What I have learned so far is that Lycra is strong polyurethane fiber segments joined with stretchy (soft) polyester or polyether fiber segments. The amounts of each varies with the blend. The polyurethane provides the mechanical body to the fiber while the other stuff provides the elasticity. The elasticity is constant in the range from 50F to 113F which is why it works well for clothing. Beyond 113F up to about 356F (depending on the blend) it contracts to 15% of what it was at 113F. Somewhere near 374F the polyester/polyether parts turns plastic and melt. The fiber breaks at that point. There is nothing to connect the polyurethane fibers to each other. Incidentally, the solvent dimethyl acetamide is used to make the stuff and some remains in the fiber after manufacture. It is the buyer's responsibility (the mill I guess) to keep the product ventilated enough while the residual solvent concentration is still at hazardous levels.
One might say the kites would tighten up as they are in the shrinkage temperature range assuming that they are not being cooled by sprinkler spray faster than what is heating them up and they would rip apart at that 374F temperature range. Based on that assumption, would increasing the design area by 30%, as in delayed water-to-fire situations and also increasing the application rate to OH1 be a logical fire protection approach to this situation to bring to the Fire Marshall? Thanks again for your comments, Allan Seidel St. Louis, MO _______________________________________________ Sprinklerforum mailing list http://lists.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
