The problems and solutions of laser marking in the packaging and printing industry

The application of laser marking machines in the packaging and printing industry is increasing year by year. The anti-counterfeiting packaging of all high-end daily consumer products is inseparable from the laser marking machine. The following are the problems and solutions in production.

　　 During the marking process of the laser marking machine. Common quality problems and their solutions are as follows.

    　(1) The marking pattern of the laser marking machine is partially unclear

    　Cause: The thickness of the molded plate is uneven. The molding pressure is too small. The heating temperature is too low or the accuracy of the machine is not high.

Solution: Check whether the thickness of the molded plate is uniform. Is the molding pressure too small? Is the temperature too low? Whether the accuracy of the machine has decreased.

Key points of process control: the thickness error of the molded plate should be controlled at 0. Within O01mm. The hardness should be maintained at 230-280N/mm. Because the hologram is molded out of interference fringes by applying a certain pressure to the molding roller. If the hardness of the molded plate is not enough, in the process of embossing. Internal stress can deform or damage the molded plate.

    　(2) The logo pattern of the laser marking machine is dim and dull

    　Causes: Generally related to heating temperature and molding pressure.

    　Solution: Check whether the heating temperature is too low. Whether the molding pressure drops.

    　The key points of process control: the setting of molding pressure should comprehensively consider the molding temperature, the type of holographic material, the softening point of the coating layer, and the situation of the molded plate. The pressure is too high. The molded plate is easily damaged. Or crush the holographic material; the pressure is too low. The molded image is unclear and incomplete. For the round pressing method. The initial pressure of the pressure rollers on both sides is generally around 0.08MPa. After the molding begins. Slowly increase the pressure of the pressure roller uniformly to 0 30 ~ 0.50 MPa. The molding speed can be comprehensively adjusted according to the imprint quality and machine performance.

    　(3) The logo pattern of the laser marking machine is whitish

   　 Solution: Check whether the molding speed is too slow. Whether the molding temperature is too high.

    　(4) Marking film sticking plate of laser marking machine

    　Causes: The hot pressing temperature is higher than the degradation temperature, and the viscosity of the coating increases. It will cause the plate to stick and the film will be wound on the holographic embossing roller.

    　Solution: lower the hot pressing temperature.

    　(5) One piece of the laser marking machine's logo pattern is clear and one piece is blurred. Cause: The temperature distribution of the hot pressing device is uneven or the molded plate is uneven.

    　Solution: Check whether the temperature distribution of the hot pressing device is even. Whether the molded plate is deformed or worn.

   　 (6) The marking film of the laser marking machine has wrinkles in the horizontal (longitudinal) direction. Causes: improper control of unwinding or rewinding tension.

    　Solution: Properly adjust the unwinding tension or rewinding tension. Until the wrinkles are eliminated. Problems and solutions in the application:

    　(1) The logo of the laser marking machine is warped

    　 Reason: The base of the laser holographic mark is aluminum film. The aluminum film has a certain degree of hardness and is relatively strong; the viscosity of the adhesive is not enough. This phenomenon is easy to occur when the medicine box or wine box is sealed and labeled.

    　Solution: Appropriately reduce the thickness of the aluminum film, thicken the glue layer or increase the viscosity of the adhesive. Key points of process control: the thickness of the adhesive must be mastered. Especially in the summer when the temperature is relatively high, the adhesive will melt and overflow due to the high temperature. Cause the printed matter to smudge.

    　(2) The scratching layer of the anti-counterfeiting mark of the laser marking machine is difficult to scrape off

    　Cause: The scratch layer and the laser holographic layer are too tightly bonded

    　Solution: You can spray an anti-counterfeiting code on the laser holographic logo first. Then the glazing treatment is carried out, and finally the scraping layer is coated.

    　The key points of process control: pay attention to the quality of varnish coating. Otherwise, the anti-counterfeiting code will be scratched off when it is scratched. From the interview, we learned that the production technology of laser holographic anti-counterfeiting marks is mature and popular. Relying solely on the laser holographic anti-counterfeiting mark has lost its anti-counterfeiting effect. There are two options for laser holographic marking: one is to increase the technical content. Innovate through the old and develop higher-tech laser anti-counterfeiting labels: The second is to combine with printing to achieve a three-dimensional combination of printing anti-counterfeiting and laser holographic anti-counterfeiting.