PolyFil ND is a "neutral density" filler designed for use with polyurethane liquid rubbers and plastics for several purposes. PolyFil ND can be used to reduce the cost of a resin or rubber casting without changing it's density. Adding PolyFil ND to polyurethane plastics such as EasyFlo and Poly 15-Series plastics can also dramatically reduce shrinkage in larger castings which are prone to gelling while hot and shrinking as they cool. PolyFil is a moisture-free filler which mixes into polyurethanes very readily and does not cause foaming. Experimentation with filler levels is required as fillers added to rubbers may increase hardness and reduce physical properties such as elongation and tesile strength. Adding too much PolyFil may increase viscosity greatly making air entrapment more likely.
PolyFil ND MSDS