1. Increase the amount of glue applied. If the amount of glue is too small or the surface of part of the substrate is not coated with adhesive, it will be difficult for the two substrates to be bonded during compounding. We can choose an anilox roller with a deeper cell, or increase the amount of glue on the substrate surface by increasing the pressure of the rubber roller and reducing the contact pressure between the doctor blade and the anilox roller. For some plastic film substrates, corona treatment can be performed before coating to make the surface fluffy, thereby improving the ability of the substrate to absorb the adhesive and increasing the amount of glue on the surface.
2. Selecting a suitable drying temperature that is too high or too low will affect the bonding fastness of the composite film. When the coated substrate is dried, the heating temperature is too high or after high temperature cooking, the surface layer of the adhesive will be carbonized, thereby destroying the bonding ability of the adhesive. If the drying temperature is too low, the manufacturer’s information will cause the adhesive to be incompletely cured, the adhesive’s viscosity is poor, and the composite is not strong. After a period of time, bubbles are likely to form in the composite film, which will damage the composite quality of the product. Of course, we can choose the adhesive digital printer with good high temperature resistance and retort resistance to adapt to higher temperature drying, such as the use of polyurethane adhesive.
3. Increase the composite pressure appropriately. Excessive composite pressure or uneven pressure at both ends of the composite roller will cause wrinkles on the surface of the composite film, and empty tunnels will be formed at the wrinkles after composite, which will affect the bonding fastness of the finished product. Appropriately increasing the compound pressure is beneficial to improve the bonding force of the compound.
In addition, in order to improve the bonding effect of the composite film and the quality of dairy packaging, it is necessary to avoid foreign matter, dust and other debris from adhering to the adhesive or the composite surface of the substrate. Concluding remarks When operating, carefully observe various problems and failures in the production process, and use the above methods to eliminate the failures reasonably. When there are multiple problems or failures, it may not be possible to use a single method. At this time, packaging machinery should be avoided, focusing on solving key problems, and then using other methods to solve minor problems one by one.
Post time: Apr-16-2021