The Simulation Of The Flexible And Thin Materials Folding And The Development Of The Automatic Packaging Device

Folding packaging without adhesives and easily degradable materials is an environmentally friendly packaging method.The physical properties of the packaging materials used are quite different from those of common materials such as cardboard and plastics,and they are easily damaged during the packaging process.The difficulty of restraint and control during the folding and deformation process is the key problem that restricts the automation of folding and packaging of flexible and thin materials.This paper focuses on the research on the folding and packaging technology of flexible and thin materials.The main work and results are as follows:The functional requirements of the packaging device are proposed at first,based on the requirements of the automatic folding packaging equipment for flexible and thin materials.Combined with the motion analysis of the manual packaging and the characteristics of flexible and thin materials,the folding packaging process was conceived and decomposed.The sequence of the folding packaging actions was determined and all actions were uniformly abstracted as a geometric change of the soft and thin material.The reliability of the folding actions is an important factor determining the stability of the automatic folding system.This work analyzed the technical principle of the folding of flexible and thin materials and designed the structure of the folding device.Based on the geometric principle,we deduced the morphological evolution equation of the folding process and established the dynamic equation of the material with the interaction of the compliant structure,determining the factors influencing the effect of the folding device operation.Besides,for the simulation and optimization of the folding device,Recur Dyn was used to establish the finite element models of the folding processes of the flexible and thin materials.The stress-and-strain distribution of the flexible and thin materials during the folding deformation was analyzed.The results show that the lateral position of the crease structure,the speed of the folding plate,and the friction coefficients of the folding plate and the compliant structure have the most significant influence on the folding effect of the material.The optimal combination of four significant parameters is determined through multi-factor analysis,and the speed limit of the folding board is determined according to the obtained optimal parameter combination.In addition,the influence of the lateral position of the crease structure on the folding effect is analyzed through experiments,and the change trend of the crease width and height is consistent with the simulation results.Finally,according to the results of the process action and simulation optimization,the overall scheme of the folding packaging device for flexible and thin materials was proposed and the prototype machine was established.The automatic folding packaging control system with S7-200 SMART ST40 as the control core was designed including designs of the control circuit and the main control program.The performance test of the prototype was carried out.The results show that the qualification rate of the samples is 93% and the packaging speed is 5.6 s/pack,demonstrating the feasibility of the automatic folding packaging scheme and the reliability of the prototype.