Zoltek’s new carbon fiber PX35 KS commercializes production

Zoltek, a subsidiary of Japan Toray Corporation, which specializes in the large tow carbon fiber business, recently announced that its newly developed patented PX35 KS carbon fiber has been commercialized. This new product splits the traditional 50K wire into 3K wire, winds it into a multi-head tow, and then performs a chop, and evenly spreads it in the SMC resin paste. It is said that the new product will significantly improve the processability, uniform dispersion and wettability of the fiber, produce a more homogeneous fiber layer, and improve the fluidity of the composite material in the production process of the molded SMC sheet.

“This means that companies can achieve the high performance that can be achieved with small tows under normal conditions at a lower cost,” said Christopher Thomas, Regional Manager, Zoltek Automotive Division. “Equivalent to the price of an automotive grade 50K wire, the performance of an aviation grade 3K wire is available,” added Tobias Potyra, Regional Manager, Zoltek Automotive Division Europe.

Zoltek is mainly engaged in the production of low-cost large tow carbon fiber. The new product developed this time solves the problem that the fiber bundle cannot be dispersed with high quality in the thixotropic polymer system represented by SMC sheet. “Converting large tows into small tows can greatly increase the uniformity of fiber dispersion,” Thomas said. The company has sent samples to some European and American customers, and the promotion has been greatly improved in the past one or two years. This new product can be used both for the production of structural parts and for the production of decorative parts. This new product is the first to land in the automotive market, but it is not limited to this. Zoltek said that the PX35 KS will bring convenience to all SMC sheet manufacturers and mold makers.

Taking the resin commonly used in SMC systems as an example, this new carbon fiber tow has been tested with vinyl, epoxy and polyurethane for performance testing. The reason why the unsaturated polyester resin is not taken into account is because the intervention of carbon fiber presupposes the threshold of high temperature application environment/excellent mechanical performance. Among the three conventional resins, the vinyl resin formulation can be classified into styrene-containing, low-styrene, and styrene-free resins, all of which are classified as solvent-based systems and correspond to hot-melt systems. For the above three resin systems, any combination with the PX35 KS achieves a significant increase in dispersion uniformity.

So far, this new product has not been validated in other thermoset/thermoplastic resin systems and has not been used in production processes other than molding. “Although the PX35 KS is designed for SMC products and used in conjunction with SMC’s common resins, we believe it also has great potential for other processes and resin systems, including thermoplastic resins,” Potyra said. “But our current The first priority is to ensure its successful application on SMC products.”

“The appropriate adjustments in the process will further optimize the dispersibility of the fiber, but the chopping equipment does not need to be oversized. “Although the design of the SMC line is different, Zoltek can provide fiber treatment, dispersion, sizing, etc. The corresponding technical support.

The PX35 KS is a derivative of the Zoltek’s best-selling PX35 50k carbon wire. “The PX35 KS is just right for the industry in terms of processability and cost, but we will also sell the standard 50K wire at a slightly lower price.” Potyra said, “In any case, the market will have the final say.”

Zoltek did not disclose whether the product will have other derivatives, but revealed that the evaluation is still ongoing. According to unofficial sources, the KS in the PX35 KS comes from the Japanese word “Kassen”, which translates into English as “split”, which means split.