According to statistics, about 2,000 sets of molds are directly and indirectly related to items of every ordinary people! Degree of development of mold industry can be said to have become one of important signs of a country's industrial modernization. Mold department of many large domestic enterprises has an important position in the whole company. For example, BYD in Shenzhen was originally developed by a small mold workshop, and Chery’s moulding die manufacturing technology is also first-class in the world. With continuous development of Pearl River Delta economy, more and more international companies are looking at mature moulding die manufacturing technology, technical talents with rich experience in the industry. They have all transferred their plastics and molds here, or sent molds to be manufactured here. Number of mold exports in Pearl River Delta has increased year by year, and has become the most important mold production and processing base in China and even in the world, especially in household appliances mould and automotive molding. When it comes to Pearl River Delta moulding die manufacturing industry, it has to mention Hong Kong and Taiwan. In the 1980s and 1990s, Pearl River Delta economy just took off, and its mold technology was almost blank. With transfer of factories to mainland by Hong Kong and Taiwanese companies, its advanced moulding die manufacturing technology was brought over here. At that time, a skilled mold engineer had a monthly salary of tens of thousands of RMB. Among them, the most important technology is CAD/CAM, which is computer technology of mold design and computerized technology of molding processing (CNC, computer technology). At present, mold design and manufacturing technology of Shenzhen and Dongguan in Pearl River Delta have reached a high level. In annual mold exhibitions of this kind, there are many new leading international technologies and new equipment. Talents in this area have also become popular, and even companies in Yangtze River Delta, Jiangsu and Zhejiang provinces have joined this talent war, robbing talents in various job fairs!
In order to get more basic knowledge about young friends and beginners who are interested in joining this industry, Gud Mould have summarized some basic experience in the past few years and information collected in the past for your reference.

Plastic mold is a production tool that people make to meet needs of production and life and are manufactured according to certain requirements. Molds are production tools that are generally reusable. Commonly used in the industry are plastic mold, metal stamping dies, die-casting dies, blow molding dies, extrusion dies, etc. Broadly speaking, some die cutters, paper molds, plaster molds, and even wood molds for moon cakes in daily life can be called molds. Plastic mold is a mold used in injection molding production. Plastic mold is mainly used when loading plastic products on plastic injection molding machines.

1. Basic knowledge: trigonometric functions, plane & solid geometry, analytical geometry, engineering drawing, descriptive geometry, mechanical foundation, hardware & chemical basis;
2. Basic practical experience;
3. Software knowledge: AutoCAD, PRO-E, UG, SilodWorks, CATIA, MasterCAM, CIMATRON IT, MOLDFLOW, etc.;

1. plastic mold base.
Plastic mold base is skeleton of the whole mold, construction of all mold parts must consider structure of plastic mold base. Cost of mold base generally accounts for about 30% of the whole set of molds. Plastic mold base is manufactured by a special large plastic mold base factory and has been standardized. Each mold manufacturer only needs to customize it to plastic mold base factory according to its own needs. Plastic mold base is divided into panel, A plate, B plate, C plate (square iron), bottom plate, thimble panel, thimble bottom plate, cylinder, guide post, back needle, thimble, support pillar, stop button, etc. At present, large-scale plastic mold base manufacturers in Pearl River Delta region have Longji Mold Base (LKM), Hongfeng mold base, Chinese mold bases, etc. Among them, LKM is the most famous, its mold base are widely used by mold manufacturer, quality and precision are guaranteed.
2, Mold core, that is, molding core embedded in plastic mold base. Divided into front mold core and rear mold core, commonly known as cavity and core. Why it need to embed a mold core in plastic mold base? Mainly to save costs. Because plastic has high requirements on steel properties of mold, such as hardness, corrosion resistance, high temperature resistance (thermal deformation), etc.; and plate of plastic mold base does not need too high requirements. Hardness of mold core is generally 45~65HRC, hardness of plastic mold base is 30~45HRC, steel used as mold core can reach RMB200 per kilogram, and steel material of plastic mold base generally only needs RMB20~30 yuan.
3. Sprue. Nozzle of injection molding machine barrel injects molten plastic material into cavity through this device.
4, Slider. Structural components that must be used for smooth demoulding. Because some products have special structure, such as there are empty sides, reverse buckles (hooks), etc., you need to use slide to demoulding.
5, Angle-Lifter. Similar to slider, it is also a structural component that must be used for smooth demoulding.
6, There are some terms related to mold: parting line (P / L), mold benchmark, shrinkage, layout, steel, copper (electrode, its material has copper, graphite, etc. ), reverse buckle, water transport, draft angle, cold well, runner, injection simulation, parting, demoulding, opening & closing step, mold NO, polishing, soft mold , hard mold, mold trial (TEST MOLD), mold modification, mold loading, mold transfer, etc.
Following is a set of mold structure drawings with front mold positions:

 

7, From above, according to function of its various components, we can see a set of mold can be subdivided into: runner system, molding system, temperature regulation system, exhaust system, ejection system, opening and closing system, reset system.

1, According to structure, it is divided into two categories: Large nozzle mould and fine nozzle mold.

 

 

1, Mold opening step description:
First step, P / L-1 first open about 10mm, hook will pull nozzle away from product;
Second step, P / L-2 open at least about 100mm (this distance is very important, mold base must be referenced to it. Generally not less than size of an adult fist or robot, and size of space can ensure smooth demoulding of nozzle), nozzle will be taken out between two boards;
Third step, P/L-3 is opened, product is taken out. Similarly, distance is also determined by size of product.
2, According to runner is divided into: ordinary cold runner mold and hot runner mold. In addition to meeting needs of special structures and extra-large products, hot runner mold also have characteristics of high production efficiency and little waste. Although it is much more expensive in terms of mold cost, it is still very cost-effective in terms of long-term production.

 

Figure (4) Hot runner mold
4, According to amount of color of injection molding: monochrome mold, two-color mold, three-color mold.
5, According to hardness of mold steel can be divided into soft mold, hard mold. Hard mold is usually made of a hard steel (such as LKM8407# steel), or soft mold is heat treated. Some large companies generally open a set of soft molds first. After molds are improved and samples are OK, several sets of same hard molds are opened. For example, NOKIA's mobile phone will open soft molds at development stage, and must be hard molds for formal production. In addition to high unit price, hard mold has a high service life, stable injected product quality and excellent appearance. If some hard molds are well maintained, after millions times of molding, injected product is still very beautiful, almost like a new mold!