注射模具外文翻译---注射模具的介绍

注射模具的介绍

1.模具基本知识

1.1引言

我们日常生产、生活中所使用到的各种工具和产品，大到机床的底座、机身外壳，小到一个胚头螺丝、纽扣以及各种家用电器的外壳，无不与模具有着密切的关系。模具的形状决定着这些产品的外形，模具的加工质量与精度也就决定着这些产品的质量。因为各种产品的材质、外观、规格及用途的不同，模具分为了铸造模、锻造模、压铸模、冲压模等非射胶模具，以及射胶模具。近年来，随着射料工业的飞速发展和通用与工程射料在强度和精度等方面的不断提高，射料制品的应用范围也在不断扩大，如：家用电器、仪器仪表，建筑器材，汽车工业、日用五金等众多领域，射料制品所占的比例正迅猛增加。一个设计合理的射料件往往能代替多个传统金属件。工业产品和日用产品射料化的趋势不断上升。

1.2 模具的一般定义

在工业生产中，用各种压力机和装在压力机上的专用工具，通过压力把金属或非金属材料制出所需形状的零件或制品，这种专用工具统称为模具。

1.3 模具的一般分类

可分为射胶模具及非射胶模具：（1）非射胶模具有：铸造模、锻造模、冲压模、压铸模等。 A．铸造模——水龙头、生铁平台 B．锻造模——汽车身 C．冲压模——计算机面板 D．压铸模——超合金，汽缸体（2）射胶模具根据生产工艺和生产产品的不同又分为：A．注射成型模——电视机外壳、键盘按钮（应用最普遍） B．吹气模——饮料瓶 C．压缩成型模——电木开关、科学瓷碗碟 D．转移成型模——集成电路制品 E．挤压成型模——胶水管、射胶袋 F．热成型模——透明成型包装外壳 G．旋转成型模——软胶洋娃娃玩具

注射成型是射料加工中最普遍采用的方法。该方法适用于全部热射性射料和部分热固性射料，制得的射料制品数量之大是其它成型方法望尘莫及的，作为注射成型加工的主要工具之一的注射模具，在质量精度、制造周期以及注射成型过程中的生产效率等方面水平高低，直接影响产品的质量、产量、成本及产品的更新，同时也决定着企业在市场竞争中的反应能力和速度。注射模具是由若干块钢板配合各种零件组成的，基本分为： A 成型装置（凹模，凸模） B 定位装置（导柱，导套） C 固定装置（工字板，码模坑） D 冷却系统（运水孔） E 恒温系统（加热管，发热线） F 流道系统（唧咀孔，流道槽，流道孔） G 顶出系统（顶针，顶棍）

1.4 模具的类型

根据浇注系统型制的不同可将模具分为三类:（1）大水口模具：流道及浇口在分模线上，与产品在开模时一起脱模，设计最简单，容易加工，成本较低，所以较多人采用大水口系统作业。（2）细水口模具：流道及浇口不在分模线上，一般直接在产品上，所以要设计多一组水口分模线，设计较为复杂，加工较困难，一般要视产品要求而选用细水口系统。（3）热流道模具：主要由热浇口套，热浇道板，温控电箱构成。热流道模具是在一个半模有流道加热系统的两板式模具。热流道系统分成两个部分：分流板和喷嘴。分流板的通道将射料传送到一个和分型线平行平面，这个平面在型腔的上面。喷嘴垂直于分流板安装，把射料从分流板送进行腔。热流道系统的优势:（1）无水口料，不需要后加工，使整个成型过程完全自动化，节省工作时间，提高工作效率。（2）压力损耗小。

2．注射模

设计模具有很多的规则。这些规则和标准的做法，都是基于逻辑，过往的经验，方便性，经济性。设计，模具制造，和成型，它通常的优势就是遵循规则。但有时候，它可能会做出更好的，如果一项方法是被忽视和另一种方法被选择。在一些书中,最普通的规则都会一一列出,而设计者设计的东西也仅仅是跟着以往的经验走而已。设计者应该研究出新的想法和方法,来进行新的成型和选择模具材料。

