Back when everyone was running injection molding machines with plungers, if you needed to color material, you had to have it pre-colored at a compounder. The compounder would melt the natural material down, blend in raw pigments and other additives and then re-pelletize the material.
The advent of screw type injection machines and color concentrates significantly reduced the cost of coloring plastic materials. However, running material blended with color concentrate has its challenges. It has to be mixed carefully and the material has to be processed carefully to get good results. Sometimes, even if you do everything right, you end up with nothing but problems.
I’m not sure if anyone does this anymore but when I was a kid it was great fun to shuffle your feet on carpeting and then zap your unsuspecting sibling with a nice static shock. This typically worked best if you had nylon carpeting and it was nice and dry in the house like in the winter time.
This worked because plastic is a great insulator and thus cannot dissipate static electricity very well. When we need to reduce the likelihood of static build up in plastics, we have some options. There are materials described as having anti-stat additives and other materials described as being statically dissipative and still others as being conductive. What’s the difference?
When specifying materials for food contact applications, you have to consider the physical and thermal properties, whether it is safe for use in a food contact application and whether the material can handle repeated cleaning and/or dishwasher cycles. In addition to the above, you also have to consider the consumer’s perception of safety.