Plastic mold structure by function

                             Plastic mold structure by function

   Mainly by: pouring system, temperature control system, molding parts system, exhaust system, guidance system, ejection system and other components.The casting system and molding parts are the parts that contact with plastics directly and change with plastics and products. They are the most complex part in the mold with the greatest change and require the highest degree of finish and precision.

1. Casting system:

   It refers to the part of the flow channel before the plastic enters the mold cavity from the nozzle, including the main channel, the cold material hole, the diverging channel and the sprue.

2. Molding parts system:

   It refers to the combination of various parts, including moving mold, fixed mold and cavity (concave die), core (punch die) and molding rod.The core forms the inner surface of the product, and the cavity (concave die) forms the outer surface of the product.The mold cavity is formed by the mold core and the mold cavity.According to the process and manufacturing requirements, sometimes the core and die are composed of several pieces, sometimes the whole is made, only in the parts that are easy to damage and difficult to process the insert.

3. Temperature adjusting system:

   In order to meet the requirements of injection technology for mold temperature, a temperature control system is needed to adjust the mold temperature.For thermoplastic injection moulds, a cooling system is designed to cool the moulds (or to heat the moulds).The common method of mold cooling is to open a cooling water channel in the mold, using the circulating cooling water to take away the mold heat;In addition to hot water or hot oil from cooling water, electric heating elements can be installed inside and around the mold.

4. Exhaust system:

   It is designed to remove the gas generated by the air and plastic melting in the mold during the injection molding process. When the exhaust is poor, the surface of the product will form air marks (air lines), burning and other defects.The exhaust system of the plastic mold is usually a grooved air outlet opened in the mold to discharge the air from the original cavity and the air brought into the melting.

   When the molten material is injected into the mold cavity, the air stored in the cavity and the gas brought by the melt must be discharged to the mold outside through the exhaust port at the end of the feed flow. Otherwise, the product will have a hole, poor connection, unsatisfactory mold filling, and even the accumulated air will burn the product due to high temperature caused by compression.In general, the vent can be located either at the end of the molten flow in the mold or on the parting surface of the mold.

   The latter is a deep 0 on one side of the die.03-0.2mm, width 1.5-6mm shallow groove.In the injection, the vent will not have a lot of molten material leakage, because the molten material will be in the place of cooling solidification will block the passage.The position of the vent should not be open to the operators to prevent accidental discharge of molten material injury.In addition, can also use the ejection rod and the ejection hole's coordination clearance, the ejection block and the template and the mold core's coordination clearance and so on to exhaust.

5. Guidance system:

   In order to ensure that the moving mold and the fixed mold can be accurately aligned when the die is closed, guide parts must be set in the mold.In the injection mold, four sets of guide pillars and guide sleeves are usually used to form guide parts. Sometimes, internal and external conical surfaces that are consistent with each other should be set on the moving mold and fixed mold respectively to assist the positioning.

6. Ejection system:

   Generally includes: thimble, front and rear thimble board, thimble guide bar, thimble reset spring, thimble board lock screw and other parts.When the product is formed and cooled in the mold, the front and back molds of the mold are separated and opened, and the plastic products and their condensate in the flow channel are pushed out or pulled out of the mold cavity and flow channel by the ejection mechanism -- thimble driven by the ejector bar of the injection molding machine for the next injection molding working cycle.