A new sand binder system cured by CO2 was prepared based on the animal bone glue.To overcome the disadvantages of animal glue such as agglomeration at room temperature,high energy consumption and low efficiency,an alk...A new sand binder system cured by CO2 was prepared based on the animal bone glue.To overcome the disadvantages of animal glue such as agglomeration at room temperature,high energy consumption and low efficiency,an alkaline decomposition process was selected,and certain modifier was used to modify the performance of the animal glue binder.For the alkaline decomposition,NaOH was used as the catalyst with an addition of 4wt.% to the animal glue.A modifier was determined through the orthogonal experiment with a weight ratio of glycerin:glycol:dextrin:animal glue = 9:16:15:100,and the optimal modification reaction should be performed at 75 ℃ with a reaction time of 90 min.Ca(OH)2 was used as a promoter;the optimal CO2 gas flux blowing into the sand was 0.7 m3.h-1 for a duration of 60s under the experimental conditions.Results show that an original strength above 0.7 MPa and a final strength about 4.2 MPa can be achieved,which could meet the requirement of rapid moulding and core-making for foundry.The new binder was characterized and analyzed by means of IR,and the modification and CO2-cured mechanisms of this animal glue binder were also discussed.展开更多
A new casting binder was prepared based on an animal bone glue. In order to overcome the disadvantages of the animal glue agglomeration at room temperature, an alkaline decomposition process was used, with acrylic aci...A new casting binder was prepared based on an animal bone glue. In order to overcome the disadvantages of the animal glue agglomeration at room temperature, an alkaline decomposition process was used, with acrylic acid, ammonium persulfate, and glucose as modifiers of the animal glue to obtain a high strength of binding. In the process of alkaline decomposition, Na OH was used as the catalyst with the addition of 3, 4, 5, 6, 7, 8wt.%, respectively, into 100 g of animal glue and the alkaline decomposition temperature was set for 30, 40, 50, 60, and 70 °C, with an identical decomposition time of 30 min, in order to reduce viscosity of the animal glue and maintain a liquid state at room temperature. The added acrylic acid, ammonium persulfate and glucose were determined through an orthogonal experiment. The experimental results are as fol ows: the optimal amount of NaOH addition is 5wt.%; alkaline decomposition temperature is 50 °C; the optimal weight ratio of three kinds of modifiers to animal glue is acrylic acid : ammonium persulfate : glucose : animal glue = 30:3:15:100; the modification reaction should be performed at 75 °C with a reaction time of 90 min. With the addition of 3% binder to sand, a final tensile strength of about 3.36 MPa and surface tension value of about 25.387 m N·m^(-1) are achieved; the gas evolution at 850 °C is 19 ml·g^(-1) and the residual strength after high temperature(700 ■× 10 min) is 0 MPa. Finally, the new binder was characterized and analyzed by means of element analysis and an IR infrared spectrum.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant No.51275313)
文摘A new sand binder system cured by CO2 was prepared based on the animal bone glue.To overcome the disadvantages of animal glue such as agglomeration at room temperature,high energy consumption and low efficiency,an alkaline decomposition process was selected,and certain modifier was used to modify the performance of the animal glue binder.For the alkaline decomposition,NaOH was used as the catalyst with an addition of 4wt.% to the animal glue.A modifier was determined through the orthogonal experiment with a weight ratio of glycerin:glycol:dextrin:animal glue = 9:16:15:100,and the optimal modification reaction should be performed at 75 ℃ with a reaction time of 90 min.Ca(OH)2 was used as a promoter;the optimal CO2 gas flux blowing into the sand was 0.7 m3.h-1 for a duration of 60s under the experimental conditions.Results show that an original strength above 0.7 MPa and a final strength about 4.2 MPa can be achieved,which could meet the requirement of rapid moulding and core-making for foundry.The new binder was characterized and analyzed by means of IR,and the modification and CO2-cured mechanisms of this animal glue binder were also discussed.
文摘A new casting binder was prepared based on an animal bone glue. In order to overcome the disadvantages of the animal glue agglomeration at room temperature, an alkaline decomposition process was used, with acrylic acid, ammonium persulfate, and glucose as modifiers of the animal glue to obtain a high strength of binding. In the process of alkaline decomposition, Na OH was used as the catalyst with the addition of 3, 4, 5, 6, 7, 8wt.%, respectively, into 100 g of animal glue and the alkaline decomposition temperature was set for 30, 40, 50, 60, and 70 °C, with an identical decomposition time of 30 min, in order to reduce viscosity of the animal glue and maintain a liquid state at room temperature. The added acrylic acid, ammonium persulfate and glucose were determined through an orthogonal experiment. The experimental results are as fol ows: the optimal amount of NaOH addition is 5wt.%; alkaline decomposition temperature is 50 °C; the optimal weight ratio of three kinds of modifiers to animal glue is acrylic acid : ammonium persulfate : glucose : animal glue = 30:3:15:100; the modification reaction should be performed at 75 °C with a reaction time of 90 min. With the addition of 3% binder to sand, a final tensile strength of about 3.36 MPa and surface tension value of about 25.387 m N·m^(-1) are achieved; the gas evolution at 850 °C is 19 ml·g^(-1) and the residual strength after high temperature(700 ■× 10 min) is 0 MPa. Finally, the new binder was characterized and analyzed by means of element analysis and an IR infrared spectrum.
