Root Cause Analysis (8D): RubberQ’s Process for Resolving Quality Deviations.

Root Cause Analysis (8D): RubberQ’s Process for Resolving Quality Deviations

Problem Statement

A client reported premature failure of EPDM gaskets in a high-temperature coolant system. The gaskets exhibited excessive compression set (>50%) after 500 hours at 150°C, leading to leakage. The root cause was traced to inadequate polymer formulation and improper curing.

Material Science Analysis

EPDM rubber typically performs well in coolant systems due to its resistance to water and steam. However, standard EPDM formulations degrade under prolonged exposure to temperatures above 120°C. The failure occurred due to insufficient crosslinking density and low ethylene content, which reduced thermal stability. RubberQ’s custom EPDM compound addresses this by optimizing ethylene-to-propylene ratio and incorporating peroxide curing agents for enhanced crosslinking.

Technical Specs

• Shore A Hardness: 70 ± 5
• Tensile Strength: 12 MPa
• Elongation at Break: 300%
• Temperature Range: -40°C to 160°C
• Compression Set (22 hrs @ 150°C): <30%

Material Comparison

Parameter	Custom EPDM	Standard EPDM	FKM
Shore A Hardness	70 ± 5	65 ± 5	75 ± 5
Tensile Strength (MPa)	12	10	15
Elongation at Break (%)	300	250	200
Temperature Range (°C)	-40 to 160	-40 to 120	-20 to 200
Compression Set (%)	<30	>50	<20

Standard Compliance

RubberQ adheres to IATF 16949 standards for batch traceability and process control. Each production batch undergoes rigorous testing per ASTM D2000 and ISO 3601 specifications. Documentation includes PPAP submissions, material certifications, and detailed process flow charts to ensure compliance and reproducibility.

CTA

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