Polyester Technology
polyester-technology: Slides from presentation by Mr. Zainul Abideen, SDM (Product Development), Gatron Industries
Electrospinning
In the electrospinning process a high voltage is used to create an electrically charged jet of polymer solution or melt, which dries or solidifies to leave a polymer fiber. One electrode is placed into the spinning solution/melt and the other attached to a collector. Electric field is subjected to the end of a capillary tube that contains the polymer fluid held by its surface tension. This induces a charge on the surface of the liquid. Mutual charge repulsion causes a force directly opposite to the surface tension. As the intensity of the electric field is increased, the hemispherical surface of the fluid at the tip of the capillary tube elongates to form a conical shape known as the Taylor cone. With increasing field, a critical value is attained when the repulsive electrostatic force overcomes the surface tension and a charged jet of fluid is ejected from the tip of the Taylor cone. The discharged polymer solution jet undergoes a whipping process wherein the solvent evaporates, leaving behind a charged polymer fiber, which lays itself randomly on a grounded collecting metal screen. In the case of the melt the discharged jet solidifies when it travels in the air and is collected on the grounded metal screen. [http://www.che.vt.edu/Wilkes/electrospinning/electrspinning.html]
Note: To avoid confusion ignore the figure on electrospinning from the above source. Instead, here is a link to a better, and more easy to understand diagram.
Spider Silk
Here’s a link to the youtube video we saw and discussed in class showing the spinning of spider silk from the milk of genetically modified goats.
Ok so here they are. The last few remaining notes and handouts for this course.
I’m posting the material on proteinic fibres, synthetic fibres and fibres for technical textiles. Here are the slides we discussed in class along with the primary reference source to study from to understand the transitions that would otherwise look like jargon to those who weren’t there in class. (more…)