注射工艺过程就是从给料斗送进粉状或粒状的射料混合物，经过定量区和熔化区，然后将其注射到模具型腔中。注射过程说明：模具是一种生产射料制品的工具。它由几组零件部分构成，这个组合内有成型模腔。注射时，模具装夹在注射机上，熔融射料被注入成型模腔内，并在腔内冷却定型，然后上下模分开，经由顶出系统将制品从模腔顶出离开模具，最后模具再闭合进行下一次注射，整个注射过程是循环进行的。

注射模至少是由装在注射机的两个压板上的两部分组成，以便可以开模和合模。在合模的时候,模具的两半部分形成的产品成型表面是由射料熔体通过浇口和热流道系统注入模具型腔形成的。模具中冷却的原则是产品要在模具中冷却和凝固,以便随后可以脱模。

随着产品注射的完成,模具就必须开模。产品的形状决定着它是否由模具两部份简单地开模或由有侧向分型来开模。模具的设计是由产品的形状和产品开模的方式决定的。注射成型的产品可以分为以下几类:

无侧抽芯的产品；

有侧向开口的外侧抽芯的产品；

有内侧抽芯的产品；

有外侧抽芯和内侧抽芯的产品。

3．注射模具的组成

3.1 型腔空间

型腔空间是在模具中的一个形状,当注射的材料充满这个空间的时候,它就会呈现出和型腔空间一样的形状。在注射成型时,射料是通过很高的压力注射入型腔空间的,所以模具必须要足够的坚固来抵抗注射的压力,以防变形。

3.2 型腔的数量

许多的模具，特别是较大产品的模具，仅仅只有一个模具型腔，但是也有许多的模具，特别是比较大型的模具，都会有2个或更多的型。究其原因就是它纯粹的经济性。它仅仅是注入多个型腔比注入一个型腔多花了一点的时间。今天,大多数的模具型腔数量都是以这些数字为参考的: 2,4,6,8,12,16,24,32,48,64,96,128。选择这些数字（偶数）的原因是为了在长方形区域内布置型腔方便，这样就有利于设计、定尺寸、加工制造和围绕机器中心对称，这种对称分布对于保证每个型腔分配到相同的锁模力非常重要。

3.3 型腔和型芯

按照习惯，腔空间的中空部分称为型腔。与型腔空间所匹配的部分称为型芯。大部分射胶制品是杯形的。但这并不意味着它们看起来就像是一个杯，只是它们有一个内部和外部。产品的外部是由型腔形成的,而内部是有由型芯形成的。通常情况下,型腔是位于注射一边的那半模具上,而型芯是位于可以移动的那半模具上的。这样安排的原因是注射机上的移动板有一个弹射装置,而产品是收缩和包紧在型芯上的,然后产品就可以通过此来弹射出来。大部分的注射机在注射的一边都不会安装弹射装置。

对于模具包含复杂型腔和多型腔模具，试图象整体模具那样在一块钢板加工型腔和型芯是不让人满意的。型腔和型芯分别决定着成型的外部和内部的形状,而它们的整体决定着整个成型的方式。

3.4 分模线

为了能够生产出一个模具,我们必需具备有两个分半的模具,一半装型腔一半装型芯。这两个板分离时的部分叫做分模线,简称P/L。其实,这是一个分离的区域或面,但是为了方便,我们习惯叫它成一条线。模具的分型面是两模板接近型腔的那些部分，它们对接一起形成油封并且避免型腔里射性材料的损失。分模线可以是任何形状的, 许多的注射成型都是要求分模线是不在同一平面或是曲面的,但是为了便于模具制造,最好设计在同一个平面上。为了能够在模具上脱出产品,分模线总是在分布在产品最宽的圆周区域。对一些形状来说，设置分模线或其角度是非常有必要的，但是在任何情况下，都要有目的地让它容易加工，以确保当注射的时候模具能够紧紧地合在一起。如果分模线设计不好,射料将会溢出来,那样产品就会有一个非常大的凹陷,那样的产品肯定会被拆除,否则那样的产品是不能够使用的。甚至更危险的是,射料喷射进模具的时候,它会飞溅出伤害到人本身。

