夹芯注射成型零件由2种塑料组合而成,表层塑料要有好的表面性能,而芯层材料则有高的力学性能。由于涉及的工艺参数多、成型机理复杂,夹芯注射成型时易出现芯层材料突破壳层的现象,导致成型制品报废。本文以模流分析软件M P I为工具,以...夹芯注射成型零件由2种塑料组合而成,表层塑料要有好的表面性能,而芯层材料则有高的力学性能。由于涉及的工艺参数多、成型机理复杂,夹芯注射成型时易出现芯层材料突破壳层的现象,导致成型制品报废。本文以模流分析软件M P I为工具,以桶形制件为试验模型,通过正交试验的方法,研究了夹芯注射成型工艺参数对芯层熔体突破的条件,并得到了最佳的成型工艺参数。研究结果表明,夹芯注射成型时,对芯层熔体突破影响最大的工艺参数是芯层熔体的注射温度,其次分别是芯层熔体的注射速率和壳层熔体的注射速率,而模具温度和壳层熔体注射温度的影响最小。展开更多
The desulfurization of hot metal by the mono-injection of lime powder and the co-injection of lime, calcium carbide and magnesium powders is mathematically modeled. The mono-injection model is derived from the continu...The desulfurization of hot metal by the mono-injection of lime powder and the co-injection of lime, calcium carbide and magnesium powders is mathematically modeled. The mono-injection model is derived from the continuity equation and is validated using experimental results and data previously reported in the literature. The co-injection model and the rate constant of the injected mixture are determined from the molar fractions and rate constants of the individual powders. The effect of the lime content of the mixture on the desulfurization dynamics is studied and discussed.展开更多
Micro powder injection molding (μPIM),a miniaturized variant of powder injection molding,has advantages of shape complexity,applicability to many materials and good mechanical properties. Co-injection molding has bee...Micro powder injection molding (μPIM),a miniaturized variant of powder injection molding,has advantages of shape complexity,applicability to many materials and good mechanical properties. Co-injection molding has been realized between met-als and ceramics on micro components,which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio,micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or micro-structured components in microsystems technology (MST) field.展开更多
The aim of this study was to establish a model by single injection of Aβ1-40+IA into rat brain basal ganglion and examine the effect of ZDY101, an active component of a Yin tonic from Chinese traditional medicinal he...The aim of this study was to establish a model by single injection of Aβ1-40+IA into rat brain basal ganglion and examine the effect of ZDY101, an active component of a Yin tonic from Chinese traditional medicinal herb. The results showed that the amnestic effect of co-injection of Aβ and IA lasted for at least 2 months. At same time, the total M-receptor density in model brain was significantly lower than blank control, indicating the change is profound enough for long term pathological studies or drug screening. It can be clearly seen that the decreased brain M-receptor density caused by Aβ was significantly increased by ZDY101. Such an elevation effect was significantly correlated with dose of ZDY101 when the dose was examined in a certain reasonable range. It can also he clearly seen that such an elevation of M-cholinergic receptor density was significantly correlated with the improvement of memory which indicated that the increase of M-cholinergic receptor density was an important factor in improving the memory of such animal model.展开更多
In co-injection molding,the properties and distribution of polymers will affect the application of products.The focus of this work is to investigate the effect of molding parameters on the skin/core material distribut...In co-injection molding,the properties and distribution of polymers will affect the application of products.The focus of this work is to investigate the effect of molding parameters on the skin/core material distribution based on three-dimensional(3-D)flow and heat transfer model for the sequential coinjection molding process,and the flow behaviors and material distributions of skin and core melts inside a slightly complex cavity(dog-bone shaped cavity)are predicted numerically.The governing equations of fluids in mold are solved by finite volume method and Semi-Implicit Method for Pressure Linked Equations(SIMPLE)algorithm on collocated meshes,and the domain extension technique is employed in numerical method for this cavity to assure that the numerical algorithm is implemented successfully.The level set transport equation which is used to trace the free surfaces in co-injection molding is discretized and solved by the 5 th-order Weighted Essentially Non-Oscillatory(WENO)scheme in space and 3 rd-order Total Variation Diminishing Runger-Kutta(TVD-R-K)scheme in time respectively.Numerical simulations are conducted under various volume fraction of core melt,skin and core melt temperatures,skin and core melt flow rates.The predicted results of material distribution in length,width and thickness directions are in close agreement with the experimental results,which indicate that volume fraction of core melt,core melt temperature and core melt flow rate are principal factors that have a significant influence on material distribution.Numerical results demonstrate the effectiveness of the 3-D model and the corresponding numerical methods in this work,which can be used to predict the melt flow behaviors and material distribution in the process of sequential co-injection molding.展开更多
文摘夹芯注射成型零件由2种塑料组合而成,表层塑料要有好的表面性能,而芯层材料则有高的力学性能。由于涉及的工艺参数多、成型机理复杂,夹芯注射成型时易出现芯层材料突破壳层的现象,导致成型制品报废。本文以模流分析软件M P I为工具,以桶形制件为试验模型,通过正交试验的方法,研究了夹芯注射成型工艺参数对芯层熔体突破的条件,并得到了最佳的成型工艺参数。研究结果表明,夹芯注射成型时,对芯层熔体突破影响最大的工艺参数是芯层熔体的注射温度,其次分别是芯层熔体的注射速率和壳层熔体的注射速率,而模具温度和壳层熔体注射温度的影响最小。
文摘The desulfurization of hot metal by the mono-injection of lime powder and the co-injection of lime, calcium carbide and magnesium powders is mathematically modeled. The mono-injection model is derived from the continuity equation and is validated using experimental results and data previously reported in the literature. The co-injection model and the rate constant of the injected mixture are determined from the molar fractions and rate constants of the individual powders. The effect of the lime content of the mixture on the desulfurization dynamics is studied and discussed.
