Technology And Mechanism Of Liguid Packing Boxes Recovery And Utilization

The liquid packing box is a kind of compound packing material mainlyconsist of paper, aluminum foil and low density polyethylene plastics (LDPE),which contains a small amount of printing ink, coating, glue stick and so on. It iswidely used in the packing of beverage, food, chemicals and daily necessitiesbecause of its characteristics of conveniently using, non-poisonous, low cost,beautiful printing and so on. Though the use of the deserted liquid packing box isincreasing year by year, the efficiency of recycling is not high, only have15%.Besides the recycling system is established imperfect, which is due to the lack ofthe basic theory and key technology of the Aluminum-plastic Separation relatedchemical reaction.This paper mainly investigated the influence of the density, time,temperature and the pH on paper pulp yield, and gained the optimum process ofthe fiber recycling through orthogonal test. For the efficiency of theAluminum-plastic Separation is low and the loss of the recycling is great, themicro area changing characteristics in dissociation process between theinterfaces of the Aluminum-plastic should be researched firstly, which is also theeffectively way to control the separation process, as a result the utility value ofthe Aluminum-plastic resources can be raised. By comparing the separationmethods by organic acid, alkali, mixed solvent, we can get one optimization. Theresult shows that the mixed solvent method, that is, using the mixture ofbenzene(methylbenzene), alcohol and water as separating medium can separatethe Aluminum-plastic thoroughly in a short time, has the good separation effect.This kind of separating medium can be recycled and used again after many times’usage.At last analytic study can be made on the content of the aluminum ion in theseparating medium, the structure of matter of plastic after separation, the surfacestate and substance of aluminum foil and plastic adopting ICP-AES, FTIR, SEM modern analytical instrument to obtain the interface disintegrate behavior. Byanalyzing the interface disintegrate behavior, scientific basis can be provided forcontrolling the interface separation reaction process, realizing the efficientseparation of Aluminum-plastic and the maximize use of resources, and pushingforward the development and promotion use of the paper-plastic aluminumcompound packing material’s recycling technology of our country.The result of the fiber recycling shows that in the case of reducing thedamage rate of the Aluminum-plastic as soon as possible, the optimum processcondition of fiber recycling is: pulp density8%, time20min, temperature50°C,pH9. At this time the recycling rate of the fiber is95.23%.When benzene-alcohol-water was used as separating medium, the resultsshowed that the three-component best volume ratio in the separating medium canbe obtained easily and quickly through triangle coordinate way, that isV(benzene):V(absolute ethyl alcohol):V(water)=30:20:50, temperature60°C, theseparation time5.85minutes, is the best separation effect of Aluminum-plastic.At this time, the separation rate is100%, the total yield reaches97.46%.When methylbenzene-alcohol-water was used as separating medium theresults showed that: the optimum separation of Aluminum-plastic can beobtained through orthogonal test and variance analysis, that is:V(Methylbenzene):V(absolute ethyl alcohol):V(water)=20:40:40, temperature60°C, the separation time5minutes. At this time, the separation rate is100%,the total yield reaches94.37%.The instrument test results showed that: separating medium only produceseffect on plastic and adhesive and don’t damage or dissolve aluminum foil; thestructure of matter of plastic before or after the Aluminum-plastic separationdon’t change, and the plastic after recycled can be used again through moltengranulation.In conclusion, it is feasible to adopt the hydrolic pulping method to recyclethe fiber, the mixture of benzene (methylbenzene), alcohol and water asAluminum-plastic separating medium. And the results can satisfy the target ofthe regeneration of the deserted liquid packing box, and the reuse of the resource.