Tiger lines are radial shadows on the surface of the moulding. Caused by pulsating polymer melt flow. Some compounds naturally exhibit a slip stick flow effect that
can show up as tiger stripes, but a common cause is worn screw, barrel or check ring.
1. Increase the temperature of the melt.
2. Increase the temperature of the mould.
3. Check the temperature profile and operation of the hot runner system.
4. Enlarge the gate cross section.
5. Choose an easier flowing material.
6. Check fow worn screw, barrel of check ring.