ASTM F955:2021

• A sample of material is mounted on a vertical inclined plane and exposed to a pour of molten substance of prescribed minimum temperature, volume, pour rate, and vertical height.
• The amount of heat energy transmitted through the test specimen during and after exposure to the molten substance is measured using two copper bar calorimeters. The heat transport response is assessed against the Stoll curve, an approximate human tissue tolerance predictive model that projects the occurrence of a second degree skin burn injury manifested by a blister.
• A specific set of subjective assessments of the response of the test specimen to exposure to the molten substance is made using a standardized rating scale for assessment.

• Lot Size: For acceptance sampling purposes, a lot is defined as 5,000 yd [4572 m] or a single shipment of a single style of material, whichever is smaller. A batch shall be permitted to constitute all or part of a single customer order.
• Lot Sample: As a lot sample, take a 2.2 yd [2 m] full-width piece of material from both the beginning and end of the lot.
• Test Specimens: Cut and identify three test specimens from each sample. Make each test specimen at least 12 ± 1⁄16 x 18 ± 1⁄16 in. [305 ± 2 mm x 460 ± 2 mm]. Do not cut the samples less than 10% of the width of the material from the edge and place the samples along the length of the sample to obtain the most representative sample possible.

Sensor care:

• Initial Temperature: Cool the sensor after a pour-over exposure with an air blast to approximately 70°F [21°C] just prior to placing the test sample.
• Surface Reconditioning: Clean the face of the sensor with a non-abrasive material immediately after each run, while hot, to remove any decomposition products that condense as they could be a source of error. If there is a deposit on the sensor surface that appears to be thicker than a coat of paint, or is uneven, the sensor surface requires reconditioning.

TABLE 1 Test parameters

NOTE 1: When this test method is used for substances other than the following, use a pouring temperature equal to or sufficiently above the melting point to give reproducible pouring characteristics.

• Sensor response: The response of each calorimeter is determined shortly before, during, and for 45 s after a pour has started.
• Once the initiation point of the pour is determined, the temperature data collected from the calorimeters before and up to the initiation point is averaged to obtain an initial calorimeter temperature, Tinitial (°C), for each respective sensor.
• The heat capacity of each copper ingot at the initial temperature is calculated using:

Display two cylinders for each sample tested.

t = (measured temperature °C + 273.15) ⁄ 1000
A = 4.237312
B = 6.715751
C = –7.46962
D = 3.339491
E = 0.016398

The heat capacity of copper in J/g°C at any temperature between 289 K and 1358 K is determined by Eq. 1 (Shomate Equation with NIST coefficients).

The total incident energy versus time for both thermal energy sensors in the panel is determined and plotted.

The heat capacity of the copper block is determined at each time step. This is done by calculating an average heat capacity for each sensor from the initial, determined heat capacity and the measured temperature of the time step.

The total incident energy at each time step is determined in J/cm2 using the relationship

Predicted Determination of Second Degree Skin Burn Injury (Stoll Curve Comparison): Measured thermal energy as a function of time for each copper bar calorimeter monitor sensor, compared to an empirically predicted second degree skin burn in humans. lesion model,3 commonly known as the “Stoll Curve” or “Stoll Response”.

• The sequence of layers as they would be used starting with the outermost layer, the type of material in each layer, the areal density in g/m2 [oz/yd2] of each layer of material, the color of each layer of material , the preconditioning in terms of washing, dry cleaning, or ambient conditioning, or combinations thereof, for each specimen prior to testing.
• The time it would take, under test conditions, to produce a second degree burn according to the Stoll curve of heat transferred through the test material. (No blister is a possible value.) All calorimeter values ​​will be used throughout the 45 s acquisition period (worst-case interpretation).
• The temperature rise in degrees Celsius during the 30 s exposure.
• Physical damage to the test material.
• Adhesion, flames, etc., observed during the test.
• Visual response of the material substance to contact with the molten substance: After the exposed sample has cooled, carefully remove it from the sensor plate and observe the effect of the exposure.
• Breakage, charring, dripping, embrittlement, ignition, melting, shrinkage, and adhesions of the substance to the test material, such as the number of adhesions, the size of the adhesions, and the location in relation to the sensor disk. Adhesion, char, shrinkage and breakage will be rated on a scale of 1 to 5, as shown in Annex A1

Photographs to classify materials after molten splash test in accordance with test method F955.

NOTE A1.1—Testing with various cast metal alloys can change the appearance of the test specimens, so the following photos are not representative. The photographs in Annex A1 were taken from tests carried out using cast iron.

A1.1.1 Pasting of qualification photos (Fig. A1.1):
A1.1.2 Classification of photos for carbonization (Fig. A1.2):
A1.1.2.1 Charring Level 1 does not represent evidence of charring.
A1.1.3 Shrinkage Rating Photos (Fig. A1.3): A1.1.4 Tearoff Rating Photos (Fig. A1.4): Adhesion Ratings Photos: