Winding


Definition: Winding is the process of moving yarn from a source, such as a ring, bobbin, or hank, to a suitable package. This can be done either electrically or mechanically.

Yarn Types:

  • Warp: Yarn used for the lengthwise threads in weaving.
  • Weft: Yarn used for the crosswise threads in weaving.

Types of Packages:

  • Cone, Cheese, Flanged Bobbin: Common packages for storing and transporting wound yarn in a conical or cylindrical shape.
  • Pirn, Cop: Specific types of bobbins or tubes used for winding yarn.

Objectives or purposes of winding:

  1. Transfer for Weaving:
    • The primary goal is to transfer yarn from one package to another, making it convenient for use in weaving.
  2. Fault Removal:
    • Winding helps in eliminating yarn faults such as hairiness, neps, slubs, or foreign matter, improving yarn quality.
  3. Yarn Cleaning:
    • The process involves cleaning the yarn, ensuring it is free from impurities or unwanted elements.
  4. Quality Improvement:
    • Winding contributes to enhancing the overall quality of the yarn, making it more suitable for downstream processes.
  5. Package Suitability:
    • The objective is to obtain a suitable package, whether it’s a cone, cheese, flanged bobbin, pirn, or cop, depending on the intended use.
  6. Yarn Storage:
    • Wound yarn is stored on the new package, providing a practical and organized way to keep the yarn for future use.

The requirements of winding:

  1. Low Fault Level:
    • Ensure that the winding process results in yarn with minimal faults.
  2. No Yarn Damage:
    • Prevent any damage to the yarn during the winding process.
  3. Easy Unwinding:
    • The wound package must permit easy unwinding during subsequent processes.
  4. Suitable Package Size & Shape:
    • Choose a package size, shape, and build that align with technological requirements for the intended end use of the yarn.
  5. Economical Conditions:
    • Control the package size based on economic requirements, ensuring cost-effectiveness in the process.
  6. Avoid Excess Looseness or Tightness:
    • Maintain an optimal balance to avoid excessive looseness or tightness in the wound yarn package.
  7. Cost-Effective Packages:
    • The packages used should be cost-effective, considering the overall profitability of the process.
  8. Optimized Economic Performance:
    • Ensure that the winding operation is geared to provide the best possible economic performance for the entire process.

The necessities of yarn preparation:

  1. Yarn Transfer:
    • Objective: Transfer yarn from one package to a suitable form or package.
    • Method: Winding.
  2. Imperfection Removal:
    • Objective: Eliminate some yarn imperfections.
    • Method: Utilize processes like cleaning and inspection.
  3. Weaving Efficiency:
    • Objective: Enhance weaving efficiency.
    • Method: Use sizing to prepare yarn for smoother weaving.
  4. Fabric Quality Preservation/Improvement:
    • Objective: Preserve or improve fabric quality.
    • Method: Employ processes that enhance yarn quality, such as cleaning and sizing.
  5. Yarn Arrangement for Weaving:
    • Objective: Organize yarns for weaving into fabric.
    • Methods: Warping, drafting, and denting.
  6. Yarn Cleaning:
    • Objective: Clean the yarn to some extent.
    • Method: Employ cleaning processes to remove impurities and contaminants.

Types of Packages:

  1. Parallel Wound Package:
    • Examples:
      • a. Warp Beam
      • b. Weavers Beam
    • Description:
      • Threads are laid parallel to each other, similar to a warp beam. A flanged package or beam is necessary for stability, and no traversing is required.
    • Advantages:
      • Can wind many yarns simultaneously.
      • No need for a traversing mechanism.
      • Side withdrawal is possible.
      • Higher yarn density.
    • Disadvantages:
      • Requires flanges on both sides of the package.
      • Separate mechanism needed for yarn unwinding.
      • Overwithdrawal is not possible.
  2. Near Parallel Wound Package:
    • Examples:
      • a. Pirn
      • b. Cop
      • c. Flanged Bobbin
    • Description:
      • Comprises threads laid nearly parallel to existing layers on the package.
    • Advantages:
      • No need for flanges.
      • Side withdrawal is possible.
      • No change in the number of yarn turns per inch during winding.
  3. Cross Wound Package:
    • Examples:
      • a. Cone
      • b. Cheese
    • Description:
      • Consists of a single thread laid at a helix angle for stability.
    • Advantages:
      • No need for flanges.
      • Overwithdrawal is possible.
      • Stable yarn package.
    • Disadvantages:
      • Changes in the number of yarn turns per inch.
      • Lower yarn quality.
      • Requires traversing mechanism.

Types of Winding:

  1. According to Density:
    • a. Precision Winding
    • b. Non-precision Winding
  2. According to Type of Package:
    • a. Cone Winding Package
    • b. Pirn Winding Package
    • c. Flange Winding Package
    • d. Cheese Winding Package
    • e. Cop Winding Package
  3. According to Build of the Package:
    • a. Parallel Winding
    • b. Near-Parallel Winding
    • c. Cross-Winding
  4. According to Methods of Drive:
    • a. Positive or Direct Drive
    • b. Negative or Friction or Indirect Drive
  5. According to Features of Automation:
    • a. Conventional Winding
    • b. Modern winding

Winding parameters:

  1. Winding Rate:
    • Definition: The amount of yarn wound on the package per unit of time.
    • Unit: meters per minute (m/min).
  2. Winding on Diameter:
    • Definition: The diameter of the package on which winding is performed.
    • Unit: centimeters (cm).
  3. Winding on Surface:
    • Definition: The place on the package where winding is done concerning time.
    • Unit: meters per minute (m/min).
  4. Traverse Velocity:
    • Definition: The amount of traverse (crosswise movement) during winding per unit time.
    • Unit: meters per minute (m/min).
    • Denoted by: Vt.
  5. Angle of Wind:
    • Definition: The angle between the yarn and a vertical line.
    • Effect: Increasing the angle of wind decreases the number of coils in a layer, resulting in less yarn on the package.
    • Denoted by: θ.
  6. Surface Velocity:
    • Definition: The rate of winding on the diameter of the package.
    • Unit: meters per minute (m/min).
    • Denoted by: Vs.
  7. Net Winding Velocity/Rate:
    • Calculation: Dividing traverse velocity by the sine value of the winding angle.
    • Real Winding Rate: Represents the effective winding rate.
    • Denoted by: Vr.
  8. Coil Angle:
    • Definition: The angle between the horizontal axis and the yarn.
    • Denoted by: β.
    • Relationship: Coil angle may increase as the angle of wind decreases.

Why spinner’s yarn cannot be used directly for weaving:

Reasons:

  1. Faults or Imperfections in the Yarn:
    • Explanation: Yarn produced by spinning may have various imperfections or faults that deviate from the standard specifications. These faults can negatively impact the quality of the final fabric.
  2. Not Ready to Be Used Directly:
    • Explanation: The yarn produced by spinners is not in its final, ready-to-use form for weaving. Additional processes are required to prepare the yarn for weaving efficiently.
  3. Not in the Right Form:
    • Explanation: Spinner’s yarn may not be in the appropriate form for weaving. It needs to undergo further treatments and transformations to meet the specific requirements of the weaving process.

Types of Faults in Yarn:

  • Slub
  • Nep
  • Hairiness
  • Gout or foreign matter
  • Irregular (Thick & thin places)
  • Soiled or dirty yarn
  • Snarl
  • Twity or cockled yarn
  • Trash
  • Irregular twist
  • Flying or adhering fibers
  • Foreign fiber or wild fiber
  • Immature or dead fiber
  • Low twist or soft spun

Leave a Reply

Your email address will not be published. Required fields are marked *