Edwin Lui, Patrick Huynh
David Thompson Secondary
Floor Location : M 081 R
Plastic is being generated faster than ever and is harmful to the environment; it can take over a century to degrade. Although it can be recycled, the process creates harmful greenhouse gasses. To create a biodegradable plastic substitute, carnauba wax and beeswax were tested. In this project, the materials, carnauba wax, beeswax, and a mix of the two were compared with HDPE obtained from a milk jug. A tensile strength and impact test were used to observe the strengths of the materials
For the tensile strength test, three types of materials were molded into three thicknesses, 1 mm, 2 mm, and 3 mm. The tensile strength is a type of mechanical testing which applies controlled tension to a subject before it fails. A machine was built to complete the tensile strength tests. Those tests were conducted by mounting a sample onto two wooden blocks attached to the machine. After the wooden blocks were tightened, the winch would be pulled while a digital hanging scale recorded the amount of force (in kg). The beeswax survived the most tension, the carnauba wax surviving much less tension, and the hybrid surviving the least.
The fragility test set up required the materials to be moulded into a square. The hammer was dropped from a controlled distance to ensure consistency among the trials, and the number of hits before the sample broke would be recorded. The 3 mm thickness beeswax samples did the best, suggesting a correlation between the tensile strength and the impact test results. The hybrid samples did second-best, while carnauba came in last.
HDPE was also put through the tensile strength and impact tests as it was the control variable, then compared with the other materials. It was found that beeswax survived the best under the tensile strength test, with carnauba wax coming in second; however, the hybrid samples did not do as well as the others. The experiment showed that although carnauba, beeswax, and the hybrid samples had great benefits like being biodegradable, HDPE was still stronger and less fragile. The waxes tested in the experiments are not a good substitute for HDPE. The limited carrying capacity due to the inferior tensile strength and thickness required to compensate for it, along with the frequent critical failures caused by the fragility of the waxes far outweigh any benefit that biodegradability grants.