As a commitment to the health and safety of workers across the apparel industry, Levi Strauss & Co. and Hennes & Mauritz AB (H&M) announced plans to implement a global ban on sandblasting in all of their f...As a commitment to the health and safety of workers across the apparel industry, Levi Strauss & Co. and Hennes & Mauritz AB (H&M) announced plans to implement a global ban on sandblasting in all of their future展开更多
The defects created in commercial dental alloys during blasting with alumina particles propelled in compressed air under pressure 0.1 and 0.4 MPa have been studied using positron annihilation spectroscopy, scanning el...The defects created in commercial dental alloys during blasting with alumina particles propelled in compressed air under pressure 0.1 and 0.4 MPa have been studied using positron annihilation spectroscopy, scanning electron microscopy and X-ray diffraction. It was observed that higher pressure causes the increase in roughness and damaged zone range. The type of defects was determined as vacancies on dislocations. The defect concentration decreases with the depth and depends on alloys' type and applied pressure. The Rutherford backscattering spectroscopy and variable energy positron beam studies indicate shallow alumina deposition in material and show that small pressure of 0.1 MPa is not enough to remove metal surface oxides completely in 60 s in all studied dental alloys.展开更多
Different surface morphologies of polyimide(PI)foils widely applied in flexible electronics were obtained using the technique of sandblasting.Copper(Cu)films were subsequently deposited on the treated surface of PI su...Different surface morphologies of polyimide(PI)foils widely applied in flexible electronics were obtained using the technique of sandblasting.Copper(Cu)films were subsequently deposited on the treated surface of PI substrates.Upon tensile loading, the critical strain,crack density and count of cracks were measured to examine the ductility of Cu films on PI substrates.Obtained results show that after sandblasting treatment,the critical strain of Cu film decreases from 8.0%to 6.9%and,in comparison with the case without sandblasting,its surface crack density decreases remarkably,with no saturation of the crack density.The reduced crack density is attributed to the increase of contact area and interfacial adhesion after sandblasting,and whether the crack density is saturated or not is dependent upon the morphology of the cracks formed as a function of tensile strain.展开更多
Sandblasting machines are widely used in chemical, mechanical and other engineering fields. The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow, and impact by the continuo...Sandblasting machines are widely used in chemical, mechanical and other engineering fields. The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow, and impact by the continuous abrasive sand can cause the machine to wear or even fail. In this study, the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion, dynamic and collision characteristics of the sand. Air in the sandblasting machine was treated as the ideal gas and the continuous phase. The sand was regarded as the discrete phase solid in the computation. Using the Archard wear model, the wear amount of the sandblasting machine was calculated and the wear law was analysed, to provide a theoretical basis for optimising the design and operation method of the blasting machine.展开更多
Sandblasting machines are widely used in chemical,mechanical and other engineering fields.The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow,and impact by the continuous ...Sandblasting machines are widely used in chemical,mechanical and other engineering fields.The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow,and impact by the continuous abrasive sand can cause the machine to wear or even fail.In this study,the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion,dynamic and collision characteristics of the sand.Air in the sandblasting machine was treated as the ideal gas and the continuous phase.The sand was regarded as the discrete phase solid in the computation.Using the Archard wear model,the wear amount of the sandblasting machine was calculated and the wear law was analysed,to provide a theoretical basis for optimising the design and operation method of the blasting machine.展开更多
This paper describes a mechanical technique to reduce the nozzle reaction force of a sandblasting rig. A theoretical evaluation of the magnitudes and direction of action of typical sandblasting nozzle forces has been ...This paper describes a mechanical technique to reduce the nozzle reaction force of a sandblasting rig. A theoretical evaluation of the magnitudes and direction of action of typical sandblasting nozzle forces has been conducted and a technique for exploiting available energy in order to reduce the magnitude of the forces at the nozzle has been developed.Experimental results from a variety of tests in different configurations have confirmed the theoretically determined force magnitude’s accuracy and shown that forces of up to 106N can be present in typical sandblasting operations. The results have also shown that an up to 77% reduction of force at the nozzle can be achieved by applying the developed mechanicaltechnique.展开更多
In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were e...In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were examined,including parameters such as particle size,particle blasting pressure,and particle blasting angle.The surface treatment of the samples was performed using the SLA+Anodizing method.AFM testing was performed for each of the 18 different states,and the average surface roughness of each of these was compared with each other.Then,a bone layer was placed on the sample with the closest average surface roughness to the standard and the least amount of aluminum oxide on its surface among the 18 different states,to confirm the accuracy and quality of the desired surface roughness by examining the bone formation process and speed.The results showed that state No.4(sandblast particle size:75µm,spraying pressure of sandblast particles:4 bar,sandblast particle spraying angle:30 degrees),which was prepared using the SLA+Anodizing method and had a surface roughness of 1.989µm(The percentage of Al_(2)O_(3)on the surface=6%),had the best sandblasting conditions and showed 95%cell viability and accelerated the treatment and bone formation process for about a week.The simulation results,using Abaqus software,indicated that the stress distribution on the surface of the implant fixture in contact with the bone surface has increased by approximately 4.3%for state No.4.This will help prevent loosening of the dental implant fixture over time.展开更多
Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical...Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical strength.Sandblasting by gravitation from a fixed height causes damages by the free fall of different quantities of sand,which we performed for a selected grain size and at different angles of inclination.To characterize the surface state,we used different roughness measures(the arithmetic mean value of the roughness Ra,the root mean square roughness Rq,and the maximum roughness Rmax)and measured the optical transmission(transmittance)at different points on the specimen surface using a profilometer.To determine the mechanical strength,we proceeded by two methods:first,by a shock ball(falling ball),and then by biaxial bending using circular supports.The effects of the surface damage on the optical transmission and the mechanical strength of the glass are graphically presented and discussed in this paper.展开更多
文摘As a commitment to the health and safety of workers across the apparel industry, Levi Strauss & Co. and Hennes & Mauritz AB (H&M) announced plans to implement a global ban on sandblasting in all of their future
文摘The defects created in commercial dental alloys during blasting with alumina particles propelled in compressed air under pressure 0.1 and 0.4 MPa have been studied using positron annihilation spectroscopy, scanning electron microscopy and X-ray diffraction. It was observed that higher pressure causes the increase in roughness and damaged zone range. The type of defects was determined as vacancies on dislocations. The defect concentration decreases with the depth and depends on alloys' type and applied pressure. The Rutherford backscattering spectroscopy and variable energy positron beam studies indicate shallow alumina deposition in material and show that small pressure of 0.1 MPa is not enough to remove metal surface oxides completely in 60 s in all studied dental alloys.