基金National Basic Research Program of China (Grant No. 2004CB719802)Hi-Tech Research and Development Program of China (Grant No. 2006AA03Z113)
文摘Micro powder injection molding (μPIM),a miniaturized variant of powder injection molding,has advantages of shape complexity,applicability to many materials and good mechanical properties. Co-injection molding has been realized between met-als and ceramics on micro components,which become the first breakthrough within the PIM field. Combined with the prominent characteristics of high features/cost ratio,micro powder injection molding becomes a potential technique for large scale production of intricate and three-dimensional micro components or micro-structured components in microsystems technology (MST) field.
基金Supported by the National Natural Science Foundation of China (39570835)
文摘The aim of this study was to establish a model by single injection of Aβ1-40+IA into rat brain basal ganglion and examine the effect of ZDY101, an active component of a Yin tonic from Chinese traditional medicinal herb. The results showed that the amnestic effect of co-injection of Aβ and IA lasted for at least 2 months. At same time, the total M-receptor density in model brain was significantly lower than blank control, indicating the change is profound enough for long term pathological studies or drug screening. It can be clearly seen that the decreased brain M-receptor density caused by Aβ was significantly increased by ZDY101. Such an elevation effect was significantly correlated with dose of ZDY101 when the dose was examined in a certain reasonable range. It can also he clearly seen that such an elevation of M-cholinergic receptor density was significantly correlated with the improvement of memory which indicated that the increase of M-cholinergic receptor density was an important factor in improving the memory of such animal model.
基金supported by Science and Technology Research Key Project of the Education Department of Henan Province(20A430023,20B130002,20A110031)Natural Science Foundation of Henan Province(202300410340)+1 种基金National Natural Science Foundation of China(11901504)Nanhu Scholars Program for Young Scholars of Xinyang Normal University。
文摘In co-injection molding,the properties and distribution of polymers will affect the application of products.The focus of this work is to investigate the effect of molding parameters on the skin/core material distribution based on three-dimensional(3-D)flow and heat transfer model for the sequential coinjection molding process,and the flow behaviors and material distributions of skin and core melts inside a slightly complex cavity(dog-bone shaped cavity)are predicted numerically.The governing equations of fluids in mold are solved by finite volume method and Semi-Implicit Method for Pressure Linked Equations(SIMPLE)algorithm on collocated meshes,and the domain extension technique is employed in numerical method for this cavity to assure that the numerical algorithm is implemented successfully.The level set transport equation which is used to trace the free surfaces in co-injection molding is discretized and solved by the 5 th-order Weighted Essentially Non-Oscillatory(WENO)scheme in space and 3 rd-order Total Variation Diminishing Runger-Kutta(TVD-R-K)scheme in time respectively.Numerical simulations are conducted under various volume fraction of core melt,skin and core melt temperatures,skin and core melt flow rates.The predicted results of material distribution in length,width and thickness directions are in close agreement with the experimental results,which indicate that volume fraction of core melt,core melt temperature and core melt flow rate are principal factors that have a significant influence on material distribution.Numerical results demonstrate the effectiveness of the 3-D model and the corresponding numerical methods in this work,which can be used to predict the melt flow behaviors and material distribution in the process of sequential co-injection molding.
