Application
The Surface Flash Tester is designed to test the rapid spread of flame over the surface of materials without igniting their base structure. It is primarily used for pile or fur fabrics to determine if surface flash occurs. The tester features a swiveling butane burner that moves across the fabric’s surface to assess any surface ignition and record damage to the base fabric. The device operates with an automatic gas and timing control system, including a solenoid-controlled gas valve, automatic ignition timer, and controls.
Testing Method
Test Principle
The test is conducted by holding a fabric sample vertically in a draft-free enclosure. A flame is moved across the surface of the pile at a known speed to determine if the flame flashes over the surface of the pile without igniting the base fabric. The movement of the flame is critical in assessing the fabric’s surface flash behavior.
Sample Preparation
- Cutting Samples:
- Cut two samples according to the specified dimensions with the long edges parallel to the longitudinal direction of the fabric.
- Mark the Needle Position:
- Mark the fabric at the location of the needle before cutting the sample.
- Shake the Fabric:
- Shake the fabric to ensure that all loose fabric fibers or isolation coils are removed.
- Sample Conditioning:
- Condition the sample in a box at a temperature of 23 ± 2°C and a relative humidity of 50 ± 2% for at least 24 hours before testing.
Test Procedure
- Sample Fixing:
- Place the fabric sample on the needle frame and position the cover plate on the edge of the fabric. Ensure the sample is taut and without any tensile stress. Secure the cover plate with a clamp.
- Flame Adjustment:
- Adjust the flame height of the burner to 50 mm using the high flame gauge. Ensure that the distance between the needle frame and the burner is set so that the sample surface is 5 mm from the burner port when the burner is in motion. The end cover of the combustion tube should only touch the fabric’s pile surface.
- Setting Up Tripping Wires:
- Attach three tripping wires across the sample at 150 mm, 300 mm, and 600 mm from the combustion tube. Ensure the wires are placed horizontally by using the grooves in the cover plate.
- Burner Movement and Test:
- Place the burner in the horizontal position. Move the burner from 50 mm beyond one side of the sample to 50 mm beyond the other side in 2 ± 0.2 seconds at a constant speed. Observe and record the test results, noting if surface flash occurs.
Test Considerations
- The tripping wires are fragile and should not be stretched. Use two lines for the microswitch and clamp to avoid breakage.
- Begin the test when the burner is in the horizontal position and press the timer button simultaneously.
- For the second sample, reverse the direction of the fabric’s villi and repeat the test procedure.
