 |
| Talc is an important functional filler for compounded thermo-plastic and thermoset polymers.
Because of its platy particle shape & purity is used in plastic primarily as reinforcing filler. It increases the stiffness of polypropylene by 80% at a 20% loading and by 150% at a 40% loading. It also increases the heat resistance of polypropylene, reduces mold shrinkage, improves melt rheology, and reduces molding cycle time. Compared to other reinforcing fillers, such as fiberglass, mica, talc is much less abrasive. It gives polypropylene superior low-temperature shock resistivity.
In polyethylene film talc is used as an anti-block agent, an additive that roughens the surface of tacky film to prevent it from adhering to itself. Loading levels range from 0.5 to 1.0%. In vinyl talc is used to improve the hot strength of profile extrusions and to reduce the shrinkage of floor tile. Fine particle size grades are used as nucleating agents for semi-crystalline polyolefins, nylon, polyesters, and chlorinated polyethylene.Talc can be used in polyolefins at loading levels ranging from 1 to 50% by weight. Talc particles may be described as a series of very small plate-shaped particles which, when aligned, tend to make possible a finished part with improved physical properties.
|
|
|
|
 |
 |
