Cone calorimeter sample holder

The cone calorimeter is also used to quantify the corrosivity of products of combustion as described in ASTM D 5485. The Cone Corrosimeter uses the same load cell, specimen holder, retainer frame, spark igniter, conical heater, and exhaust system as the cone calorimeter. A heated stainless steel sampling tube is connected to a funnel placed on top of the conical heater. A gas sample is continuously drawn from the tube at a rate of 4.5 L/min. The sampling tube is connected with silicone rubber tubing to the pump via an 11.2L exposure chamber, a filter, and a flow meter. A target is placed in the exposure chamber at the start of the test and exposed to the corrosive atmosphere of the gas sample for 60 min or until the specimen has lost 70% of its total mass loss, whichever occurs first. 

The PHRR in the cone calorimeter is strongly dependent on the test setup and the specimen, as well as the intrinsic fire properties of the materials. To obtain comparable results, it is essential for the specimen and sample holder to be used as defined in the standard. This is illustrated in Figure 15.7, where the cone calorimeter HRR curves are compared with results using a modified sample holder.80 81... 

FIGURE 15.7 HRR for HIPS (noncharring) and PP-g-MA/LS (char/residue-forming) if the standard or a modified sample holder is used in the cone calorimeter. In the modified setup the sample is placed at a conductive 1 cm thick Cu plate. 

FIGURE 15.19 Sample holders used to measure the temperature on the back of coated steel plates (a) and at different positions within polymer samples (b) during flaming combustion in a cone calorimeter. 

Prior to the tests, all the samples were dried in a vacuum oven at 80°C for at least 72 h to minimize the moisture effect and then transferred to a desiccator. Measurements were carried out on a cone calorimeter provided by the Dark Star Research Ltd., United Kingdom. To minimize the conduction heat losses to insulation and to provide well-defined boundary conditions for numerical analysis of these tests, a sample holder was constructed as reported in [14] with four layers (each layer is 3 mm thick) of Cotronic ceramic paper at the back of the sample and four layers at the sides. A schematic view of the sample holder is shown in Figure 19.12. Three external heat fluxes (40, 50, and 60kW/m2) were used with duplicated tests at each heat flux. 

A schematic view of the sample holder used in cone calorimeter tests. 

FIGURE 5.5 Heat release rate monitored in cone calorimeter experiments (irradiance = 50 kW/m ) (a) PP-g-MA, PP-g-MA measured with the modified sample holder and PP-g-MA/5 wt% E (b) Epoxy, Epoxy measured with the modified sample holder, and... 

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