Research On High-efficiency Surface Lapping And Polishing Technology Of Die For Plastic-coated Iron Can

With the gradual improvement of the level of human social and economic development,the market scale of food and beverage has increased by a large margin.The resulting increase in packaging requirements has led to the creation of a new type of canning material named plastic-coated iron,which combines the properties of plastic film and sheet metal.It not only can play a better role in the in the preservation,fresh-keeping and protection of the contents of the can,it also has a distinct advantage in green environmental protection and cost saving.However,the forming process of plastic-coated iron has higher requirements on the forming die,higher requirements are put forward for the lapping and polishing quality of the dies therefore.In order to improve the surface processing quality of the die for plastic-coated iron can-making,the method of grinding and polishing die surface by using resin copper plate and resin copper block combined with free abrasive is presented in this thesis.First of all,according to the plane machining requirement of the concave die for plasticcoated iron can,the relevant processing technology of the annular cemented carbide concave die was explored with the precision plane lapping machine,and the machining method of lapping and polishing die plane with resin copper plate and free abrasive has been put forward.The influences of processing parameters such as abrasive concentration,abrasive particle size,abrasive flow velocity,lapping plate rotational speed,abrasive pressure and abrasive type on the polishing effect of cemented carbide YG15 were investigated by systematic experiments and the optimum processing parameters were obtained by orthogonal test,using lapping fluid made of 3?m diamond abrasive of 2.5wt.% concentration and deionized water for the lapping and polishing under the experimental conditions of abrasive flow velocity of 15 m L/min,lapping plate rotational speed of 85r/min and the lapping pressure of 0.133 MPa,the surface roughness could be reduced to Sa5.41 nm from Sa0.989?m in 10 min,thus the plane lapping and polishing process of high efficiency and high quality for the material of plastic-coated iron concave can has been achieved.Secondly,in view of the structural characteristics of the plastic-coated iron convex can with variable shape and size,a new method of using resin copper lapping tool block which can be fitted to the external cylindrical surface of the workpiece with free abrasive for lapping and polishing the cylindrical surface of the die was presented in this thesis,it can quickly meet the requirement of cylindrical surface lapping and polishing process under different diameters of the die.In addition,In addition,epoxy modified phenolic resin powder and spherical copper powder were used to prepare resin-copper lapping tools,the particle size was 38?m(400 #)with the content of 75 wt.% has been selected through the analysis of the properties of hardness,flexural strength and wear resistance of the resin copper lapping tool.Finally,the prepared resin copper lapping tool has been adopted on the lapping and polishing experimental study of the cylindrical surface of the die steel DC53.Using lapping fluid made of 3?m diamond abrasive of 2.5wt.% concentration and deionized water for the lapping and polishing under the experimental conditions of workpiece rotational speed of800r/min,Z feed speed of 400mm/min,abrasive flow velocity of 3m L/min and lapping pressure of 50 N,the surface roughness could be reduced to Ra11 nm from 1.901?m in 40 min when the Z motion amplitude of the workpiece was 40 mm,the rate of reduction reached 99.42%and thus the cylindrical surface lapping and polishing process of high efficiency and high quality for the material of plastic-coated iron convex can has been achieved.