Gasket material
PORON® Polyurethane Foam Gasket Material
PORON is a microcellular urethane foam made by Rogers Corporation for thin gaskets, cushions and seals that must not take a compression set. It is the display, keypad, enclosure and battery-pack gasket sheet, cut to your drawing on our waterjet, plain or with adhesive backing.
- Family
- Microcellular polyurethane foam
- Temperature
- 90 C (194 F) constant use; 121 C (250 F) intermittent
- Thickness
- 0.031 in to 0.5 in (0.79 mm to 12.7 mm)
- Formats
- Rolls and sheets from the maker; PSA-laminated
- Designations
- Rogers PORON grade numbers, e.g. 4701-30
- Product
- Sheet gaskets waterjet-cut to your drawing in Orange, California
Figures are the cited maker or standards values; the sheet datasheet and your application govern the final choice.
Every common gasket sheet material is quick for us to source, and we cut it to your print on our waterjet.
What PORON foam seals
PORON foam holds its thickness after years under a bezel or a lid where an ordinary sponge would flatten and stop sealing. That low compression set, with a fine cell structure that seals against dust at very little force, is why it is specified in displays, keypads, electronics enclosures, battery packs and appliance panels [S1]. It is a cushioning and dust-sealing sheet; it is not a flange gasket for pressure.
The cited grade is rated for constant use at 90 C and intermittent use to 121 C, and it embrittles below -51 C [S1]. Above that, silicone sponge takes over; for oil or weather at ordinary temperatures, neoprene sponge costs less.
Grades and adhesive
Rogers sells PORON by grade number, and the number sets density and firmness: the 4701-30 series is the very soft grade, with firmer series above it. Most PORON gaskets are ordered with a pressure-sensitive adhesive laminated to one face by the sheet maker so the part stays put in assembly. Name the grade, the thickness and the adhesive on the print.
Specifications
PORON Polyurethane Foam specifications
| Property | Value (in / mm, C / F as stated) | Source |
|---|---|---|
| Maker and grade | Rogers Corporation PORON 4701-30 (the very soft industrial grade cited here) | [S1] |
| Density | 240, 320 or 400 kg/m3 (15, 20 or 25 lb/ft3) | [S1] |
| Compression force deflection at 25 percent | 35 kPa (5.1 psi) at 320 kg/m3; 62 kPa (9.0 psi) at 400 kg/m3 | [S1] |
| Temperature | Constant use to 90 C (194 F); intermittent use to 121 C (250 F); embrittlement threshold -51 C (-60 F) | [S1] |
| Thickness | 0.031 in to 0.5 in (0.79 mm to 12.7 mm), the span across the three densities; 0.5 in is the 240 kg/m3 grade | [S1] |
| Designations | Rogers PORON grade callouts on the print (family, density, thickness) | [S1] |
How we cut it
Gaskets are waterjet-cut to your drawing in Orange, California. Send a DXF, DWG or PDF with the thickness, the material or the specification callout, and the quantity. There is no die to build, so a single prototype and a repeat run go through the same setup, and a revision needs only a new file. The sheet comes from the sheet makers we buy from, to the callout on your print; the cutting is ours. PORON is thin and often adhesive-backed, so it is cut with the liner on; kiss-cut parts that stay on their carrier are not a waterjet job; they are cut by a converting partner and quoted from the same drawing.
Where PORON Polyurethane Foam is used, and the usual alternatives
The print or the sheet datasheet governs; these are the sheets usually specified instead:
- Closed-cell sponge: when the gasket is thicker, sees weather or oil, and cost matters.
- Silicone sponge: when the enclosure runs hotter than 90 C or colder than -51 C.
- Adhesive backing: for the adhesive systems laminated to foam and sponge sheet.
- Felt: when a wicking or polishing pad is wanted instead of a seal.
Related gasket materials: Closed-Cell Sponge Rubber Gasket Material, Silicone Sponge Gasket Material, Adhesive-Backed (PSA, Peel-and-Stick) Gasket Material, Wool Felt Gasket Material. The full index is on the gaskets hub; send the drawing through request a quote.
Frequently asked
What is PORON?
A microcellular polyurethane foam made by Rogers Corporation. Its fine, uniform cells give it very low compression set, so a gasket keeps sealing after years under load.
How hot can a PORON gasket run?
The cited 4701-30 grade is rated for constant use at 90 C and intermittent use to 121 C. Check the Rogers sheet for the grade on your print.
Does it come with adhesive?
Yes. The sheet maker laminates pressure-sensitive adhesive to one face, and the gasket is cut with the liner on.
Which PORON grade should the print name?
The grade number sets density and firmness: 4701-30 is the very soft series, and firmer series suit gaskets that carry more load. The print or your engineering names the grade, and Rogers publishes the figures for each.
Is PORON a pressure gasket?
No. It seals dust, light and moisture at low closing force. A bolted joint with pressure behind it wants solid sheet or compressed fiber.
Sources
- [S1] PORON 4701-30 Polyurethane, Rogers Corporation, https://rogerscorp.com/elastomeric-material-solutions/poron-industrial-polyurethanes/poron-4701-30, accessed 2026-09-13.
PORON is a trademark of Rogers Corporation. No affiliation or endorsement is implied.
Related guides
Send the PORON Polyurethane Foam gasket drawing and the quantity
Upload a DXF, DWG or PDF of the gasket with the quote request, or a photo of the part with a ruler if no drawing exists. Add the sheet thickness, the durometer or grade, the quantity and whether adhesive backing is wanted. Gaskets are cut in our own shop in Orange, California; a Conquest representative replies.
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