Shelf Life of Rubber Parts: How to Store Seals to Prevent Ozone Cracking.

Shelf Life of Rubber Parts: How to Store Seals to Prevent Ozone Cracking

Problem Statement

Rubber seals stored in environments with high ozone concentrations exhibit premature cracking, compromising sealing integrity. This issue is prevalent in EPDM and NBR materials exposed to outdoor storage or industrial atmospheres.

Material Science Analysis

Ozone cracking occurs due to the reaction of ozone molecules with unsaturated carbon-carbon double bonds in rubber polymers. EPDM and NBR are particularly susceptible due to their molecular structure. FKM and HNBR, with higher saturation and fluorine content, resist ozone degradation. Proper storage conditions and anti-ozonant additives mitigate this issue.

Technical Specs

• EPDM: Shore A Hardness 70, Tensile Strength 15 MPa, Elongation at Break 300%, Temperature Range -50°C to 150°C
• FKM: Shore A Hardness 75, Tensile Strength 20 MPa, Elongation at Break 200%, Temperature Range -20°C to 200°C
• HNBR: Shore A Hardness 80, Tensile Strength 25 MPa, Elongation at Break 250%, Temperature Range -40°C to 180°C

Material Comparison

Material	Ozone Resistance	Compression Set (%)	Chemical Resistance	Temperature Range (°C)
EPDM	Low	25	Moderate	-50 to 150
FKM	High	15	Excellent	-20 to 200
HNBR	High	20	Good	-40 to 180

Standard Compliance

RubberQ adheres to IATF 16949 standards for batch-to-batch consistency. Our compounding process ensures compliance with ASTM D2000 for material callouts and ISO 3601 for sealing performance. Anti-ozonant additives are precisely measured to meet specific shelf-life requirements.

Storage Recommendations

• Store rubber seals in cool, dry environments below 25°C.
• Use UV-resistant packaging to minimize ozone exposure.
• Avoid direct sunlight and proximity to electrical equipment generating ozone.

For custom material compound development or IATF 16949 documentation, consult RubberQ's engineering department.