Needle bonding a nonwoven uses structured needle movements to move with the material as they penetrate it and release the fiber loops by rotation in the needling cycle

摘要

To needle bond a nonwoven, hooked needles (1) are used which form interlinked fiber chains on the non-woven web (5) with a release by needle rotation in a stitching cycle. The fiber loop from the previous stitching is stripped from the needle, before forming a new loop, the needle is moved against the direction (L) of nonwoven movement to relieve the draw tension on the fiber loop to be laid on the nonwoven. The nonwoven material is moved continuously through the needle bonding station and the needles move with the fabric while they are penetrating into the material. As the needles are retracted, they are given a movement component during a part of their retraction path in the direction of fabric travel, but at a faster speed than the nonwoven movement rate. The final fiber loop is tensed on the next needle penetration, and then relaxed as the needle is retracted. The fiber loop is tensed by a combination of the nonwoven forward movement and the needle movement while it is within the fabric, or the loop is expanded by conical needles. During a part of the needle retraction movement, when it is clear of the nonwoven, it is moved across the line of fabric travel with a cycled direction reverse. The nonwoven has been initially stabilized before the needle bonding action. The nonwoven is also needled by standard needles, in the same stitching cycle and with a forward alignment. The fibers pulled from the nonwoven are held at the side of the needles away from the forward movement of the material. The nonwoven is needle bonded on both sides, with the bonding stitches offset from each other on each of the sides. The needles penetrate into the nonwoven to a depth where the fibers caught by the needle hooks (6) are not carried as far as the other side of the material. The nonwoven is needle bonded in a single row or in a number of rows where their stitches or offset from each other at the sides of the rows. An Independent claim is included for a bonding needle, with the hook carried by an intermediate shaft with a structured spaced gap from the needle point according to the fabric thickness, giving a conical rearwards transit.