Factors causing uneven plastic deformation of the

2022-10-16
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Factors of uneven plastic deformation of rubber blanket

different pressures on rubber blanket in use will lead to different plastic deformation of rubber blanket thickness, which will lead to uneven thickness of rubber blanket. For example, after printing 4 folio products for a long time on the folio machine, then print the folio products. When printing 4-part products, the pressure between the rubber cylinder and the plate cylinder is evenly distributed on the whole blanket. However, the pressure between the rubber drum and the embossing drum is uneven due to the existence of the printed paper. At the corresponding position of the 4-opening paper, the pressure on the blanket is large, and the pressure on the position other than the 4-opening paper is small or no pressure. Therefore, the plastic deformation of the blanket at the corresponding position of the 4-opening paper is large, and the thickness is reduced much. When changing the printing of split paper, this position is prone to insufficient pressure. Because this lack of pressure is caused by the local depression of the rubber blanket, even if the overall pressure between the rollers is increased to provide technical support for the transformation and upgrading of the polymer surface material industry, there can be no significant improvement. The only way to remedy this pressure is to supplement the rubber, and this rubber blanket can not be used to print products with high quality requirements. This kind of uneven plastic deformation is related to the following four factors:

1. Printing pressure. The greater the pressure, the greater the plastic deformation of the blanket at the paper, and the more likely this uneven plastic deformation will occur. Therefore, when printing, under the condition of good ink transfer, the field brush pressure should not be too large, and the best pressure printing brush should be used

2. Tightness of rubber blanket. The tighter the tension, the thinner the adhesive layer of the rubber blanket, the worse the sensitivity and elasticity, and the more prone to uneven plastic deformation

3. Performance of rubber blanket. Air cushion rubber blanket is not prone to uneven plastic deformation because of its good sensitivity, elasticity and recovery ability of micro foam sponge layer

4. printing quantity. Printing a certain size of paper in large quantities for a long time will lead to large local plastic deformation

5. Accumulation of paper wool and ink. After printing for a period of time, the surface of the blanket adheres to a lot of paper wool and paper dust because of physical adsorption. If it is not cleaned in time, the thick paper wool and paper powder will increase the local printing pressure, making local plastic deformation occur. When printing paperboard, the paper scraps produced by cutting at the trailing edge are easy to accumulate on the blanket under the action of oil and water, relative to the position outside the edge close to the edge of the paperboard. Due to uneven paperboard cutting, when printing some slightly longer paperboards, the accumulated paper scraps cause local depression. Therefore, when printing paper that is easy to fall off wool, powder and chips, as long as the measuring circuit has no defects, you should pay special attention to cleaning the blanket in time. There is dry ink adhered to the embossing cylinder, which will also cause local depression of the blanket due to uneven local pressure during printing. Therefore, after the printing of each size of product and after the printing of each day, 11. It can realize the adjustment of the speed of lifting and lowering of the beam during sample clamping. The blanket and the embossing cylinder should be cleaned in time

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