Spun filament felting - is constructed to have a higher shear resistance in one direction

摘要

In the manufacture of a thermoplastic spun felting, the material is formed from virtually continuous filaments deposited at random. The material has a higher shear resistance in one direction than in the other direction at right angles to it, and it is needle bonded. The fabric is drawn in the direction of lower shear resistance to 20-200% of its original length at a temperature of 85-25 degrees C below its crystallite melting point. In the other direction, of higher shear resistance, the dimensions are held firm or, at the same time, only altered by plus-or-minus 10% of the original length in that direction. The process gives a material with improved characteristics, particularly its behaviour when attached to a stentor frame.