Causes and solutions of bubbles in the production of protective

  • Protective film for aluminium composite panels is a common die-cutting material used in die-cutting production, but it is believed that many manufacturers of protective film sometimes have problems with air bubbles during the production process. Let's take a look at the causes of bubbles in protective film.


    Poor wettability of protective film for aluminium composite panel film


    The main cause: when the manufacturer makes the film, it adds a slip agent and antistatic agent, which slowly dip into the surface of the film during the storage process, so that the surface tension of the film is reduced; in addition, the film is not strong enough for corona treatment during the processing process or the storage time is too long, the surface tension drops is also an important reason for the poor wettability of the film.


    Low temperature and poor wettability


    The low temperature of the main agent leads to a lower liquid temperature, which increases the viscosity of the prepared adhesive and results in poor wettability; protective film for aluminium composite panel is affected by the low temperature and flows poorly after the application of adhesive, resulting in blockage and poor wettability.


    Insufficient coating and gluing


    Main cause: Insufficient glue application due to high or low viscosity during glue application.


    Bubbles in the glue


    Main cause: High oven temperature, glue bubbles.


    Protective Film for Aluminum Composite Panel

    What methods can we use to solve these problems?


    (1) Choose the right ink and increase the amount of coating; it is particularly important to choose a dry laminating white ink, which has a multifaceted impact.


    (2) Strengthening the wetting of the film with glue and improving the defects of poor local gluing; increasing the amount of glue applied; increasing the temperature and pressure of the laminating rollers and using smooth rollers; reducing the laminating rate and increasing the wetting time and gluing time; choosing a glue with good wetting properties and preheating it.


    (3) Preheat glue and film and increase the temperature of the laminating press rollers.


    (4) Clean the coating rollers and strengthen the management of the coating volume and coating rollers. For general new rolls are used to 5 million meters (5000R/S) after the coating rolls are aluminized, 3 times, and then chrome plated treatment before engraved plate treatment, so that management can prevent problems such as poor housing appearance and low peel strength due to inadequate coating rolls. (b) Eliminating static electricity from the film during use, paying attention to maintaining the environmental hygiene of the workbench, and keeping and filtering the receiving solvent completely sealed.


    (4) Adjusting viscosity, replacing the coating rollers, and achieving the required amount of coating within the range of viscosity required by the process, through the solid content of the glue and the coating rollers.



    adjust the drying conditions, small air volume, easy to produce solvent residues, general drying box nozzle per second should be wind speed between 30-35 m, drying box temperature Ⅰ section for 50-60 ℃, Ⅱ section for 60-70 ℃, Ⅲ section for 70-80 ℃, import I section temperature should not exceed 60 ℃.


    (7) Increase the amount of coating, increase the temperature and pressure of the compound press rollers, and increase the rubber hardness of the press rollers, so that the rubber hardness of the press rollers reaches 80~85℃. And introduce the angle adjustment of the film "wrap angle" in front of the pressure roller to make the compound roller move in the tangential direction as far as possible.


    Take measures to prevent moisture, such as avoiding the reaction of moisture-absorbing materials such as nylon and cellophane with NCO groups to generate CO2, keeping the environment dry, and sealing the package with curing agents.


    (9) Increase the temperature and pressure of the coating and laminating rollers used to manufacture protective film for aluminum composite panels, and increase the hardness of the rubber used in the rollers, so that the rubber hardness of the rollers is increased to 80-85°C. Also, introduce an angular adjustment of the film "wrap angle" in front of the press rolls so that the laminating rolls move in the tangential direction as far as possible.


    (10) In the protective film for aluminum composite panel forming process to take moisture-proof measures, such as moisture, curing, sealing, covering materials, etc., can also play a certain role in improving the bubble problem, thus greatly improving the quality of the protective film and the use of the effect.


    As a professional protective film for aluminum composite panel manufacturer, Xinhao has the professional equipment and experienced technicians, we are sure our protective film for aluminum composite panel will satisfy you.