What is the Injection mold structure and function?

1. Definition of injection mold

The mold used for plastic injection molding is called injection molding mold, or injection mold for short. Injection molds can mold plastic products with complex shapes, high dimensional accuracy or with inserts in one go.

"70% mold, 30% process". For injection molding, the mold has a great influence on the quality of the molded product, just like the injection molding machine. It can even be said that the mold plays a greater role than the injection molding machine; if you do not fully understand the mold during injection molding, it is difficult to get a good molded product.

2. Structure of injection mold

The structure of injection mold is determined by the type of injection molding machine and the structural characteristics of plastic parts. Each mold consists of a movable mold and a fixed mold. The movable mold is installed on the movable plate of the injection molding machine, while the fixed mold is installed on the fixed plate of the injection molding machine. During injection molding, the movable mold and the fixed mold are closed to form a pouring system and a cavity. When the molds are separated, the plastic part or beer part remains on the movable mold side, and then the demolding mechanism set in the movable mold ejects the plastic part. According to the different functions of each component in the mold, a set of injection molds can be divided into the following parts:

1. Molding parts

Parts that give molding materials shape, structure, and size, usually composed of cores (convex molds), concave mold cavities, threaded cores, inserts, etc.

2. Casting system

It is a channel that guides the molten plastic from the injection machine nozzle to the closed mold cavity, usually composed of main channels, branch channels, gates, and cold wells.

3. Guide components

In order to ensure that the movable mold and the fixed mold can be accurately aligned when closed, the guide components play a guiding and positioning role. It is composed of guide pins and guide sleeves. Some molds also have guide components on the ejector plate to ensure that the demolding mechanism moves smoothly and reliably.

4. Demolding mechanism

The device that realizes the demolding of plastic parts and casting systems has many structural forms. The most commonly used demolding mechanisms include ejector pins, ejector tubes, ejector plates, and pneumatic ejectors. They are generally composed of ejector pins, reset pins, slingshots, ejector fixing plates, ejector plates (ejector rings), and ejector plate guide pins/guide sleeves.

5. Mold temperature control system

In order to meet the mold temperature requirements of the injection molding process, a mold temperature control system heating rod is required to adjust the mold temperature.

6. Exhaust system

In order to smoothly discharge the gas in the mold cavity, exhaust grooves are often opened at the mold parting surface and the matching place of the insert and insert.

8. Other structural parts

Refers to parts set up to meet the requirements of the mold structure (such as: fixed plate, movable/fixed template, support column, support plate and connecting screws, etc.).

3. Composition and function of injection mold

1. Injection mold consists of the following parts.

2. Component details and functions

1. Upper fixed plate: an indispensable part for the opening and closing of the machine table, fixing the mold and the front mold part of the mold.

2. Stripper plate: fix the pull gate plate.

3. Magnet: control the opening and closing of the mold through magnetism.

4. Square iron: cooperate with magnets to control the opening and closing of the mold.

5. Male mold plate: fix the male mold core and the mold core support plate.

6. Template support plate: fix the male mold plate and insert the heating rod at the same time.

7. Guide pin: fix the material belt.

8. Limiting column: limit the ejection height of the guide pin.

9. Mold angle: fixed function, and at the same time give the ejector plate enough height movement stroke

10. Upper ejector plate: fix the ejector.

11. Lower ejector plate: fix the upper ejector plate.

12. Lower fixed plate: fix the mold foot, garbage nail, and at the same time give the lower mold a basic fixation and use it for the opening and closing of the machine table to fix the mold.

13. Trash nail: limit the height, so that the lower ejector plate and the lower fixed plate can cooperate smoothly, prevent debris from flowing into the space between the two plates, and make the ejector and guide pin eject unevenly.

14. Ejector column (K.O column): used to eject the ejector and guide pin of the machine.

15. Small ejector plate: fix the guide pin.

16. Small ejector plate: fix the guide pin.

17. Ejector: eject the material belt to separate the material belt from the mold.

18. External pull rod: used to pull the cavity open and limit the cavity mold opening distance.

19. Heating rod: heat up the mold.

20. Mold core support plate: fix the rear mold core and the rear mold insert.

21. Male mold core: fix the insert pin and insert sleeve, mainly used for product molding.

22. Runner: part of injection molding.

23. Female mold core: fix the front mold insert, mainly used for product molding.

24. Mother mold plate: fix the mother mold core.

25. Small pull rod: fix the mold opening stroke of the upper fixed plate and the stripper plate.

26. Mother mold core pad: fix the mother mold core and insert the heating rod at the same time.

27. Pulling fixed plate: fix the pulling needle to prevent the mold from pushing the pulling needle out during the injection molding process.

28. Nozzle: the main entrance for machine nozzle injection molding.

29. Pulling plate: pull up the pulling needle.

30. Pulling gate plate: fix the pulling needle.

31. Front mold insert: fix the runner plate and mother mold core.

32. Back mold insert needle and sleeve: mainly used for product cup mouth molding.

33. Pulling needle: pull the gate.

4. Structural classification of injection molds

1. Classification by molding method:

(1) Injection mold: A mold used on an injection molding machine. It is mainly used to mold thermoplastics, and a few types of thermosetting plastics are suitable for molding with this mold.

(2) Compression mold: A mold that uses a compression process on a hydraulic press to mold plastic parts. It is mainly used to mold thermosetting plastics.

(3) Press-injection mold: A mold that uses a press-injection process on a hydraulic press to mold plastic parts. It is suitable for molding thermosetting plastics.

2. Classification by the number of cavities:

(1) Single-cavity mold

It is a mold with only one cavity, which molds one plastic part at a time.

(2) Multi-cavity mold

It is a mold with two or more cavities, which can mold multiple plastic parts with one mold.

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