Temperatures Food Packaging Materials

As China's most populous country in the world,every year consume a lot of heat-sensitive items,including the medical field insulin,blood,vaccines and perishable food and other agricultural products.Of course,these temperature-sensitive goods also requires a lot of cold chain transport also brings a lot of energy consumption.With the increasingly prominent issue,phase change energy storage technology has been more and more attention and understanding.Global chocolate consumption market has exceeded $ 56 billion in recent years,the average annual growth of China's chocolate consumption reached 15 percent higher than the global average.China's chocolate industry is out of the woods,is expected in the next 10 years,China will become the world's second largest chocolate market,but due to chocolate products easily melt at high temperatures,resulting in lower use value,taste worse,aroma loss and a series of adverse effects,causing huge losses to the manufacturer.In order to be sufficient to cope with a wide variety of chocolate climate change,it is bound to put forward higher requirements chocolate packaging.The phase change material can be a good solution to this problem,to ease pressure on resources consumption.Phase change materials is an energy storage material,meaningful energy storage material is that it may be some form of energy stored under certain conditions,and can be released and utilized under certain conditions,it can achieve energy supply and demand people consistent purpose.Microencapsulated phase change materials plays an important role in the field of storage insulation,conventional phase change materials in practical applications need to be encapsulated or use special containers to prevent leakage.The micro-encapsulated phase change material consists of a core material and wall material composition,in the event of solid-liquid phase change after maintains its structure and shape in the solid state,is an encapsulated phase change material is not required.Therefore,absorption and release process cooling capacity,there is no package thermal resistance and heat transfer between the media.This topic combing through the literature and research to develop a feasible plan.Paraffin as a core material,urea-formaldehyde resin as wall material,prepared by in-situ polymerization phase transition temperatures were 14?,16?,18?,20?,22?,24?,six kinds of paraffin/urea formaldehyde resin microcapsules phase change material,such as a water-in-oil microencapsulation structure(O/W).By DSC differential scanning calorimetry,scanning electron microscopy and laser particle size analyzer and infrared spectrometers and other equipment for the obtained micro-encapsulated phase change material properties were characterized and analyzed.And discusses the different types of emulsifiers,emulsifier and the solution pH influence on phase transformation microcapsules coated rate value.The results show that:the subject prepared paraffin/urea formaldehyde resin-encapsulated phase change material has not changed in terms of the phase transition temperature than single substance paraffin,and latent heat greatly reduced.Covering rate is an important factor in reducing the latent heat,so by changing the type of emulsifier with HLB value found emulsifier sodium dodecyl sulfate and an HLB of 14,the highest paraffin coating rate.