This week I experimented with bending PVC pipe that had been filled with sand to prevent the pipe collapsing under heat.
Also after consulting with my lecturer I changed the grade of pipe I was bending, up from 20 mm to 35 mm. Thicker pipe being stronger and capable of holding more sand, meaning sand shifting while bending becomes less of an issue.
My first test bend resulted in a terrible form, full of large folds and creases. three major factures in combination we responsible for this; one; point heat, applying pressure to quickly, and sand shifting
with only small surface area’s heated and malleable at a time there was only a very limited amount of plastic capable of moving, this coupled with the high level or force lead to sharp folds instead of gentle bends, this coupled with shifting internal sand resulted in a terrible bend full of structural weaknesses
The second two bends came out much better. While still full of creases the indentations are smaller and more even along the length of the pipe. The sand was packed in tighter on this pipe meaning there was less internal shifting and the pressure was applied much slower.
Forth bend; this was the best bend out of this set, heat was applied evenly over a much larger space continually through the bending process, and I did my best to keep the area under a constant even level of pressure.
First Bend
Second bend
Third Bend
Forth bend
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