How to identify the quality issues of water-soluble film products, it is recommended to consider the following aspects.

1、 Water solubility:

Cold water soluble film (low-temperature water soluble film) is required to be soluble in water above 5 ℃. The faster it dissolves, the better. The less residual residue after dissolution, the better. The clearer the water quality after dissolution, the better.

2、 Appearance quality:

The smoother the winding, the better. The outer surface of the winding should not have obvious bumps or wrinkles. The two end faces of the winding film should be as flat as possible, with a requirement of within ± 5mm. The surface of the film should not have or have few defects such as bubbles, perforations (excluding cross stitch water-soluble film), slag inclusions, black spots, etc.

3、 Mechanical strength:

The tensile strength is required to be above 25Mpa (depending on the thickness of the film, the thicker the film, the greater the tensile strength). Too little is easy to break.

The higher the elongation at break, the harder the film, and the less it is, the softer it becomes.

The requirement for right angle tear resistance is around 80KN/m. Otherwise, it will be brittle when broken.

4、 Storage time:

Stable quality water-soluble films can be stored for more than 1-2 years in sealed packaging without being affected by moisture.

However, water soluble films with poor quality are stored for less than 6 months. Due to unstable quality, many chemical components will separate from the film, resulting in a lot of white dust. In severe cases, the rolled film will become darker.