Figure 8: The Pinch Blade

There are four main advantages Pinch Blade needles have over triangulated bladed needles: more effective fiber transportation, improved needle strength, superior fabric surface qualities and less damage to warp yarns and woven backings.

More effective fiber transportation is possible with the Pinch Blade because of two main reasons. First, the two rows of barbs work independently. Each barb in each row of a triangular bladed needle will partially needlepunch the same fibers, which are also being engaged by barbs on adjacent rows. With the Pinch Blade, the opposed location of the two barbed rows assure that separate fiber loads are being needlepunched by each row. Secondly, the two edges of the Pinch Blade into which the barbs are placed have a narrower cross section than found on the edge of a triangular blade. This narrower edge allows for a narrower fiber engaging surface.

Pinch Blade needles offer improved needle strength as a result of reduced deflection when penetrating the fiber batt. The two barbed rows of the Pinch Blade pull directly against one another, thus stabilizing the penetration of the needle and reducing the tendency for needle deflection. Improved fabric surface qualities is due to the shape of the hole made by the Pinch Blade. The two rows of opposed barbs produce an eyelid effect as they penetrate the fiber batt, transport the fibers and then withdraw from the fiber batt. This eyelid shaped hole closes less noticeably than holes left by a triangular blade.

Figure 9 offers a close-up of the Pinch Blade photographed with a scanning electron microscope.