1. Shrinkage
Shrinkage test machine, hot air drying box, etc. are required for shrinkage measurement. Take 55cm of the beech cloth and place it for more than 10 hours to make its shape stable. Use the beating device to make the distance of 50em along the longitudinal direction and make three width marks along the transverse direction. The measurement shall be ensured to 0.1em. Put the hot water in the water tank of the shrink machine (60 raw water 2) ℃ to the specified mark, put the sample into operation, and cover the sealed heat preservation. After the motor is stirred continuously for 15min, take out the cloth sample, put it in water and level, fold it in four fold along the radial direction, press the water by hand, then level the sample on the metal net and dry in an oven (60t5) ℃. Take out the cooling for 0.5h, place for 4h, measure the distance of each sign, and take the arithmetic mean of the data measured in the longitudinal (or horizontal) direction as the standard.
2. Heat shrinkage
Heat shrinkage refers to the dimensional change rate of thin nonwovens, such as interlinings, measured by press, expressed as a percentage. Cut 2 samples, each 15cm wide and 50cm long. Mark the two samples longitudinally and transversely, and make three marks 45cm apart. The samples were pressed at 180 ℃, 196kpa (2 kgf / cm2) for 20 minutes. Take out the sample from the press, cool it for 0.5h, measure the distance between the marks, and the arithmetic mean of the three data measured in the longitudinal (or transverse) direction shall prevail.
