| With the continuous development of society,more emphasis has been put on the quality and safety of food packaging.In present period,most of the materials mainly used in food packaging are petroleum-based materials,which exists many problems such as degradation,pollution and so on.It does great harm to the environment.The content of this article is primarily based on the support of the key project of Natural Science Foundation of Tianjin about the study of the rheological properties and spray atomization law of soybean protein solution.It analyzes rheological properties of soybean protein and measures spray particle size distribution of soybean protein as well as atomized particle velocity field to study the heterogeneity and average density of soybean protein solution that compounded on the vegetable paper as well as the effect of the heat-seal strength on composite paper with different parameters.The main contents of this paper are as follows:1)In order to make the vegetable paper have a good heat sealing effect,the paper used parchment paper as raw material to simulate the heterogeneity of soybean protein solution sprayed on vegetable paper.Firstly,the samples were collected by the camera.Secondly,the paper obtained the image area of the soy protein coating area through the MATLAB programming.Finally,the influence of different parameters on the area ratio of soybean protein coating was analyzed by Origin.When the hydraulic pressure and air pressure increased from 0.120 MPa to 0.220 MPa,the area ratio of soybean protein coating increased firstly and then decreased;when the flow rate increased from 35cc/min to 60cc/min,the area ratio of soybean protein coating increased firstly,and stability was in the middle.And when the single parameter was less than 0.160 MPa,0.180 MPa or 50cc/min,the spraying effect is the best.2)The effect of spraying parameters and belt speed on the average density of soybean protein was studied by response surface methodology.First,to find a suitable spraying spraying parameters by changing single factors,secondly according to the conclusion of the single factor experiment to design the optimal experiment scheme,The model was established to determine the effect of each parameter on the average density of the spray.The experiment showed that the influence of the hydraulic pressure and the belt speed on the average density of the spray is very significant,but the air pressure has no significant effect on it.Based on the analysis software,the model of the relationship between the area ratio of soybean protein solution and the spraying parameters and the belt speed was established,obtaining the optimum spraying conditions.When the hydraulic pressure attained 0.159 MPa,air pressure reached 180 MPa,speed was 11.93mm/s,soybean protein solution at the area ratio can reach 79.91%.3)Through the research on the heat sealing strength of soy protein celery composite paper in different heat sealing temperature,heat sealing pressure and heat sealing time,we can get a conclusion that when the heat sealing temperature increased from 80 degrees to 130 degrees,the heat-seal strength started to increase continuously,but when the temperature was higher than 100 degrees,the heat-seal strength gradually decreased and stabilized,and the maximum heat-seal strength was 218.35N/m.When the pressure increased from 20 N to 45 N,the heat sealing strength was increasing,however,when the pressure was higher than 30 N,the heat-seal strength gradually decreased and stabilized with the increased pressure,and the maximum heat-seal strength was 218.35N/m.When the heat sealing time increased from 5s to 10 s,the heat sealing strength increased continuously;however when the time was longer than 7s,the heat-seal strength gradually declined with the increase of time,and tends to a stable state.When the heat sealing time is 7s,the average heat-seal strength was 218.35N/m. |
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