Silk Cotton

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In the Shambu Prasad article on the Innovation trajectory of Spirulina Algal Technology (http://www.crispindia.org/docs/Shambu~s_EPW.pdf) he talks of an engineer at the Shri AMM Murugappa Chettiar Research Centre (MCRC) who was “asked to make paper from silk Cotton”. It was actually me. Well, me and Vailoor Vasanth (B-Tech, IITM, 1980) were asked to do this by Dr C V Seshadri.

There was a silk cotton tree (Ceiba Pentandra) in the MCRC campus that had just borne fruit. There was plenty of silk cotton to collect and work with. The cotton is generally used to stuff mattresses and pillows. Each fibre has a coat of wax which prevents moisture entering the fibre. So typically a pillow stuffed with the fibre will provide years of comfort. If you keep the pillow for a day out in the sun, it will drive out any other moisture accumulated in the pillow and become fluffy again.

Vasant and I trawled the library and read up on the industrial paper making process, the entry in “How stuff works” and also the properties of silk cotton from the Wealth of India.

At our first attempt we ignored the wax and found that despite our great efforts at cooking the fibre it was not making a satisfactory pulp. It just became a fluffy mass when left in the sun to dry. We tried washing with soap to remove the wax and got a slightly better result and finally decided to cook it with a strong solution of NaOH. This gave us a decent material which we ran through a household grinder (mixie). We then placed the pulp in a wire mesh and with a plastic sheet squeezed to drain out the water, removed the plastic sheet with the pulp attached and left in the sun to dry. After drying, when we peeled of the mat we could write on one side with our ball point pen. Success!! One of many Eureka moments at MCRC!

Later there were attempts to do the various steps with microbes to reduce the energy requirement. That is another story and not mine to tell but can be seen here http://www.amm-mcrc.org/programmes/ecotech/paper.html.