Shanghai Daoqin Plastics Co., Ltd.

micro fine foaming injection molding parts molding technology using/adopting ultra- 临界 gas as is material foaming agent, in injection molding parts parts in micro fine foaming. micro large small generally in 5-100μm between. gas usually using/adopting oxidation carbon or nitrogen gas. micro fine foaming injection molding parts molding process 包含四 steps: 1) gas solvent understanding; 2) uniform formed 核; 3) micro long large; 4) product molding. micro fine foaming injection molding parts molding technology for injection molding parts mold design upper has especially requirements. in micro fine foaming injection molding parts molding stage/phase, polymer and gas formed mono versus melt, due to pressure from MPP(micro fine foaming formed pressure) decline to large gas pressure, make gas 体析出而形 formed a large amount of formed 核点. this formed rear long large formed micro 泡. micro 泡一直 in long large, to formed new pressure balanced or material by 冻结. micro long large and bubbles density 直接取决于 molding process, injection molding parts amount, melt temperature degree, injection molding parts mold temperature degree, injection molding parts pressure, injection molding parts speed rate, ultra- 临界 liquid 体(SCF) content and other. research molding process and micro long large 关系. its in heavy injection molding parts time, injection molding parts mold temperature degree, melt temperature degree and filling amount for micro long large effect/influence. using/adopting value as is 实验手段, process parameters for micro long large effect/influence 判断则 using/adopting 田口实验 methods 进行, optimization injection molding parts molding process, to relatively excellent micro large small distribution and structure. in 此基础 upper, 进一步 research process parameters for micro long large effect/influence degree. 1 实验模 type and optimization methods in for micro fine foaming injection molding parts molding process 进行数 value in, need provide conditions remove injection molding parts molding analysis need process parameters outer, also need provide below/following parameters as is value: foaming 开始时 plastics filling amount, micro 泡直径, mono 位体积 inner micro amount and gas concentrated degree. 1.1 实验模 type 本文以一 平 sheet/plate parts is 例进行 research, its dimensions is 320mm*280mm*2mm, product type, system and cooling system 如图1 示. from front research 知道, in gate micro 泡实际 large small and 模拟结果误差 relatively small. therefore selection gate 附近 特征点 is 参考点, research molding process parameters for micro large small effect/influence. 图 1: 实验模 type plastics material using/adopting grade is HCA-352P PP material. its main/primary property can parameters table/sheet 1 示. gas using/adopting nitrogen gas. table/sheet 1: HCA-352P property can main/primary for micro dimensions effect/influence comparison large injection molding parts mold temperature degree, melt temperature degree, injection time and filling amount and other parameters research. cooling system and system rear, according to material recommendation parameters and 初步模拟结果, 选取 各 process parameters water table/sheet 2 示. need is, SCF use amount for micro structure effect/influence very large, research in false 定SCF use amount to 定, in conditions lower process optimization research. remove research parameters, its it parameters formed density 2×10 11次方/立方米, gas concentrated degree Co＝0.25％, 初始泡孔 semi 径Ro＝1.1×10 negative 6次方m. 1.2 optimization methods using/adopting 田口实验 design method as is optimization methods, according to parameters and water 平 设置, 选取四 parameters water L9 positive table/sheet 安排实验. positive table/sheet table/sheet 3 示. use 田口实验 design method in amount analysis, can 计算出各 process parameters for micro dimensions effect/influence and most excellent process parameters combined. meanwhile for 实验结果进行直观 analysis, 即计算各 process parameters in water lower micro dimensions value. in in micro dimensions as is quality indicators, is most small value issues. therefore 计算公式如 lower: in, m is process parameters in certain water lower value; n is water 平出现 数; y is process parameters in water lower value. rear process parameters most large value and most small value 之差计算出极差R. according to 极差R value, can to process parameters for micro large small effect/influence. 2 实验结果 according to L9 positive table/sheet 安排模拟实验, 获取 参考点处 micro dimensions. 模拟实验 安排／顷序 and 结果见 table/sheet 3. meanwhile according to 方程(1), 计算 每 process parameters in water lower value. in obtain process parameters most large and most small value upper, 计算 极差 value, utilizing optimization obtain process parameters combined 进行模拟, to 模拟结果如图2 示. 结果显示 micro 泡 直径 large separation distribution in 23―27μm between, distribution uniform, from micro structure to optimization. 2进行 analysis, process parameters for micro large small 关系. 3 结论 1) from table/sheet 4 in large small can 直观 出各 process parameters for micro dimensions effect/influence 次序由 large to small is: melt temperature degree, filling amount, injection time, injection molding parts mold temperature degree. 2) in process parameters water upper, for/regarding in type, most optimization process parameters combined is injection molding parts mold temperature degree 10 C, melt temperature degree 180 C, injection time 1s and filling amount 95％. 3) utilizing optimization obtain process parameters combined 进行模拟, 结果显示 micro 泡 直径 large distribution in 23～27μm between, distribution uniform, from micro structure to optimization. 4) for/regarding material PP, in process parameters scope/range inner, reduce melt temperature degree and improve/increase filling amount can optimization micro fine foaming injection molding parts products micro dimensions; shrink short injection molding parts time and reduce injection molding parts mold temperature degree can optimization micro dimensions, is effect/influence large