An enclosure door gasket that stays flat after a few years of service lets dust and water creep through the gap. The Silicone Foam / Sponge Series has strong elastic recovery and resists lasting deformation under long-term pressure, and its 28 ± 3 Shore A softness lets a cover panel compress the seal line without heavy bolt force. Two decisions settle the choice: pick strip or tube and the squeeze from your gap and closing force, then ask for compression set data to confirm the recovery margin.
Seals that spring back after long compression
The product page states that the series has strong elastic recovery and resists set after long-term pressure, keeping the seal stable. Every time a cover closes, the recovery left in the gasket decides how much contact pressure remains. When recovery holds, the contact line along the door stays continuous and service intervals become easier to plan.
Soft enough for thin sheet-metal covers
Hardness is listed at 28 ± 3 Shore A, a soft grade of silicone foam sponge. A given squeeze needs less closing force, which suits enclosures with wide fastener spacing, thin covers or quick-release latches. The full technical table is on the Silicone Foam / Sponge Series product page.
Uniform foam for even squeeze around the frame
The page describes uniform foaming density with minimal surface tolerance, and lists specific gravity at 0.65 to 0.90 g/cc. A consistent cross-section around the whole frame keeps the squeeze similar on every side once the cover is fastened, so one section is less likely to be overcompressed while another barely touches.
Recovery that survives hot and cold cycles
The rated temperature range is -100°C to +300°C, within which the page says physical properties are maintained. The series also meets UL 94V-0 and resists acids and alkalis. Equipment that cycles between cold shutdowns and hot operation keeps an elastic seal, which suits outdoor cabinets and gaskets near heat-generating equipment.
Flexible routing around corners
Ultimate elongation is listed at 200%, so strips and tubes can follow a door frame or a cover groove around corners. The usable minimum bend radius depends on the cross-section, so trial-fit a sample first.
Where it fits
The product page positions the series for precision sealing, cushioning and thermal insulation in electronics and electrical equipment, with breakdown voltage above 3000 VAC. Typical spots include control cabinet doors, equipment service covers and instrument housing seams. Its job is sealing and cushioning. When heat must flow from a component to the housing, choose a thermal interface material such as a thermal gap pad instead of a foam strip.
For a deeper look at how cell structure carries load, see The Mechanics of Microcellular Buffering: Silicone Foam Pad Compression and Sealing.
Engineering note: reading recovery data with the compression set equation
ASTM D395 Method B (compression set under constant deflection) calculates compression set as:
C_B = (t0 – ti) / (t0 – tn) × 100%
C_B is compression set as a percentage of the original deflection (%); t0 is the original specimen thickness (mm); ti is the thickness after release and 30 minutes of cooling (mm); tn is the spacer bar thickness that fixes the deflection (mm). The numerator is the thickness that did not come back and the denominator is the deflection applied, so a lower C_B means more complete recovery.
In the test, spacers fix the deflection and the fixture stays in an oven at a specified temperature for a suggested 22 or 70 hours, followed by 30 minutes of cooling before measurement. Results shift with temperature, time, deflection and specimen shape, so compare values only under identical conditions. Sponge and foam rubbers are often specified under ASTM D1056 with different conditions. The product page publishes no compression set value for this series, and the equation only helps you read supplier data. It is not a product specification or guarantee. Source: Intertek, Compression Set Under Constant Deflection ASTM D395.
Three inputs to bring to a quote
- Installation gap and tolerance, which set the original thickness t0 and the fastened height.
- Closing force and fastener spacing. With limited force, consider hollow tubing first, since a hollow section of the same outer diameter generally compresses more easily.
- Operating temperature and time under load, used to request compression set data under matching conditions.
Want door seals that last longer?
If enclosure door or cover seals flatten and leak after a few service cycles, start with recovery. Review the technical data for the Silicone Foam / Sponge Series, then send a cross-section sketch and the three inputs above to Lixing Composite Materials Co., Ltd. for samples or a specification consultation at yw@zh-lx.com.
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