1) Water solubility:
Cold water soluble film requires that water can be dissolved in water above 4 ℃. The faster it dissolves the better. The less residue remaining after dissolution, the better. The clearer the dissolved water, the better.
2) Appearance quality:
The smoother the winding, the better. There should be no obvious unevenness and wrinkles on the outer surface of the roll. The flatter the two end faces of the roll film, the better, within ±2mm. The surface of the film should not have defects such as bubbles, perforations, slag inclusions, and black spots.
3) Mechanical strength:
The tensile strength is required to be above 25Mpa. Too little is easy to pull off. The elongation at break is required to be above 180%. Less is not soft. The right-angle tear resistance is required to be about 80KN/m. Otherwise it is brittle when broken.
4) Storage time: The water-soluble film with stable quality can be stored for more than 1-2 years (without moisture).