The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean an...The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands.In this study,flame-retardant rubber seed oil-based plasticize(FRP)was prepared via epoxidation reaction and ring opening addition reactions,which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer.When DOP was replaced with FRP,the torque of PVC blends increased from 11.4 to 18.4 N⋅m,the LOI value increased from 24.3%for PVC-FRP-0%to 33.1%for PVC-FRP-20.The THR value diminished from 39 MJ/m^(2)(pertaining to PVC-FRC-0)to 22 MJ/m^(2)Tg increased from 23°C to 47°C,the weight loss of plasticized PVC blends significantly reduced from 22.6%to 2.8%in leaching tests.The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.展开更多
For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the war...For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.展开更多
The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variat...The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment, The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.展开更多
Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold g...Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold glass tightly,thus resulting in the unsteady quality of toughened glass and encapsulated plastic. To solve this problem,a novel holding method called magnetic high-pressure holding with twin bags is proposed to address the features of toughened glass and the encapsulation injection process. Firstly,a pair of permanent magnets is introduced as energy source,followed by the magnetization of a couple of magnetic particle bags. Contact between the single bag and the glass surface will enable the couple of magnetic particle bags to hold glass tightly and to self-adapt the freeform of the glass. Secondly, an experimental system with mechanical and control systems is designed. This system is controlled by the opening and closing force of the mold,which turns the magnetic field on or off to hold or loosen the glass. The magnetic field distributions are measured at important positions of the permanent magnets and in the magnetized particles in the experiments to determine the holding performance. Finally, the process of determining the parameters of the magnet and its attenuation is analyzed, including the minimum friction force between the glass and the particle bag during injection molding,the magnetic energy product and the magnetized filed distributions,and the re-checking method for these parameters. The theoretical analysis and the experimental result show that this flexible holding system may produce sufficient holding force,which not only protects glass but self-adapts the glass freeform as well. The production practice meets the technical requirements of injection molding with a defect-free surface,with no scratches and cracks on the glass and no slight glass movements in the mold cavity.展开更多
In this study, Virtual Reality (VR)-based plastic injection molding training system (VPIMTS), which can be modeled as an integrated system with a task planning module, an intelligent instruction module, a simulation m...In this study, Virtual Reality (VR)-based plastic injection molding training system (VPIMTS), which can be modeled as an integrated system with a task planning module, an intelligent instruction module, a simulation module, and virtual envi-ronment (VE) module, was developed. Presented in this paper are an architecture of VPIMTS, a practical knowledge modelling approach for modelling the training scenarios of the system by using Petri nets formalism and key techniques (FEM, injection molding procedure modelling) which have been developed independently. The utilization of the Petri net model realized the environment where the trainee can behave freely, and also made it possible to equip the system with the function of showing the next action of the trainee whenever he wants. The overall system is a powerful approach for highly improving the trainee’s comprehension and injection molding study-efficiency by building digital, intelligent, knowledgeable, and visual aids.展开更多
Shandong Gaomi Mida Rubber & Plastic Products Co., Ltd. (est. 1992) is a new high-technology enterprise that produces various kinds of parts for both washing machines and automobiles.
Calotropis procera(Aiton)W.T.Aiton,belonging to the family Apocynaceae,is C3 evergreen plant species in arid and semi-arid areas of the Punjab Province,Pakistan.It grows in a variety of habitats like salt affected and...Calotropis procera(Aiton)W.T.Aiton,belonging to the family Apocynaceae,is C3 evergreen plant species in arid and semi-arid areas of the Punjab Province,Pakistan.It grows in a variety of habitats like salt affected and waterlogged area,desert/semi-desert,roadside,wasteland,graveyard,forest,crop field,coastline,and river/canal bank.A total of 12 populations growing in different ecological regions were sampled to evaluate their growth,physio-biochemical,and anatomical responses to specific environmental condition.Population adapted to desert/semi-desert showed vigorous growth(plant height,shoot length,and number of leaves),enhanced photosynthetic level(chlorophyll a,chlorophyll b,carotenoids,and total chlorophyll),and apparent anatomical modifications such as increased stem radius,cuticle thickness,storage parenchyma tissues(cortex and pith),and vascular bundles in stems,while the maximum of midrib and lamina