UL 94 Flammability: Understanding V-0, V-1, and HB Ratings for Rubber.

UL 94 Flammability: Understanding V-0, V-1, and HB Ratings for Rubber

Problem Statement

Rubber components in high-temperature environments face chemical degradation and flammability risks. For example, NBR seals degrade at 200°C, losing tensile strength and increasing flammability. This compromises safety and performance in applications like EV battery cooling and AI server manifolds.

Material Science Analysis

Flammability resistance depends on polymer composition. FKM excels due to its high fluorine content (66-70%), which inhibits combustion. EPDM, with its saturated backbone, offers moderate flame resistance. NBR, with unsaturated carbon bonds, is prone to ignition and rapid flame spread.

Technical Specs

• FKM: Shore A 70-90, Tensile Strength 15-25 MPa, Elongation at Break 150-250%, Temperature Range -20°C to 250°C.
• EPDM: Shore A 50-90, Tensile Strength 10-20 MPa, Elongation at Break 200-400%, Temperature Range -50°C to 150°C.
• NBR: Shore A 40-90, Tensile Strength 10-25 MPa, Elongation at Break 200-600%, Temperature Range -30°C to 120°C.

Material Comparison

Parameter	FKM	EPDM	NBR
UL 94 Rating	V-0	V-1	HB
Temperature Range (°C)	-20 to 250	-50 to 150	-30 to 120
Compression Set (%)	15-25	20-30	25-35
Chemical Resistance	High	Moderate	Low

Standard Compliance

RubberQ ensures batch-to-batch consistency under IATF 16949 standards. PPAP documentation includes material certifications, flammability test reports, and traceability records. ASTM D2000 and ISO 3601 compliance guarantees material performance and dimensional accuracy.

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