What kinds of molds are there?

There are many friends who are engaged in the injection molding industry. Because they are only engaged in one of the varieties, they may not know much about other molds, but we can learn more about the upstream and downstream of the mold industry by understanding the mold industry as a whole, so I All types of molds are classified. I hope to be helpful.

1. Plastic molds: iniectio corona, blister molding, blow molding, extrusion, compression molding, rubber molds, etc.
2. Cold punching die: punching, bending, stretching, undulating forming, spinning, cold extrusion, etc.
3. Die casting mold:
4. Hot forging die:
6. Foaming mold:
7. Casting mold;
8. Zinc-based alloy mold:
9. Wire drawing die:
10. Glass mold:
11. Ceramic mold:
12. Each industry has its own mold.

Injection mold The plastic mold is composed of a movable mold and a fixed mold. The movable mold is installed on the movable template of the injection molding machine, and the fixed mold is installed on the fixed template of the injection molding machine. During injection molding, the movable mold and the fixed mold are closed to form a pouring system and cavity.

When the mold is opened, the movable mold and the fixed mold are separated to take out the plastic product. Although the structure of the plastic mold may vary widely due to the variety and performance of the plastic, the shape and structure of the plastic product, and the type of injection machine, the basic structure is the same.

The die-casting mold is composed of two parts, the covering part and the movable part. The combined part is called the parting line. In hot chamber die casting, the covering part has a gate, while in cold chamber die casting, it is an injection port. Molten metal can enter the mold from here, and the shape of this part matches the injection nozzle in the hot chamber die casting or the injection chamber in the cold chamber die casting. The movable part usually includes a push rod and a runner. The so-called runner is the channel between the gate and the cavity through which the molten metal enters the cavity. The covering part is usually connected to the fixed pressure plate or the front pressure plate, and the movable part is connected to the movable pressure plate. The cavity is divided into two cavity inserts, which are independent parts that can be removed or installed from the mold relatively easily by bolts.

The mold is specially designed so that the casting will remain in the movable part when the mold is opened. Hoc modo, the push rod of the movable part will push the casting out. The push rod is usually driven by the pressure plate. It will accurately drive all the push rods at the same time with the same amount of force, so as to ensure that the casting is not damaged.

When the casting is pushed out, the pressure plate shrinks to retract all the push rods to prepare for the next die casting. Since the casting is still at a high temperature when it is demolded, only the number of push rods is large enough to ensure that the average pressure on each push rod is small enough to not damage the casting. tamen, the push rod will still leave traces, so it must be carefully designed so that the position of the push rod will not have too much influence on the operation of the casting.

Other parts in the mold include core slides and so on. Cores are parts used to make holes or openings in castings. They can also be used to increase the details of the casting. There are three main types of cores: fixed, movable and loose. The direction of the fixed core is parallel to the direction of the casting out of the mold. They are either fixed or permanently connected to the mold. The movable core can be arranged in any direction except the ejection direction.

After the casting is solidified, before the mold is opened, the movable core must be taken out of the cavity by a separating device. The slider and the movable core are very close, the biggest difference is that the slider can be used to make an undercut surface. The use of cores and sliders in die casting will greatly increase costs. Loose cores are also called take-out blocks and can be used to make complex surfaces, such as threaded holes. Before the start of each cycle, the slider needs to be manually installed, and finally pushed out together with the casting. Then take out the loose core. The loose core is the most expensive core because it requires a lot of labor to manufacture and it increases cycle time.

Die-casting molds are usually made of hard tool steel. Because cast iron cannot withstand the huge internal pressure, the molds are expensive, which also leads to high mold opening costs. Die-cast metals at higher temperatures require the use of harder alloy steels.
The main defects that occur in the die casting process include wear and erosion. Other defects include thermal cracking and thermal fatigue. When the mold surface has defects due to too much temperature change, thermal cracks will occur. After too many uses, the defects on the surface of the mold will cause thermal fatigue.

1. Cold runner: refers to the part between the mold entrance and the product gate. The plastic is kept flowing in the runner by the injection pressure and its own heat. The runner is part of the molding material, but it is not a product. Ergo, when we design the mold, we must consider both the filling effect and how to save material by shortening and reducing the runner. This is the ideal situation, but it is difficult to achieve the best of both worlds in practical applications.
Secundus, hot runner: As a common component of the injection mold system, heating is used to ensure that the plastics in the runner and gate remain molten. Since there is a heating rod and a heating ring near or in the center of the runner, the entire runner from the nozzle exit of the injection molding machine to the gate is in a high temperature state, so that the plastic in the runner is kept molten. Fere, there is no need to open the runner to take out the condensate after shutdown. When starting the machine, you only need to heat the runner to the required temperature. Ergo, the hot runner process is sometimes referred to as a thermal header system, or as runnerless molding.