Silicone Products Bonded Gaskets

What Are Bonded Gaskets?

Bonded gaskets are custom sealing components created by joining silicone extrusion profiles into continuous loops or application-specific shapes. The ends of the material are vulcanized together to create a durable bond, allowing straight extrusions to be transformed into finished gaskets such as spliced O-rings, custom bonded O-rings, picture frame gaskets, and complex perimeter seals.

Bellofram Elastomers manufactures custom bonded gaskets using both solid silicone and silicone sponge materials, providing options for different levels of compressibility, flexibility, and sealing strength. With in-house material blending and fabrication capabilities, gasket material, profile geometry, and finished shape can be tailored to meet specific static and dynamic sealing requirements.

Key Takeaways

• Bonded gaskets are created by vulcanizing extruded silicone profiles into continuous loops or custom shapes.
• Available in both solid silicone and silicone sponge materials.
• Common configurations include spliced O-rings, bonded O-rings, picture frame gaskets, and custom perimeter seals.
• Vulcanized bonding creates a continuous finished gasket without relying on mechanical joining methods.
• Custom material and profile options allow compressibility, flexibility, and sealing strength to be matched to the application.
• Designed for both static and dynamic sealing environments.
• Flame-retardant, FDA-grade, and NSF-certified silicone material options are available.
• Common applications include aerospace, automotive, medical, food processing, electronics, and industrial equipment.

Why Choose a Custom Bonded Gasket?

Bonding allows extruded silicone profiles to be converted into finished sealing geometries without requiring the entire gasket to be molded as a single component. This makes bonded gaskets a flexible solution for applications requiring continuous loops, large perimeter seals, or custom shapes.

By combining custom extrusion capabilities with vulcanized bonding, Bellofram Elastomers can tailor the gasket profile and finished geometry around the sealing surface and application requirements.

Benefits of Custom Bonded Gaskets

BENEFIT	WHY IT MATTERS
Continuous Gasket Construction	Joins an extruded profile into an endless loop or custom perimeter shape for continuous sealing around an assembly.
Vulcanized Bond	Creates a durable connection between profile ends without relying on a mechanical joint.
Custom Gasket Geometry	Supports O-rings, picture frame gaskets, perimeter seals, and other shapes tailored to the mating surface.
Solid and Sponge Options	Allows material construction to be selected around required compressibility, flexibility, sealing force, and structural support.
Reduced Assembly Complexity	Provides a finished gasket configuration that can simplify installation compared with joining or positioning multiple individual sealing sections.
Application-Specific Materials	Flame-retardant, FDA-grade, NSF-certified, and other silicone formulations can support specialized performance or compliance requirements.

Custom Bonded Gasket Configurations

Bellofram Elastomers can bond silicone extrusions into a variety of finished gasket geometries. The appropriate configuration depends on the shape of the sealing surface, extrusion profile, assembly design, and required sealing performance.

Common Bonded Gasket Configurations

CONFIGURATION	TYPICAL USE
Spliced O-Rings	Round continuous seals created by joining extruded cord into the required finished diameter.
Custom Bonded O-Rings	Application-specific O-ring configurations manufactured from selected silicone extrusion materials and profiles.
Picture Frame Gaskets	Rectangular or frame-like perimeter seals for doors, panels, enclosures, covers, and similar assemblies.
Perimeter Seals	Custom bonded shapes designed to follow the sealing perimeter of a specific component or assembly.
Custom Profile Gaskets	Complex extruded silicone profiles bonded into finished geometries for application-specific sealing requirements.

Solid Silicone vs. Silicone Sponge Bonded Gaskets

Bellofram Elastomers manufactures bonded gaskets using both solid silicone and silicone sponge materials. Choosing between them depends largely on the amount of compression, closure force, conformability, and mechanical support required by the application.

Solid Silicone vs. Silicone Sponge Bonded Gaskets

FEATURE	SOLID SILICONE GASKETS	SILICONE SPONGE GASKETS
Construction	Dense, non-cellular silicone rubber.	Closed-cell silicone sponge.
Density	Denser and heavier, solid elastomer construction.	Lighter-weight profile construction.
Compression	Firmer and less compressible, providing greater sealing force and mechanical stability.	Highly compressible and suited for lower closure-force sealing.
Gap Filling	Best suited where a firm, dimensionally stable seal is required.	Well suited for uneven gaps and sealing surfaces requiring greater conformability.
Typical Priority	Mechanical durability, dense sealing, firmness, and dimensional stability.	Compression sealing, cushioning, gap filling, insulation, and low closure force.

For more information about available solid silicone extrusions, explore our Silicone Profiles.

For applications requiring greater compressibility, explore our Silicone Sponge Profiles.

Bonded O-Rings and Spliced O-Rings

Bonded O-rings provide a custom-sized circular sealing solution by joining the ends of an extruded profile and vulcanizing the connection. This approach allows Bellofram Elastomers to produce spliced O-rings and custom bonded O-rings using selected solid or sponge silicone extrusion materials.

