注塑模具是注塑成型中不可缺少的一部分。我們介紹了注塑模具的型腔數(shù)量、澆口位置、熱流道、裝配圖的設(shè)計原則以及注塑模具的材料選擇。今天我們將繼續(xù)介紹塑料注射模排氣系統(tǒng)的設(shè)計。
Injection mold is an indispensable part of injection molding. We introduced the design principles of cavity quantity, gate position, hot runner, assembly drawing and material selection of injection mold. Today we will continue to introduce the design of exhaust system of plastic injection mold.
除了型腔中的原始空氣外，型腔中的氣體還包含由注射成型材料的加熱或固化產(chǎn)生的低分子揮發(fā)性氣體。有必要考慮這些氣體的順序放電。一般來說，對于結(jié)構(gòu)復(fù)雜的模具，很難預(yù)先估計氣鎖的準(zhǔn)確位置。因此，通常需要通過試模確定其位置，然后打開排氣槽。排氣槽通常在空腔Z填充的位置打開。
In addition to the original air in the cavity, the gas in the cavity also contains low molecular volatile gases produced by the heating or curing of injection molding materials. It is necessary to consider the sequential discharge of these gases. Generally speaking, for the mold with complex structure, it is difficult to estimate the accurate position of air lock in advance. Therefore, it is usually necessary to determine its position through die test, and then open the exhaust slot. The exhaust slot is usually opened where cavity Z is filled.
排氣方式是利用模具零件配合間隙，打開排氣槽排氣。
The exhaust mode is to open the exhaust slot for exhaust by using the matching clearance of die parts.
注塑件成型需要排氣，注塑件脫模需要排氣。對于深腔殼體注射成型零件，注射成型后，腔中的氣體被吹走，在脫模過程中，塑料零件的外觀和型芯的外觀之間形成真空，這是很難脫模的。如果強制脫模，注塑件很容易變形或損壞。因此，有必要引入空氣，即在注塑件和芯之間引入空氣，以便塑料注塑件能夠順利脫模。同時，在分型面上加工幾個淺槽，以便于排氣。
Exhaust is required for injection molding, and exhaust is required for injection mold demoulding. For deep cavity shell injection molding parts, after injection molding, the gas in the cavity is blown away. In the demoulding process, a vacuum is formed between the appearance of plastic parts and the appearance of core, which is difficult to demould. If forced demoulding, the injection molded parts are easy to deform or damage. Therefore, it is necessary to introduce air, that is, between the injection molded part and the core, so that the plastic injection molded part can be demoulded smoothly. At the same time, several shallow grooves are machined on the parting surface to facilitate exhaust.
1.腔體和芯的模板需要使用錐形定位塊或精 密定位塊，該指南安裝在四個側(cè)面或模具周圍。
1. The template of cavity and core needs to use conical positioning block or precision positioning block, and the guide is installed on four sides or around the mold.
2.模架A板與復(fù)位桿的接觸面需使用平墊或圓墊塊，以免損壞A板。
2. Flat pad or round pad shall be used for the contact surface between the a plate of the mold base and the reset rod to avoid damaging the a plate.
3.導(dǎo)軌的穿孔部分應(yīng)傾斜2度以上，以避免毛刺和毛刺，穿孔部分不得為薄葉片結(jié)構(gòu)。
3. The perforated part of the guide rail shall be inclined more than 2 degrees to avoid burrs and burrs. The perforated part shall not be of thin blade structure.
4.為防止注塑制品產(chǎn)生凹痕，加強筋寬度應(yīng)小于外觀表面壁厚的50%（理想值<40%）。
4. In order to prevent dents on injection molded products, the width of stiffener shall be less than 50% of the wall thickness of the appearance surface (ideal value < 40%).
5.產(chǎn)品的壁厚應(yīng)為平均值，且至少應(yīng)考慮突變，以避免出現(xiàn)凹痕。
5. The wall thickness of the product shall be the average value, and at least sudden change shall be considered to avoid dents.
6.如果注塑件是電鍍件，則活動模具也需要拋光。拋光要求僅次于鏡面拋光要求，以減少成型過程中冷材料的產(chǎn)生。
6. If the injection molded part is electroplated, the movable mold also needs polishing. Polishing requirements are second only to mirror polishing requirements to reduce the generation of cold materials in the forming process.
7.必須嵌入通風(fēng)不良的型腔和型芯中的肋和凹槽，以避免不滿意和燒焦痕跡。
7. Ribs and grooves in poorly ventilated cavities and cores must be embedded to avoid dissatisfaction and scorch marks.
8.鑲件、鑲件等應(yīng)定位固定牢固，圓片應(yīng)有防旋轉(zhuǎn)措施。不允許在插入件下方墊銅和鐵片。如果焊墊較高，則焊接部分應(yīng)形成較大的表面接觸并磨平。
8. Inserts, inserts, etc. shall be positioned and fixed firmly, and the disc shall be provided with anti rotation measures. It is not allowed to pad copper and iron under the insert. If the welding pad is high, the welded part shall form a large surface contact and be ground flat.
