The invention relates to a food special
tin foil and a preparation method thereof. Encapsulization
sodium metabisulfite and
powder of
calcium chloride are uniformly coated on a composite paper according to the elemental
area ratio to be prepared into the
tin foil. The preparation method of microcapsule sulphite comprises the following steps:
ethyl cellulose is added to
cyclohexane which is an
organic solvent, a motor stirrer is started to stir the mixture of the
ethyl cellulose and the
cyclohexane, meanwhile the mixture of the
ethyl cellulose and the
cyclohexane is heated by a water bath, thereby the ethyl
cellulose is made to be fully dissolved in the cyclohexane, the
powder of the
sodium metabisulfite as a core material is added according to the ratio, the mixture is continuously stirred, fine particles are made to be uniformly distributed into the cyclohexane solution of the ethyl
cellulose, then the temperature is slowly lowered,
sodium metabisulfite microcapsules are formed and then cooled to the
room temperature until
sodium metabisulfite microcapsules are solidified, and
sodium metabisulfite microcapsules are recovered by
filtration, washed twice by cyclohexane, and naturally aired and crashed at the
room temperature for standby. The prepared encapsulization antistaling agent and the
calcium chloride are uniformly mixed according to the ratio, and the mixed
powder is uniformly coated on the composite paper by a binding agent to be dried and packed.