TALC for nucleation

In order to achieve higher mechanical properties and to reduce processing time, semi-crystalline polymers are modified with nucleators.
Nucleators raise the crystallization temperature. They also shorten the time required for crystallization, thus reducing the cycle time in injection molding processes. As direct consequence, mechanical properties are boosted and, in particular, both stiffness and dimensional stability are improved. There is a positive trend on impact strength, as well.
Micronized fine talc is a perfect functional additive for the crystallization of semi-crystalline polymers to enhance nucleation properties. Pureness, tight particle size distribution and lamellarity are the keys for effective polymer nucleation: IMI Fabi has proven experience in supplying cost-effective nucleating agents to the polymer industry for many years.

Crystallization is a process in which molten polymer is cooled below its melting temperature so that a crystalline order begins to re-establish. Micronized fine talc provides such function for heterogeneous nucleation in several semi-crystalline polymers. The best known results are achieved in isotactic polypropylene and in block copolymer polypropylene. Micronized fine talc is also used in several other polymers for the same function.
The advantage in using nucleators in semi-crystalline polymers is not only related to shorter cycle times. Infact, micronized talc provides a significant increment in stiffness with minor or no loss in impact strength. Because of the lamellar shape of talc, molding shrinkages are equalized in all directions, minimizing the risk of warpage even in complex molded geometries.
Talc is a cost-effective functional additive that provides the right balance in properties (fast processing, high mechanical properties and excellentdimensional stability). Most semi-crystalline polymers can take advantage of the effect of talcas nucleator. The widest application of talc as nucleating agent is related to polypropylene (bothhomopolymer and block copolymer), but it is also extensively used in polyamides and polyesters. Also“green” polymers like PLA can take advantage of the nucleation effect achievable by using micronized talc.

For even higher efficiency, talc can be used in combination with other organic nucleators or clarifiers for synergic effect or as carrier for more expensive additives.

IMI Fabi micronized talc grades are generally offered incompacted form for:
• improved bulk handling;
• low dust generation;
• increased achievable throughput;
but they are also available inpowder form to satisfy anytype of handling requirement.