Combustion properties test methods

In another test method (ASTM D-5515), a dilatometer is used to measure the swelling of bituminous coal. The test method is limited in applicability to coal that has a free swelling index < 1 (ASTM D-720). The principle of this test method is that the final volume of char obtained at the conclusion of a standard dilatation test is dependent on the mass of coal in the coal pencil and on the radius of the retort tube. This test method incorporates a procedure that determines the mass of air-dried coal in the coal pencil, provides a means to measure the average retort tube radii and employs a means to report coal expansion on an air-dried coal weight basis. The value of the dilatation properties of coals may be used to predict or explain the behavior of a coal or blends during carbonization or in other processes, such as gasification and combustion. 

Am. Soc. Testing Materials, Philadelphia, A STM Designation E 69-50, Standard Method of Test for Combustible Properties of Treated Wood by the Fire-Tube Apparatus. 

The thermal combustion properties measured in the test are related to the flammability characteristics of the material.5155 For example, the heat release temperature from method A approximates the surface temperature at ignition (Section 14.3.2.1). The net calorific value from method B approximates the net heat of combustion measured in an oxygen bomb calorimeter. 

A number of fire tests for polymeric materials have been developed, during the past several years, by the International Standards Organization (ISO). Hopefully, these tests will replace the present national test methods, which often correlate badly with each other. I he development at ISO is aimed at describing the fire properties of polymeric materials comprehensively, with test methods chosen so as to be applicable to all types of samples. At present, the ISO fire test methods are published as standards (ISO R 1182-79 for non-combustible materials, ISO R 1326-70 and ISO R 1210-70 for flame spread, etc.), or as draft for development (DP 5657, ISO/TC 92 N 531-79 as an ignitability test). One can only sympathize with using certain complex fire hazard indices for describing material behavior in fire... 

The second section is a somewhat detailed discussion of twenty-two (22) foam properties tested by standard test methods. In most cases only one or a few methods are listed and discussed, but, in the case of combustion properties a total of thirteen (13) methods are considered. This emphasis was made partly because of the considerable attention given to this important subject in recent years. 

Combustion properties of interest in cellular plastics and elastomers include ease of ignition (ignitibility), support of combustion (oxygen index), relative extent and time of burning, surface flammability, flame read, smoke evolution properties, and rate of beat release. The following test methods are either concerned solely with cellular plastics, m are used for both cellular and solid plastics. 

However, the smoke point is not always a reliable criterion of combustion performance and should be used in conjunction with other properties. Various alternative laboratory test methods have previously been specified such as the lamp burning test (ASTM D-187, IP 10) and a limit on the polynuclear aromatic content (ASTM D-1840), as well as the luminometer number (ASTM D-1740). 

An alternate method of calculation of the calorific value, when an experimental determination is not available or cannot be made conveniently, involves an estimate of this property (ASTM D-6446). In this test method, the net heat of combustion is calculated from the density and sulfur and hydrogen content, but this calculation is justifiable only when the fuel belongs to a well-defined class for which a relationship between these quantities has been derived from accurate experimental measurements on representative samples. Thus the hydrogen content (ASTM D-1018, ASTM D-1217, ASTM D-1298, ASTM D-3701, ASTM D-4052, ASTM D-4808, ASTM D-5291, IP 160, IP 365), density (ASTM D-129, ASTM D-1250, ASTM D-1266, ASTM D-2622, ASTM D-3120, IP 61, IP 107), and sulfur content (ASTM D-2622, ASTM D-3120, ASTM D-3246, ASTM D-4294, ASTM D-5453, ASTM D-5623, IP 336, IP 373) of the sample are determined by experimental test methods, and the net heat of combustion is calculated with the values obtained by these test methods based on reported correlations. 

Coal is a naturally occurring combustible material with varying composition and it is not surprising that the properties of coal vary considerably from coal type to coal type and even from sample to sample within a specific coal types. This can only be ascertained by application of a series of standard test methods (Zimmerman, 1979 Speight, 2005). 

Before discussing the fire-retardant properties of tin compounds, it is necessary to outline briefly some of the main laboratory test methods which are used to assess the combustion behaviour of materials. 

As a results of the rapid increase in the fire model there is a great demand for the fire property and specialized test methods. New test methods have been developed such as [36] cone calorimeter, heat release measurements, etc. With these methods, the following fire properties have been measured for PO critical heat flux, thermal response parameter surface radiation loss, heat of gasification, flame heat flux limit, yield of products, heat of combustion, corrosion index, flame extinction index, fire propagation index, etc. [37]. 

The lowest temperature at which a material will ignite and sustain combustion in the absence of a spark or flame. The properties of liquid can be tested by standardized methods (ASTM E659-78 (2005) Standard Test Method for Autoignition Temperature of Liquid Chemicals). The ignition temperature is the temperature in degrees Centigrade at which the substance shows spontaneous combustion when touching hot bodies. 

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