3.5 流道和浇口

现在,增加介绍的是把射料从外面带到型腔空间的装置。在射料冷却之前(也就是射料冷却后不能在流动之前),它必需有足够的压力以便使射料能够充满型腔。流动的通道就是流道,它把注射机的喷嘴和模具连接了起来,流道是一个独立的型腔, 流道本身要光滑,以便可以阻止射料自由流动。同时, 型腔被充满后，浇口处先凝固，注射机螺杆抽回时可防止成型中的回流。浇口是一个小型的开口,它引导着流道到型腔空间。浇口是一个渠道,是连接与流道相通的小口。与其他的进料系统相比,它有一个很小的横截面积。在射料充满型腔后,浇口很快就会冷却,注射的喷嘴往后退,在模具退后的时候射料还是留有在喷嘴中的。

4. 注射机的工作过程

注射模具是安装在注射机上的，它的注射成型过程是由注射机来完成的。以下是注射机的工作过程：注射成型机通过抽真空把射料原料从干燥机吸到料斗里面。料斗实际上是一个小的漏斗，它被安装在机台料筒的后面。开始起实际作用的地方是料筒，料筒实质上是四周都是加热器的一个很大的螺杆安放室，它把原料送向模具。随着螺杆的旋转，原料在料筒里前进并成为熔融状态。只有完全熔融后，原料才会在螺杆高速旋转产生的挤压力下射进模腔。当螺杆前端压室注满射料时，螺杆被迫后退，断开限位开关而开动液压缸，从而向前推动螺杆，将熔融射料注射到闭合的模具型腔中。型腔被充满后，浇口处先凝固，注射机螺杆抽回时可防止成型中的回流。螺杆端部称为喷嘴，从这里开始直到模具型腔这段空间内，熔融材料没有被加热，并且一直处于被冷却的状态。流道水口料就是在喷嘴到模腔之间冷却固化的射料，属于工艺废料。实际上，在喷嘴到模腔之间的冷却射料是“主流道”，但它和流道是连在一块的。有一些关于处理水口料的方法，但这不是我们这里要讨论的。大多数人以前都见过流道，但却没有认出。最容易见到他们的地方是由单独零件构成的飞机和汽车模型上，在这些零件上面一般都附着着流道系统。一般地，水口料被顶出，落进安放在模具下面的落料装置（通过一个斜坡传送通道），或者被机械手取出，然后投入粉料机。粉料机把水口料绞成碎料并送回干燥机。

尽管塑料一旦被加热就会发生降解，而且有些成型工艺不允许碎材混入原材料里面，因为这样会导致成品的缺陷。这种情况下水口料可以用到其他地方或者干脆不用。收缩在成型中影响深远，大部分塑料冷却后会收缩20%。为了在重点（关键）塑料零件上--当然不只是玩具---克服这种现象，模具设计者必须把这个要素考虑到设计里面去，那样成型出来的产品才能满足设计规格。顶针是模具本身的零件，用来在模具打开的时候顶出产品。整个过程都有注射成型机控制。一个成型周期实际上就是合模--注射--开模--顶出。模具被锁紧在机台上，前模固定不动（在机台的料筒侧），后模则可以移动。上面说的顶针就是后模侧。当模具打开，产品吸附在后模侧以被顶出。

