOLID SILICONE TUBING
Construction	Closed-cell silicone sponge.	Dense, non-cellular silicone rubber.
Density	Lighter-weight hollow profile construction.	Denser and heavier, solid elastomer construction.
Compression	Highly compressible and suited for lower closure-force sealing.	Firmer and less compressible, providing greater structural support and mechanical stability.
Gap Filling	Well suited for sealing applications requiring greater conformability and cushioning.	Best suited where a firmer, more dimensionally stable tube is required.
Typical Priority	Compression sealing, cushioning, insulation, environmental protection, and low closure force.	Mechanical durability, dimensional stability, fluid transfer, protective sleeving, and firmer sealing.

For applications requiring a dense, non-cellular hollow extrusion, explore our Silicone Tubing.

Common Applications for Silicone Sponge Tubing

Silicone sponge tubing is used where a hollow, compressible extrusion can provide sealing, cushioning, insulation, or environmental protection.

Common Applications for Silicone Sponge Tubing

APPLICATION	HOW SILICONE SPONGE TUBING HELPS
Protective Sleeving	Provides cushioning and environmental protection around sensitive components, wires, tubing, or assemblies.
Compression Sealing	Hollow sponge construction compresses easily to create a flexible seal around mating components.
Electronics	Helps cushion, insulate, and protect sensitive electronic components from vibration and environmental exposure.
Industrial Equipment	Provides flexible sealing, cushioning, insulation, and protection in demanding machinery and assemblies.
Food and Beverage Equipment	FDA-compliant and NSF 51 certified options can support applicable regulated applications.
Medical Equipment	Specialty silicone formulations can support cushioning, sealing, and protective applications in sensitive environments.
Outdoor Equipment	Closed-cell construction and environmental resistance help protect against moisture and weather exposure.
Custom Assemblies	Custom ID, OD, wall thickness, and density allow the tube to be tailored around unique component geometry.

Custom Silicone Sponge ID and OD Tubing

One of the biggest advantages of Bellofram Elastomers' silicone tubing is the ability to customize both the inner and outer diameter.

Bellofram Elastomers can manufacture virtually any ID/OD combination up to a maximum of 2.5" OD. This allows engineers to specify internal fit, overall diameter, wall thickness, and material hardness around the application rather than selecting from a limited range of standard silicone tube sizes.

Custom silicone sponge tubing can be designed around:

• Component outside diameter.
• Required internal clearance.
• Wall thickness.
• Compression requirements.
• Required density.
• Cushioning performance.
• Environmental exposure.
• Flammability requirements.
• Food, beverage, or sanitary requirements.

For more complex extrusion geometries beyond a hollow round tube, explore our Silicone Sponge Profiles.

For simple round sponge sealing without a hollow center, explore our Silicone Sponge Cords.

When Should You Choose Silicone Sponge Tubing?

Silicone sponge tubing may be the right solution when your application requires a hollow round profile combined with greater compressibility than solid silicone.

Silicone sponge tubing may be ideal when:

• A hollow round sealing or cushioning profile fits the application.
• Custom ID and OD dimensions are required.
• An OD up to 2.5” is required.
• Low closure force is important.
• Cushioning or vibration isolation is needed.
• Moisture absorption and environmental exposure must be minimized.
• Continuous operating temperatures may reach +400°F.
• A softer or firmer density must be selected for compression performance.
• UL 94 V-0 or UL HB flame performance is required.
• FDA-compliant or NSF 51 certified material is needed.

Why Choose Bellofram Elastomers for Silicone Sponge Tubing?

Bellofram Elastomers combines silicone material expertise and extrusion capabilities to manufacture custom sponge tubing around application-specific dimensions and performance requirements.

Bellofram Elastomers offers:

• Virtually any inner diameter and outer diameter combination.
• Maximum outer diameter up to 2.5”.
• Soft through firm density options.
• Closed-cell silicone sponge construction.
• Continuous temperature capability up to +400°F.
• Resistance to compression set, weathering, moisture intrusion, and environmental degradation.
• UL 94 V-0 and UL HB flame-retardant options.
• FDA-compliant and NSF 51 certified options.
• Custom formulations and dimensions.
• U.S.-based manufacturing and technical support.

Frequently Asked Questions About Silicone Sponge Tubing