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How to test the conformity of the moulding part, parting surface and exhaust slot of plastic mould

A plastic mould is a tool in the plastic processing industry used with a plastic moulding machine to give plastic products a complete shape and precise size. Because of the variety of plastic and processing methods, plastic moulding machines and plastic products, and the structure of the simple and complicated plastic mould types and structures are also various.

A combination plastic mould for compression moulding, extrusion, injection moulding, blow moulding and low foam moulding, which mainly includes a concave mould with variable cavities composed of concave mould combination substrate, concave mould assembly and concave mould combination card plate, and a convex mould with a variable core composed of convex mould combination substrate, convex mould assembly, convex mould combination card plate, cavity cut-off assembly and side cut-off combination plate. Coordinated change of mould convex and concave dies and auxiliary moulding system. It can process a series of plastic parts of different shapes and sizes. It is a tool for the plastic processing industry and plastic moulding machines to give plastic products a complete configuration and precise size. Because of the variety of plastic and processing methods, plastic moulding machines and plastic products and the structure of the simple and complicated plastic mould types and structures are also varied.

Plastic mould is a kind of tool for producing plastic products. It is composed of several groups of parts, and this combination has moulding cavities inside. The mould is clamped on the injection moulding machine during injection moulding, and the molten plastic is injected into the moulding cavity and cooled and shaped. The upper and lower moulds are separated, and the product is ejected from the cavity and leaves the mould through the ejector system. Finally, the mould is closed again for the next injection; the process is cyclic.

Generally, the plastic mould consists of two parts: the movable mould and the fixed mould, the movable mould is installed on the moving template of the injection moulding machine, and the fixed mould is installed on the fixed template of the injection moulding machine. During injection moulding, the mould and the fixed mould are closed to form the pouring system and cavity, and when the mould is opened, the mould and the fixed mould are separated to take out the plastic products.


Although the mould structure may vary depending on the variety and properties of plastics, the shape and structure of plastic products and the type of injection machine, the basic structure is the same. The mould comprises a pouring system, temperature regulating system, moulding parts and structural parts. Among them, the pouring system and moulding parts are the parts in direct contact with plastic and change with plastic and products. These are the most complicated and changeable in the mould and require the highest processing finish and precision.

The pouring system is the part of the flow channel before the plastic enters the cavity from the injection nozzle, including the main flow channel, cold cavity, manifold and gate, Etc. Moulding parts are the various parts that make up the product’s shape, including moving mould, fixed mould and cavity, core, moulding rod and exhaust port, Etc.

Today we want to talk about how to test the plastic mould moulding parts, parting surface, exhaust slot qualification, moulding, and parting type can be said to be the most important part of the plastic mould, mould after completion; these parts of the test are also to be very strict, we can test from these points to carry out.

1. the surface of the front and rear mould should not have unevenness, pits, rust and other defects that affect the appearance.

2. the inserts and mould frame with rounded corners should be less than 1 mm clearance. 3.

3. the fractal surface is kept clean, neat and tidy; no hand-held grinding wheel to avoid hollowness and no depression in the sealing part.

4. the depth of the venting groove should be less than the value of the overflow edge of the plastic.

5. The insert should have smooth placement and reliable positioning.

6. Inserts, cores, Etc. should be reliably positioned and fixed; round pieces have a stop turn and no copper or iron pads under the insert.

7. the top bar end face and core are consistent.

8. before and after the mould-forming part without inverted buckle, chamfering and other defects.

9. The ejection of the bar should be smooth.

10. multi-cavity mould products, left and right pieces symmetrical, should be indicated L or R, customer requirements for the location and size should be in line with customer requirements, generally in the place does not affect the appearance and assembly plus, the number of 1/8.

11. mould frame locking surface research and matching should be in place, more than 75% of the area encountered.

12. the top bar should be arranged closer to the side wall and next to the tendons and tabs, and use a larger top bar.

13. The same piece should indicate the number 1, 2, 3, Etc…

14. each touch through the surface, insert through the surface, and parting surface should be in place.

15. The sealing part of the parting surface should conform to the design standard. Below medium-sized mould 10 ~ 20 mm, large mould 30 ~ 50 mm, the rest of the machine processing to avoid empty.

16. the skin pattern and sandblasting should evenly meet customer requirements.

17. the appearance of products with requirements and products on the screw should be anti-shrinkage measures.

18. the depth of the screw column of more than 20 mm should be selected to use the top tube.

19. The product’s wall thickness should be uniform, and the deviation should be controlled below ±0.15 mm.

20. the width of the bar should be in the appearance of the wall thickness of sixty per cent or less

21. the slanting top and the core on the slider should be a reliable way to fix it.

22. the front mould inserted into the back mould or the back mould inserted into the front mould should be locked around and machined to avoid hollowness.

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