kSil® GP350
kSil® GP350 is a closed cell, lightweight silicone sponge with a density of 300 kg/m³ and a compression force deflection of 48 kPa. It is rated for service from -60°C to +230°C and features a very low compression set of 5% and a tensile strength of 750 kPa. Water absorption is less than 5%, and the material is available in thicknesses from 1.5 mm to 35 mm.
Key Properties
- Compression Force Deflection: 48 kPa (ASTM D1056)
- Tensile Strength: 750 kPa (ASTM D412)
- Elongation: 120% (ASTM D412)
- Compression Set: 5% (ASTM D1056)
- Density: 300 kg/m³ (ASTM D1056)
- Operating Temperature Range: -60°C to +230°C
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- Specifications
- Applications
- General Info
- FAQs
Physical Properties
| Property | Value | Test Method |
| Density | 300 kg/m³ | ASTM D1056 |
| Minimum Thickness | 1.50 mm | — |
| Maximum Thickness | 35.00 mm | — |
| Colors Available | White, Black, Riox | Visual |
Mechanical Properties
| Property | Value | Test Method |
| Compression Force Deflection | 48 kPa | ASTM D1056 |
| Compression Set | 5% | ASTM D1056 |
| Tensile Strength | 750 kPa | ASTM D412 |
| Elongation | 120% | ASTM D412 |
| Water Absorption | <5% | ASTM D1056 |
Thermal Properties
| Property | Value | Test Method |
| Min Operating Temperature | -60°C | — |
| Max Operating Temperature | 230°C | — |
- Die-cut gaskets requiring a firm, resilient sponge with very low long-term compression set
- Flexible sealing solutions in extreme temperature environments up to 230°C
- Aerospace sealing applications requiring a closed cell silicone sponge with high tensile strength
- Automotive sealing components demanding durable elastic recovery under sustained load
- Water contact sealing where low water absorption and closed cell construction are required
Common industries: Aerospace, Automotive, Industrial Manufacturing, Water Infrastructure.
kSil® GP350 is a higher-density grade in the kSil® GP general purpose closed cell silicone sponge range, offering a firm compression response at 48 kPa CFD and a very low compression set of 5%. It is formulated for applications requiring a resilient, firm sponge that maintains its sealing profile over extended service cycles, including die-cut gaskets and flexible sealing solutions in demanding temperature and environmental conditions.
Tensile strength of 750 kPa and 120% elongation reflect robust mechanical performance for a cellular sponge material at this density. The 5% compression set, tested per ASTM D1056, is among the lowest in the GP cellular range, making GP350 well suited where long-term seal integrity under sustained compression is critical. Water absorption remains below 5%, consistent with its closed cell construction. The material is rated for service from -60°C to +230°C and is available in White, Black, and Riox colorways.
What differentiates GP350 from GP250 and GP400 in the kSil® GP cellular sponge range?
GP350 offers a compression set of 5% — significantly lower than GP250 (12%) and only marginally above GP400 (4%) — combined with a tensile strength of 750 kPa. Compared to GP250, it provides firmer compression resistance (48 kPa CFD vs. 34 kPa) and markedly better elastic recovery. Compared to GP400, it has a slightly lower density (300 kg/m³ vs. 400 kg/m³) and lower CFD (48 kPa vs. 76 kPa).
Why is compression set critical for cellular silicone sponge materials?
Compression set measures the permanent deformation that remains after a material has been held under compressive load. In sealing applications, a high compression set results in loss of contact force between the gasket and the mating surface, leading to seal degradation over time. GP350's compression set of 5% per ASTM D1056 indicates excellent resistance to permanent deformation under load.
What is the operating temperature range for GP350?
GP350 is rated from -60°C to +230°C.
Is GP350 suitable for regulated environments?
No compliance standards are specified on the manufacturer's TDS for GP350. Suitability for regulated environments must be confirmed through application-specific testing.
How should GP350 be specified?
Specify grade (GP350), thickness, color (White, Black, or Riox), compliance requirements, dimensional tolerances, and finished format.
