Fiber migration

Bag An extended surface filter in the form of a pocket or bag. A typical example of a bag filter is a mineral fiber bag made up of three layers, in which the first layer acts as a prefilter, the second is for fine filtration, and the third prevents fiber migration from the material used. 

The amorphous orientation is considered a very important parameter of the microstructure of the fiber. It has a quantitative and qualitative effect on the fiber de-formability when mechanical forces are involved. It significantly influences the fatigue strength and sorptive properties (water, dyes), as well as transport phenomena inside the fiber (migration of electric charge carriers, diffusion of liquid). The importance of the amorphous phase makes its quantification essential. Indirect and direct methods currently are used for the quantitative assessment of the amorphous phase. 

The leveling capacity of dyes is an important characteristic that can be determined empirically. Unevenness results if dye adsorption occurs too quickly, and can frequently be traced to mistakes made in the addition of dye or salt. The leveling of uneven dye distribution proceeds via desorption of the dye and readsorption on the fiber (migration). 

To simulate the fiber migration numerically, one can use the diffusive flux model proposed by Philhps et al. (1992), which is given by... 

Once the relative velocity u) is known, we can obtain the fiber migration velocity (Wfiber) because the resin velocity ( resin) is computed from the mold filling analysis. Then, we can obtain the distribution of fiber volume fraction by solving the conservation equation of fiber content. 

Flexibility Polymer percentage Carrier type and percentage Twister speed Fiber migration Twist influences the fiber migration and the ability of the sheath to restrict the mobility of the yarn. 

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