Post processing application of BOPP laser film
BOPP laser film has many functions, such as decoration, anti-counterfeiting, environmental protection, and low cost, durable, gradually get wide recognition and application of the packaging industry, is an ideal high-grade packaging materials, can be widely used in cigarettes, wine, drugs, gifts, cosmetics packaging.
Main sequence Technology
1, process flow
Substrate - molding - rewinding - aluminum - cutting - Composite
2. Substrate requirements
BOPP substrate, also known as base film, has high tensile strength, good thermal stability, low shrinkage, low fog, good transparency, smooth and smooth surface, high gloss.
3. Molding process
It is the information reproduction process of laser pattern, which transfers the laser pattern on the working template to the substrate under certain temperature and pressure.
4. Aluminum plating process
After rewinding, the film substrate is mounted on the rewinding station of the vacuum aluminizing machine, and the film is wound on the rewinding station through the cooling roll (evaporation roll). The vacuum degree in the evaporation chamber is above 4 10-4 MBA by vacuum pump. The high purity aluminum wire is melted and evaporated into gaseous state at 1300 ~1400. Aluminum. Start the film winding system, when the film running speed reaches a certain value, open the baffle to make the gaseous aluminum particles deposit on the moving film substrate surface, and then form a continuous and bright aluminum layer. The thickness of aluminized layer is controlled by controlling the evaporation rate of aluminium, the moving speed of substrate film and the vacuum degree in the evaporation chamber.
5, composite process
Laser composite film is directly combined with paper products or film after aluminum plating and used in cigarette boxes, wine boxes, pharmaceutical and food packaging boxes.
Two. Quality requirements for laser films after processing.
1, the surface of the membrane must be smooth and not allowed to have wrinkled deformation wrinkles.
2, holographic layout pattern is clear, does not allow more small black spots or highlights;
3, the brightness of the film surface must be close, and the brightness between the batches should be kept between 90% and 94%.
4. The uniformity of the aluminum coating is good. There is no possibility of having an empty line or a yellow and dark condition caused by the uneven aluminum layer.
Three, laser film processing defects and Solutions
1. The brightness of molded products is not enough.
Methods: increase preheating and increase template pressure.
2. Moulded products turn white.
Methods: reduce molding temperature and increase speed.
3. Uneven molding products
Methods: check the temperature distribution of the preheating roller, or replace the template.
4, the film has longitudinal wrinkles.
Methods: reduce winding tension.
5. There are transverse wrinkles on the membrane.
Methods: increase the tension of winding or unwinding.