Not molding a disk could suck out too much heat and can cause a cold slug
to form behind the gate.
It also offers options with which users can specify runners, sprues, and Cold slug
This process results in a lower cavity and gate area temperature, lower injection pressures at injection start and no pushing into the product a cold slug
as is normally the case with single heater hot runner systems.
If it is fully solidified, it is called a cold slug
Or, in one example, "a PVC pipe was found to have a crack that was caused by a cold slug
from the molding process.
This causes excessive heat loss that will result in a cold slug
, drooling, or stringing, all of which cost molders thousands each day.
A dimple can be used to aid flow at the gate because it permits a well for the frozen cold slug
to be blown into.
This cold slug
remains in the gate during the mold-open step, part ejection, and mold-close motion.
While it often is tasked to do that job, that's not the cold slug
well's only function.
Figure 2 shows what a cold slug
in the nozzle looks like.
Also, what about the cold slug
that sometimes comes out with the sprue, and sometimes stays in the nozzle tip?
Another source of temperature-related flow imbalances is the formation of small frozen plugs in the gate at the end of each hot tip, much like a cold slug
that forms on each shot at the tip of the machine nozzle.