Study On Express Temperature Controlling Packaging Of Quick-frozen Seafood

Frozen seafood belongs to perishable foods,it will have different shelf lives with ambient temperature,humidity and other conditions.In order to reduce the environmental effects of temperature and humidity on the quality of frozen seafood,this paper selects the best insulation material,coolant and package structures,and designed reasonable transport packaging form,which maintain frozen seafood always being a reasonable temperature range in the express transport.Selecting the thermal insulation materials of EPS、XPS with density of 1skg/m3、34kg/m3 respectively,combining the above two materials with different thickness,making into insulation boxes with a total thickness of 3cm.Through testing average temperature rising speed of center point of different thickness combinations incubators,we found that the average temperature rising speed of 3cnEPS、lemXPS+2cmEPS、1.5cmXPS+1.5cmEPS、2cmXPS+1cmEPS and 3cmXPS boxes were 0.5108℃/h、0.4585℃/h、0.4238℃/h、0.399℃/h and 0.3639℃/h respectively.The results showed that the box bigger the proportion to total thickness of XPS,the better heat preservation performance the box has.Testing five boxes with an average temperature rise speed of center point under the same inside volume and the different outside surface area condition,and compared thermal insulation properties of the boxes.The average temperature rising speed of incubators with inside dimension 256*210*256mm、312*210*210mm、360*210*182mm、410*210*160mm and 460*210*143mm were 0.3792℃/h、0.3909℃/h、0.4115℃/h、0.4238℃/h and 0.4800℃/h respectively.The results showed that the smaller outside surface area,the better thermal insulation properties of the boxes under the same packaging material and inside volume.Studying the effect of 12 different coolant and frozen sea products amount ratio on holding time of covered with aluminum foil insulation boxes under 23oC/50%RH extermal temperature and humidity conditions.Results showed that when coolant and frozen seafood amount ratio is 0.15:1,the holding time of six test points of the box reach 12h;When coolant and frozen seafood amount ratio is 0.45:1,the holding time of six test points of the box reach 24h;When coolant and frozen seafood amount ratio is 0.75:1,the holding time of six test points of the box reach 48h.Under 23℃/50%RH external temperature and humidity and varying temperature conditions,the paper verified the holding time of three different mass ratio above,and then obtained the mass ratio of transporting 12h,24h and 48h.Under the transport time for 48h,the relational model between coolant mass and holding time can guide manufacturers choose a suitable coolant in express transportation,and besides saving transportation costs.