An example of processing the calendering problem a

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Examples of treatment of post press polishing problems

there were quality defects of wrinkles and stripes on the surface of the surface paperboard of a batch of beer packaging boxes after press polishing. According to the quality requirements, the appearance of the paper after calendering should be clean, flat, free of scratches and wrinkles. Under the condition that the calendering process parameters (such as calendering temperature, pressure, speed, etc.) remain unchanged, we calendered the surface paperboard of the packaging box with another batch of varieties prepared for the upcoming fuel test. As a result, this batch of surface paperboard did not appear wrinkles and stripes after calendering. Through comparative analysis, it is believed that the reason is the quality difference between the two kinds of surface paperboard. The paper of the batch of surface paperboard that will produce wrinkles and stripes after calendering is relatively poor. However, this batch of surface paperboard has been polished. If it is scrapped because some wrinkles and stripes will appear after calendering, which cannot meet the quality requirements, it will result in late delivery and large waste loss. If it can be handled through appropriate remedial measures, it relies on the reciprocating motion of the plunger in the cylinder block to make the calendering quality meet the requirements. On the one hand, it can be delivered on time, and on the other hand, it can reduce losses

for this reason, we chose one of the effective measures to solve the problem through the treatment and test of several different methods. The method is: polish the surface paperboard that has not been calendered after polishing again, and then heat dry it on the calender first. The temperature of heat drying is the same as that of calendering. When heat drying on the calender, you can add rare earth elements of tens of thousands or tens of millions without pressure. Under the condition of steel belt transmission of the calender, put the paperboard on the surface of the steel belt at the end of the discharge port, The tissue paper is brought into the drying channel and returned to the feeding port of the calender by the steel belt. After such hot baking and then calendering according to the normal calendering process (i.e. adding one glazing and one hot baking), the wrinkles and stripes on this batch of face paperboard disappeared. Incidentally, under normal circumstances, the calendering temperature is generally controlled at 115 ℃ ~ 120 ℃, the pressure is controlled at 150 ~ 180kg/m2, and the speed is 6-10m/min. Of course, in the field operation, it is also necessary to reasonably adjust and master according to the thickness of the cardboard, and the remaining debris in the machine room should be removed first. It is worth noting that for the paper products to be calendered, there must be a choice in paper, otherwise the calendering quality requirements cannot be met

reprinted from: Shenzhen printing

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