Wollastonite Short Fiber (L/D 10:1)

Wollastonite is a naturally occurring calcium metasilicate (CaSiO₃) mineral with a distinctive acicular (needle-like) crystal morphology. This short fiber grade features a length-to-diameter (L/D) ratio of approximately 10:1, providing significantly higher reinforcing efficiency than isometric fillers at equivalent mass loadings.

The acicular morphology of wollastonite creates a fiber-like reinforcing mechanism in thermoset and thermoplastic matrices: under applied stress, the high-aspect-ratio particles efficiently transfer load from the matrix to the mineral fiber, increasing tensile strength, flexural modulus, and impact resistance. Wollastonite at 20–40 phr in UPR increases flexural modulus by 25–45% and tensile strength by 15–25%, at significantly lower cost than glass fiber and without the associated fiber orientation effects.

Wollastonite's needle-like crystals also improve dimensional stability and reduce shrinkage in molded composites, making it valuable in precision engineering components. Its naturally white color (brightness ~92%) allows use in natural and lightly pigmented composites without discoloration. Unlike ATH or Mg(OH)₂, wollastonite is stable to temperatures above 1000°C, making it suitable for high-temperature applications. The white color and needle-like crystallography make wollastonite an effective extender in primers and anti-corrosion coatings.