Mold manufacturing is a complex process, from design, processing, assembly, commissioning and other steps, to the final real use, in the whole life cycle, there are 10 main factors that affect the quality of the mold.
Steel is a decisive factor in the quality of the mould, and the selection of a reasonable steel is of paramount importance. The criteria for selecting steel are.
①Requirement of injection material
The use of different steels for different plastics, such as requirements for high polish, corrosion resistance, etc..
Steel properties can be good, not the more expensive the better; taking into account the cost factors of the mold, mold steel should be used and mold life of the corresponding materials to avoid unnecessary waste; general P20 material life of about 300,000; 2738 material in 500,000 no problem, H13/2344 usually in the 800,000-1 million or more, can be selected according to the situation;.
③ Surface treatment
The surface treatment of moulds is also very important. Nitriding can enhance the surface hardness of the steel and effectively extend the life of the mold; plating can effectively modify the mold steel, and for some plastic parts that need high brightness and corrosion resistance can use plating to enhance and improve the performance of the steel.
- Structural design
Mature mold structure not only takes into account the product material properties, shrinkage rate, molding temperature, elastic tensile deformation coefficient, etc., but also takes into account the cooling water circuit, the speed of opening and closing the mold, etc. Reasonable mold structure can effectively extend the mold life and ensure the smooth production of the mold, improve efficiency and reduce costs.
The arrangement of the mould process is particularly important. A reasonable process arrangement can speed up the production cycle, shorten the processing time and effectively save costs. And more importantly, precise and reasonable processing can ensure the stability of the mold in the production process and extend its life.
Processing errors can lead to mold burnout, no matter how well welded, it is a loss for the mold; in addition, poor processing may also affect the mold action, reduce mold life, resulting in the mold in the production process of pulling crack or even broken.
- Standard parts
Standard parts are not directly involved in the molding, but they control the whole operation of the mold. A good standard part should be able to wear resistant, hard enough, high precision and should not be deformed.
- Collisions (flying dies)
The clash relies on the experience of the mould clampers, and what seems to be a simple job is the most technical one. Complex moulds mainly depends on this kung fu. Flat die is the easiest, as long as there is no flying edge breakage on the fractal surface, it is basically OK.
Like auto parts mould is very troublesome, not only the fractal surface is relatively irregular, but also often includes multiple sliders and top blocks. At the same time, other problems of the mold can be improved and perfected by clashing, so it is a comprehensive work.
- Polishing/skin grain
The polishing of the mold is the last part of the manufacturing of the mold. The polishing reflects directly on the plastic part, so it is a most facetious job. Polishing also helps and complements the mold action, and is especially meaningful for mold release. Often some molds are not produced smoothly because of poor polishing, excessive resistance, difficult release, or even top white, top cracking, etc.
- Mould assembly
Mold assembly is like assembling a machine, every part, every screw can not be wrong, otherwise the consequences will be quite serious, the light will lead to product defects, affecting production, the heavy will completely damage the mold, resulting in scrap. So the assembly work must be very careful. Assembly process especially to pay attention to the clean work of the mold, especially the waterway, screw holes, must be blown clean inside the iron chips.
- Hot runner or cold runner
This actually has the least impact on the quality of the mold, because the hot runner is usually the brand specified by the customer, especially some large customers. Foreign well-known brands are doing very well in terms of quality or after-sales service, so there is generally no problem in quality.
It's just that some of the domestic hot runners fall back on quality that varies greatly. Individual small enterprises in order to save costs, to fight for the price advantage, with some unreliable heating and conduction accessories, it is easy to have problems. The main problem of cold runner is how to ensure the balance of injection, gate size, injection pressure and so on.
- Cooling water circuit
Anyone who has experience with molds knows how important cooling is to a mold. With the increase in prices and labor wages, it is unimaginable how much profit can be made by not reducing the injection cycle by one second when mass producing products.
But speed up the production cycle at the same time will be the rise of the mold temperature, if not effectively controlled, it will make the mold due to too hot can not be formed, or even lead to mold deformation failure scrap. So good water circuit design is especially important, including the density of water circuit layout, diameter, the link between each other and so on.
- Mould maintenance
Mold maintenance is mainly the maintenance and care during the production process. Moulds are just like cars, if they are not used for a long time and not maintained, they may be scrapped. Therefore, every time after the use of the mold should be a comprehensive maintenance, especially the molding part of the rust prevention, the main moving parts of the rust prevention.
Because the mold due to the production process to receive water, there may be sleep in the installation or removal process to get on the mold, so be sure to ensure that the mold is dry, and then brush a layer of oil to protect.
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