Research On Key Technologies Of Food Packaging Based On Central Kitchen Scenario

With the upgrading of refrigeration technology and the diversification of dining methods,the status of frozen ready to eat meals in the catering industry is gradually increasing.In recent years,the rampant COVID-19 epidemic has made people pay more attention to convenient and hygienic dining experience.At present,although takeout has brought great convenience to people,the frequent occurrence of poor sealing and easy leakage in its existing packaging has also caused a series of problems.In addition,traditional takeout production and packaging processes are manually operated,resulting in low production efficiency and difficulty in meeting the daily order demand of thousands of people in major commercial areas.The emergence of the central kitchen model has improved these problems.This project aims to study key technologies such as frozen food packaging design and packaging process in the central kitchen mode.Based on the actual application and processing scenarios of frozen food packaging,the structural design,simulation,and performance testing of food packaging are completed.A packaging structure that is convenient to use and can be heated and vented is designed,and a matching process plan is proposed.In addition,the key packaging mechanism parameter design and the establishment of a three-dimensional mechanical model are completed,this provides a certain reference basis for the innovation and upgrading of the central kitchen.The main research content and conclusions are as follows:(1)Researched the packaging types,structures,materials,and their advantages and disadvantages of common food products in the market.Combined with the usage scenarios of frozen food packaging in central kitchens,and based on the two major packaging requirements of materials and functions,the packaging form of frozen food products was determined to be composed of a box body,a cover film,an exhaust valve,and a box cover.The process plan for this packaging form was proposed to adopt a linear horizontal process route.(2)The microwave heating mode was selected as the application scenario of packaging to explore the impact of packaging film on the microwave heating of food in the central kitchen.The boxed mashed potatoes were used as the research object,and two geometric modeling were constructed with COMSOL,with or without packaging film.The results showed that the RMSE values of the temperature uniformity coefficient(COV_T)of the characteristic point temperature simulation value and the experimental value of the covered film group and the uncovered film group were 0.011 and 0.022,respectively,which were less than 1.The simulation temperature curve had a high fitting degree with the experiment,providing a reliable simulation method for the study of microwave heating frozen food packaging.At the same time,the simulation and experimental results of the covered film group were smaller than those of the uncovered film group,verifying that the packaging cover film has a promoting effect on the microwave heating effect of food.Using FLUENT to simulate the heating and exhaust process of food products,the model was simplified to the exhaust problem during liquid water boiling.The results showed that setting the exhaust hole at 53.3 mm horizontally and 36.7 mm longitudinally from the center position,with a diameter of 2.6 mm,was the most suitable exhaust parameter.Starting from the sealing performance and user experience,it was determined to use PP for the packaging box body and PA/PE composite film for the packaging cover film.Finally,the one-way exhaust valve structure was designed,and the overall design of the exhaust packaging was completed.(3)A sample was prepared for the heat sealing tape of the lunch box,and the optimal parameters for the heat sealing of PA/PE composite film and PP sheet were determined to be a heat sealing time of 1.5 seconds,a heat sealing temperature of 140℃for the lower pressing plate,and a heat sealing pressure of 0.5 MPa.Currently,the experimental results of the heat-sealing strength were higher than the simulation values,proving the reliability of the packaging heat sealing strength.The compressive strength test and heating exhaust performance test of the designed packaging structure were conducted using ANSYS.The results showed that the mechanical strength of the designed packaging can meet the compressive strength requirements in practical application scenarios,and the gas inside the packaging will not break through the packaging cover film during the exhaust process,resulting in good exhaust effect.(4)Completed the design of the packaging process plan for the designed meal packaging and the parameter design of the key mechanisms of the packaging equipment.Used MATLAB to analyze the speed and acceleration motion characteristics and determine that the planetary gear mechanism with a tooth ratio of 3 is the optimal design plan for the box picking mechanism.Determined the design of the six stage cam as the filling mechanism,and found when the corresponding motion angles for short range rest,medium range rest,remote range rest,back distance,return distance and push distance were 40°,120°,10°,30°,100°,and 60°,the operation was stable,the impact was small,and the motion characteristics met the design requirements.Finally,three-dimensional mechanical design was carried out on the box picking and delivery device,meal filling and measuring device,packaging cover film adding valve device,heat sealing device,lid picking and closing device,and product conveying device,completing the three-dimensional modeling of the virtual prototype of the meal packaging production line.