26th May - Banana Waste Utilization

We went to the farm and cut down some banana stems for us to experiment on. We then went to the NIF fablab and tried to see what were the various tools that could be used to separate the fibres of the banana plant. We first tried to see what the effect of squeezing the banana stem pieces through rollers would be. We noticed that a large percentage of the sap of the banana squeezed out and that sometimes, though not always, the two layers of the stems separated. We figured that this may make removing of the banana fibres easier

Th cross-section of a banana pseudo-stem, with the concentric layers of each sheath visible

We also tried using a brush made of metal bristles (used to clean up metal welds) While it felt like the fibres that were made were of good quality and very fine, however, we noticed that a large number of fibres were breaking and getting caught up in the bristles. This was making a huge mess, and also reduced the efficacy of the brush once it got too full of knotted fibres and scutcher(this is the waste removed during fibre extraction).

We also used a serrated band saw. We noticed that a large number of repeated, uni-directional combing actions was necessary. Thus we thought that we might be able to make a rotary blade that could be used to replicate this repeated uni-directional action.

Meanwhile the group members researched extensively on the existing mechanical fibres extractor machines. A lot of videos were watched in order to understand the exact process through which fibre and scrutcher was separated.

We also discussed the possibilities of making an automated machine, one that would just require feeding of banana stems and no other manual intervention. However. this seemed to be a difficult task to accomplish within a limited budget.