Post-spinning

In most cases the consistency of the polymer film at the end of spinning ranges from a highly viscous liquid to a wet solid. The as-deposited film is therefore usually treated by post-spinning bake at a higher temperature or in vacuum to remove any remaining solvent in order to produce a dry solid film. Two film thicknesses are therefore to be distinguished. The as-deposited wet film thickness h or H(H = where hg is some initial thickness,... 

Solution Modifications Spinning Modifications Post-Spinning Modifications... 

Table 1 Comparison of synthetic and biopolymer solvent compatibilities and post-spinning crosslinkers investigated to date... 

One of the well-known posts spinning treatment for PAN fiber precursor is modification through coatings. The PAN fibers are coated with oxidation resistant resins such as lubricant (finishing oil), antistatic agents, and emulsifiers which are basically used as spin finish on the precursor... 

Spinning of yams (from godown to post-spinning operations)... 

Potentially, at least, the mechanical properties of these fibres can be varied over a wide range, simply by varying the post-spinning heat treatment to which they are subjected. Unfortunately the increases in fibre initial moduli and tenacities brought about by heat treatment are normally accompanied by reduction in the extensibilities, as shown in Tables 2 and... 

The properties of artifidally spun silk fibers are extremely dependent on processing conditions. Most work to create fibers from silk utilizes a wet spinning process, whereby the concentrated silk dope is extruded through an orifice on the order of 100 pm in diameter into a coagulation bath. A subsequent post-spin draw is performed, whereby the fiber is constrained in a stretched state and allowed to dry or further coagulate. 

Mittal J, Maihur RB, Bahl OP (1997) Post spinning modification of PAN fibres - a review. Carbon 35 1713-1721... 

Yusof N, Ismail AF (2012) Post spinning and pyrolysis processes of polyacrylonitrile (PAN)-based carbon fiber and activated carbon fiber a review. J Anal Appl Pyrol 93 1-13... 

Fig. 2(a) represents the XRD profiles for samples PCa5P3 subjected to the post-spinning treatments. Here, those post treatments were subjected in the order that each sub-code appeared e.g., for AGS, A— G— S. Sample with sub-code AG gave the Ca-P diffractions as that with A80-xh (x 1, 2, 24) in Fig. 1. It foUows that the cross-Unk by glutaraldehyde should...

PAN-based carbon fiber and activated carbon fiber is not an easy task, since it involves many steps that must be carefully controlled and optimized. Such steps are the dope formulation, spinning and post spinning processes as well as the pyrolysis process. At the same time, there are several factors that need to be considered in order to ensure the success of each step. However, among all steps, the pyrolysis process is the most... 

Various methods are used to improve the membrane properties. One major factor is the relationship between membrane thickness and permeation properties. Figure 4 shows the relationship for cuprammonium rayon hollow fiber which has been subjected to various post-spinning treatments. Cuprammonium rayon hollow fibers can now be produced to meet a broad range of property requirements, by modification of the hollow fiber dimensions and post-spinning treatment. Figure 5 shows that the ultrafiltration ratio and the mass transfer coefficient are virtually independent. 

Another approach is to make ultra-fine (submicron diameter) filaments by the island-in-the-sea technique, where the sacrificial matrix (sea) polymer is removed in a subsequent post-spinning process. Thus, by using bicomponent spinning technology, the material strength profile, resorption profile, and the biological properties can be engineered into the fiber to meet specific medical requirements. 

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