In recent years, the manufacturing technology of offset printing presses has grown by leaps and bounds. From the recent large-scale printing equipment and equipment exhibitions across the country and the provinces and districts, the flat sheet offset presses that once represented the higher level of printing presses in China have emerged. , 05 machine has almost no trace on the exhibition, and scalable units or multicolor machines have become mainstream products at all levels of all kinds of exhibitions, these machines in terms of function, quality, regardless of modeling, human-machine function design The visual appearance has almost equaled that of foreign brands, and some of the performance and indicators have been comparable to international famous brands. However, the user's expectation of using the equipment of the offset printing press is also getting higher and higher. The human-oriented humanized design concept has become the common goal of the supply and demand sides, especially the protection of the machine operator's environmental conditions, lowering the skill requirements of the operator, and reducing labor. In the past, strength has not been given due attention as a minor contradiction. Now these minor contradictions have risen into major contradictions and have become the focus of common concern.
The speed of the offset printing press used to be around 1 000 printed hours per hour. The effect of noise on people is often overlooked. For foreign offset presses, for example, the maximum speed has reached 15,000 to 16,000 impressions per hour. Many domestic machines are also sprinting to this limit speed. The increase in printing speed has greatly increased the difficulty of machine design and manufacturing. The issues that need to be tackled are exposed. For example, the noise of the machine is obviously increased. In the past, although domestic offset presses also paid attention to the problem of noise reduction, most of the energy was placed on the rule system and the paper-feeding mechanism because there were many reciprocating oscillating devices in these two parts. Composition, inertia, is a recognized core organization, high precision requirements. They are both a source of high noise and have a crucial influence on the print register. People think that grasping the main contradiction, we must grasp the paper rule system, because they are the heart components, are the parts of the people most concerned about, from the cam movement analysis speed, acceleration size, stress conditions, select parts materials, heat treatment process requirements, etc. , Strict and serious efforts to solve the problem, in fact, in recent years, under the efforts of various manufacturers, the printing machine's paper feeding system has indeed greatly improved, even in the high-speed printing state, the reference accuracy and machine noise are significantly improved and Improvements such as Beirenâ€™s N300, Shanghai Guanghuaâ€™s PZl020, Jiangsu Rugao's Changsheng series machines, etc., their rules and delivery mechanisms have been designed and manufactured to a high level, yet they are the other major source of noise for offset presses. The progress of component improvement is relatively slow.
The high-speed friction between the sleeve roller chain and the guide rail driven by the offset press-driven tooth row is one of the main noise sources of the machine. Reducing or eliminating the noise of this part is also a problem for offset printing manufacturers at home and abroad. Some foreign manufacturers Reduce the noise caused by the friction between the chain guide rail and the take-up tooth row sleeve roller chain, adopt the fully-enclosed guide rail scheme, and reduce the clearance between the guide rail and the chain roller to improve the manufacturing precision of the roller chain guide rail, in the receiving plate row When climbing high or passing through the arc, the chain can only close to the surface of the guide rail. The centrifugal inertia force of the chain is eliminated by the guide rail restraint. The running noise is partially controlled. Of course, the guide rail cannot be made very precise, and the gap cannot be absolutely absent. This kind of noise reduction measures imposes higher requirements on design and manufacturing, and relatively high demands are placed on the lubrication of the contact surfaces of the chain and the guide rails. If the lubrication is not sufficient, the chain will run easily, wear will increase, and even the card Resistance phenomenon. Some manufacturers also improve the guideway curve design. Instead of using simple arcs to climb the chain, they use a function curve with a smaller acceleration value, and two phase back arcs at the inflection point of the guideway. A straight line is arranged so as not to suddenly reverse the centripetal acceleration of the row of teeth, thereby reducing the impact vibration in the running of the chain guide. In addition to the improved design of the delivery chain guide rails in terms of shape and accuracy, there are some manufacturers who have made bold attempts on the selection of guide rail materials. For example, there are engineering plastics for the chain guide rails on some manufacturers' products, like reinforced nylon, but due to nylon Changes in self-lubrication caused by the differences in the types of material components and the thermal deformation in the use of drying and drying equipment, etc., have a certain impact on the speed and scope of the promotion. Recently, some companies have tried to use new materials of special carbon fiber composite technology and produced guide rails to obtain satisfactory results. Jiangsu Rugao No. 2 Printing Machinery Factory cooperated with experts from Xi'an and Shanghai Materials Research Institute to carry out bold practical trials by adopting different formulation processes. Finally successfully developed a self-lubricating, maintenance-free, refueling-free, wear-resistant, shock-absorbing and noise-reducing effect of the ideal delivery paper chain guide rail, due to the self-lubricating mechanism of guide rail material, friction coefficient is small, resistance is small, less wear, can be completely The maintenance-free function is realized, especially when printing large-ink prints on coated paper with high printing speed. The ink is not easy to dry. To prevent picking, the printing machine often needs to spray the toner, and the dust is evenly distributed. When flying on the surface, the oil stains on the ordinary metal printer guide rails can be covered with dust. When cleaning and maintaining the equipment, the operator is strenuous and the cleaning is not complete. The dust on the surface of the rails can accelerate the wear of the machine parts. The guide rails of the new material realize refueling-free and maintenance-free operation, and the dust removal work becomes very easy. The new material guide rails have a self-lubricating function with a small friction coefficient and do not suffer from poor movement or jamming. The power consumption of the entire machine is low, while the resistance is low. The high-temperature characteristics are more suitable for multi-receiving chain offset presses with gloss drying. The unique shock absorption function of the guide rail is very beneficial to reduce high-speed running chain noise, reduce machine vibration, reduce noise, improve the working environment effectively, improve the stability of the machine, and even help improve the quality of machine prints.
The use of special modified carbon fiber composite engineering guideway materials on offset presses is a bold attempt in the application of new materials. It is the result of innovative thinking. The effect of the preliminary inspection is comparatively exciting. Many of its advantages have been gradually recognized. The continuous improvement of the material technology can be expected to improve its performance.