Week 5

When we looked at the sample made during Week 4's lab we realized that it was flawed. It shrunk to about half its thickness and it had a lot of flashing. The samples also had a lot of bubbles that would affect the breaking point while testing it. These flaws would highly affect our tensile testing, so during Week 5's lab we spoke to Professor Speidel and Mr. Pagano about what changes we could make to our mold in order to get rid of the imperfections. Two more pieces of acrylic were laser cut. They are both the same size as our mold, but they don't have the shape of the sample cut into them. Once we made the new batch of plastic, we put one of the acrylic rectangles underneath the mold, poured the plastic in, put one of the negatives of the original mold (acrylic pieces in the shape of the sample) in each plastic sample and then put the other acrylic rectangle on top of everything. We pressed them together using duct-tape and heavy books. The whole setting is shown in the pictures below. In order to get rid of some of the bubbles formed, we put the mold on an ac unit that constantly vibrates for the first few minutes of the drying process.

Figure 5.a: Mold Arrangement

Figure 5.b: Mold Arrangement