What is the Jetting defect on the plastic product?

It means that the melt flow through nozzle, runner gate to the cavity by fast-speed,ejected without contacting mold wall.

There are a few reasons caused this problem:
1. the gate is designed not so good;
2. The section of gate and runner is too small;
3. The cold-slug well location is unreasonable;
4. The injection speed sets unreasonable;
5. The melt temperature is too low;

The solution are as below:
1. Redesign or change the gate,lead the melt to contact mold wall;
2. Enlarge the size of gate and runner;
3. Enlarge the cold-slug well;
4. Adjust the injection speed, leading the melt flow through the gate, increase the speed after melt flow out of gate;
5. Increase injection temperature.