The effects of process parameters in rapid heat cycle moulding(RHCM) on parts warpage were investigated.A vehicle-used blue-tooth front shell(consisting of ABS material) was considered as a part example manufactured b...The effects of process parameters in rapid heat cycle moulding(RHCM) on parts warpage were investigated.A vehicle-used blue-tooth front shell(consisting of ABS material) was considered as a part example manufactured by RHCM method.The corresponding rapid heat response mould with an innovational conformal heating/cooling channel system and a dynamic mould temperature control system based on the J11-W-160 type precise temperature controller was proposed.During heating/cooling process,the mould was able to be heated from room temperature to 160 °C in 6 s and then cooled to 80 °C in 22 s.The effects of processing conditions in RHCM on part warpage were investigated based on the single factor experimental method and Taguchi theory.Results reveal that the elevated mould temperature reduces unwanted freezing during the injection stage,thus improving mouldability and enhancing part quality,whereas the overheated of mould temperature will lead to defective product.The feasible mould temperature scope in RHCM should be no higher than 140 °C,and the efficient mould temperature scope should be around the polymer heat distortion temperature.Melt temperature as well as injection pressure effects on warpage can be divided into two stages.The lower stage gives a no explicit effect on warpage whereas the higher stage leads to a quasi-linear downtrend.But others affect the warpage as a V-type fluctuation,reaching to the minimum around the heat distortion temperature.Under the same mould temperature condition,the effects of process parameters on warpage decrease according to the following order,packing time,packing pressure,melt temperature,injection pressure and cooling time,respectively.展开更多
A CAD approach which can optimize and automate the parting direction determination is presented. The approach is based on the geometrical and topological information of the solid modelling of the plastic moulded part ...A CAD approach which can optimize and automate the parting direction determination is presented. The approach is based on the geometrical and topological information of the solid modelling of the plastic moulded part in order to select a pair of optimal parting directions of a two plate mould which minimizes the number of side cores. The shell of a part is divided into inter influential regions and non influential faces in the mould design point of view. Through analyzing and computing the accessibility direction cones of the inter influential regions, the optimal parting directions can be determined automatically.展开更多
基金Project(20122BAB206014)supported by National Natural Science Foundation of ChinaProject(51365038)supported by the Natural Science Foundation of Jiangxi Province,ChinaProject(GJJ13068)supported by the Science and Technology Program of Educational Committee of Jiangxi Province,China
文摘The effects of process parameters in rapid heat cycle moulding(RHCM) on parts warpage were investigated.A vehicle-used blue-tooth front shell(consisting of ABS material) was considered as a part example manufactured by RHCM method.The corresponding rapid heat response mould with an innovational conformal heating/cooling channel system and a dynamic mould temperature control system based on the J11-W-160 type precise temperature controller was proposed.During heating/cooling process,the mould was able to be heated from room temperature to 160 °C in 6 s and then cooled to 80 °C in 22 s.The effects of processing conditions in RHCM on part warpage were investigated based on the single factor experimental method and Taguchi theory.Results reveal that the elevated mould temperature reduces unwanted freezing during the injection stage,thus improving mouldability and enhancing part quality,whereas the overheated of mould temperature will lead to defective product.The feasible mould temperature scope in RHCM should be no higher than 140 °C,and the efficient mould temperature scope should be around the polymer heat distortion temperature.Melt temperature as well as injection pressure effects on warpage can be divided into two stages.The lower stage gives a no explicit effect on warpage whereas the higher stage leads to a quasi-linear downtrend.But others affect the warpage as a V-type fluctuation,reaching to the minimum around the heat distortion temperature.Under the same mould temperature condition,the effects of process parameters on warpage decrease according to the following order,packing time,packing pressure,melt temperature,injection pressure and cooling time,respectively.
文摘A CAD approach which can optimize and automate the parting direction determination is presented. The approach is based on the geometrical and topological information of the solid modelling of the plastic moulded part in order to select a pair of optimal parting directions of a two plate mould which minimizes the number of side cores. The shell of a part is divided into inter influential regions and non influential faces in the mould design point of view. Through analyzing and computing the accessibility direction cones of the inter influential regions, the optimal parting directions can be determined automatically.
