The method of checking and assessing the shrinkage of the fabric used is AATCC 135. According to this standard, the fabric will be drawn with 380 x380 mm squares not in the same horizontal or vertical rows on the fabric surface, before washing. Then the fabric is washed and dried with the specified parameters such as the specifications of the washing machine, weight, quality of laundry, temperature, time …. (For details, you want to know, please contact to be provided) .
After drying, also with standard parameters, the size of the squares will be measured and calculated% percentage of fabric shrinkage according to the following formula:
% DC = 100 (B-A) / A
Where:% DC is the% change in size of the fabric. A: It is the size before washing (380mm); B: size after washing.
Here is the result of the shrinkage of a fabric in an ITS report:
Result of changing size after 3 washing times: Vertical (Warp): No contraction (Negligible); Horizontal (Weft) -1.1%. (+): Means to stretch, (-): means to shrink.
8 / Deviation of fabric after washing (Skewness):
Fabric channel deviation or skewness is an error that occurs in a fabric that occurs when the weft in a woven fabric or loops in a knitted fabric is skewed at an angle to the edge of the fabric, the cause of which is uneven tension action in the fabric during the complete dyeing and weaving process results in a horizontal channel that is not perpendicular to the vertical channel. If this error is not dealt with immediately, it is a cause of particularly serious problems for product quality, starting with the trend of channel skewers in the constituent parts of garments (also called is the embryo).
Although it is possible that the post-cutting, ironing and packaging products may look perfect, the channel skew error will appear after washing. This distortion can also be explained similarly to the phenomenon of fabric shrinkage above. This phenomenon is also known as “Spirality”, “Twist”, and “Torque”.
Therefore, in order to avoid this error for the product, this channel deviation must be checked both during the pre- and post-sewing stages.
As with the shrinkage test, the fabric must be lined in front of the squares or Sundays on the fabric, the square edges parallel to the edge of the fabric. After washing and drying (usually 3 times), the deviation of this line from the original position will be measured and calculated% of channel deviation of the fabric.