According to the carton factory, due to the different raw materials used in the production of cartons, the probability of white spots is also different. There are two common cases of white spots on aluminum composite film: one is when it is off the machine and basically disappears after ripening; Second, it will not disappear after ripening. The latter one seriously affects the appearance. Why do printing white dots appear?

纸箱厂纸箱印刷出现白点原因及解决方法：

Causes and solutions of white spots in carton printing in carton factory:

1.上胶量不足。如果上胶网线出现堵塞或者磨损，引起胶粘剂固含量不足就会导致上胶量小而出现白点。经常清洗上胶网线辊，保证上胶量。在停机时保持发动网线辊空转，防止堵板，根据印刷品状态调整胶水浓度选择合适的网线辊。

1. Insufficient glue amount. If the gluing screen cable is blocked or worn, resulting in insufficient solid content of adhesive, it will lead to small gluing amount and white spots. Clean the gluing wire roller frequently to ensure the gluing amount. When the machine is shut down, keep the wire roller idling to prevent blocking. Adjust the glue concentration according to the print state and select the appropriate wire roller.

2.纸箱厂印刷工序溶剂残留高和复合工序溶剂残留高都会出现白点，因为发生这两种情况材料阻隔性比较好，在复合后导致溶剂残留高，熟化后复合膜内的大量溶剂被释放出来形成气泡和白点，甚更多的白点。

2. The high solvent residue in the printing process and the high solvent residue in the composite process in the carton factory will lead to white spots, because the barrier property of the material is relatively good in these two cases, resulting in high solvent residue after compounding. After curing, a large amount of solvent in the composite film is released to form bubbles, white spots, or even more white spots.

解决方法：尽量控制印刷工序及复合工序溶剂残留量，必要情况下将下机样品放入80℃烘箱中30分钟，观察白点有无消失，在这里提醒大家烘箱温度分段设定，避免刚开始温度过高，涂胶界面结皮，溶剂挥发不完全。

Solution: try to control the residual amount of solvent in the printing process and composite process. If necessary, put the off machine sample into the 80 ℃ oven for 30 minutes and observe whether the white spot disappears. Here, we remind you to set the oven temperature in sections to avoid excessive temperature at the beginning, peeling at the gluing interface and incomplete solvent volatilization.

3.油墨隐瞒力差。纸箱厂介绍油墨隐瞒力差会引起白点，特别是淡色油墨。光线穿过油墨层而被铝层反射回来，发生的白点选择隐瞒力好、油墨粒度细的油墨。恰当增加上墨量，进步隐瞒率。这儿并不是说粘合剂本身，这种粘合剂表面张力高，涂布性能差，涂布不均形成的白点现象。

3. Poor concealment of ink. Carton factory introduced that the poor concealment of ink will cause white spots, especially light ink. The light passes through the ink layer and is reflected back by the aluminum layer. For the white spots, choose the ink with good concealment and fine ink particle size. Properly increase the amount of ink and improve the concealment rate. This is not the adhesive itself. This adhesive has high surface tension, poor coating performance and uneven coating.

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This article is provided for you by the carton manufacturer. Our website is https://www.shuangfengbaozhuang.cn We will wholeheartedly welcome your visit