thickness,epidermal cells,cuticle thickness,cortical proportion,abaxial stomatal density,and its area in leaves.There was high plasticity in structural and functional features of these populations,which enable them to survive and tolerate under such hot and dry desert environment.Population of saline areas exhibited very critical modifications to sustain under salt prone environment.At physiological level,it possesses the maximum amount of organic osmolytes(glycine betaine and proline)and antioxidants(superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)),while at anatomical level,it showed intensive sclerification,large phloem region(inner and outer),pith parenchyma cells,and metaxylem vessels in stems and leaves.The population of dry mountains showed very distinctive features,such as increased shoot ionic contents(K+and Ca2+),collenchyma and sclerenchyma thickness in stems,trichomes size,and numerous small stomata on abaxial surface of leaves.It is concluded that no definite or precise single character can be taken as a yardstick for adjudging the biomass production in this rubber bush weed population.展开更多
In order to improve the machinability but not to impair other properties of the prehardened mold steel for plastic, the composition was designed by application of Thermo-Calc software package to regulate the type of n...In order to improve the machinability but not to impair other properties of the prehardened mold steel for plastic, the composition was designed by application of Thermo-Calc software package to regulate the type of non-metallic inclusion formed in the steel. The regulated non-metallic inclusion type was also observed by SEM and EDX. Then the machinability assessment of the steel with designed composition under different conditions was studied by the measurement of tool wear amount and cutting force. The results show that the composition of free cutting elements adding to mold steel for plastic can be optimized to obtain proper type of non-metallic inclusion in the aid of Thermo-Calc, compared with the large volume fraction of soft inclusion which is needed for promoting ductile fracture at low cutting speeds, the proper type of inclusion at high cutting speeds is glassy oxide inclusion. All those can be obtained in the present work.展开更多
The pyrolysis experiments were carried out in a continuous feeding rotary kiln pyrolyzer system and the influence of residence time and temperature on the pyrolysis of waste rubber and plastics has been investigated i...The pyrolysis experiments were carried out in a continuous feeding rotary kiln pyrolyzer system and the influence of residence time and temperature on the pyrolysis of waste rubber and plastics has been investigated in this paper.It shows that the extent of pyrolysis was maximum when the revolving speed was 1~2r/min and the temperature was 600℃.展开更多
基金funded by the Science and Technology Project of Henan Province(202102310593)and Science and Technology Project of Kaifeng City(2002003).
文摘The application of phthalate plasticizers has been restricted around the world due to their poor migration and potential harm to the human body.Hence,producing functional bio-based plasticizers via exploiting clean and reusable resources meets the satisfaction of current demands.In this study,flame-retardant rubber seed oil-based plasticize(FRP)was prepared via epoxidation reaction and ring opening addition reactions,which was used as a flame-resistant plasticizer for polyvinyl chloride to replace petroleum-based phthalate plasticizer.When DOP was replaced with FRP,the torque of PVC blends increased from 11.4 to 18.4 N⋅m,the LOI value increased from 24.3%for PVC-FRP-0%to 33.1%for PVC-FRP-20.The THR value diminished from 39 MJ/m^(2)(pertaining to PVC-FRC-0)to 22 MJ/m^(2)Tg increased from 23°C to 47°C,the weight loss of plasticized PVC blends significantly reduced from 22.6%to 2.8%in leaching tests.The study provided a new way to prepare flame retardant plasticizer using rubber seed oil as raw material.
基金Supported by the Key Program of National Natural Science Foundation of China(11432003)the Key Research Project for Henan Universities(15A430009)
文摘For most strip-like plastic injection molded parts, whose cross section size is much smaller than their length, the traditional Hele-Shaw model and three-dimensional model do not work well in the prediction of the warpage be- cause of their special shape. A new solution was suggested in this work. The strip-like plastic part was regarded as a little-curved beam macrnscopically, and was divided into a few one-dimensional elements. On the section of each elemental node location, two-dimensional thermal finite element analysis was made to obtain the non- uniform thermal stress caused by the time difference of the solidification of the plastic melt in the mold. The stress relaxation, or equivalently, strain creep was dealt with by using a special computing model. On the bases of in-mold elastic stress, the final bending moment to the beam was obtained and the warpage was predict- ed in good a^reement with practical cases.
基金This project is supported by National Natural Science Foundation of China (No.50275102)Opening Foundation of State Key Lab of Fluid Power Transmission and Control of Zhejiang University, China (No.GZKF2002004).
文摘The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment, The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit.
