PCM Testing Update

Toward the end of July, Saad and I took an afternoon to try out some improvements to our PCM encapsulation process. Specifically, we wanted to try a simple method for securing the empty PCM packet in place while pouring in the paraffin, which we melted in an aluminum can "crucible" of sorts using a hot water kettle as a double boiler.

Here's an informal video overview of the process:

Materials

Electric hot water kettle, paraffin wax, empty PCM packets, 1/2" bore steel 'flask-filling' funnel, small spring-loaded clamps, cardboard box, pop/soda can, sharp scissors, long-stem digital thermometer, heating pad, handheld heat sealer, tabletop heat sealer, electrical access, water access

Process

1. Place a few cm of water in a typical electric hot water kettle.
2. Cut the soda can open at the top and squeeze one of the edges to make a little spout.
3. Place a few hundred grams of paraffin wax in the aluminum can.
4. Place the can in the kettle along with the thermometer, and turn the knob until you reach a water temperature of at least 65C (which is way above the 40C paraffin melting point but will speed up the filling process).
5. Wait until the paraffin is completely melted, perhaps 10 minutes. Meanwhile, cut off the top of the cardboard box and clamp the empty PCM packet to the sidewall, with the heating pad also clamped, behind it. The PCM packet should rest against the heating pad. Plug it in and turn it to a medium heat setting (say around 40C).
6. Place a heavy-ish object like a full 1L bottle of water in the box as a counterweight.
7. Insert the spout of the funnel into one of the PCM packet lanes and hold it in place.
8. Carefully pour paraffin up to the marked "fill line" on the PCM packet.
9. Repeat until all of the PCM packet lanes are full.
10. Wait until paraffin has solidified partially (so that it resists movement when squeezed) and use the handheld heat sealer to seal the top edge of the PCM packet.
11. Or, wait until paraffin has completely solidified and use tabletop heat sealer to seal the top edge of the PCM packet.

Some Conclusions

From this brief experiment we were able to extract a few salient points:

1. We need to design a rack that can hold multiple PCM packets at once so that filling, solidifying and sealing can be completed in parallel.
2. Alternately, we could design an easily replicable PCM packet filling rack for each packet.
3. Refrigeration would of course speed up the solidification step.
4. The heat pad may not be adding much here. Its intended purpose is to reduce premature freezing of the wax ("self sealing") that sometimes occurs during filling. It seems that this can be accomplished fairly well by increasing the molten wax temperature. However, the heating pad may in fact be useful in colder environments; this experiment was carried out in a room that with an ambient temperature of around 27C.

HeatSource Textiles on MAKE TV

Last Sunday, Saad and I were interviewed by the excellent folks at Make TV for a segment on the Lemelson-MIT Eurekafest! Look for our segment this August and watch us as we shout out "I'm an inventor!" ...earnestly.

HeatSource on TV in the Philipines

The HeatSource team was recently interviewed by a film crew from the Philipines last week as part of the coverage of the MIT IDEAS Competition. One of our team members kindly stepped into the limelight to represent us and demonstrate our first round of prototypes - thanks Celeste!

Non-Profit Entrepreneurship

Last week I met with Kay Paine, a manager of the Boston-based non-profit InnerCity Entrepreneurs (an affiliate of Root Cause) to discuss some of the possible ways we can structure HeatSource Textiles as it grows beyond the prototype phase. At the moment, the clearest way I can describe these options would be:

1. As a non-profit that directly manages its own business ventures (design, manufacturing, sales and distribution of socially-beneficial products in developing countries).
   
2. As a non-profit that establishes new semi-autonomous for-profit enterprises with local partners who manage part or even the entirety of the business ventures.
3. Some variation I haven't thought of (admittedly a wide range of possibilities)

Given Kay's experience with InnerCity Entrepreneurs, which focuses on developing MBA-type certificate programs for small business owners in urban areas, I believe that she will be able to bring some real sophistication to this discussion as we move ahead. Kay succinctly described a few aspects of the strategy that ICE employs: avoid growing bureaucracies, create services that can be offered by other non-profits (and for-profits).

One fascinating story from her past was the process of incubating one of the first online anti-smoking support networks, QuitNet, into a financially-self sustaining non-profit that has substantially impacted the health of its target user group over the last 15 years. The crucial shift came when the managers of the program discovered an appreciable demand for "premium" services that could be sold to organizations interested in the health of its employees and members. This allowed free services to continue to improve through a sort of trickle down (for lack of a better term) of features from from the for-pay services.

I look forward to our next conversation so that I can share more of her interesting thoughts and experiences.

HeatSource Textiles In China / Kitchen Chemistry

After a very busy (and ultimately triumphant!) push for the MIT IDEAS competition this spring, the HeatSource Textiles team finally took some time to celebrate by spending some quality time together (among other things, by watching the strangest BBC show on Youtube).

Ah, but how time flies! Last weekend we assembled a ton of encapsulated PCM packets in Celeste's kitchen, being careful to avoid accidentally pouring molten wax down the drain (which, it turns out, looks identical to water). It was great fun, what with the parents and quizzical roommates and the upscale pastries.

The purpose of our frantic rush was to prepare a batch of PCM and textile prototypes for Scot Frank, Catlin Powers and Amy Qian to take with them on their journey to western China this summer.  

So, thanks to the excellent efforts of all who participated, we're fortunate to have the materials and team-members in place to do some serious testing and product evaluation in China over the summer. It's all quite exciting. Check out Catlin's blog at Change.org for field updates. This blog will generally re-report field updates and record our teams' planning efforts in Boston.