Fibrous general aspects

The effects of toxins are, generally, proportional to dosage. Well-controlled dosage, as in these cell systems, provides the best opportunity for relating carcinogenicity to levels of exposure. In live animal experiments, the amount administered is usually defined as the exposure. However, not all fibrous particles will ultimately reach a specific target tissue. Measurement of the fiber load at the tissue site and the pathologic response are tedious but necessary procedures to evaluate this aspect of the problem. 

Cellulose is also an acceptable support and can be activated in a similar way. The binding capacity for enzymes is generally lower as compared to agarose but it is inexpensive and commercially available in fibrous and granular forms. Some drawbacks are the low particle sizes, which impairs the use in rapid high-pressure applications, and its susceptibility to microbial cellulases. Some immobilization and engineering aspects have been reviewed [63]. 

Improper location of the gate or multiple gates may produce a zone where the two melt fronts meet (weldline). For unfilled polymers, this region usually has inferior properties compared to other locations within the part mechanical weakness becomes more pronounced in the presence of high aspect ratio fibers and flakes, which may not interpenetrate and instead lie in their most unfavorable orientation for effective reinforcement. A more moderate detrimental effect on properties has been observed vdth low aspect ratio fillers. In general, fibrous fillers cause up to 50% loss in... 

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