Microcellular urethane foam is the go-to material when you are in the market for a thin, consistent gasket or cushion that compresses easily, yet recovers every time.Microcellular urethane foam handles sealing, cushioning and vibration control across electronics, lighting, transport, appliances and dozens of other assembly types.
At iTapeStore you can order standard sheets and rolls, or we can laminate adhesive and convert the foam into ready-to-use parts for your production line. We carry Rogers PORON®, E-A-R™ 3M™ ISOLOSS™ LS and Griswold™ microcellular urethane foam.
Why choose microcellular urethane foam
Microcellular urethane foam has been expertly engineered for controlled compression. The material's fine cell structure provides a soft feel with excellent compression set resistance as the foam continues to seal and cushion, even after thousands of compression cycles. With this in mind, it is preferred by engineers.
Common applications for microcellular urethane foam include:
- Dust and light seals in electronic housings and LED luminaires
- Gap filling and rattle prevention between plastic and metal components
- Cushioning pads under PCBs, batteries and displays
- Foam pads and bumpers where controlled compression matters more than high tensile strength
Compared to conventional PU foam or rubber sponge, microcellular urethane delivers:
- Stable thickness control and tight tolerances for precise gasket designs
- Excellent compression force deflection control across the sheet, so your seal behaves predictably from edge to edge
- Good vibration damping and impact absorption for electronics, handheld devices and equipment panels
- Long-term durability in demanding assemblies including automotive interiors, appliances and industrial enclosures
Pair it with the right pressure sensitive adhesive and microcellular urethane becomes a high-performance, peel-and-stick seal, one that can replace messy liquid sealants and mechanical fasteners in many assemblies.
Technical specifications
It is important to note that specific values vary by grade however, in general, microcellular urethane foams offer:
- Thickness range: Commonly from very thin 0.5 mm foams up to around 12 mm, with tight thickness tolerances for precision gasketing.
- Density and firmness options: Multiple densities and compression force deflection profiles to match your required closure force and seal level.
- Temperature performance: Many grades work from approximately -40 °C up to 80–90 °C; some high-temperature versions push beyond that range.
- Environmental resistance: Good ageing characteristics in indoor and many sheltered outdoor applications, with options that offer improved UV resistance and solvent resistance when required.
- Compression set resistance: Designed to recover after repeated compression, unlike cheaper foams that take a permanent set and lose sealing performance over time.
When we add adhesive to the foam, we match the adhesive system to your specific substrate and environment:
- Acrylic adhesives: Excellent long-term holding power, good shear strength and tensile strength, better for high surface energy (HSE) metals and many plastics. Acrylic adhesives are also great for applications exposed to higher temperatures, UV and chemicals.
- Rubber adhesives: Very high initial tack, often preferred for difficult low surface energy (LSE) substrates in indoor applications, especially when fast handling strength matters.
- Specialty systems: Differential adhesives (removable one side, permanent the other), or adhesives engineered to bond to powder-coated metals and textured plastics.
Our team of professionals can help you match foam grade and adhesive to your substrates, surface energy, temperature range and environmental conditions.
Custom converting options
iTapeStore is a Made-in-the-USA converter that handles short runs and production quantities.
We supply microcellular urethane foam as:
- Master rolls or slit to your required width
- Sheets cut to standard or custom sizes
- Kiss-cut parts on a roll for fast peel-and-stick application on the line
- Individual die-cut gaskets, pads and spacers packed in bags or stacks
Are you looking for adhesive? We can laminate genuine 3M™ pressure sensitive adhesives to one or both sides of the foam and then convert to your finished part:
- Die cutting to complex shapes with internal cutouts and tight tolerances
- Laminating with liners suitable for manual application or automated dispensing
- Prototypes and test runs with no minimum order quantity on many configurations, buy by the yard and prove out your design before scaling up
Email sales@iTapeStore.com with your part number, substrate, dimensions and quantity. Our team will help specify a foam-and-adhesive combination that meets your performance and cost targets.
Application guide
The correct application is vital for achieving full bond strength and long-term sealing performance:
1. Surface preparation
- Ensure surfaces are clean, dry and free of oil, dust and release agents.
- Wipe with a suitable cleaner such as isopropyl alcohol and allow it to flash off completely.
- For very low surface energy plastics or difficult powder coats, a suitable adhesion promoter or primer may be recommended.
2. Layout and positioning
- Dry-fit your die-cut parts to verify alignment and compression before removing the liner.
- Avoid stretching the foam during application, as this can create internal stress and affect long-term performance.
3. Application pressure
- Remove the liner and apply the foam to the substrate, starting at one edge and working across to avoid trapping air.
- Apply firm, even pressure to activate the pressure sensitive adhesive and maximize contact with the substrate.
4. Cure time
- Many acrylic adhesives reach handling strength quickly, yet full bond strength typically builds over 24–72 hours, especially at lower temperatures.
- Wherever possible, avoid putting the joint under maximum load until the adhesive has reached its recommended cure time.
Following these steps will help you get the best balance of strength, peel performance and long-term sealing from your microcellular urethane foam.
FAQs
What is microcellular foam?
Microcellular foam is a urethane foam manufactured with billions of uniformly sized gas bubbles, usually under 100 microns across. That very fine, consistent cell structure gives the material its useful combination of softness, low compression set and high energy absorption. In industrial applications it is the preferred gasketing and cushioning material for electronics, lighting fixtures and equipment enclosures where precise compression control is non-negotiable.
Is microcellular urethane foam removable?
Removability comes down to the adhesive. Foam supplied bare can be mechanically removed without much trouble. When a high-performance acrylic adhesive is applied, the bond is generally permanent and may need mechanical removal or an adhesive remover to break it. If you need a removable or repositionable option, let us know and we can advise on a lower-tack or differential adhesive system.
Will this foam stick to powder-coated or painted metal?
Yes, with the right adhesive system. Many powder coats and paints sit at lower surface energy than bare metal. We generally recommend a high-performance acrylic adhesive for these substrates, sometimes paired with a primer. Give us details of your coating system and we can suggest a suitable foam-plus-adhesive combination.
Can microcellular urethane foam be used outdoors?
Some grades can be used in protected outdoor environments, especially when paired with an adhesive that offers good UV resistance and solvent resistance. For continuous direct UV and weather exposure, service life will depend on the specific formulation and design. Share your application details and we can recommend an appropriate grade or alternative material.
What thickness and hardness should I choose?
The right thickness and firmness depend on your gap, required seal level and available closure force. Thicker, softer foams will compress easily to take up larger tolerances, while firmer foams can provide a more robust seal under higher loads. Our team can help you select a grade that achieves the compression you need without overstressing your hardware or components.
What is the difference between polyurethane foam and urethane foam?
They are the same thing. Polyurethane is a polymer made from repeating urethane groups, so "urethane foam" is simply the shorter name. If you see "microcellular urethane foam" or "microcellular polyurethane foam" on a data sheet, both refer to the same product category.