Research On Preparation Of Polyvinyl Alcohol Modified Non-woven Fabric Antibacterial Composite Membrane And Its Anti-bacterial And Fragility-maintaining Properties On Dried Fish

In recent years,with the social progress,economic development,people's living standards further improved,leisure food demand is also growing,because of its special taste,brittle leisure food are popular among consumers,but during storage,brittle food is easy to damp soft,and even breed microorganisms,which will reduce food quality,even lead to safety hazards.Therefore,how to use packaging materials to ensure the quality and safety of food during storage is an important research direction in the field of packaging.In this paper,polypropylene non-woven fabric were used as substrate,modified by polyvinyl alcohol non-woven mother liquor,the whole experiment mainly explored the optimal coating modification methods by the means of surface coating method.Including the direction and times of coating,the drying temperature,drying time,the moisture absorption rate as the main index,the mechanical properties,optical properties and thermal stability as the auxiliary,optimal coating process was studied;then,adding antibacterial agent sodium dehydroacetate,sorbic acid potassium and sodium benzoate into polyvinyl alcohol liquor,preparing with the antibacterial polyvinyl alcohol liquor,use the liquor modify non-woven fabric,research the influence of the type and dose of antibacterial agent on composite film's mechanical properties,water absorption,optical properties,thermal stability and the antibacterial properties,pick out the best antibacterial polyvinyl alcohol composite membrane;finally,use antibacterial composite membrane as the inner packaging,PP film,PA film and anti-fog/anti-mold film as the outer packaging to do research on the anti-bacterial properties and keep-fragile properties of the combination.The main conclusions are as follows:(1)The research on the effect of direction of coating,the times of coating,drying temperature and drying time on modified composite membrane water absorption rate were conducted.The experimental results show that the transverse(long side direction and non-woven)as the coating direction,coating two times,the heating temperature is 70? and dry time is 8 minutes,by which can make the modified composite membrane with the best water absorption rate and smooth appearance,which means not fold,not curled up.Made by the best production process,the polyvinyl alcohol modified polyvinyl alcohol non-woven composite film was with good adhesion of mother liquor on the non-woven surface,the part of the mother liquor infiltrated into non-woven fiber.The mechanical properties are improved a lot.Transverse tensile strength increased by 69.35%,the longitudinal tensile strength increased by 64.63%;The optical properties and the thermal stability was reduced,but the composite film is in stable quality at 150?.(2)there are three kinds of antibacterial composite membrane PVA/NWF-SD(Dehydroaceticacid PVA modified antibacterial non-woven composite membrane(PVA/NWF-PS),potassium sorbate modified polyvinyl alcohol non-woven composite antibacterial membrane)and PVA/NWF-SB(sodium benzoate modified polyvinyl alcohol non-woven composite antibacterial membrane),water absorption properties,tensile strength and antibacterial properties of PVA/ NWF-SD is best,and when the dosage of the antibacterial agent is 2%,water absorption of PVA/NWF-SD is the best;when the addition amount was 2.5%,tensile strength is the highest;antibacterial effect increased,3% is the optimal dosage.The addition of antibacterial agent can improve the sealing performance of the composite membrane,and the thermal conductivity of the composite film PVA/NWF-SB is better than that of PVA/NWF-PS and PVA/NWF-SD.(3)Compared to the ordinary dried fish packaging PP film(group A),group C(inner packaging is PVA/NWF-SD film,outer packaging is anti-fog anti mold cling film)and group D(inner packaging is PVA/NWF-SD,outer packaging is the PA film),group B(inner packaging is PVA/NWF-SD,outer packaging is PP film)which can effectively separate water molecules,prevent water molecules attaching on the surface or filtrating into internal dried fish tissue,and control water content of dried fish,which can help dried fish effectively maintain quality and color during storage time,delay the increasing speed of the water content of the fish body,and the decreasing speed of oxidation of fat,texture and sensory index score,and the combination of group B can inhibit the growth and reproduction of bacteria in dried fish to ensure food quality and safety.