Studied On Preparation And Application Of Saturated Polyester Coatings Of Aluminum Cans Outer Wall

In this paper,a kind of aluminum cans outer wall coatings with high hardness,high adhesion and excellent flexibility has been prepared,and the various factors which affect the performance of paints were studied.The study of the aluminium cans outer wall were classified as following three parts:(1)A kind of aluminum cans outer wall coatings with high hardness,high adhesion and excellent flexibility has been prepared by choosing and matched analysing of film-forming resin and matched analysis to obtain reasonable solvents,additives,pigments and catalysts.The effects of the different film-forming resins,the types and addition ratio of amino resin and different catalysts on physical mechanical properties and chemical properties of aluminum cans outer wall coatings were studied.Experimental results show that the paint film with excellent baking resistance,the hardness is 4 H,the adhesion grade is 0 levels,was obtained when the saturated polyester resins were used as film forming resins.The best film of the crosslinking rate,complete response group,adhesion rating of 0,flexibility<1 mm,impact resistance,water resistance with good;The prepared films has better crosslinking rate which the ratio of high methyl etherification melamine formaldehyde resin as the curing agent and saturated polyester resin is 1:5,the adhesion grade is 0 levels,The flexibility is less than 1 mm,and the film has excellent resistance to impact and water.when p-toluene sulfonic acid was used as catalyst,the curing cross-linking can be faster completed,the preparation of the coating have excellent adhesion,hardness,water resistance and flexibility and impact resistance.(2)This paper also discussed the effects of roller coating process parameters such as viscosity,space between feeding rolle and coating roller,mandrel speed and rubber roller speed on bottom coating film properties,and further optimized the roller coating process.In addition,the effects of finishing varnish coating process parameters such as viscosity,curing time and baking temperature on film quality were studied.Some conclusions are drawn as follows: when roller coating process parameter is seted with viscosity of 370 secs(DIN4 viscosity cup),space between feeding rolle and coating roller is-4 μm,mandrel speed/ rubber roller speed is 2:1,adhesion is 0,hardness>H,heat resistance can attain the required,the coating film has the best comprehensive performance;Finishing varnish coating process parameters were set to as follows: the hardness,glossiness,and water resistance of the film are best when the viscosity is 85 secs,curing time is 7 min,curing temperature is 170°C.(3)In a word,the density of coating is declined with the increasing of the neck passes based on the analyses of neck passes,forming process and extrusion stress,and contact angle testing of primary coat and finishing varnish on modification,electrochemical testing and surface characterization of the aluminium cans samples for different passes.