Dull, hazy surface (blush, haze)
The expected gloss is missing; the surface becomes dull or hazy.
Symptoms
- Dull ring around the gate
- Some areas of the part glossy, others dull
- Cloudiness in a transparent part
Tip: Condensation on a cold mold can spoil the surface; keep the mold temperature above the ambient dew point.
Order of solutions
- Increase the mold temperature
- Increase the holding pressure
- Clean the mold surface and check the polish
- Work above the dew point to avoid condensation
- Dry the raw material
Likely causes
Process setting
- Mold temperature low, the surface cannot replicate the mold
- Holding insufficient
- Speed too low/too high
Raw material
- Moisture, lubricant build-up
Mold
- Surface polish damaged or dirty
- Condensation (moisture) in the mold
Was this information helpful? If you notice anything missing or wrong, please .
Related articles
Other defects
Short shot (incomplete fill)
The cavity does not fill completely; the farthest or thinnest area of the part stays incomplete.
Flash
Plastic escapes through the parting line or around the ejector pins.
Sink mark
A dent on the surface opposite a thick section; the surface is drawn inwards.
Void (internal vacuum void)
Internal cavity in a thick section of the part; the outer surface may look perfect.