- Why do some places need to have inserts in plastic mold design? First, let me introduce what is an insert?
Insert is a mold term, also called insert or insert, with different names. It refers specifically to mold accessories used to be embedded in the mold core in the mold. Inserts can be square, round, or sheet-shaped. Like all mold accessories, they also have very high requirements for precision. Generally, there are no finished products, and they are customized according to the needs of the mold.
Types of inserts: insert pins, insert blocks, insert columns, insert rings, etc.;
Material: SKD61, SKH51, ASP23, SKD11, etc., or the same as the corresponding mold core material;
Hardness: above 50HRC;
Standard accuracy: ±0.01mm, depending on the specific mold accuracy requirements. - Then the question is, under what circumstances do you need to make inserts?
- Save mold materials
As we all know, when the mold is set, it is set as a piece of steel with a relatively regular shape. However, the material of the front and rear molds is determined by the highest point. Therefore, whether it is the front mold or the rear mold, if a certain place is higher than other places, this place can be made into an insert to lower the height of the mold core, so that the mold core does not need to be set so high, thus saving mold materials. - Convenient mold modification
The parts of the mold that are often modified can be disassembled and made into inserts. In the future, when the mold is modified, only the inserts need to be replaced. Even more spare parts of the inserts can be made for replacement when the mold is opened, which is convenient for modifying the mold. For example, some ODM manufacturers, the product appearance remains unchanged, and only the LOGO needs to be changed to become a product of another brand. At this time, the LOGO part of the mold can be disassembled and made into an insert, so there is no need to open a new set of molds. - It is conducive to the exhaust of the mold.
Mold exhaust is very important. If the exhaust is not good, air will be trapped in the mold cavity, especially in the deeper bone position, which is more likely to cause air to be trapped. During injection molding, the product is prone to bubbles or shrinkage, lack of glue, whitening or black spots. Therefore, inserts can be added to the places where the mold needs to be vented, and the exhaust can be exhausted by using the matching gap of the inserts.https://solidcomould.com/product-category/injection-mould/office-furniture-mould/ - Convenient mold processing
We know that in some deep bone positions in the injection mold, it is difficult for the tool to cut and process. For example, EDM discharge machining is used. As we all know, EDM machining is the slowest and the machining efficiency is too low. Therefore, inserts are generally chosen here to reduce the difficulty of machining and facilitate exhaust. There is also the deep bone position of the mold. It is quite inconvenient to save the mold in the places where the mold must be saved, but it is much more convenient to open inserts in these places and remove them separately. - Increase the service life of the mold
Generally speaking, the places where the mold needs to be designed with inserts are often places that are easy to damage, such as some places with sharp steel and thin steel. Once the inserts are damaged, they can be replaced, thereby extending the service life of the mold. - Conducting mold temperature
Generally, molds are cooled by designing water channels, but there are places where water channels cannot be designed or cannot be reached. In these places, heat can be dissipated by making inserts. Of course, the material of this insert must be selected with good thermal conductivity, such as beryllium copper. - Of course, mold inserts also have certain defects, such as the following points:
- Increase the difficulty of mold assembly;
- It is easy to produce overflow flash around the insert;
- The mold with inlay structure sometimes increases the mold design and processing costs, thereby increasing the cost;
- Too many inlay structures will affect the design of the mold cooling water channel;
- Too many inlay structures will affect the strength of the mold core.
IV. Summary
Inserts are a very common structure in molds. Although they have defects, their advantages are also obvious. When designing a mold, we should determine which places need to be inlaid according to the specific product structure and which places can be left as is. At the same time, it should be noted that there will generally be inlay marks or inlay lines in the places where inlays are made. When reviewing the mold, the customer needs to confirm whether it is acceptable.http://Research article High-strength, impact-resistant PP/PTFE composite foam with enhanced surface appearance achieved through mold-opening microcellular injection molding
