from my external references:
For an IP68 application, the suitable rubber material should provide excellent resistance to water, dust, and harsh environmental conditions while maintaining durability and flexibility. Here are some common rubber materials suitable for IP68 applications:
Silicone Rubber:
Temperature Resistance: -60°C to +230°C
Water Resistance: Excellent, suitable for continuous immersion.
Key Features: High flexibility, UV and ozone resistance, excellent sealing properties.
EPDM (Ethylene Propylene Diene Monomer):
Temperature Resistance: -50°C to +150°C
Water Resistance: Excellent, resistant to water, steam, and chemicals.
Key Features: Good weatherability, ozone, and UV resistance.
Nitrile Rubber (NBR):
Temperature Resistance: -40°C to +100°C
Water Resistance: Good, especially for oil-contaminated environments.
Key Features: Resistant to oils, fuels, and some chemicals.
Fluorosilicone Rubber:
Temperature Resistance: -60°C to +200°C
Water Resistance: Excellent, similar to silicone with added chemical resistance.
Key Features: Combines properties of silicone with added fuel and oil resistance.
Viton® (FKM):
Temperature Resistance: -20°C to +200°C
Water Resistance: Very good, excellent chemical and heat resistance.
Key Features: Suitable for harsh chemical environments and high temperatures.
For most IP68 applications, silicone rubber is often preferred due to its excellent sealing properties, wide temperature range, and long-term durability in extreme environments.
R.Efendy