Post-drawing

In the preceding section it has been shown that it is unlikely that a post-drawing step improves the fibre strength. However, in the case of rigid-rod polymer... 

Experimentally, a 0.3. The value of K is a measure of inherent fiber strength and will depend on the molecular weight of the polymer. This parameter will also increase if post-draw heatsetting is used to crystallize the oriented structure. 

Zong, X., Ran, S., Fang, D. et al. (2003) Control of structure, morphology and property in electro-spun poly(glycolide-co-lactide) non-woven membranes via post-draw treatments. Polymer, 44, 4959-4967. 

PEN mnltifilament fibers are commercially available from several polyester fiber prodncers. These include Teijin in Japan, Honeywell (formally AlliedSignal) in the United States and Enrope, Kosa in Europe, and Hyosimg in Korea. PEN fibers are produced in a melt spinning/post-drawing process similar to that used in PET fiber manufacture. All production to date is in the form of continuous multifilament yarn, although staple and monofilament fabrication have also been reported. 

One effective approach to stabilize the fiber stmcture and properties is to apply a heat treatment process after drawing. This post-drawing process often is called heat setting . The pmpose of the heat treatment is to ... 

Sun W, Cai Q, Li P, Deng X, Wei Y, Xu M, Yang X (2010) Post-draw PAN-PMMA nanofiber reinforced and toughened bis-GMA dental restorative composite. Dent Mater 26 873-880... 

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