Composite Devices

Using Jute and the resin to make a Urinal

Composite materials
Creating a mixture of materials using an adhesive to bond them together

The Why of my assignment

India has a massive open defication issue, with the Swachh Bharat Scheme looking to put toilets into homes of all its citizens. Reap Benefit is getting youth to solve local civic and environment issues, and sanitation is one. After using PET bottles and metal funnels as waterless urinals, I am experimenting if we can cast an urinal out of Jute. Jute is a commonly available materail all across India as rice, our staple diet is still sold in Jute bags. If this fails, I will make a laptop stand from the same material. I estimate that due to the shape and size of the urinal, and due to the roughness of the jute bag used (I'm mimicing the quality of bags available), it might fail.


Moulding process


Using clingwrap to ensure the cast slips off the Mould


Clingwrapped Urinal


Mixing the resin


An art shot for fun - notice the thikness of the hardner


Resin and Hardner as layers


Ming the resin took 2 minutes. The colour changed, and the resin heated up


Applying the resin before I put on Jute.


The challenge was to get an even coat due to poor clingwrapping and the angle of placing the urinal while working


The space between weaves of the jute bag


Jute took time and absorbed the resin, and I had to put in multiple layers to get what I felt was a good finish


The look post application of the resin

This effort ended in a fail, as the gap between the jute fibres created a similar gap between the resin.

Mistakes and Learning

  • Jute bag quality I used is inappropriate for composite work. It was oily, thick, unwieldy, and had large gaps. When stuck to the urinal using the resin, it slowly peeled off in places.
  • Layers and Resin work I should have started with a finer quality of jute and layered up to the locally available quality. I also should have put in more resin. This will be corrected in the next attempt.

Round #2, with a parametric laptop stand

I took my friend, Chandni Chabra's paramteric laptop stand and decided that I'd try making a jute based composite form on it to elevate my laptop and act as a stand. Thank you Chandni! The learning last time was finer jute first, and then more resin. This has been corrected this attempt.

How it was done

  1. I collected all the material - mould, 2 qualities of jute, resin, clingwrap, gloves, toungue depresser, vaccum bags.
  2. I tested if the mould would go into the vaccum bag, which it did.
  3. I covered the mould in clingwrap, taking care to loosen the material enough to ensure that the form was preserved.
  4. Aiming to have 1:1 ratio of the Resin and Hardner, I poured in 200gms of Resin.
  5. Next in was 200 gms of Resin.
  6. As usual, the layers of Resin and Hardner is beautiful.
  7. Putting the mould on a flat stone outside, I put the finest jute first and ensured I put enough Epoxy for it to be absorbed and change colour.
  8. Next up was the rougher quality of the jute, again coated with enough resin to hold it, but not so much that the drying would slow down.
  9. On top was the last and final layer of fine jute, as I fell in love with the colour. .
  10. I inserted the mould into the vaccum bag, which it did.
  11. I opened the vaccum lid, and using a vaccum cleaner, sucked the air out of it.

The Outcome

As it looked when I took it out of the Vaccum bag
The contours as compared when looked at from the bottom
The contours as compared when looked at from the top

Learnings

  • Put a few drops of Resin evenly on the cling wrap, so that the jute on it holds form well
  • When sucking air out of the bag, make sure that you hold the bag in such a way that the air is sucked out of the farthest corner first, else the vaccum will suck air out in the area closest to the opening first and allow air to stay trapped inside the bag
  • The white clip used to seal the zip-lock of the bag is the most important component of the bag. Do not loose it!

Conclusion

Firstly, composites are an interesting area I never explored earlier. I am now thinking that this is a great way to embed wires and seal them, electrically and from water. This is a task to be done. Thank you Chandni for the mould, Arpi Maheshwari and Rakshita Modi for the help with the clling wrap and photography. Thank you Viraj for ebing my running partner in the exercise.