Why does the stretch film have black or gray mottling?

Stretch film is widely used in various fields. As manufacturers and consumers who often use it, it is necessary for us to understand its characteristics. However, some manufacturers will show mottled appearance when producing stretched film. However, this situation will affect the quality and sales of stretched film. Sometimes, black or gray mottled appearance will occur during production and processing, The main reasons are as follows.

Reasons for mottled stretch film 1. The adhesive concentration is too high and the viscosity is too large. Simply stick the ink back to the glue, so as to change the color of the printing layer. At the same time, if the viscosity of the adhesive is too large, the fluidity will be poor, which will simply cause uneven glue amount, affect the reflective function of the appearance of the aluminized layer and cause mottling.

Reasons for mottle of stretch film 2. The mismatch between stretching film ink and adhesive makes the adhesive have poor penetration function to the ink, showing the phenomenon of exclusion, and mottle will also occur.

Reasons for mottle of stretch film 3. The external tension of stretch film printing ink is low, the coating effect of adhesive is poor, and the glue is uneven. Therefore, the bonding force and layer tightness between ink layer and aluminized layer will vary, and then the reflective effect of aluminized layer is also strong or weak, forming white or gray mottle visually.

Reasons for mottled stretch film 4. The concealment force of stretch film printing ink is not strong or the flatness is poor, which constitutes uneven concealment (especially white ink and light yellow ink). In places with poor concealment effect, the color of aluminized layer will be soaked through the ink.

Reasons for mottle of stretch film 5. The quality of aluminized tensile film is relatively poor and there are more light transmission points. After compounding, mottle is formed due to the different repair rate of aluminized layer.

Reasons for mottled stretch film 6. The tensile film is dry and incomplete, and the solvent volatilization is insufficient. There is too much solvent residue in the adhesive, part of the ink is dissolved, and then mottled. In severe cases, many small bubbles will be formed after aging.