How to Maximize Hot-Runner ?

1. MAINTAIN A FLAT THERMAL PROFILE

With many hot-runner systems, and with certain resins, you may need to lower the temperature of the material right at the gate to prevent drooling, stringing, or other part-quality problems.

2. MINIMIZE RESIN LEAKAGE

3. PREVENT BUBBLING/DROOLING

Preventing plastic from bubbling out of nozzles is essential to ensuring part quality as well as prolonging the life of your molds. Bubbling is caused by either gas or material that is trying to escape the constraints of the nozzle. Gas bubbles are a sign of a hot spot in your manifold causing material off-gassing. If the gases can’t vent properly, they will bubble out of the nozzle tips.

4.MAINTAIN EVEN PRESSURE

Excessively high or uneven pressure can burn material and leave silver streaks on your parts. One of the most common causes of this issue is having the wrong nozzle orifice size.
Make sure that the nozzle radius on the molding machine matches the nozzle-seat radius of the hot-runner system. If not, adjust the machine nozzle orifice appropriately.

5.START UP YOUR SYSTEM PROPERLY

In a new system, nozzle tips are among the smallest and therefore most vulnerable components when subjected to injection pressure. For this reason, it’s a good idea to backfill the system with plastic prior to the first cycle. This action helps protect the tips from fracturing, since the tips are reinforced by the surrounding plastic.

6. ENSURE UNIFORM COOLING

To ensure proper cooling of all areas of a mold, you should have a water circuit for each individual cavity.

7. USE THROUGH-HARDENED PINS

Use through-hardened valve-gate pins, you can grind down a pin to refresh it and still reuse it as it wears.