How to Identify the Quality of Plastic Hangers?

Injection molding hangers mean plastic hangers, mainly made through injection molding process. Since environment of most plastic hangers production workshop is terrible, if the machine has low anti-interference ability, phenomenon like electronic feet beat, chaotic of machine’s program, malfunction and system halted will occur, which directly affect quality and production of the plastic hangers. In this case, what aspects should be considered to identify the quality of plastic hangers and how to identify qualified plastic hangers? 

Of course, we judge the quality of plastic hangers mainly through naked eyes, analyzing whether some status on the surface of hangers are unqualified or not, commonly including the following several aspects:
If there is scorch on the surface, which is caused by high temperature leading to decomposition of materials.
Mixed colors, including miscellaneous point, black or mixed with other stains cannot appear, not absolutely but cannot be more than four points and the proportion cannot be huge and centralized.
Water lines problem includes water lines and flow lines. Water lines refer to stripes of the plastic hangers that look like dry river, and flow lines refers to the lines dissolved together in cold front material.
Convex and concave points, refers to the plastic hanger is uneven and not smooth.
Fog point problem means that the surface of a plastic hanger is clear when the production comes out but some areas are hazy.
Scratch, of course it is not clear, if it is a little bit, it belongs to normal phenomenon, but it can't be too long nor too wide, that is, not too obvious.
Observe whether the plastic hangers shrink from 45 to 90 degrees, it is ok if there is no water mark and no depression feeling when touching.