Examples of common failures of composite membranes and their solutions

There are shark skin, fish eye spots and other phenomena in the composite film.

1. The temperature of the extruder is improperly set, especially the temperature of the die and the resin is too low, resulting in poor resin plasticization, causing the shark skin phenomenon or fish-like marks to appear on the molten resin.

2. Resin contains moisture, affecting the plasticization of the resin.

3. The resin is mixed with other resins with different melt index or density, so that the resin is not plasticized or the plasticization is not complete.

4. When the resin was replaced, the cartridge was not thoroughly cleaned, and other resin or impurities remaining in the cartridge adversely affected the plasticization of the resin.

Solution:

1. The extrusion temperature of the extruder and the temperature of the resin are adjusted to appropriate values ​​to ensure good plasticization of the resin.

2. The resin is stirred and dried to remove the moisture contained therein, so that the resin can be fully plasticized.

3, replace the melt index and density of the appropriate resin.

4. Thoroughly clean the barrel to remove impurities and other effects.

Composite film has odor problems Cause:

1. The extruder temperature or resin temperature is too high, causing the resin to decompose and produce odors.

2. The air gap is too large, the resin oxidizes excessively, and various oxygen-containing groups with odors are generated on the surface, causing the composite membrane to generate odors.

3. The resin itself has an odor, and the composite film after extrusion compounding also has an odor.

4. The use of a high-boiling, non-volatile solvent in the primer causes some of the solvent to remain, causing odor in the compounded film.

Solution:

1. Properly reduce the extrusion temperature to prevent decomposition of the resin.

2. Adjust the size of the air gap to the proper value.

3. Low-odor resin is used for extrusion compounding.

4. Improve the drying temperature of the drying tunnel, increase the amount of air blowing, and ensure that the solvent is fully dried.

Composite film pattern tensile deformation failure causes:

1. Improper tension setting and control, the tension values ​​between the various parts are not suitable.

2. The drying tunnel temperature setting is too high.

3. Excessive composite pressure causes the composite film to stretch.

4. The surface temperature of the cooling steel roller is too high, the composite film cooling effect is poor, and the dry roller tends to produce a stretching phenomenon.

Solution:

1. Check and determine where the stretching phenomenon occurs on the equipment. Adjust the tension value of the section to the appropriate conditions and match the tension of the other sections.

2. Reduce the temperature of the drying tunnel appropriately.

3. Reduce compound pressure appropriately.

4. Reduce and control the surface temperature of the cooling steel roll to make it evenly distributed and have a good cooling effect.

The reason why the composite film sticks to the surface of the cooling steel roller is as follows:

1. The surface temperature of the cooling steel roller is too high, and the cooling effect on the molten resin is not good, which affects the cooling, curing and forming of the composite film, resulting in the molten resin sticking to the surface of the cooling steel roller.

2. The temperature of the molten resin during compounding is too high.

3. The winding tension is too small to peel off the composite film from the surface of the cooling steel roll.

Solution:

1. Appropriately reduce the temperature of the cooling water and cool the surface temperature of the steel roll to improve the cooling effect.

2. According to the specific circumstances, the temperature of the resin is appropriately lowered, the size of the air gap is adjusted, and the temperature of the molten resin is controlled within an appropriate range.

3. Appropriately increase the winding tension and peel off the composite film from the surface of the cooling steel roll.

Composite film transparency difference failure causes:

1. Extruder extrusion temperature is too low, resulting in poor resin plasticization, which has a certain impact on the transparency of the composite film.

2. The surface temperature of the cooling steel roller is too high and the cooling effect is too poor, which greatly reduces the transparency of the composite film.

3. The transparency of the substrate itself is not good.

Solution:

1. According to the characteristics of the resin performance and actual production conditions to set and control the corresponding extrusion temperature to ensure good resin plasticization, which is one of the prerequisites to improve the transparency of the composite film.

2. Reduce the temperature of the cooling water and cool the surface temperature of the steel roll. In general, the temperature of the cooling water is controlled below 20c, and the surface temperature of the cooling steel roller is controlled below 60C.

3. Replace the transparent substrate.