ZOLTEK, a subsidiary of Toray Corporation specializing in large tow carbon fiber business, recently reported that its newly developed patented product PX35 KS carbon fiber has been commercialized. This new product cuts traditional 50K filaments into 3K filaments, winds them up into multi-filament tows, then chops them and spreads them evenly in 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 during the production process of the molded SMC sheet.
"This means that companies can achieve high performance typically achieved with small tows at a lower cost," said Christopher Thomas, Americas Regional Manager for ZOLTEK Automotive. "Equivalent to the price of automotive-grade 50K wire, the performance only available in aviation-grade 3K wire." Tobias Potyra, European regional manager of Zoltek Automotive Division, added.
ZOLTEK is mainly engaged in the production of low-cost large tow carbon fibers. The new product developed this time solves the problem that fiber bundles cannot be dispersed in high quality in thixotropic polymer systems represented by SMC sheets. "Converting large tows into small tows can greatly improve the uniformity of fiber dispersion," Thomas said. The company has sent samples to some European and American customers, and the promotion efforts have been greatly improved in the past one or two years. The new product can be used for both structural and decorative parts. This new product is the first to enter the automotive market, but it is not limited to this. According to Zoltek, PX35 KS will bring convenience to all SMC sheet manufacturers and mold makers.
Taking the resin commonly used in the SMC system as an example, this new carbon fiber tow has been used with vinyl resin, epoxy resin and polyurethane and has been tested for performance. The reason why unsaturated polyester resins are not taken into account is that the intervention of carbon fiber presets a high temperature application environment / excellent mechanical performance threshold for it. Among these three conventional resins, vinyl resin formulations can be divided into three types: styrene-containing, low-styrene, and non-styrene. They are all classified as solvent-based systems and correspond to hot-melt systems. As for the three resin systems mentioned above, when used in combination with PX35 KS, any one has achieved a significant improvement in dispersion uniformity.
To date, the new product has not been validated in other thermoset / thermoplastic resin systems and has not been used in production processes other than molding. "Although PX35 KS is designed for SMC products and used with SMC 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 in SMC products. "
"Appropriate adjustments in the process will further optimize the dispersion of the fiber, but the short-cut equipment does not need to be changed too much." Although the design of the SMC production line is different, Zoltek can provide fiber treatment, dispersion, sizing, etc. Corresponding technical support.
PX35 KS is a derivative product based on ZOLTEK's best-selling PX35 50k carbon filament. "The PX35 KS can meet the needs of the industry in terms of processability and cost, but we will also sell standard 50K silk at a slightly lower price." Potyra said, "In any case, the market will have the final decision.
ZOLTEK did not disclose whether this product will have other derivatives, but disclosed that evaluation work is still ongoing. Unofficial sources say that the KS in PX35 KS comes from the Japanese word "Kassen", which translates to "split" in English, which means splitting.