UL94 horizontal and vertical combustion tester introduction

The horizontal and vertical combustion tester UL94 is mainly used to determine the combustion performance of plastics, rubber or thin films at specified fire sources to determine their fire resistance rating. Not only applicable to the lighting equipment, low-voltage electrical appliances, household appliances, electrical, tools, instruments and other equipment, and electrical and electronic plastic or rubber products such as electrical connectors and their component parts in the research, production and quality inspection departments, can also be applied to insulation materials, engineering plastics, fireproof plugging material type approval or other solid combustible materials industry.

Test standard

The horizontal and vertical combustion tester meets the following test criteria, as well as other test methods and organizations.

UL94, ISO 1210, GB/ t2408-2008 / iec60695-11-10:19, GB/T 5169.16-2008/IEC 60695-11-10: 2003/ASTM D635, GB/T 8332-2008/ISO 9772-2001/ASTM D4986, ASTM D4804 /ISO 9773,GB/T 5169.17-2008/IEC 60695-11-20 :2003/ASTM D 5048

The calibration

Calibration objectives and requirements

The calibration of test flame is the most basic guarantee to ensure the reliability of the test. The test requires a 50w flame height of 20±1mm, a 500w flame with an external yellow flame height of 125mm and an internal blue flame height of 40mm. Using the flame to heat the copper block, the required time for the warm copper block to rise from 100 degrees to 700 degrees is 44±2s in the 50W test flame and 54±2s in the 500W test flame

Calibration method

Flame gauges are generally used to calibrate the copper blocks accurately using flame heating.

Calibration pass decision

Flame calibration heating time requires the time needed for temperature measurement of copper block to rise from 100 ° c to 700 ° c. The 50W flame is 44±2s, and the 500W flame is 54±2s

1. The test

50w horizontal combustion test

1) enter the 50w horizontal combustion test operation interface from the touch screen

2) at 25mm and 100mm at one end of the sample, draw two lines perpendicular to the long axis, and at the other end marked by 25mm, make the sample parallel to the vertical axis, and hold the sample at a 45-degree tilt to the horizontal axis, and adjust the relative position of the Bunsen lamp and the sample

3) rotate the pressure gauge. The pressure gauge is only used as a switch, and generally does not display readings, so that the flow meter can display suitable gas flow rate, and then fine tune the meter

4) press the ignition button on the instrument panel to ignite the Bunsen burner

5) adjust the gas flow, and adjust the knurled nut at the lower end of the Bunsen lamp, so that when the lamp tube is in the vertical position, it will produce a 20mm high blue flame. Tilt the Bunsen burner 45 degrees.

6) push the Bunsen lamp push bar, push the Bunsen lamp to the designated position, start the countdown of flame time

7) when the flame time is over, pull back the Bunsen burner. After the flame is stopped, if the sample continues to burn (including flame burning or no flame burning), use the panel button key to record the burning time t(per second) from the combustion front to the termination of combustion, and record the burning loss length L (per millimeter) from the 25 mm mark to the termination of combustion.

Note: if the combustion front crosses the 100m mark, the time t required for combustion between the 25mm mark and the 100mm mark shall be recorded. At this time, the burning loss length shall be 75mm.

If the flame is extinguished or the combustion front does not reach 25m mark after the ignition source is removed, the combustion time, burning loss length and linear combustion speed are excluded.

Input the actual combustion length, and the system calculates the combustion speed according to the following formula

Where: V -- linear combustion speed, (mm/min), L -- burning loss length (mm), t -- time spent on burning loss L length (S).

50W vertical combustion test

1) enter the 50w vertical combustion test operation interface from the touch screen

2) fix the sample vertically so that the bottom end of the sample and the top end maintain a height of 10mm. Calibrate the position of Bunsen lamp and sample with standard scale, and ensure the distance of 10mm

3) pull back the Bunsen lamp, light the Bunsen lamp and adjust it to produce a blue flame of 20mm±2mm high.

4) push the Bunsen lamp push bar, move the Bunsen lamp to the lower end of the style, and apply flame to the style. When the flame firing time is over (10s), pull back the Bunsen lamp. At this time, manually start and press the timer to record the burning afterflame time t1.

5) after the residual flame (even if the Bunsen burner is not leave), position the Bunsen burner back to the sample, the sample on fire, when ShiYan (10 s) after the end of time, back to the Bunsen burner, the manual open press the timer, record residual flame burning time of the second residual flame burning time t2, after the residual flame, press the timer again, the record for the second time after time t3.

Note: in the process of styling, if there is any phenomenon of dropping substance igniting the absorbent cotton, the test of this sample shall be finished manually. If the flame spreads to the fixture during the flame firing time, the test of this sample shall be finished manually.

500W vertical combustion test

1) enter the 500w vertical combustion test operation interface from the touch screen

2) fix the sample and adjust the position of Bunsen burner and sample

3) then back and forth Bunsen lamp, press the ignition button, adjust the internal flame height of the flame 40mm, 125mm, adjust the Bunsen lamp Angle

4) push the Bunsen lamp push bar, move the Bunsen lamp to the designated position, apply flame to the style, when the flame time is finished (5S), pull back the Bunsen lamp, wait for 5S, push back the Bunsen lamp again, flame 5S, repeat 5 times.

5) press the timing button to record the afterflame time and afterglow time after the fifth flame.

Film material vertical combustion test

1) enter the operation interface of vertical combustion test of thin film material from the touch screen

2) fix the sample vertically so that the bottom end of the sample and the top end maintain a height of 10mm. Calibrate the position of Bunsen lamp and sample with standard scale, and ensure the distance of 10mm

3) pull back the Bunsen lamp, light the Bunsen lamp and adjust it to produce a blue flame of 20mm±2mm high.

4) push the Bunsen lamp push bar, move the Bunsen lamp to the lower end of the style, apply the flame to the style, when the flame time is finished (3S), pull back the Bunsen lamp, at this time, manually start and press the timer to record the burning afterflame time t1.

5) after the residual flame (even if the Bunsen burner is not leave), position the Bunsen burner back to the sample, the sample on fire, when ShiYan (3 s) after the end of time, back to the Bunsen burner, the manual open press the timer, record residual flame burning time of the second residual flame burning time t2, after the residual flame, press the timer again, the record for the second time after time t3.

Horizontal combustion test of foam materials

1) enter the horizontal combustion test operation interface of foam materials from the touch screen

2) at one end of the sample, 25mm, 60mm and 100mm, mark the line perpendicular to the long axis and put it on the trawl. The position of the Bunsen lamp is adjusted relative to the sample

3) press the ignition button on the instrument panel to ignite the Bunsen burner, adjust the gas flow, and adjust the knurled nut at the lower end of the Bunsen burner to adjust the Bunsen burner flame. (the burner airfoil is used for this experiment)

4) push the Bunsen lamp push bar, push the Bunsen lamp to the designated position, countdown the flame time, remove the Bunsen lamp after 60s.

A) timer yi at the time of contact

B) the second timer is timed when the afterglow reaches 25 mm mark

C) when the afterflame and afterglow reach the 60mm mark, or when the sample stops burning or glowing before the 60mm mark, the yi timer stops timing

D) after the afterflame and afterglow reaches the 125 mm mark, or when the sample stops burning or glowing before the 125 mm mark, the second timer will be used to measure the time