以上就是关于注射模具的相关介绍。

The introdution of the Injection Mold

1. Mold basic knowledge

1.1 Introduction

There is a close relationship with all kinds of mold,which are refered to our daily production, and life in the use of the various tools and products, the large base of the machine tool, the body shell, the first embryo to a small screws, buttons, as well as various home appliances shell. Mold’s shape determine the shape of these products, mold’s precision and machining quality determine the quality of these products,too. Because of a variety of products, appearance, specifications and the different uses,mold devide into Die Casting into the mould, die forging, die-casting mould, Die, and so on other non - plastic molds, as well as plastic mold. In recent years, with the rapid development of the plastics industry, and GM and engineering plastics in areas such as strength and accuracy of the continuous enhancement , the scope of the application of plastic products have also constantly expanded, such as: household appliances, instrumentation, construction equipment, automotive, daily hardware, and many other fields, the proportion of plastic products is rapidly increasing. A rational design of plastic parts often can replace much more traditional metal pieces. The trend of industrial products and daily products plasticed is rising day after day.

1.2 Mold general definition

In the industrial production，with the various press and the special instruments which installed in the press,it produces the required shape parts or products through pressure on the metal or non-metallic materials, this special instruments collectively call as the mold.

1.3 Mold general classification

Mold can be divided into plastic and non - plastic mould: (1) Non-plastic mould: Die Casting, forging Die, Die, die-casting mould and so on. A. Die Casting - taps, pig iron platformB. Forging Die - car body C. Die - computer panel D. Die Casting Die - superalloy, cylinder body (2) For the production technology and production, the plastic mold are divided into different products: A. Injection molding die - TV casing, keyboard button (the most common application) B. Inflatable module - drink bottles C. Compression molding die - bakelite switches, scientific Ciwan dish D. Transfer molding die - IC products E. Extrusion die - of glue, plastic bags F. Hot forming die - transparent shell molding packaging G. Rotomoulding mode - Flexible toy doll. Injection Molding is the most popurlar method in plastics producing process. The method can be applied to all parts of thermoplastic and some of thermosetting plastics, the quantity of plastic production is much more than any other

forming method.Injection mold as one of the main toolsof injection molding processing,whosh production efficiency is low or high in the quality of precision、manufacturing cycle and the process of injection molding and so on,directly affect the quality of products, production, cost and product updates, at the same time it also determines the competitiveness of enterprises in the market's response capacity and speed. Injection Mold consists of a number of plate which mass with the various component parts. It divided into: A molding device (Die, punch)B positioning system (I. column I. sets) C fixtures (the word board, code-pit) D cooling system (carrying water hole) E thermostat system (heating tubes, the hotline) F-Road System (jack Tsui hole, flow slot, streaming Road Hole) G ejection system (Dingzhen, top stick).

1.4 Type of mold

It can be divided into three categories according to gating system with the different type of mold :(1) intake die: Runner and gate at the partig line,it will strip together with products when in the open mode,it is the most simple of design, easy processing and lower costing.So more people operations by using large intake system. (2) small inlet die:It general stay in the products directly,but runner and gate are not at the partig line.Therefore,it should be design a multi-outlet parting line.And then it is more complex in the designing, more difficult in processing, generally chosing the small inlet die is depending on the product’s requirements.

(3) hot runner die:It consists of heat gate, heat runner plate, temperature control box. Hot runner molds are two plate molds with a heated runner system inside one half of the mold. A hot runner system is divided into two parts: the manifold and the drops. The manifold has channels that convey the plastic on a single plane, parallel to the parting line, to a point above the cavity. The drops, situated perpendicular to the manifold, convey the plastic from the manifold to the part. The advantages of hot runner system ：(1)No outlet expected, no need processing, the whole process fully automated, save time and enhance the efficiency of the work. (2) small pressure loss.

