DO YOU KNOW HOW TO CHOOSE THE RIGHT GATE POSITION OF THE PRODUCT?

Soon after injection, the gate is cold

Dewatering port is simple

Dewatering finished, leaving only a few traces

The stuffing of multiple die holes is easier to control

Reduce the phenomenon of excessive filling

Gate location and size

1) Place the gate at the thickest part of the product, and pouring from the thickest part can provide better filling and pressure retaining effect. If the pressure retention is insufficient, the thinner area will solidify more quickly than the thicker area, and avoid placing the gate at a sudden change in thickness to avoid hysteresis or short shots.

2) If possible, pouring from the center of the product, placing the gate in the center of the product can provide an equal flow length, the size of the flow length will affect the required injection pressure, the central pouring makes the pressure holding pressure in all directions uniform, can avoid uneven volume shrinkage.

3) When the plastic flows into the flow channel, the plastic near the mold surface first reduces heat (cooling) and solidifies. When the plastic flows forward, it is only the plastic that has solidified here. And because plastic is a low heat transfer material, the solid plastic forms a green layer and the retaining layer can still flow.

Therefore, in an ideal situation, the gate should be set at the position of the cross-runner layer to make the best plastic flow effect. This condition is most commonly seen in round and hexagonal crossings. However, trapezoidal cross-runner cannot achieve this effect, because the gate cannot be set in the middle of the runner.

When deciding the location of the gate, adhere to the following principles:

A. The rubber material injected into each part of the mold hole should be as equal as possible; B. The rubber material injected into the mold should maintain a unified and stable flow front at all stages of the feeding process;

C. Consideration should be given to possible welding marks, bubbles, pits, empty spots, insufficient injection glue and spray glue.

D. The dewatering port operation should be as easy as possible, preferably automatic;

E. The location of the gate should be compatible with all aspects.

There are no hard and fast rules for gate design and most of them are based on experience, but there are two basic elements that need to be compromised:

A. The larger the cross-section area of the gate, the better, and the shorter the length of the channel, the better, to reduce the pressure loss when the plastic passes through.

B. The gate should be narrow to facilitate cold condensation and prevent excess plastic backflow. Therefore, the gate is in the center of the runner, and its cross section should be as circular as possible. However, the gate switch is usually determined by the switch of the module.

The size of the gate can be determined by the cross-cut area and the length of the gate. The following factors determine the optimal size of the gate:

1. Rubber flow characteristics

2. The thickness of the module

3. Insert the glue into the mold cavity

4. Measure the melting temperature

5. Mold temperature