What is the Composition of the Plastic Mold？

Whether it is a two-plate mold, a three-plate mold, or a hot runner mold, it is composed of two parts: a moving mold and a fixed mold. According to the different functions of each part in the plastic mold, the plastic mold can generally be divided into 8 main parts: structural parts, molding parts, exhaust system, lateral core pulling mechanism, pouring system, temperature control system, molding system, and guiding positioning system.

Plastic Mold Structural Parts

Structural parts include formwork (embryo), formwork, support columns, limiters, locking parts and springs, etc. The mold base (embryo) is divided into a fixed mold and a movable mold. The fixed mold includes a panel, a runner push plate, a fixed mold plate A, a Fixed plate and pusher base plate, a support column, etc. Limiting parts such as fixed-distance parting mechanism, buckle base, nylon plug, limit screw, first reset mechanism, reset spring, reset lever, etc.

Plastic Mold Parts

Molded parts are the parts that make up the cavity of the mold, including fixed mold inserts, movable mold inserts, cores, etc., which are the parts that give the shape and size of the molded plastic parts. Formed parts are the core part of the mold, and better steel must be used to achieve higher dimensional accuracy.

Plastic Mold Exhaust System

The exhaust system is a mold structure that discharges the air in the cavity from the mold when the melt is filled and allows the air to enter the cavity in time when the mold is opened to avoid a vacuum. Generally speaking, the structure that can exhaust can also intake air.

Exhaust methods include parting surface exhaust, exhaust groove exhaust, insert exhaust, push rod exhaust, exhaust needle exhaust, breathable metal exhaust, and exhaust plug exhaust, etc. In most cases, the design of the exhaust system is very simple, but for those thin-walled plastic parts, precision plastic parts, deep bone, deep blue, deep column, or deep cavity plastic parts, if there is no consideration venting well may lead to failure of mold design.

Plastic Mold Side Core Pulling Mechanism

When the side of the plastic part has concave-convex and hole structures before the plastic part is pushed out, the lateral core (or insert) must be pulled out first so that the plastic part can be molded smoothly. The lateral core-pulling mechanism includes positioning parts such as inclined guide pillars, sliders, inclined sliders, inclined push rods, bent pins, T-shaped buckles, hydraulic cylinders, and springs. The lateral core itself can be regarded as a molding part, but because this part has a complex structure and various forms, it is necessary to study it separately as an important part of the plastic mold.

Plastic Mold Gating System

The gating system is a transition channel before the melt in the mold enters the cavity, and its function is to guide the molten plastic from the nozzle of the injection molding machine to the closed cavity. The design of the gating system directly affects the labor productivity of the mold and the molding quality of the plastic parts. The form, position, and quantity of the gate will determine the form of the mold base. The gating system includes an ordinary gating system and a hot runner gating system. The ordinary gating system includes a sprue, runner, gate, and cold cavity. The hot runner gating system includes a hot nozzle and hot runner plate.

Plastic Mold Temperature Control System

This part of the structure that controls the mold temperature within a reasonable range is called the temperature control system. The temperature control system of the plastic mold includes two aspects of cooling and heating, but most of them need to be cooled, because the temperature when the melt is injected into the mold is generally between 00 and 300°C, and when the plastic part is pushed out of the mold, the temperature is generally at Between 60~80℃.

The heat released by the melt is absorbed by the mold, and the temperature of the mold absorbing the heat of the melt will inevitably rise. To reduce the injection molding cycle of the mold and improve labor productivity of the mold, it is necessary to continuously take away the heat in the mold in time, to The mold temperature is more precisely controlled. Injection mold temperature control system includes cooling water pipes, cooling water wells, beryllium copper cooling, etc. Temperature control media include water, oil, beryllium copper and air, etc.

Mold Release for Injection Molding

Other names for the ejection system are ejection system and ejection system. It is a device that enables the secure and unharmed removal of plastic components from the mold. It has a wide range of forms and a relatively intricate structure. The most frequently utilized ones include composite push-out, pneumatic push-out, push rod push, push tube push, and push plate push.

Plastic Mold Guide Positioning System

The guiding and positioning system includes two parts: the guiding system and the positioning system. The guiding system mainly includes guide posts and sleeves of the movable and fixed molds and the guiding groove of the lateral core-pulling mechanism, etc., and the positioning system mainly includes structures such as side locks and inner mold pipe positions. Their function is to ensure accurate positioning when the movable mold and the fixed mold are closed, reliable movement when demolding, and lateral force when the mold is working.