Research On Recovery Technique And Mechanism Of Mobile Phone Protector Film

Plastic film products have penetrated into every household since their birth,bringing convenience to people,but also brought environmental problems that can not be ignored.Most of the plastic film consumer garbage is eventually disposed by traditional landfill and incineration methods,resulting in subsequent secondary pollution problems.In addition,with the continuous progress of communication technology,smartphones have gradually changed from optional consumption to compulsory consumption.The popularity of smartphones has led to the rapid growth of the production of mobile phone protective film,which is a subsidiary product of smartphones.In the production process of mobile phone protection film,it is necessary to cut precisely according to the screen size,which will produce a large number of edges and corners.As an important part of plastic film consumer goods,mobile phone protective film edge materials are lack of targeted recycling methods.Most mobile phone protective films are coated with a layer or multi-layer adhesive to improve adhesion.The recycling process needs to be separated by technical means,but the technology in this respect is deficient.In this paper,polyethylene terephthalate(PET)mobile phone protective film edge material with adhesive coating was selected as the research object,and the effects of alkali concentration and reaction temperature on adhesive removal efficiency were explored.The results show that the decoating process can be accelerated by increasing the reaction temperature and alkali concentration.The optimum conditions are c(NaOH)=1 mol/L,90 C and 60 min.At the same time,the structure of the base material and waste rubber separated after degumming treatment was characterized.The characterization results showed that the main component of the recycled waste rubber was polyacrylate.The chemical structure of the recycled PET was basically unchanged,and the structure of the recycled PET matrix was not destroyed.The mechanism study shows that during the alkali hydrolysis process,polyacrylate is partially hydrolyzed to form carboxylate,which decreases the bonding force between the adhesive coating and the substrate and then removes it.During the hydrolysis process,1-butanol and 2-ethylhexanol enter the alkali solution.The main component of the gel layer after partial hydrolysis is the blend of butyl polyacrylate-polyacrylic acid-2-ethylhexanol ester.This indicates that it is feasible to separate the rubber coating and recover the base material by alkali hydrolysis,which provides the method and theoretical basis for further device design.The recycling process of mobile protective film will be accompanied by a large number of waste rubber,which will cause secondary pollution if discharged into the environment.Therefore,in order to further realize the reuse of waste rubber,high temperature carbonization was used to prepare carbon materials from waste rubber.The results show that the carbon materials prepared by high temperature carbonization are mainly amorphous carbon,and the degree of graphitization is low.Increasing the carbonization temperature will increase the specific surface area.Generally,the carbon materials produced by carbonization at three different temperatures belong to multi-stage porous(micro-mesoporous)structure materials.Carbon materials were modified by alkali impregnation method,and the modified materials were characterized.The adsorption properties of VOCs on carbon materials before and after modification were compared.The results showed that after alkali treatment,the chemical groups on the surface of carbon materials decreased,the non-polarity increased,the pore of carbon materials increased,the specific surface area increased,and the adsorption capacity of styrene and ethyl acetate increased significantly,which indicated that the carbon materials modified by alkali had good adsorption performance.Furthermore,a small-scale recycling device was designed and its stability,recycling performance and cost-effectiveness were studied.The operation data of the small-scale recycling batch without replacing alkali solution showed that the removal rate of the first 17 rubber coatings was above 97%,which indicated that the small-scale test device had better stable operation ability.Through benefit analysis,the cost-profit ratio of the pilot system reaches 647.44%,which has considerable economic benefits.The pilot test can provide technical support for large-scale equipment pilot test in the follow-up field.