Physical Compression Test
In order to conduct the physical test, samples of 90 ppi foam of circular cross-sectional area (1" diameter and 1" depth) were used. First, a trial using four samples was conducted. The four pieces of foam were placed on a level table and even spaced underneath a plastic beaker such that all four pieces were entirely covered. Water was gradually added to the beaker until slight compression was noticeable. This minimum water volume was recorded. Water was then continuously added to the beaker again until full compression occurred. This maximum water volume was also recorded. Similar experiments following the same procedure were conducted once using two pieces of foam and three times using one piece of foam.
Note: It was important to record the maximum water volume as the point where the foam first reaches 100-percent compression.
Using the recorded volume of water and the specific density of water, the mass of the water can be calculated (using density = mass / volume). By including the mass of the cylinder itself, the total mass on top of the foam can be found. Using gravity, the total force pushing down on the foam samples can be determined (using force = mass x gravity). One can then easily find the total pressure on all foam pieces (using the equation total pressure = force / total cross sectional area). Consequently, the pressure one one foam piece can be calculated by dividing total pressure by the number of foam samples.
The subsequent calculations conducted for each trial determine both the minimum pressure required to trigger foam compression and maximum pressure to reach full compression. A full discussion of these calculations can be viewed in the Foam Compression (Physical) Test MathCAD file. Results from the five total experiments are discussed below.
Summary of Results
Ideally, the resulting min. and max. pressures for one piece of foam found from each of the trials should be the same.
Write small commentary on summary of results (ex: any discrepancies between values, how much error, why did error occur, etc.).
