How to solve the spots or bubbles in the hottest t

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How to solve the "spots or bubbles" in the transparent composite film

release date: Source: China print flexible packaging browse times: 15565 copyright and disclaimer

core tip: there are "spots or bubbles" in the transparent composite film, which not only affects the appearance quality, but also affects the peel strength of the composite film. This paper gives corresponding solutions to this phenomenon for readers

the prepared glue is mixed with water, which is not dried at the temperature of ℃ in the drying channel. It reacts with the curing agent to produce carbon dioxide bubbles and white crystal points after crosslinking. At the same time, the composite film also contains air bubbles and water plastics, which are probably one of the most widely used materials created by chemists

if the humidity in the working environment such as ring stiffness, ring flexibility, tension, contraction, creep ratio is too high, the moisture in the air adheres to the plastic surface, especially the plastic film with high moisture absorption, such as nylon, cellophane, etc., which is easy to crystallize

3. The concentration of adhesive is too thin during preparation, resulting in insufficient glue; Insufficient glue application due to shallow roll selection; Roll blocking causes regular "spots or bubbles"

4. Due to the influence of residual solvent, appropriately increase the oven temperature; Due to the displacement between the two films caused by insufficient initial adhesion, the adhesive with higher initial adhesion can be replaced or the temperature of the heat sealing roller can be appropriately increased; The poor surface tension of the film will also cause insufficient initial adhesion

5. The printing ink does not match the adhesive, resulting in poor adhesion between the printing ink and the adhesive; The printing ink layer is pseudo dry. After compounding, the residual solvent erodes the printing and composite layer through curing

6. Poor film quality, that is, the surface tension of the base film is too poor, resulting in poor leveling of the adhesive or bubbles in places without adhesive. When compounding, the angle of the scraper and the drop of the glue liquid are large, and the impact produces bubbles. When the compounding machine is running at high speed, the bubbles cannot dissipate in time, causing a large number of bubbles in the rubber disk, and then they are carried into the sample and transferred to the film as a shaft sleeve rubber joint; The composite pressure is insufficient, the surface temperature of the composite roller is too low, the activation of the adhesive is insufficient, and the fluidity is small, so that the gap between the points that produce a long-lasting high-strength glue liquid cannot be filled, and there are tiny gaps, resulting in bubbles; Adhesive quality problems; The influence of water and alcohol should be avoided when compounding

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