Analysis of tension control on intaglio printing press
Author： Shenzhen HappyField Packaging Machinery Manufacturing Co., Ltd.Publication time：2018-06-04 09:35:06Views：2417【SLM】
Before describing this problem, we should know something about tension control. At present, the use of gravure press requires the application of tension control principle. There are mainly two parts：...
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Before describing this problem, we should know something about tension control. At present, the use of gravure press requires the application of tension control principle. There are mainly two parts：
The first part is from the feed to the feed roller. Overprint error, that is, the difference of printing accuracy between multi color printing. The position relationship of the printing machine is correct. The error is caused by elongation or shortening of the material, and a certain elongation is controlled within the allowable range. The tension control is effective.
The second part is from the receiving roller to the various parts after receiving, we should pay attention to the tension, uniformity, reliability and other factors.
Tension control between feeding shaft and feeding roller：
The traction roll moves the printing material out of the feed shaft at a certain speed and tension and sends it into the printing section. The tension is greater than the tension of the printing section, and the tension is usually controlled by the brake on the paper shaft. As is known to all, the volume of the operation at the same time gradually becomes smaller. In recent years, with high speed and diversified materials, coil diameter has changed greatly. Manual mechanical brakes used in the past could not reach high quality prints. It is necessary to choose automatic control mode, especially using tension gauges to manage data. The detection methods include spring roll type and micro displacement type. Mechanical brakes have been used for a long time since they are cheap, but the torque values are not accurate. There are other forms of appearance. The magnetic powder brake is made of magnetic powder as the friction medium, and its torque - current characteristic has good linearity. It is widely used. Pneumatic brake has many uses in printing machinery, but the nonlinearity of torque characteristics and large wear factor. It is also gradually replaced by large capacity magnetic powder brake.
Feeding tension control problem, feeding tension is determined by the following factors：
The uneven thickness causes the tensile change.
Material skidding and even being hung up slowly;
The material and shaft are deviated from the center, and the material and shaft are not installed well.
The change of the circumferential speed is produced during the rotation of the turning device.
The counterforce of the press roll and the cutter when the paper is connected.
The roundness of each roller is not enough.
Most of these changes occurred in a short time, and all of them were transmitted to the printing department as tension changes. From the point of view of the mechanical structure, it is necessary to notice that the inertia and manufacturing error of the guide roll between the feed shaft and the traction roller are the causes of the increase of tension, especially the low tension under a few kilograms that cannot be ignored.
Tension change and control between the traction roll and the plate：
In the gravure press, the traction roller is adjacent to the first roller and usually has a peripheral synchronous mechanism. This is different from the feeding condition, the diameter is not changed, and the tension is controlled by other principles.
Printing materials are elastic and plastic like general objects. Printing must be carried out within elastic limits. The tension is controlled by the law of elasticity. This is to understand the characteristics of different materials.
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