2、Injection Mold

There are many rules for designing molds.These rules and standard practices are based on logic,past experience,convenience,and economy.For designing,mold making,and molding,it is usually of advantage to follow the rules.But occasionally,it may work out better if a rule is ignored and an alternative way is selected.In some texts,the most common rules are noted,but the designer will learn only from experience which way to go.The designer must ever be open to new ideas and methods,to new molding and mold material that may affect these rules.The process consists of feeding a plastic compound in powdered or granular form

from a hopper through metering and melting stages and then injecting it into a mold.Injection molding process: Mold is a production of plastic tool. It consists of several parts and this group contains forming cavities. When it injects molding, mold clamping in the injection molding machine, melting plastic is Injected forming cavities and cooling stereotypes in it, then it separate upper and lower die,it will push the production from the cavity in order to leave the mold through ejection system, finally mold close again and prepared the next injection. The entire process of injection is carried out of the cycle.

An injection mold consists of at least two halves that are fastened to the two platens of the injection molding machine so that can be opened and closed.In the closed position,the product-forming surfaces of the two mold halves define the mold cavity into which the plastic melt is injected via the runner system and the gate.Cooling provisions in the mold provide for cooling and solidification of the molded product so that it can be subsequently ejected.

For product ejection to occur,the mold must open.The shape of the molded product determines whether it can be ejected simply by opening the two mold halves or whether undercuts must be present.The design of a mold is dictated primarily by the shape of the product to be molded and the provisions necessary for product ejection.Injection-molded products can be classified as:

1).Products without undercuts.

2).products with external undercuts of lateral openings.

3).products with internal undercuts.

4).products with external and internal undercuts.

3.The composition of injection mold

3.1 Mold Cavity Space

The mold cavity space is a shape inside the mold,when the molding material is forced into this space it will take on the shape of the cavity space.In injection molding the plastic is injected into the cavity space with high pressure,so the mold must be strong enough to resist the injection pressure without deforming.

3.2 Number of Cavities

Many molds,particularly molds for larger products,ate built for only 1 cavity space,but many molds,especially large production molds,are built with 2 or more cavities.The reason for this is purely economical.It takes only little more time to inject several cavities than to inject one.Today,most multicavity molds are built with a preferred number of

cavities:2,4,6,8,12,16,24,32,48,64,96,128.These numbers are selected because the cavities can be easily arranged in a rectangular pattern,which is easier for designing and dimensioning,for

manufacturing,and for symmetry around the center of the machine ,which is highly desirable to ensure equal clamping force for each cavity.

3.3 Cavity and Core

By convention,the hollow portion of the cavity space is called the cavity.The matching,often raised portion of the cavity space is called the core.Most plastic products are cup-shaped.This does not mean that they look like a cup,but they do have an inside and an outside.The outside of the product is formed by the cavity, the inside by the https://www.360docs.net/doc/3c12718852.html,ually,the cavities are placed in the mold half that is mounted on the injection side,while the cores are placed in the moving half of the mold.The reason for this is that all injection molding machines provide an ejection mechanism on the moving platen and the products tend to shrink onto and cling to the core,from where they are then ejected.Most injection molding machines do not provide ejection mechanisms on the injection side.

For moulds containing intricate impressions,and for multi-impression moulds, it is not satisfactory to attempt to machine the cavity and core plates from single blocks of steel as with integer moulds. The cavity and core give the molding its external and internal shapes respectively, the impression imparting the whole of the form to the molding.

3.4 The Parting Line

To be able to produce a mold,we must have ta least two separate mold halves,with the cavity in one side and the core in the other.The separation between these plates is called the parting line,and designated P/L.Actually,this is a parting area or plane,but,by cinvention,in this intext it is referred to as a line. The parting surfaces of a mould are those portion of both mould plates, adjacent to the impressions, which butt together to form a seal and prevent the loss of plastic material from the impression.The parting line can have any shape, many moldings are required which have a parting line which lies on a non-planar or curved surface,but for ease of mold manufacturing,it is preferable to have it in one plane.The parting line is always at the widest circumference of the product,to make ejection of the product from the mold possible.With some shapes it may be necessary to offset the P/L,or to have it at an angle,but in any event it is best to have is so that itan be easily machined,and often ground, to ensure that it shuts off tightly when the mold is clamped during injection.If the parting line is poorly finished the plastic will escape,which shows up on the product as an unsightly sharp projection,which must then be removed;otherwise,the product could be unusable.There is even a danger that the plastic could squirt out of the mold and do personal danger.

