Study On The Adhesion Of Nylon Grid With VMPET Film And Its Properties

The aluminum plastic composite film has many excellent performances,such as blocking water,blocking gas,reflective insulation,convenient packaging.As packaging materials,it is being used in more and more top-end fields.An aluminum-plastic composite film with orthogonal nylon 66 grid as reinforcements has been produced by an aircraft manufacturing company in the USA,which is used for encapsulating aviation insulation materials-glass fiber felt.The adhesive attaching on the grid yarn can not only bond grid yarns and aluminum surface,but also acts as heat sealing materials.Firstly,adhesive mixed maleic acid modified chlorinated vinegar resin and polyurethane were used to bond the nylon grid and the VMPET film,and an orthogonal experiment was designed on the three major component factors,the introduction of maleic acid,the solid content of adhesive,polyurethane addition.Then the range-method of orthogonal experiment was utilized to obtain the optimum peeling strength and sealing strength.Wet-heat aging behavior and aging mechanism were studied.The result showed that composite film had the optimum overall performance with introduction of maleic acid being 3wt%,the solid content of adhesive being 20% and polyurethane addition being 8wt%.During wet-heat aging experiment,both peeling strength and sealing strength showed a decreasing trend.The former was due to the swelling of adhesive and the latter was due to the deduction of the activity of the polymer chain.Secondly,composite films were prepared with the adhesive of optimum proportion.Through experiment test,theoretical analysis and finite element numerical simulation,the influence of grid spacing and grid size on the tensile properties,hydraulic burst strength and bursting performance were mainly studied.The result showed that the tensile fracture process of composite films included three stages,namely elastic stage,plastic deformation stage and elongation stage.The tensile strength increased with the decrease of grid spacing,and increased with the increasing of the grid yarn size.The hydraulic burst strength and the tensile strength were proportional on the numerical value.The proportional coefficient was a constant related to the breaking elongation rate of the composite film.The bursting process of composite film was demonstrated dynamically by finite element numerical simulation.For the composite film with grid spacing of 3mm and grid yarn size of 233 D,the bursting failure firstly started by nylon grid yarn.The initial damage occurred at the puncture displacement of 5.50 mm,the grid yarn fracture firstly occurred at the puncture displacement of 7.49 mm,and the basement film damage occurred at the puncture displacement of 8.99 mm.The failure diagram obtained from the simulation was basically consistent with the one obtained from the test.Finally,the effects of grid spacing and grid yarn size on the acoustic properties of composite film has been studied,and the acoustic properties of composite film with glass fiber felt and carbon fiber board has been explored.The results showed that the sound insulation performance of composite film was affected by the grid line spacing and yarn size.The sound transmission loss increased with the decrease of grid spacing and the increase of yarn size.For the composite structure formed by laminated film and glass fiber felt,the sound insulation property got better while the acoustic incident surface was laminated film.The sound insulation property was improved effectively as air layers were embedded into the composite sound proof construction consist of laminated film,glass fiber felt and carbon fiber board.