Because the gasket is created from an extrusion, the profile itself can be selected around the application's sealing requirements before being fabricated into the required finished diameter or shape.

Picture Frame Gaskets and Custom Perimeter Seals

Not every sealing surface is round. Bellofram Elastomers can fabricate extruded silicone profiles into picture frame gaskets and other custom perimeter configurations designed to follow rectangular or application-specific sealing surfaces.

These bonded gasket configurations can be used around doors, panels, covers, housings, enclosures, and other assemblies where a continuous perimeter seal is required. Profile geometry and material construction can be selected based on the mating surfaces, required compression, and environmental demands of the application.

Bonded Gasket Material and Compliance Options

Bellofram Elastomers manufactures bonded gaskets using a range of silicone rubber materials, including options for applications with specialized flammability or regulatory requirements.

Bonded Gasket Material and Specialty Options

OPTION	TYPICAL APPLICATION
Solid Silicone	Applications requiring firmer sealing, mechanical support, and dimensional stability.
Silicone Sponge	Applications requiring greater compressibility, cushioning, conformability, or lower closure force.
Flame-Retardant Silicone	Applications with material-specific flammability requirements.
FDA-Grade and NSF-Certified Options	Applicable food processing and other regulated equipment requiring appropriate silicone materials.
Custom Material Formulations	Application-specific silicone materials developed around sealing and performance requirements.

Common Applications for Bonded Silicone Gaskets

Custom bonded gaskets can support both static and dynamic sealing environments across industries where continuous sealing, material performance, and custom geometry are important.

Common Applications for Bonded Gaskets

APPLICATION	HOW BONDED GASKETS HELP
Industrial Enclosures	Provides continuous perimeter sealing around doors, panels, covers, and equipment housings.
Aerospace	Supports custom sealing configurations where precise geometry and reliable elastomer performance are required.
Automotive	Provides custom seals for assemblies exposed to vibration and demanding operating conditions.
Medical Equipment	Supports custom sealing and protective applications using application-appropriate silicone materials.
Food Processing Equipment	FDA-grade and NSF-certified material options can support applicable regulated sealing applications.
Electronics	Provides perimeter sealing, vibration protection, and environmental isolation around sensitive assemblies.
Custom Equipment	Allows gasket geometry and material construction to be tailored around unique sealing surfaces and assembly requirements.

Bonded Gaskets vs. Flash Cut Gaskets

Bonded and flash cut gaskets provide two different approaches to producing custom silicone seals. Bonded gaskets begin with an extruded profile that is formed and vulcanized into the required finished geometry, while flash cut gaskets are digitally cut from flat silicone sheet material.

Bonded Gaskets vs. Flash Cut Gaskets

FEATURE	BONDED GASKETS	FLASH CUT GASKETS
Construction	Extruded silicone profile formed into the required shape and vulcanized at the joint.	Flat gasket digitally cut directly from silicone sheet material.
Density	Can be manufactured from solid or sponge silicone extrusion materials.	Determined by the selected solid or sponge silicone sheet material.
Compression	Can be tailored through extrusion profile and material selection.	Determined primarily by sheet material, thickness, and formulation.
Gap Filling	Custom profile geometry can provide three-dimensional compression and conformability around a perimeter.	Well suited for flat sealing surfaces and two-dimensional gasket geometries.
Typical Priority	Continuous perimeter seals, O-rings, picture frame gaskets, and custom extruded gasket geometries.	Rapid prototyping, flat custom shapes, intricate cutouts, and tooling-free gasket production.

For custom flat gaskets produced directly from silicone sheet without hard tooling, explore our Flash Cut Silicone capabilities.

When Should You Choose a Bonded Gasket?

A bonded gasket may be the right solution when your application requires a continuous sealing geometry created from an extruded silicone profile.

Bonded gaskets may be ideal when:

• An endless-loop gasket is required.
• A custom bonded or spliced O-ring is needed.
• A picture frame or custom perimeter gasket fits the assembly.
• A specific extrusion profile is needed to create the required sealing geometry.
• Solid silicone is required for firmer sealing and mechanical stability.
• Silicone sponge is preferred for greater compressibility and lower closure force.
• The application requires a custom gasket for static or dynamic sealing.
• Flame-retardant, FDA-grade, or NSF-certified silicone material is required.

Why Choose Bellofram Elastomers for Custom Bonded Gaskets?

Bellofram Elastomers combines silicone material expertise, extrusion, in-house fabrication, and material blending capabilities to develop bonded gasket solutions around specific sealing requirements.

Bellofram Elastomers offers:

• Solid silicone and silicone sponge gasket options.
• Vulcanized bonded seals.
• Spliced and custom bonded O-rings.
• Picture frame gaskets.
• Custom perimeter seals.
• Custom extruded profile geometries.
• Flame-retardant material options.
• FDA-grade and NSF-certified silicone options.
• Solutions for both static and dynamic sealing environments.
• In-house fabrication and material blending capabilities.
• U.S.-based manufacturing and technical support.

Frequently Asked Questions About Bonded Gaskets