Rogers

Static vs Dynamic Seals

Choose the right sealing approach—and the right gasket material—for enclosures that stay closed or open repeatedly. When an enclosure leaks, the root cause is often not the “wrong gasket” but the wrong type of seal design. The first question to answer is simple:

Will the enclosure remain closed for most of its life, or will it be opened and re-closed as part of normal use?
That single decision determines whether you need a static or dynamic seal—and it directly impacts material selection, closure force, durability, and service life.

Static vs Dynamic Seals in 30 Seconds

  • Static seal = compressed during assembly and intended to stay closed (service access is rare).

  • Dynamic seal = designed to open/close repeatedly and still reseal consistently over many cycles.

If your product is serviced, inspected, cleaned, recharged, or accessed frequently, treat it as dynamic—even if it “moves” only occasionally.

Request a Material Recommendation

Share your enclosure details and cycle requirements—our team will propose the right PORON®/BISCO® grade, thickness, and adhesive system.

Uszczelnienia statyczne i dynamiczne | PORON® & BISCO®

What Is a Static Seal?

A static seal is installed and compressed once—then expected to maintain protection without routine re-compression. Typical examples include factory-sealed electronics modules, sensor housings, and sealed covers where access is limited to trained service personnel. What matters most in static sealing

  • Conformability at assembly: the gasket must fill micro-gaps and surface variation right away.

  • Environmental resistance: consider temperature range, moisture, UV/ozone exposure, and contaminant resistance.

  • Attachment strategy: many static builds benefit from adhesive-backed gaskets to ensure placement and reliable assembly.

Material tip:

Rogers PORON® polyurethane and BISCO® silicone foams are designed to be compressible and conformable while supporting long-term sealing performance.

What Is a Dynamic Seal?

A dynamic seal is expected to maintain performance after repeated open/close cycles. That repeated compression and release makes the gasket’s “memory” and force retention critical. What matters most in dynamic sealing

  • Resiliency after cycling: the gasket must rebound and continue to fill the gap.

  • Low compression set + low stress relaxation: your seal must keep thickness and maintain sealing force over time.

  • Lower closure force (when needed): helps reduce stress on hinges, latches, and thin-wall housings.

  • Realistic validation: cycle testing with the real enclosure geometry (hinges/latches, tolerances, temperature swings) is often the difference between success and field failures.

The Engineering Properties That Decide Long-Term Seal Performance

Dynamic and long-life static seals are often won or lost on two measurable behaviors:

  • Compression Set (C-Set)

    • Compression set describes how well a material returns toward its original thickness after being compressed for a defined time and temperature. If a gasket takes significant C-set, it can lose thickness and compromise sealing.
      Common test reference: ASTM D395.

  • Stress Relaxation (Force Relaxation)

    • Stress relaxation is the tendency of a compressed material to lose force over time while still under compression—meaning the gasket may still be “there,” but it pushes back less, weakening the seal.
      Common test references: ASTM D6147 or ISO 3384.

Rogers’ sealing guidance highlights that stress relaxation and compression set resistance are key attributes that significantly impact long-term performance.

Choosing Between PORON® and BISCO® for Static and Dynamic Seals

Rogers PORON® polyurethane and BISCO® silicone materials are widely used in enclosure sealing because they’re engineered for compressibility, conformability, and resistance to long-term mechanical degradation. When PORON® is a strong fit

Consider PORON® polyurethane when you need:

  • Excellent compression set resistance and strong long-term cushioning/sealing behavior

  • Low outgassing / non-fogging / non-corrosive behavior for sensitive assemblies

  • Manufacturing-friendly conversion: PORON materials are described as easy to fabricate and compatible with a broad range of adhesives

  • Dynamic designs where closure force must be kept low (material selection depends on grade and geometry)

When BISCO® is a strong fit

Consider BISCO® silicone when your application demands:

  • Wide temperature range and durability in harsh environments

  • Superior flame resistance and robust long-term sealing characteristics

  • UV/ozone resistance and low stress relaxation for demanding long-life seals

Bottom line:

  • Many static seals can be solved with either PORON® or BISCO®—the deciding factors are environment, assembly method, and long-term requirements.

  • Many dynamic seals benefit from materials proven to keep performance through cycling, where compression set and stress relaxation become primary selection criteria.

Mechanical Design Considerations (Especially for Dynamic Seals)

Dynamic enclosures often fail at corners and weak compression zones—particularly when a door-style design has hinges and limited latch points. Practical design moves that improve resealing:

  • Choose materials/grades that achieve sealing at lower closure force when hinge/latch load is limited.

  • Use gasket geometry and thickness to handle tolerance stack-up (especially on plastic housings).

  • Validate the assembled system, not just the material: compression, cycle count, and temperature exposure should reflect real use.

Get a Quote / Send a Drawing

Upload a DXF/PDF or sample part and we’ll respond with a converting plan (die-cut, kiss-cut, laser/CNC) and lead time.

From Material to Finished Gasket: EKO-TECH Converting Capabilities

Getting the seal type right is only half the job—repeatable performance also depends on how the gasket is converted, applied, and assembled.

EKO-TECH specializes in converting and supplying engineered adhesive and elastomer solutions, including Rogers materials, with modern manufacturing capabilities for both prototypes and production. What EKO-TECH can deliver for static & dynamic seals

  • Die-cutting & kiss-cutting (parts and rolls) for high repeatability

  • Laser & CNC cutting for prototypes and low-volume programs

  • Lamination with qualified pressure-sensitive adhesives (including flame-retardant/UL options and silicone adhesive systems where required)

  • Slitting / custom-width cutting, rewinding, and cross-wound spooling to match your assembly process

  • Prototype-to-series scalability, kitting and custom packaging to support lean assembly and clean application

Need help narrowing down PORON® vs BISCO®? We support application consultation, prototyping, and co-engineering—from early selection through series production.

What to Send Us (So We Can Recommend the Right Seal Fast)

To propose the correct material, thickness, and adhesive system, it helps to share:

  • Enclosure type + substrate (metal/plastic/painted/powder-coated)

  • Target environment (dust/water exposure, temperature range, UV/ozone, chemicals)

  • Expected access frequency (static vs dynamic + estimated cycles)

  • Gap and compression targets (or nominal groove depth)

  • Closure method (screws, clips, latches, hinges)

  • Drawing (DXF/PDF) or a sample part

PORON® and BISCO® are trademarks of Rogers Corporation. All designs should be validated in the final application.

Not sure if your application is static or dynamic?

EKO-TECH can help you define the seal strategy and convert Rogers PORON® and BISCO® into production-ready gaskets optimized for your enclosure.