Wonder Precision12 years of professional provision of precision plasticsTwo-color moldOne-stop service including design, manufacturing, injection molding, spray coating, silk screen printing, assembly, etc.
The basic reason for the appearance of surface depression: From the perspective of plastics, when the plastic cools and shrinks, insufficient feeding will cause depressions on the outer surface of the product or cavities inside.
Depending on where the depression occurs, the cause and solution of the defect will also be different.
XNUMX. When the depression appears in the final cooling position of the thick-walled product, or a position far away from the gate:
Cause analysis: Usually, the typical thick wall and the surface dents or cavities far away from the gate are usually caused by the increase of effective viscosity and the increase of pressure loss, resulting in insufficient cavity pressure and insufficient feeding pressure.
Solution: Increase the feeding pressure and speed up the feeding rate
XNUMX. When there are surface depressions or cavities very close to the gate
Reason analysis: the depression appears near the gate, usually due to lack of gate freezing.
There are several reasons that affect the gate freezing: it may be caused by the reduction of effective viscosity; in most cases, the gate does not freeze due to the increase of the plastic temperature; too high mold temperature will also affect the gate freezing.
Solution: Adjust the mold temperature, plastic temperature, and increase the holding time to ensure that the gate is frozen.
XNUMX. Note: Cavities and bubbles are easy to confuse.Cavities are sometimes misunderstood as bubbles.Bubbles have gas trapped in them, and the cavities are vacuumed.
Wonder Precision12 years of professional provision of precision plastic two-color mold design, manufacturing, injection molding, spraying, screen printing, assembly and other one-stop services, located in the Pearl River Delta, Guangdong-Hong Kong-Macao Greater Bay Area, with developed transportation, convenient air transportation and fast logistics.
Link to this article：How does Wonder two-color mold solve the problem of surface depression?