Research On Multi-cavity Thermoforming By Film Of Irregular Package

Although the development time of thermoforming technology is not long,but because of its high processing speed,high degree of mechanization,cheap mold and easy to replace,adaptable,easy to recycle.Thermoforming in the field of packaging applications is very extensive,thermoforming can process thinner products than other methods,of course,the demand of flexible packaging is getting higher and higher,with the continuous development of technology,thermoforming can be applied to more areas.In this paper,through the study of thermoforming process,the film material can be applied to the thermoforming production of irregular package,expand the application range of thermoforming,reduce the cost,improve the production efficiency and respond to the market demand.This is also the urgent demand of the thermoforming industry.The main research contents include:(1)Background,purpose and significance.This paper mainly introduces the film thermoforming principle,research status of related fields at home and abroad,and provides the basis for the later research and design.Analyzes the existing technology and existing problems in the industry,and determines the necessity and significance of the research.(2)Thermoforming process analysis of irregular packaging.First,according to the specific research object,analyze its structural characteristics,according to the product structure and thermoforming requirements,select the appropriate materials,and design the packaging.According to the principle of thermoforming,put forward the process flow suitable for irregular multi-cavity thermoforming.And analyzed the common quality problems,and proposed the effects of irregular packages,films and multi-cavity on the quality of thermoforming.(3)Design of key structure of film thermoforming.Put forward technical requirements of film thermoforming,and design the main system and key parts.Choose reasonable method of heating and cooling,establish the unsteady heat conduction model of heating and cooling system,and presents the heat transfer function for multi-layer composite film,then use matlab to calculate time and use fluent to simulate temperature distribution.Design the forming mold and the structure of the pre-stretch according to the shape features of the irregular package.(4)Simulation by ANSYS Polyflow.Analyzed the forming process of vacuum thermoforming and the distribution of film thickness,and the reliability of simulation analysis was proved by testing.Then,the influence of different shaped pre-plug and different pre-stretch depths on the wall thickness distribution during the pre-stretch thermoforming(h ? 0)was simulated,and chose the optimum shape of the pre-tensioner and the process parameters.(5)Design multi-cavity thermoforming device for irregular package.Complete designing two parts of thermoforming device,the heating and pre-stretching forming device,including the power mechanism and the forming device.Based on the process scheme and parameters,the opening and closing mechanism is designed.Based on the production efficiency and the capability requirement,the multi-cavity distribution is designed,and the corresponding structure in the forming device is redesigned accordingly.On this basis,drew work cycle diagram,completed the overall system layout and device.