Fiber compaction is greater with higher barb angles because the fibers do not slip off the barb face during penetration through the fiber batt. The majority of the fibers that fill the barb are carried for the entire stock. As a result, fabrics can be made stronger and more dense than if the barb angle had been lower.
Lower barb angles allow for fiber slippage as the needle penetrates the fiber batt. Fabric made with lower barb angles will be more lofty and thick; they will generally have a better hand and be of lesser strength than if barb angles had been higher. The decision to use higher or lower barb angles depends on the fabric being produced.
Figure 5: Selection of barb angles
The Barb Angle
The barb angle can also be referred to as the rake or undercut angle. The barb angle is critical to the effectiveness and efficiency of the barb. Very simply, the barb angle is the amount of degrees by which the fiber engaging surface is displaced from a vertical position. Some felting needle producers offer a selection of barb angles ranging from zero degree barb angle through 20 degree barb angle and greater. An example of this can be seen in Figure 5.
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