Weaving Mechanisms: Beating-up Motion

Weaving Mechanisms: Beating-up Motion

• Beating-up is the final primary motion of the loom, pushing newly inserted weft yarn into the cloth's fell.
• The fell divides the warp yarns and cloth.
• Beating-up is achieved with a loom accessory called a reed.
• Reeds are wooden, plastic, or metallic frames with vertically aligned metal wires spaced at fixed distances.
• Reed specifications are based on the reed number or count, representing the number of dents per unit length.

Regular Reed vs. Profiled Reed

• Diagrams (pictures) illustrate the differences.

Beating-up on Shuttle Looms

• Components include: heddle, drop wire, heddle eye, reed, shuttle, cloth fell, lay, harness, race board, front rest, and cloth roll. (A diagram is present)
• The diagrams show the arrangement and movement during the beating-up process.

Reed Mechanism (Detailed)

• The reed mechanism is connected to the crank shaft and machine pulley.
• The crank shaft has cranks connected to crank arms via crank pins.
• Each crank arm has a bearing to facilitate smooth operation.
• The crank arm and sword are attached via a sword pin.
• The reed is positioned above the sley race board.
• The reed cap is on top of the reed.
• The entire beating-up mechanism is mounted on a rocking shaft.
• The crank shaft's rotation drives the reed's forward and backward movement for beating-up.

Eccentricity

• The sley's and reed's motion deviates from simple harmonic motion (SHM) due to the cranks.
• Eccentricity is measured by Crank radius divided by Crank arm length.
• Eccentricity affects the speed of the sley's movement. The sley moves faster when near the front and slower during the back motion, affecting the picking or beat-up force.
• The typical value of eccentricity is between 0.25 and 0.4.
• Higher eccentricity leads to a greater beat-up force.

Beating-up on Shuttle-less Looms

• Components include: reed, fell, roller follower, sley, and a pair of matched cams. (A diagram is present)

Forces Acting in Beat-Up

• Diagrams representing the position of yarns during the process of beating up the weft, before and after the process of beating-up.