Flammability Of Automotive Materials Fire Testing Equipment FMVSS 302

Introduction:

FMVSS 302 is a test specification for the flammability of automotive interior materials in the U.S. Federal Motor Vehicle Safety Standards. It is designed to evaluate the combustion characteristics of vehicle interior materials when exposed to flames to reduce the risk of vehicle fires and slow the spread of fire. This standard was developed by the National Highway Traffic Safety Administration (NHTSA) of the United States and is applicable to non-metallic interior materials such as seats, ceilings, carpets, door panels, etc. of motor vehicles such as passenger cars, trucks, and buses. The following will be a detailed analysis of the standard background, test principles, equipment requirements, sample preparation, test steps, result determination, and practical applications.

Automotive materials flammability testing equipment is suitable for the combustion performance test of automobile interior materials, and complies with GB 8410, ISO 3795, FMV SS302, and other foreign standards.

Standards:

• ISO 3795,FMVSS 302,95/28/EC, etc

Test principle and parameters:

The test adopts the horizontal combustion method, using a Bunsen burner to generate a constant flame (height 38mm) to ignite a horizontally fixed sample, and measure the relationship between the flame spread distance and time. Key parameters include:
1. Flame application time: 15 seconds standard burning time
2. Burning rate calculation: calculated based on the time difference between the flame front passing the 100mm and 200mm marks
3. Self-extinguishing characteristic evaluation: record the continuous burning time after the flame leaves the sample

Main Feature:

1. The combustion test box is made of all stainless steel with a wall thickness of 2mm, which is not easy to deform after burning.
2. There are 10 19mm ventilation holes at the bottom of the box, and there are 13mm wide ventilation slots around.
3. Bunsen burner, the inner diameter of the nozzle is 9.5mm, and the flame height can be adjusted to 38mm;
4. The box is equipped with a tempered glass transparent observation window, which is convenient for testers to observe.
5. The bottom of the box is equipped with a collection plate for collecting molten drips;
6. The U-shaped stainless steel sample clamp can be inserted from the right side of the box.
7. After the U-shaped stainless steel sample clamp is inserted, the instrument can automatically time.
8. The burning flame can be automatically cut off 15s after the test starts;
9. Needle valves and ball valves are provided to adjust and cut off the gas;

Result determination and grading standards:

1. Qualified determination:
- Average burning rate ≤102mm/min
- Any sample can be directly judged as qualified when the burning distance does not exceed 51mm (2 inches)

2. Grading extension (some manufacturers adopt higher standards):
- Grade A: Burning rate ≤50mm/min (aviation material standard)
- Grade B: 51-100mm/min (mainstream automobile qualified line)
- Grade C: >102mm/min (unqualified material)