Sink marks (injection moulding defect)
A sink mark is a localized shrinkage of the material during Injection Moulding process. Sink marks appear as depressions on the surface of an injection molded part which is not aesthetically acceptable in Plastics Manufacturing. [1]
Effect[edit]
- Visual defect
- Sink marks reflect light in different directions to the rest of the part
Causes[edit]
- Thick sections in product design
Areas of the part that are significantly thicker are prone to sink mark. [2]
- Improper design of the ribs, bosses, and gussets. These features are given for strengthening of the product.
Thickness of the ribs, bosses, and gussets in a product design should be 50 to 60 percent of the attached (base) wall thickness.
- Improper gate location
Gate should be placed near to the thicker sections
References[edit]
 | This industry-related article is a stub. You can help EverybodyWiki by expanding it. |
This article "Sink marks (injection moulding defect)" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:Sink marks (injection moulding defect). Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.
