FMEA in Rubber Design: Preventing Failures before Tooling is Cut.

FMEA in Rubber Design: Preventing Failures before Tooling is Cut

Problem Statement: Compression Set Failure in High-Temperature Seals

Static seals in EV battery cooling systems require ≤15% compression set after 1,000 hours at 150°C. Standard NBR compounds degrade rapidly due to thermal oxidation of unsaturated carbon bonds.

Material Science Analysis

FKM (Fluorocarbon Rubber) outperforms NBR and EPDM due to:

• Carbon-Fluorine bonds (485 kJ/mol bond energy vs. NBR’s C=C at 265 kJ/mol)
• 70-72% fluorine content in Grade FKM-70S prevents chain scission
• Peroxide curing system eliminates post-curing compression drift

Technical Specifications

Parameter	FKM-70S	EPDM-60	NBR-70
Shore A Hardness	70 ±2	60 ±5	70 ±3
Tensile Strength (MPa)	18.5	12.0	14.2
Elongation at Break (%)	220	350	310
Compression Set (%, 22h @ 200°C)	12	45	65
Chemical Resistance (ASTM D471)	Grade A (Diesel/IP-6)	Grade C	Grade F

Standard Compliance

RubberQ’s IATF 16949 processes ensure:

• Full PPAP documentation including MSA, PFMEA, and Control Plans
• Batch traceability via RFID-tagged raw material lots
• ASTM D429 Method B adhesion testing for all rubber-to-metal components
• ISO 16232 Class A cleanliness for molded parts

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