Question: How to solve the problem of bubbles in PET film coating in carrier tape process?
Answer: the product has bubbles
(1) The printing ink layer is not completely dry: press it first and then glue it. You can also postpone the coating date to make it dry completely.
(2) The printing ink layer is too thick: the coating amount of adhesive can be appropriately increased, and the pressure and composite temperature can be increased.
(3) The surface temperature of the compound roll is too high: take cooling measures such as air cooling and closing the electric heating wire to reduce the temperature of the compound roll as soon as possible
(4) Too high drying temperature: too high drying temperature will cause peeling on the surface of the adhesive and foaming failure. At this time, the drying temperature should be appropriately reduced.
(5) Cause of film: the blistering fault caused by wrinkle or relaxation of film, uneven film or crimping can be solved by adjusting the tension or replacing the qualified film.
(6) Reasons for adhesive concentration: high adhesive concentration, high viscosity or uneven coating and low dosage are also one of the reasons. At this time, diluent should be used to reduce the adhesive concentration or appropriately improve the coating amount and uniformity.
(7) The pressure of the pressure roller is too small: there are bubbles on the whole printing surface because the pressure of the pressure roller is too small, you can appropriately increase the pressure of the pressure roller.
(8) Top paper: there are bubbles at the lap joint of the two sheets of paper because the front and rear sheets of paper are top together when laminating. This phenomenon is mainly reflected in thick paper lamination. If the print has a large mouth, adjust the hand wheel of the continuously variable transmission counterclockwise to make the two sheets of paper have a certain overlap; When the print is held in its mouth for hours, the front and rear sheets of paper can be properly separated, but it should be noted that the distance should not be too large. Otherwise, the tail film will appear after the film coated product is cut.
(9) Printed matter Ruffle: thousands of printed matter are usually stacked together, resulting in uneven moisture absorption in the whole area of the paper, and the moisture absorption in the edge area is more serious, which is the reason for the generation of ruffle. The printed matter with ruffle edge will flatten under the pressure exerted by the lamination, but it will return to its original state after leaving the pressure roller. This creates bubbles. The solution is: wet or spread the printed matter with lotus leaf edge to dry.