Study On Ultrasonic Sealing Technology Of Food Brick Package

With the quickening step of our daily life,the brick package food has been loved by people because of its convenient transportation,long shelf life and so on.At present,in our country,the types,quantity and quality of the brick package food are not as good as that of foreign countries,which seriously restricts the development of the domestic independent research and development of brick package food.Ultrasonic welding,as a rising welding form,has been widely used in the manufacture of metal and plastics in the fields of high efficiency and cleanness.In recent years,ultrasonic welding has been applied to the sealing of the brick food,but the application of this technology in our country has just started.In this paper,we mainly study the key structure of ultrasonic sealing equipment and the sealing technology of food brick package:Firstly,the dynamic characteristics of ultrasonic horn are studied.Combination of design theory and dynamic finite element analysis of conical transitional stepped horn,we learn that the simulation results can more accurately express the dynamic performance of the structure,and it can reflect the dynamic characteristics of the horn.In this paper,the dynamic finite element simulation of the horn is carried out according to the three main design parameters,which includes the area ratio,the diameter of the port and the length of the tapered transition.The results show that the three main design parameters have regular influence on the dynamic characteristics of the horn,and the related design method is proposed.Secondly,this paper studies the technology of ultrasonic heat sealing process.According to the three main factors which affects ultrasonic heat sealing,namely welding pressure,ultrasonic time and dwell time,three kinds of brick packaging materials(pure plastic materials,plastic materials,paper plastic materials)heat sealed test and tensile tests are performed by orthogonal and the heat sealing material sealing failure and the maximum tensile force are recorded.The test results show that the three kinds of brick materials have different ultrasonic heat sealing effect,and it is pointed out that the pure plastic material is not suitable for ultrasonic heat sealing.The maximum tensile force was analyzed by range method,and the influence of three main factors on the heat sealing effect of different brick materials was obtained.Then,the finite element analysis of the temperature field of the ultrasonic sealing of the brick material is carried out.Through the analysis of thermodynamics and finite element simulation,the strain distribution of three kinds of brick materials under certain working conditions is obtained,and the ratio of heat to mass of three kinds of material is obtained.The temperature distribution of three kinds of brick material is obtained by thermal conduction simulation,and the effect of three kinds of brick materials is studied.Finally,the optimal design of the cam mechanism of ultrasonic sealing equipment is presented.The five step polynomial function fitting is applied to the cam contour curve,and the time planning experiment is carried out for the moving part and the back part.On this basis,the cam mechanism is optimized,and the working angle curve is obtained through the motion simulation.