Study On Preparation And Properties Of Food Antibacterial Wrapper With Hygroscopic Properties

In a variety of food packaging materials,plastic has light weight,low price and excellent barrier characteristics,occupies a large proportion in the field of food packaging materials.However,the further development of plastics in the field of food packaging is harmful to the human body,natural decomposition is extremely difficult,and serious environmental pollution will be caused,so it is restricted.Paper is one of the most promising green packaging materials,widely used in food,medicine,home appliances,cultural products and other fields.Food wrapper is a kind of packaging products with pulp and paperboard as the main raw materials.It needs to meet the requirements of safety,oil resistance,waterproof and moisture-proof,sealing and so on.There are few food wrapper on the market that have both humidity control and antibacterial functions.Therefore,this article will propose a method for preparing food antibacterial wrapper with humidity control.Coat one side of the base paper with a cross-linked polyvinyl alcohol solution to close the pores on the surface of the paper and reduce the infiltration of air and water vapor on the outside of the package;an antibacterial agent coating liquid with bentonite as a carrier is prepared and coated on the side where the cross-linked polyvinyl alcohol has been coated.After it is naturally dried,an antibacterial wrapper with humidity control function can be obtained.The single-factor experiment is explored by using the polyvinyl alcohol concentration,cross-linking temperature,cross-linking time and cross-linking agent dosage as variables,and an appropriate orthogonal experiment is designed according to the results of the single-factor experiment.The optimal process conditions obtained are that the concentration of polyvinyl alcohol is 12%,the cross-linking temperature is 80?,the cross-linking time is 0.5 h,and the amount of cross-linking agent is 3.0 g.Because polyvinyl alcohol can form a film,the solution easily penetrates into the base paper.Under this condition,the water vapor transmission rate of the coated and dried paper is the least,and its wet tensile strength can meet the demand.Utilizing the cation exchange property of sodium bentonite,it is modified with cetyltrimethylammonium bromide to increase the interval between bentonite layers and facilitate the intercalation and adsorption of thiabendazole,thereby preparing bentonite antibacterial agents.The research results show that the modified bentonite layer spacing is significantly increased,the lamellae are stacked disorderly,some of them appear as curled-edge scale layers,and some of them form agglomerates;the bentonite intercalated by thiabendazole has a relatively loose structure and exists more curled,peeled loose sheets.It can also be seen from the energy spectrum and infrared spectrum that thiabendazole is present in the bentonite antibacterial agent.In the antibacterial experiment,the 96-well plates experiment method was used to measure the minimum inhibitory concentration and the minimum bactericidal concentration;it has also been observed that the bentonite antibacterial agent has a good antibacterial effect on Gram-negative bacteria represented by Escherichia coli and Gram-positive bacteria represented by Staphylococcus aureus by the inhibition zone method,which all indicate that the bentonite antibacterial agent has been successfully prepared.The prepared bentonite antibacterial agent is mixed with chitosan/polyvinyl alcohol solution to obtain an antibacterial coating solution,which is coated on the side where the crosslinked polyvinyl alcohol has been coated,and after it dries naturally,the antibacterial packaging paper with wet function can be obtained.The antibacterial coating solution and antibacterial wrapping paper were tested by the inhibition zone method and the agar plate diffusion method respectively,and the results showed that both have good antibacterial effects against Escherichia coli and Staphylococcus aureus.When testing the humidity control performance of the packaging paper,using bentonite antibacterial agent and glycerol as variables,the relationship between the moisture absorption amount and the moisture absorption time of the wrapper in a constant temperature and humidity box at 15? and a relative humidity of 100%was explored;The relationship between dehumidification amount and dehumidification time in a constant temperature and humidity box at 40? and a relative humidity of 13%after being placed for 48 hours.In the initial 3 hours,both the moisture absorption rate and the moisture release rate gradually increased with time,and changed significantly with variables.It stabilized after 3 hours,and the humidity of the packaging paper reached equilibrium.