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Certain needling applications place extreme levels of stress and resistance on the needle blade. Until recently the resulting high felting needle breakage was considered customary or acceptable to properly produce the desired nonwoven fabric.

Now, Foster Needle has perfected Conical Blade production which substantially reduces the needle breakage level.

The Conical Blade is produced so that the entire working blade, either Pinch Blade, Star Blade or triangular, is tapered from the smallest diameter at the point end to the larger diameter at the intermediate or shank portion. This Conical Blade shape allows the smallest diameter to more easily penetrate the web; then as resistance increases, the heavier portion of the blade has entered the web. It is in this general area of a standard blade where the needle breakage would occur. However, the heavier diameter of the Conical Blade will be successful in withstanding the stresses and penetration resistances.

The barbs are formed on the Conical Blade to help ensure successful web penetration with minimum stresses. The barbs are formed in increasing depth from the point end to the top of the blade.

In particular, the Conical Blade is proving very successful in the production of padding, wadding, and underlay fabrics made of recycled/regenerated fibers, commonly referred to as shoddy fibers. These fabrics employ varying mixtures of deniers and fiber types. This fact and the inclusion of some amounts of unshredded fabric pieces will give higher breakage to needles which are not Conical Blade.

Conical Blade needles are not ideal for all applications. They can result in a more visible needle hole pattern on the fabric surface due to the greater blade thickness at the top of the blade.

The Star Conical Blade is also available.