Lesson 2. 射出成型之認識與了解 射出成型機 模具 成形條件 分析過程

射出成型機 膠口與料管 料斗 加熱器 鎖模機構 液壓機構 料管 螺桿 模具冷卻系統

射出成型週期 開模時間 充填時間 冷卻時間 保壓時間 Cycle The cycle time may vary depending on process conditions, material, and part geometry. 2

射出成型週期 成形週期 充填時間 保壓時間 冷卻時間 開模時間 22 1 9 10 2 Sec. Injection Molding Cycle This graphic represents a typical injection molding cycle. The total cycle defines how long it takes to manufacture one part. It is comprised of all the items listed above. We will now look at each of these items and provide a definition and some valuable information. 10 2 3

射出成型過程 充填 保壓 在充填結束後到開模前的這段時間稱為“後充填時間” Hopper 充填 充填時間是指射出機螺桿向前移動並推動塑料前進所費的時間,即在壓力維持段之前的時間, 保壓 在充填結束後到開模前的這段時間稱為“後充填時間” 充填結束後以某一壓力維持住螺桿直到澆口冷卻凝固所費的時間稱為“保壓/維持時間” 彌補材料本身的可壓縮性及冷卻收縮 Barrel Screw Mold Injection Molding Process The injection molding process is relatively simple. Resin is melted, forced into a cold mold at high pressure, cooled, and then ejected from the mold. Let’s take a little more time to look at this process further. First, resin enters the hopper and then is plasticated. It is plasticated by a revolving screw located in a heated barrel. The screw moves back to develop the necessary shot size. Next, the mold closes, then the Screw is moved forward to force the molten polymer through the melt delivery system and into the cold mold. This is usually accompanied by high pressures. Once the cavity is completely filled, a pressure is applied to the screw for a certain length of time in order to keep the material in the cavity. Screw is applying a specified pressure to the polymer melt in order to pack more plastic into the cavity. Also called “compensation stage”. 3

Injection Molding Process 冷卻時間 壓力維持結束後壓力開始釋放,一直到成品固化到足以頂出時所需的時間稱為冷卻時間 也是一般所稱的固化時間(Cure Time) 開模時間 整個行程包括公模後移,模具打開,成品頂出及移出,模具關閉等 Injection Molding Process Continued Next, The packing is completed (pressure released) due to the gate freezing off. The process now enters the cooling stage. This allows the part and melt delivery system to cool enough in order to open the mold. During this cooling stage, the screw moves back to prepare for the next shot. After the cooling is complete, and the mold opens in order to eject the part. 4

射出成型模具 靜模 動模

射出成型模具 投影面積 壓力 X 投影面積 = 鎖模力

射出成型機 射出機選擇細節設定 射出行程 : 螺桿在料管裡面移動的距離 機器鎖模力: 如果分析超過預 設值; 其分析結果會提出警告 機器鎖模力: 如果分析超過預 設值; 其分析結果會提出警告 塑膠/液壓壓力比: 使用分析決 定實際上塑膠壓力在整個週期 之設定 射出行程 : 螺桿在料管裡面移動的距離 射出率 : 機器每秒注射塑料體積量 螺桿直徑: 以射出率決定螺桿前進速度 液體壓力: 通常注射壓力的10% 壓力切換: 沒有典型使用形式但可 以用來設限其最高壓力 模穴壓力切換: 如果壓力超過設定 自動切換至壓力控制 保壓時間與壓力設定

成形條件 熔膠溫度: 實際上在機器 “空射” 的溫度 能夠設定模具溫度 冷卻時間: 影響模具冷卻 開模時間: 影響模具冷卻

模型 產品模穴 模型豎膠道與澆口 噴嘴 X Y Z 冷卻系統 內定設定XY-plane分模面