3.5 Runners and Gates

Now,we must add provisions for bringing the plastic into these cavity spaces.This must

be done with enough pressure so that the cavity spaces are filled completely before the plastic "freezes"(that is,cools so much that the plastic cannot flow anymore).The flow passages are the sprue,from wherethe machine nozzle contactss the mold,the runners,which distribute the plastic to the individual cavities, the wall of the runner channel must be smooth to prevent any restriction to flow. Also, as the runner has to be removed with the molding, there must be no machine marks left which would tend to retain the runner in the mould plate.And the gates which are small openings leading from the runner into the cavity space. The gate is a channel or orifice connecting the runner with the impression. It has a small cross-sectional area when compared with the rest of the feed system. The gate freezes soon after the impression is filled so that the injection plunger can be withdrawn without the probability of void being created in the molding by suck-back.

4. The injection molding machine process

Injection Mold is installed in the injection molding machine, and its injection molding process is completed by the injection molding machine. Following is the injection molding machine process.The molding machine uses a vacuum to move the plastic from the dryer to it's initial holding chamber. This chamber is actually a small hopper on the back of the "barrel" of the machine。The barrel is where all the real work is done and it's essentially a large screw housed in a heater which moves the plastic closer to the mold. As the screw turns, the plastic traverses the barrel and reaches a molten state. Only when it's molten can it be injected into the mold with a rapid turn of the screw. As the chamber in front of the screw becomes filled, it forces the screw back, tripping a limit switch that activates a hydraulic cylinder that forces the screw forward and injects the fluid plastic into the closed mold. The gate freezes soon after the impression is filled so that the injection plunger can be withdrawn without the probability of void being created in the molding by suck-back. The tip of the barrel is called the "nozzle" and from this point to the cavity in the mold the material is not heated and is constantly cooling. The "runner" is the cooled/set plastic that extends from the nozzle to the cavity and is process scrap. Actually, the cooled material from the nozzle to the mold is the "sprue" but it's connected to the runner. There are ways around having sprues and runners, but it's beyond the scope of what we're talking about here. Most people have probably seen runners before and not realized it. The most likely place to see them are in model airplane/car kits as the individual components are left attached to the runner system. Typically the runners are ejected into a chute below the mold or else they will be picked out of the mold by a robotic arm and dumped into a regrinder. The regrinder chops the runners into bits and prepares them to be moved back into the dryer.

Though, once plastic has been heated, it degrades a bit and some molding processes will

not allow for "regrind" to be mixed back in with virgin material as it can cause problems with the final part. In cases like this the regrind is used elsewhere or it is discarded completely. Shrinkage plays a crucial role in molding and most plastic shrinks 20% as it cools. In order to combat this phenomenon in critical plastic pieces (not really toys) it is up the mold designer to build this factor into his design so that the finished parts will meet the original product design specifications. "Ejector pins" are part of the mold itself and are used to push the molded parts from the cavity once the mold is opened. This ejecting process is controlled by the molding machine. The molding cycle is basically "close - shoot - open - eject". The mold is clamped into the machine with the front half remaining stationary (on the barrel side of the machine) and the back half being the movable half. Also on this movable half are the ejector pins that push the molded parts from the cavity. The parting surfaces of a mould are those portion of both mould plates, adjacent to the impressions, which butt together to form a seal and prevent the loss of plastic material from the impression.When all molds open up, the parts are stuck to the back half of the mold so that they can be ejected with the built-in pins.

These are related to the introduction of the injection mold.