基金National Natural Science Foundation of China(No.51303027)Program for New Century Excellent Talents in Fujian Province University,China(No.NCETFJ-2010)+1 种基金Research Fund for Fujian Provincial University,China(No.JK2010038)Research Fund of Fujian Education Department,China(No.JA11189)
文摘Glass positioning and holding is difficult in the process of injection molding encapsulation of automobile glass. A suction cup or soft resin is always introduced in this process. However,these materials cannot hold glass tightly,thus resulting in the unsteady quality of toughened glass and encapsulated plastic. To solve this problem,a novel holding method called magnetic high-pressure holding with twin bags is proposed to address the features of toughened glass and the encapsulation injection process. Firstly,a pair of permanent magnets is introduced as energy source,followed by the magnetization of a couple of magnetic particle bags. Contact between the single bag and the glass surface will enable the couple of magnetic particle bags to hold glass tightly and to self-adapt the freeform of the glass. Secondly, an experimental system with mechanical and control systems is designed. This system is controlled by the opening and closing force of the mold,which turns the magnetic field on or off to hold or loosen the glass. The magnetic field distributions are measured at important positions of the permanent magnets and in the magnetized particles in the experiments to determine the holding performance. Finally, the process of determining the parameters of the magnet and its attenuation is analyzed, including the minimum friction force between the glass and the particle bag during injection molding,the magnetic energy product and the magnetized filed distributions,and the re-checking method for these parameters. The theoretical analysis and the experimental result show that this flexible holding system may produce sufficient holding force,which not only protects glass but self-adapts the glass freeform as well. The production practice meets the technical requirements of injection molding with a defect-free surface,with no scratches and cracks on the glass and no slight glass movements in the mold cavity.
文摘In this study, Virtual Reality (VR)-based plastic injection molding training system (VPIMTS), which can be modeled as an integrated system with a task planning module, an intelligent instruction module, a simulation module, and virtual envi-ronment (VE) module, was developed. Presented in this paper are an architecture of VPIMTS, a practical knowledge modelling approach for modelling the training scenarios of the system by using Petri nets formalism and key techniques (FEM, injection molding procedure modelling) which have been developed independently. The utilization of the Petri net model realized the environment where the trainee can behave freely, and also made it possible to equip the system with the function of showing the next action of the trainee whenever he wants. The overall system is a powerful approach for highly improving the trainee’s comprehension and injection molding study-efficiency by building digital, intelligent, knowledgeable, and visual aids.
文摘Shandong Gaomi Mida Rubber & Plastic Products Co., Ltd. (est. 1992) is a new high-technology enterprise that produces various kinds of parts for both washing machines and automobiles.
文摘Calotropis procera(Aiton)W.T.Aiton,belonging to the family Apocynaceae,is C3 evergreen plant species in arid and semi-arid areas of the Punjab Province,Pakistan.It grows in a variety of habitats like salt affected and waterlogged area,desert/semi-desert,roadside,wasteland,graveyard,forest,crop field,coastline,and river/canal bank.A total of 12 populations growing in different ecological regions were sampled to evaluate their growth,physio-biochemical,and anatomical responses to specific environmental condition.Population adapted to desert/semi-desert showed vigorous growth(plant height,shoot length,and number of leaves),enhanced photosynthetic level(chlorophyll a,chlorophyll b,carotenoids,and total chlorophyll),and apparent anatomical modifications such as increased stem radius,cuticle thickness,storage parenchyma tissues(cortex and pith),and vascular bundles in stems,while the maximum of midrib and lamina thickness,epidermal cells,cuticle thickness,cortical proportion,abaxial stomatal density,and its area in leaves.There was high plasticity in structural and functional features of these populations,which enable them to survive and tolerate under such hot and dry desert environment.Population of saline areas exhibited very critical modifications to sustain under salt prone environment.At physiological level,it possesses the maximum amount of organic osmolytes(glycine betaine and proline)and antioxidants(superoxide dismutase(SOD),catalase(CAT),and peroxidase(POD)),while at anatomical level,it showed intensive sclerification,large phloem region(inner and outer),pith parenchyma cells,and metaxylem vessels in stems and leaves.The population of dry mountains showed very distinctive features,such as increased shoot ionic contents(K+and Ca2+),collenchyma and sclerenchyma thickness in stems,trichomes size,and numerous small stomata on abaxial surface of leaves.It is concluded that no definite or precise single character can be taken as a yardstick for adjudging the biomass production in this rubber bush weed population.
基金Project(015211010) supported by the Key Project of Science and Technology Commission of Shanghai Local Govern ment China
文摘In order to improve the machinability but not to impair other properties of the prehardened mold steel for plastic, the composition was designed by application of Thermo-Calc software package to regulate the type of non-metallic inclusion formed in the steel. The regulated non-metallic inclusion type was also observed by SEM and EDX. Then the machinability assessment of the steel with designed composition under different conditions was studied by the measurement of tool wear amount and cutting force. The results show that the composition of free cutting elements adding to mold steel for plastic can be optimized to obtain proper type of non-metallic inclusion in the aid of Thermo-Calc, compared with the large volume fraction of soft inclusion which is needed for promoting ductile fracture at low cutting speeds, the proper type of inclusion at high cutting speeds is glassy oxide inclusion. All those can be obtained in the present work.
文摘The pyrolysis experiments were carried out in a continuous feeding rotary kiln pyrolyzer system and the influence of residence time and temperature on the pyrolysis of waste rubber and plastics has been investigated in this paper.It shows that the extent of pyrolysis was maximum when the revolving speed was 1~2r/min and the temperature was 600℃.
