High aspect ratio talc gives higher stiffness, good impact performance

Imerys Talc (Toulouse, France) has expanded its range of HAR (High Aspect Ratio) talc fillers for plastic compounds with the introduction of HAR-T77 and HAR-H92 talcs, both produced in North America. They join HAR T-84 talc, which is produced in Europe and sold globally.

Using an innovative, patented delaminating process, Imerys is able to produce HAR talc, which has a higher aspect ratio than conventionally micronized grades and brightness levels ranging from 77 to 92 Y. When introduced into TPO systems, flexural modulus can be increased by 15% and shrinkage reduced by 8 to 10% along with a reduction in coefficient of thermal linear expansion (CTLE).

In existing part designs, HAR grades may enable a reduction of talc required to maintain current stiffness performance, reducing part weight and lowering costs. HAR talcs have excellent isotropic shrinkage, and along with their CLTE performance, enable tighter gap designs and tolerance control. Heat deflection performance is also said to be enhanced.

"HAR talc is a major improvement over micronized talc with regards to a variety of criteria," explains Chris Scarazzo, Imerys Talc North America Market Manger - Polymers. "When compounded with polypropylene or TPO, it results in a unique combination of higher stiffness and good impact performance. HAR is a new tool for design optimization via down-gaging wall thickness, reducing part weight for improved fuel economy and reducing cost. Our commitment to producing high-performance talc in North America allows Imerys to offer the best cost and performance mineral portfolio available."

In addition, Imerys Talc has introduced Jetfine 3CW talc, produced in North America and positioned as a locally produced alternative to Jetfine 3CA talc, currently produced in Europe and imported to North America. Both products are manufactured utilizing a proprietary micronizing technology.

Jetfine 3CA talc has been a great success in Europe and elsewhere by providing improvement in stiffness while maintaining impact performance when used with polypropylene, TPO and PC/ABS resin systems. Both products combine a fine delaminated particle size distribution (about 1.3 microns median) with topsize control in a dispersible, but easy to feed pelletized grade. The result is a combination of stiffness and low temperature impact that extends TPO performance in automotive applications such as bumpers, plastic body panels, interior trim and a variety of non-automotive applications. Other engineered resins may also benefit from this unique combination of properties. 

In addition, both Jetfine 3CW and Jetfine 3CA talc have a 91 Y brightness level. "Our global portfolio of high bright talc continues to grow to meet the technical and economic needs of our customers," reports Chris Scarazzo, Imerys Talc North America Market Manger - Polymers. "Our investments in North America have been in response to the market's need for a North American produced ore to help assure long-term supply and better lot-to-lot consistency. These products also have an excellent balance of stiffness and impact required for part design optimization and lower part cost."