Page 227 - Injection Molding Advanced Troubleshooting Guide
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218 23 Contamination
Cardboard and wood
Metal
Grease and oils
If a material is left in an open container it is almost guaranteed that one or more of
the above contaminants will make it into the material (see Figure 23.7). Any of the
above contaminants will produce a contaminant in the molded part and cause a
reject.
Figure 23.7 Open gaylord: contamination waiting to happen
It is very important to keep all material in covered containers to minimize the ex-
posure to foreign materials. If a gaylord is sitting at a molding machine uncovered
and someone blows out a hopper next to it, cross contamination will occur. Figure
23.8 shows contamination on the lid of a gaylord with wood chips which would
have been in the material if the lid was not present.
