Factors Affecting Fabric Spreading
What are the factors that affect fabric spreading?
Factors Affecting Fabric Spreading in Garment Production
Fabric spreading (also known as laying) is one of the most critical preparatory steps in the garment industry. It involves unwinding large rolls of fabric onto a cutting table to create a "lay" of multiple plies.
If the spreading is poor, the cutting will be inaccurate, leading to rejected garments and wasted material. To ensure quality, textile professionals must understand the technical factors that influence this process.
Here are the primary factors that affect fabric spreading quality and efficiency.
1. Fabric Tension (The Most Critical Factor)
Tension is the most significant variable in spreading.
- The Rule: Fabric must be spread with zero tension.
- The Risk: If fabric is stretched while spreading (common in knits or Lycra), it will eventually relax and shrink back to its original state after the pieces are cut. This results in garment pieces that are smaller than the pattern size.
- Solution: Modern spreading machines use positive feed mechanisms to unroll the fabric at the exact speed the machine moves, ensuring the fabric remains relaxed.
2. Fabric Characteristics (Elasticity and Weight)
The physical nature of the fabric dictates how it must be handled.
- Knits vs. Wovens: Knitted fabrics are unstable and curl at the edges, requiring specialized spreaders with edge-opening devices. Wovens are generally more stable but prone to fraying.
- Fabric Weight: Heavy fabrics (like denim) are stable and easy to align but require heavy-duty machinery to lift. Lightweight fabrics (like chiffon or lining) are difficult to control because they are prone to "fluttering" (air trapping) and shifting during the process.
- Surface Friction: "Slippery" fabrics (satin, nylon) have low friction and tend to slide off one another, making edge alignment difficult.
3. Static Electricity
Static is a major issue in the cutting room, particularly with synthetic fibers (Polyester, Nylon, Acrylic).
- The Effect: Friction generated during unrolling causes the fabric plies to become charged. The layers cling together, making it impossible to smooth them out or cut them accurately without fusion.
- The Fix: This is controlled by maintaining proper humidity in the cutting room or using ionization bars on the spreading machine.
4. Alignment of Plies (Selvedge Alignment)
For the marker to fit correctly, the fabric edges must be perfectly aligned.
- Selvedge Alignment: All fabric edges (selvedges) on one side of the lay must be perfectly vertical. If the stack leans or is jagged, the cutter may miss parts of the pattern on the bottom layers.
- Photocell Sensors: Advanced machines use photocells to detect the fabric edge and automatically adjust the machine position to keep the stack straight.
5. Ply Height (Height of the Lay)
The number of layers (plies) spread affects the quality of the final cut.
- Too High: If the lay is too high, the cutting knife may bend or deflect (leaning), causing the top layers to be a different size than the bottom layers.
- Heat Generation: A higher lay generates more friction heat during cutting, which can fuse (melt) synthetic fabrics.
6. Splicing and Defect Removal
Fabric rolls are rarely perfect; they contain flaws, holes, or shade variations.
- Splicing: When a flaw is detected or a roll ends, the spreader must "splice" (overlap) the fabric to ensure the next garment piece is complete.
- Factor: The position of the splice is critical—it must fall between pattern pieces, not through the middle of a garment part.
7. Fabric Grain and Bowing
The fabric grain (warp and weft yarns) must be straight.
- Bowing/Skewing: If the yarns are distorted (bowed) during the finishing process, the spread fabric will not hang straight in the final garment. While spreading cannot fix bowed fabric, the operator must monitor it to prevent cutting defective goods.
Conclusion
Successful fabric spreading is a balance of machinery, environment, and material knowledge. By controlling tension, managing static, and ensuring precise alignment, manufacturers can save fabric and ensure the final garment fits perfectly.
Comments