Improvment Of Ink Supply Control System In Gravure Printing Application

The ink supply control system in recent years,as critical component of printing equipment,has been greatly developed along with the significant advancement of printing technology.It's been widely recognized by the market because of extraordinary merits,such as enhanced printing quality,ink saving,workload reduction as well as improved operational environment,etc.In comparison with original ink supply system,the operational efficiency is increased and direct labor involvement is deduced due to the application of current ink supply control system.From quality controlling perspective,human and equipment/system involvement are less considered,which means product quality can be more effectively stabilized without those uncertain factors accordingly.The ink supply control system of GWASY-X model printing machine been researched in this paper,essential parts of it been improved and the hardware with driver been re-designed in associated with original function model,the major research is covered as follows:1.The organization and mechanism of ink supply control system been discussed.Normally,ink supply control system is composed of printing unit,cyclic pump,viscosity sensor,control unit and execution unit.The viscosity index of ink is inspected by viscosity sensor with high accuracy,the overall system is commanded by control unit,specifically,and the solvent supply valve is adjusted to normalize the ink viscosity in accordance with defined algorithm.Meanwhile,the mixture by ink and solvent is rapidly blended by powerful loop stirring system to avoid the existence of "solvent shock".Finally,the features of ink is controlled within specifications.2.The operational process of original ink supply control system of GWASY-X gravure printing machine is demonstrated and root causes led to poor product quality is analyzed.The original ink supply control system of GWASY-X gravure printing machine,the ink viscosity and its quality can be easily influenced in production as actual operational requirements cannot be satisfied by original function models,such as viscosity sensor and execution unit,etc.,for instance,the dilution of solvent can be exaggerated by higher temperature,consequently,the defects of product clinging as well as randomly distributed ink coverage are produced by increased ink viscosity.The inaccurate quota of ink with solvent is created by the accuracy of viscosity sensor,which is the cause of chromatism on printed products,poor performance of each step in process and downgraded overall effect.Even worse,negative impact to product and its operational environment is considered,frequent maintenance,downtime,low yield,workforce overloading and messy surroundings are due to high failure rate,which is also the reason why product quality management and chromatism control are difficult to be implemented.Therefore,the demand for improvement on original ink supply control system,namely to resolve current problems,is imperative under the circumstance of driving overall equipment efficiency and obtaining controllable product quality.3.Control methodology and operational principle of original ink supply control system is analyzed.Controlling of ink viscosity is the critical part in the system of ink supply control,which is generally realized by the integration of viscosity sensor,control unit and execution unit.Real-time data of ink status is transmitted from viscosity sensor to control unit,overall system condition can be accessed and parameters can be modified by user via HMI,then ink can be adjusted to ideal status by execution unit according to modified parameters and furthermore,producing job can be automatically executed by pre-configured production profile.4.Effectiveness of each unit of original ink supply control system are analyzed and re-designed as improvement.To address the situation of diversified printing ink materials,the requirement of improving process capabilities of each unit in system is obviously foreseen.Categories of viscosity,viscosity influencing factors and inspections are analyzed,different equipment,as options,for viscosity checking are compared to conclude that the rotation method is considered as most responsive,in-time sampling for further step of control system.Sensor section is re-designed,the rotator of viscosity inspection equipment is ameliorated to work with features of different ink materials.By comparing and testing,the cost-effective and friendly accessible flush inductive proximity switch is selected to provide sound sensitive feedback for controlling.Features of BLDC motor,like rapid dynamic responding,wider scope of rotational speed and high efficiency,are source of powerful propulsion.Clutch unit is integrated to system for achieving the goal of ink viscosity regulation anytime by clutching mobile component of motor shaft,which is driven by solenoid,on/off from encoder disk.In terms of execution unit,Tiny24 chip is adopted as the control IC of valve terminal to drive real-time capability in controlling.5.Communication protocol and driver program are optimized while the improvement implementation on system hardware,real-time communication between nodes is refined and phase of development is simplified as well.Integrated clutching unit and control program of valve terminal are optimized.Finally,the solution of improvement is validated,the ink viscosity controlling by improved ink supply control system is proved to be more effective and in time,multiple benefits such as better printing quality,higher operational efficiency as well as predictable revenue increasing for end user are demonstrated.