基金supported by the National Natural Science Foundation of China(Grant No.10825210)the National "111Project" Foundation of China(Grant No.B06024)the National Basic Research Program of China("973"Program)(Grant No.2006CB601202)
文摘Different surface morphologies of polyimide(PI)foils widely applied in flexible electronics were obtained using the technique of sandblasting.Copper(Cu)films were subsequently deposited on the treated surface of PI substrates.Upon tensile loading, the critical strain,crack density and count of cracks were measured to examine the ductility of Cu films on PI substrates.Obtained results show that after sandblasting treatment,the critical strain of Cu film decreases from 8.0%to 6.9%and,in comparison with the case without sandblasting,its surface crack density decreases remarkably,with no saturation of the crack density.The reduced crack density is attributed to the increase of contact area and interfacial adhesion after sandblasting,and whether the crack density is saturated or not is dependent upon the morphology of the cracks formed as a function of tensile strain.
文摘Sandblasting machines are widely used in chemical, mechanical and other engineering fields. The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow, and impact by the continuous abrasive sand can cause the machine to wear or even fail. In this study, the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion, dynamic and collision characteristics of the sand. Air in the sandblasting machine was treated as the ideal gas and the continuous phase. The sand was regarded as the discrete phase solid in the computation. Using the Archard wear model, the wear amount of the sandblasting machine was calculated and the wear law was analysed, to provide a theoretical basis for optimising the design and operation method of the blasting machine.
文摘Sandblasting machines are widely used in chemical,mechanical and other engineering fields.The internal flow field of the sandblasting machine belongs to a complex gas-solid two-phase flow,and impact by the continuous abrasive sand can cause the machine to wear or even fail.In this study,the EDEM-FLUENT coupling method was used to calculate the transient flow field of the gas phase and the motion,dynamic and collision characteristics of the sand.Air in the sandblasting machine was treated as the ideal gas and the continuous phase.The sand was regarded as the discrete phase solid in the computation.Using the Archard wear model,the wear amount of the sandblasting machine was calculated and the wear law was analysed,to provide a theoretical basis for optimising the design and operation method of the blasting machine.
文摘This paper describes a mechanical technique to reduce the nozzle reaction force of a sandblasting rig. A theoretical evaluation of the magnitudes and direction of action of typical sandblasting nozzle forces has been conducted and a technique for exploiting available energy in order to reduce the magnitude of the forces at the nozzle has been developed.Experimental results from a variety of tests in different configurations have confirmed the theoretically determined force magnitude’s accuracy and shown that forces of up to 106N can be present in typical sandblasting operations. The results have also shown that an up to 77% reduction of force at the nozzle can be achieved by applying the developed mechanicaltechnique.
文摘In this study,different conditions of sandblasting on dental implant fixtures were investigated to achieve the best sandblasting conditions.18 different sandblasting conditions(Using 152 implant fixture samples)were examined,including parameters such as particle size,particle blasting pressure,and particle blasting angle.The surface treatment of the samples was performed using the SLA+Anodizing method.AFM testing was performed for each of the 18 different states,and the average surface roughness of each of these was compared with each other.Then,a bone layer was placed on the sample with the closest average surface roughness to the standard and the least amount of aluminum oxide on its surface among the 18 different states,to confirm the accuracy and quality of the desired surface roughness by examining the bone formation process and speed.The results showed that state No.4(sandblast particle size:75µm,spraying pressure of sandblast particles:4 bar,sandblast particle spraying angle:30 degrees),which was prepared using the SLA+Anodizing method and had a surface roughness of 1.989µm(The percentage of Al_(2)O_(3)on the surface=6%),had the best sandblasting conditions and showed 95%cell viability and accelerated the treatment and bone formation process for about a week.The simulation results,using Abaqus software,indicated that the stress distribution on the surface of the implant fixture in contact with the bone surface has increased by approximately 4.3%for state No.4.This will help prevent loosening of the dental implant fixture over time.
文摘Damage to a glass surface by sandblasting has a remarkable effect on its mechanical properties and strength.In this study,we analyze the superficial deterioration of soda-lime glass and its influence on the mechanical strength.Sandblasting by gravitation from a fixed height causes damages by the free fall of different quantities of sand,which we performed for a selected grain size and at different angles of inclination.To characterize the surface state,we used different roughness measures(the arithmetic mean value of the roughness Ra,the root mean square roughness Rq,and the maximum roughness Rmax)and measured the optical transmission(transmittance)at different points on the specimen surface using a profilometer.To determine the mechanical strength,we proceeded by two methods:first,by a shock ball(falling ball),and then by biaxial bending using circular supports.The effects of the surface damage on the optical transmission and the mechanical strength of the glass are graphically presented and discussed in this paper.
