This defect happens mostly when working with ASA in molds with satin surface finishes.
When we raise the packing pressure in order to eliminate sink marks there comes a point where marks start to appear in the seen face. The marks appear just where the ejector pins, slides and logos are, and have the same size and shape of the pins, slides, etc.
We have left the logos out of the question because there is a change in the thickness, a very small one though. The pins have been checked and they are flush with the cavity wall.
We thought that maybe it was due to a different heat transfer coefficient of the pins and slides. Changed one of the pins for a copper plug and the defect disappeared in that area.
Anybody knows of the name of this defect? We are puzzled about the origin of this but cannot find any information about it because we do not know the name of it.
I’m sorry I can’t provide photos of this, due to the difficulty of capturing them in a photo and confidentiality issues.
Thanks in advance.
Eduardo
When we raise the packing pressure in order to eliminate sink marks there comes a point where marks start to appear in the seen face. The marks appear just where the ejector pins, slides and logos are, and have the same size and shape of the pins, slides, etc.
We have left the logos out of the question because there is a change in the thickness, a very small one though. The pins have been checked and they are flush with the cavity wall.
We thought that maybe it was due to a different heat transfer coefficient of the pins and slides. Changed one of the pins for a copper plug and the defect disappeared in that area.
Anybody knows of the name of this defect? We are puzzled about the origin of this but cannot find any information about it because we do not know the name of it.
I’m sorry I can’t provide photos of this, due to the difficulty of capturing them in a photo and confidentiality issues.
Thanks in advance.
Eduardo