Update README.md

README.md

@@ -4,11 +4,16 @@ design and prototyping of a FabLab-able polypropylene melt blowing setup for dis
 
 ## literature
 dimensional analysis of process and discussion of nozzle types (1988): https://pubs.acs.org/doi/pdf/10.1021/ie00084a021
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 Exxon patent showing slot-style melt blowing nozzle: https://patents.google.com/patent/US3849241A/en?oq=3%2c849%2c241
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 UTenn study on melt blowing: https://onlinelibrary.wiley.com/doi/epdf/10.1002/pen.760302202
 
 ## melt blowing videos
 video of a polypropylene filter melt blowing line in action: https://www.youtube.com/watch?v=cGQ4piMNQ_E
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 fast construction of a melt blowing line for covid-19 masks: https://www.youtube.com/watch?v=p9lchhBE7cE
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 a smaller line with a built-in rotary mask die cutter: https://www.youtube.com/watch?v=KgWHNQo7j1k
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 pilot-scale melt blowing machine making a mess: https://www.youtube.com/watch?v=SOFfpGnMjOc