The Plastic Mold Is Made Up Of Two Parts

The plastic mold is made up of two parts, the movable die and the fixed mold, which is installed on the moving template of the injection molding machine, and the fixed die is installed on the fixing formwork of the injection molding machine. During injection molding, the casting system and the mold cavity are formed by closing the die and fixed die, and the mold is separated to remove the plastic products.

The structure of the plastic mold may vary from one to the other because of the variety and performance of the plastic, the shape and structure of the plastic and the type of the injection machine, but the basic structure is consistent.

First, plastic mold structure by function

Mainly consists of: pouring system, temperature control system, forming parts system, exhaust system, guidance system, ejector system, etc. wherein the gating system and the molded parts are directly contacting with the plastic, and vary with the plastic and the products, is the most complex in the plastic mold, the change is the biggest, requires the processing smoothness and the highest precision part.

1. Pouring system: Refers to the plastic from the nozzle into the cavity before the passage part, including the main road, cold material points, distributary channel and Gate and so on.

2. Forming parts system: refers to the composition of various parts of the shape of the product, including dynamic mode, fixed mode and cavity (die), core (convex mold), forming rod and so on. The core forms the inner surface of the product, and the mold cavity (die) forms the outer surface shape of the product. The mold cavity is formed after the die-clamping core and the cavity. According to the process and manufacturing requirements, sometimes the core and die are composed of several pieces of tile, sometimes made into a whole, only in easily damaged, difficult to process parts of the insert.

3. Thermostat system: In order to meet the injection process of mold temperature requirements, the temperature adjustment system needs to adjust the mold. For thermoplastic plastic injection mold, mainly designed cooling system to make the mold cooling (also can be heated to the mold). The common method of mold cooling is to open the cooling water channel in the mold, to take the heat of the mold with the circulating cooling water; the heating of the mold can be used in addition to hot water or hot oil, and the electric heating element can be installed inside and around the mold.

4. Exhaust system: It is designed to remove the air from the medium cavity of the injection molding process and the gas from the plastic melt to the outside of the mold. When the exhaust is not smooth, the product surface will form the gas mark (gas grain), scorch and so on bad; the exhaust system of the plastic mold is usually a groove vent in the mold, The gas that is used to discharge the air of the original cavity and the molten material.

When the melt is injected into the cavity, the air that is stored in the cavity and the gas that is brought in by the melt must be discharged through the vent to the die at the end of the material flow, otherwise the product will have the blowhole, the bad, the mold dissatisfaction, and even the accumulated air will be burned by compression to produce high temperature. In general, the vent hole can be located at the end of the melt flow in the cavity, or on the fractal surface of the mold.

The latter is opened on the side of the concave die 0. 03-0. 2mm, Width 1. 5-6mm Shallow groove. In the injection, the vent hole will not have a lot of molten material leakage, because the molten material will be cooled and solidified at the place to block the passage. The opening position of the exhaust outlet should not be on the operator, in case of accidental spraying of the molten material. In addition, can also use the top out of the rod and the clearance of the top hole, the top block and the release plate with the core of the coordination clearance to exhaust.

5. Guidance system: is to ensure that the dynamic mode and fixed die in the mold can be accurate in the setting, in the die must be set to guide parts. In the injection mold, four sets of guide pillars and guide sleeve are usually used to form the guiding parts, and sometimes the inner and outer cone of each other should be arranged on the dynamic mode and fixed die respectively to assist the positioning.

6. Top out system: Generally include: thimble, front and rear thimble plate, ejector rod, thimble Reset Spring, thimble plate locking screws and other components. When the product in the mold cooling, mold before and after the separation open, by the launch mechanism-thimble in the injection molding machine to push the plastic products and the condensate in the runner to launch or pull out the mold opening and flow path position, in order to carry out the next injection molding work cycle.

Second, the plastic mold according to the structure of the general by the mold, mold benevolence, auxiliary parts, auxiliary systems, auxiliary settings, dead-end processing institutions and other parts of the composition.

1, the mold frame: generally do not need our design, can be directly from the standard mold manufacturers there to order, greatly saving the design of the mold time required, so called it plastic mold standard mold frame. It forms the most basic part of the plastic mold frame.

2, mold benevolence: Mold benevolence is part of the core of plastic mold, it is the most important part of the mold. Plastic products forming part in the mold kernel, most of the time processing is also spent on the mold kernel. However, relative to some relatively simple mold, it has no mold kernel part, the product directly on the template above the formation. Most of the early plastic mold, relatively backward.

3. Auxiliary parts: Plastic molds commonly used auxiliary parts have positioning ring, nozzle liner, thimble, grab pin, support column, Ejector plate guide sleeve, garbage nails and so on, they are part of the standard parts, can be ordered directly in order to order, and also a part of the need for their own design.

4. Auxiliary system: The auxiliary system of plastic mold has the following four: pouring system, ejector system, cooling system and exhaust system. Sometimes, because the use of plastic materials to heat the temperature is very high, so some molds will also exist a heating system.

5, supporting settings: Plastic mold attached to the support of the ring hole, Ko hole (top stick hole) and so on.

6, dead-end treatment structure: When the plastic products have dead corners, the mold will also have one or more treatment of the structure of dead corners. such as slider, oblique top, hydraulic cylinder and so on. In most of the domestic books on this treatment of dead-end organizations called the “core-pulling mechanism.”

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