Relaxation Treatment of Knitted Fabric
A relaxing treatment is intended to get the knitted fabric into a state with the fewest stresses possible; in this balanced state, which is appropriate for the stitch, the relaxed knitted fabric is theoretically dimensionally stable. In fact, all the relaxing treatments tend towards this theoretical result, to keep the dimensional variations of the knitted fabric to a minimum. Here we will discuss more about Relaxation Treatment of Knitted Fabric.
.When all fabrics have been knitted, each one was separated into two 1/2 metre lengths and one metre length. The one meter length had no significant use at this point and was set aside the two 1/2 meter lengths were separated to the following 2 relaxation treatment.
Types of Relaxation Treatment:
There are two types of relaxation treatment of knitted fabric. They are
- Dry relaxation state
- Fully relaxed state
A short description of two relaxation is given below:
1. Dry relaxation state:
The knitted sample was laid on a flat surface in open width in a tensionless state for at least 48 hours under standard atmospheric condition.
2. Fully relaxed state:
This state was achieved by washing in automatic washing machine at 60°C for 100% cotton, 40°C for 100% polyester and (50% cotton & 50% polyester) yarn fabrics with melting agent (40ml zelex 125) for one hour. Followed tumble drying m/c. at 70°C for an hour. The sock and tumble drying cycle was repeated 3 more times. Then the fabric mere again laid on a flat surface in open width in a tensionless state for about 72hours under atmospheric condition.
Why Relax Knitted Fabrics?
Several factors contribute to knitted fabrics losing their shape and becoming stiff:
- Washing and Drying: Heat and agitation during washing and drying can cause the fibers to shrink and stiffen.
- Fiber Content: Natural fibers like wool are more prone to felting (fibers interlocking and shrinking) than synthetic fibers.
- Storage: Storing knits in a folded or squished position can lead to permanent wrinkles and loss of shape.
Relaxation Techniques for Happy Knits:
Fortunately, there are several ways to relax your knitted fabrics:
- Soaking: Fill a basin with lukewarm water (avoid hot water) and a gentle wool wash or mild shampoo. Soak your garment for 15-30 minutes, then gently squeeze out excess water (without wringing). Lay the garment flat on a towel to dry, reshaping it periodically.
- Steaming: Fill a steamer with water and steam your garment gently, holding the steamer at a safe distance to avoid scorching. Steam can help soften fibers and encourage them to return to their original shape.
- Blocking: This technique involves pinning your wet garment to a pre-measured blocking board to achieve the desired size and shape. Blocking pins are typically T-shaped and rust-proof to prevent damage to the yarn. Allow the garment to dry completely on the blocking board before removing the pins.
Key Reasons for Relaxation Treatment:
- Dimensional Stability: Prevents shrinkage or distortion of the fabric during subsequent processing and use.
- Improved Hand Feel: Enhances the softness and flexibility of the fabric.
- Consistent Performance: Ensures uniformity in fabric behavior, which is essential for garment fit and appearance.
- Reduced Residual Stresses: Eliminates internal stresses that can cause deformation during garment use.
Methods of Relaxation Treatment
Several methods are employed to relax knitted fabrics, each tailored to the specific type of fabric and its intended use. The most common methods include:
1. Dry Relaxation
This method involves allowing the fabric to relax in a dry state without any external application of heat or moisture.
- Process: The fabric is laid out in a relaxed state, either on flat surfaces or in loose folds, and left for a specified period.
- Duration: Typically ranges from a few hours to several days, depending on the fabric type and desired level of relaxation.
2. Wet Relaxation
Wet relaxation involves soaking the fabric in water to allow it to absorb moisture and relax fully.
- Process: The fabric is immersed in water at room temperature or slightly elevated temperatures, then gently agitated.
- Duration: Usually ranges from 15 minutes to an hour, followed by a gentle wringing or centrifugation to remove excess water.
3. Steam Relaxation
Steam relaxation uses steam to relax the fabric, combining the effects of heat and moisture.
- Process: The fabric is exposed to steam in a controlled environment, often using specialized equipment like steam cabinets or tunnels.
- Duration: Typically a few minutes, with careful control of steam temperature and duration to avoid fabric damage.
4. Relaxation by Tumble Drying
This method combines mechanical agitation with heat to relax the fabric.
- Process: The fabric is placed in a tumble dryer and subjected to a controlled drying cycle.
- Duration: Varies based on fabric type, usually between 15 to 30 minutes.
Benefits of Relaxation Treatment
Relaxation treatment offers several benefits that enhance the quality and performance of knitted fabrics:
1. Dimensional Stability
Relaxation treatment significantly reduces the risk of dimensional changes, such as shrinkage or elongation, ensuring that the fabric retains its intended size and shape.
2. Enhanced Comfort
By reducing internal stresses and improving fabric hand feel, relaxation treatment enhances the overall comfort and wearability of garments made from knitted fabrics.
3. Improved Appearance
Fabrics that have undergone relaxation treatment display a smoother, more uniform appearance, which is essential for high-quality garment production.
4. Increased Durability
Relaxation treatment helps to eliminate residual stresses that can weaken the fabric over time, thus enhancing its durability and lifespan.
Tips for Relaxation Success:
- Always refer to the care label: Check for specific washing instructions and recommendations for your knitted garment.
- Test on a swatch: Before applying any relaxation technique to your entire garment, test it on a small, inconspicuous area to ensure it doesn’t damage the yarn.
- Be gentle: Avoid aggressive scrubbing, wringing, or stretching of the fabric during relaxation treatments.
Conclusion
Relaxation treatment is an important stage in the manufacturing process of knitted fabrics, ensuring that they retain their ideal dimensions, look, and performance attributes. Manufacturers can exceed consumer expectations by knowing and applying proper relaxing methods to produce high-quality, durable, and comfortable knitted clothes. Whether through dry, wet, steam, or tumble drying processes, relaxation treatment is critical to the performance of knitted fabric goods.