Horizontal Burning Test


The horizontal burning method refers to a test method in which one end of a material sample is clamped horizontally, the free end is exposed to the flame of a specified gas, and the linear burning rate is measured to evaluate the combustion performance. Equipped with advanced equipment and professional material chemists, Alfa Chemistry can provide you with horizontal burning test services, including the samples you send to be tested or the samples of flame retardant materials developed in cooperation with us.


Test Content

Test range

The horizontal burn test is suitable for plastics, foams, films, textiles, coatings, rubber and other products.

Test standard

UL94 horizontal flammability test for classified materials HB

Test preprocessing

Two sets of three specimens with nominal dimensions of 125 mm x 13 mm and thickness not exceeding 13 mm.

Condition at 23±2 °C, 50±5% RH for at least 48h.

Test method

The 20mm flame is inclined at 45 degrees, and the flame is quickly removed by contacting the test material for 30 seconds or less than 30 seconds with a 1-inch length of combustion. Then, start timing from when it exceeds 25mm, and calculate the burning speed.

Horizontal Burning Test

HB flame rating

  • The burning distance is 75 mm, the sample thickness is 3.0~13 mm, and the burning speed is ≤ 40 mm/min;
  • The burning distance is 75 mm, the sample thickness is less than 3.0 mm, and the burning speed is ≤ 75 mm/min;
  • The flame stops before the 100 mm marking line;
  • The burning distance is 75 mm, the sample thickness is 3.0 mm ± 0.2 mm, and the burning speed is ≤ 40 mm/min, then when the minimum thickness is reduced to 1.5 mm, it should be automatically accepted as this level.

Why Choose Alfa Chemistry?

Experienced team of materials chemists

Leading flame retardant technology

Reliable quality and standards

Fast turnaround times and great prices

Comprehensive and systematic testing and analysis services

Research Information

In the analysis and research of flame retardant properties, the horizontal burning test is a commonly used one. Feng Yang et al. studied the effect of nanofiller types (nano-silica and attapulgite) on the flammability of nanocomposites through horizontal burning test and other methods. As shown in the figure below, nanofillers have a significant effect on the flammability of nanocomposites.

Horizontal Burning TestFlammability of PS PNCs [1]

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  1. Feng Yang, et al. (2011). "Combination effect of nanoparticles with flame retardants on the flammability of nanocomposites," Polymer Degradation and Stability 96(3), 270-276.
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