Question 44 (Textile Engineering & Fibre Science)
During beat-up possibility of bumping increases if
|(A)||Warp tension is low and cloth fell displacement is low|
|(B)||Warp tension is low and cloth fell displacement is high|
|(C)||Warp tension is high and cloth fell displacement is low|
|(D)||Warp tension is high and cloth fell displacement is high|
Frequently Asked Questions | FAQs
What is beat up in weaving?
In weaving, beat-up refers to the process of pushing the weft yarns into the fell of the cloth after each insertion of the weft during the weaving process. The beat-up operation is carried out by the reed, which is a comb-like component in the loom that moves back and forth to push the weft yarns against the previously inserted weft yarns, thereby forming a tightly woven fabric.
The beat-up process is a critical step in weaving as it determines the tightness, density, and evenness of the woven fabric. The reed, which is typically made of metal or plastic, is attached to the loom and is positioned immediately behind the fell of the cloth, which is the point where the last weft yarn was inserted. As the loom cycle progresses, the reed moves towards the fell of the cloth, pushing the newly inserted weft yarns against the previously inserted weft yarns, compacting them together to form a solid fabric structure.
The beat-up process has several important functions in weaving, including:
Weft insertion: The beat-up operation creates space for the next insertion of the weft yarn by pushing the previously inserted weft yarns towards the fabric fell. This allows the shuttle or other weft insertion device to pass through the shed (the opening created by the raised warp yarns) and insert the weft yarn across the width of the fabric.
Fabric tightness and density: The beat-up process determines the tightness and density of the woven fabric. Properly beating-up the weft yarns ensures that they are tightly packed together, resulting in a dense and stable fabric structure.
Fabric selvage formation: The beat-up process helps in the formation of selvages, which are the finished edges of the woven fabric. By pushing the weft yarns tightly against the warp yarns at the selvage areas, the beat-up operation helps in creating clean and stable selvages.
Fabric appearance: The beat-up process can affect the appearance of the woven fabric. The tension and tightness of the weft yarns achieved during the beat-up operation can influence the fabric’s surface smoothness, regularity, and overall appearance.
Proper control and adjustment of the beat-up process are important in weaving to ensure that the weft yarns are evenly and tightly packed, resulting in a high-quality woven fabric. Various factors, such as the reed design, reed speed, warp and weft tension, and fabric structure, can affect the beat-up process and may require careful monitoring and adjustment to achieve the desired fabric characteristics.