Injection mold gate type

The final gate where the plastic melt enters the cavity from the runner is the gate, which connects the end of the gating system with the cavity.

1. Injection mold gate type Gate definition: The final gate where the plastic melt enters the cavity from the runner is the gate, which connects the end of the gating system with the cavity.

2. Injection mold gate

3. Gates can be divided into large gates and small gates according to their cross-sectional dimensions.

4. Large gate: The cross-sectional size is greater than or equal to the runner area, and has no obvious effect on the filling flow and pressure holding process. It is called an unrestricted gate. Its melt filling flow resistance is small, which is conducive to material and pressure transmission, but the gate is slow to set and seal, it is easy to flow back at the gate, and the residue is difficult to remove.

5. Small gate Small gate: The cross-sectional area is about 3%-9% of the runner, which has a significant impact on the filling speed, refill time, material flow state, pressure drop, etc. It is called a restrictive gate.

6. If the gate is too small, it is easy to cause appearance defects such as insufficient filling, shrinkage, fusion line, etc., and molding shrinkage will increase. If the gate is too large, excess residual stress will be generated around the gate, causing the molded product to deform or crack.

7. G ate type

8. Application of sprue gate: 1).Because of the small pressure loss, it can be used for large and deep barrel-shaped parts. For shallow and flat rubber parts, due to shrinkage and stress. Prone to warpage and deformation. 2). For plastic parts whose appearance does not allow gate marks, the gate can be set on the inner surface of the plastic part.

9. Side gate application: suitable for various shapes of plastic parts, but not suitable for thin and long barrel-shaped plastic parts.

10. Side gate

11. Overlap gate application: suitable for flat-shaped plastic parts that require surface quality.

12. overlap gate

13. Fan gate is suitable for: It is commonly used to form thin-film plastic parts with large width and transparent plastic parts with poor flow properties, such as: PC, PMMA, etc.

14. Fan gate

15. Pin gate application: It is often applied to larger surfaces and bottom shells. A reasonable distribution of gates can help reduce the length of the flow path and obtain a more ideal weld line distribution ; It can also be used for long barrel-shaped plastic parts to improve exhaust.

16. Pin gate

17. Banana gate application: commonly used in ABS, HIPS. It is not suitable for crystalline materials such as POM and PBT, nor is it suitable for materials with good rigidity such as PC and PMMA, to prevent the curved runner from being broken and blocking the gate.

18. Banana gate

19. Sub gate application: It is suitable for plastic parts whose appearance does not allow the traces of the gate to be exposed. It should be ensured that the resistance of each cavity from the gate to the cavity is as close as possible to avoid stagnation in order to obtain a better flow balance . Note : It can be submerged in front and back mold bone position, side wall, submerged thimble and other positions.

20. Sub gate