Ticking all the boxes

To remain a player in the increasingly competitive plastics market, a leading masterbatch manufacturer in China has its eye on the bottom line. Shanghai Xiner Low-Carbon Environmental Co. Ltd. is intent on reducing costs and simplifying manufacturing processes. At the same time, however, the company remains focused on the future and serving the increasingly higher requirements of its customers.

To Zigang Wang, Shanghai Xiner President, these objectives aren’t contrary. “Innovation is necessary so that we can improve the quality of our masterbatch compounds at a reasonable cost and through an improved process. At the same time, when we improve our filler masterbatches, we are able to meet the needs of more customers,” says Mr Wang.

Shanghai Xiner turned to ExxonMobil Chemical, a company with which it had worked for more than five years, to achieve these improvements. To improve quality, reduce cost and enhance end product performance, ExxonMobil Chemical recommended the use of Vistamaxx 6102 and 6202 PBE for Shanghai Xiner’s filler masterbatch compounds.

Vistamaxx propylene based-elastomer (PBE) was developed based on ExxonMobil Chemical proprietary metallocene catalyst technology which has found uses in a wide variety of applications, including non-woven, films, adhesives and compounds. This novel PBE has the unique capability that allows masterbatch compounders to add high levels of filler, and still have a product that’s more flexible and less fragile than other filler masterbatch products. This capability stems from the semi-crystalline copolymers of propylene and ethylene, which enables high loadability for fillers and good dispersion.

Improving loadability

As typical filler masterbatches are composed of 15% carrier polymer, such as PP or PE, and 85% CaCO3, adding a low dosage of Vistamaxx PBE (about 5%) allows masterbatch compounders to partially replace the carrier polymer. In Shanghai Xiner’s experience, up to 40% of CaCO3-Vistamaxx PBE masterbatch by weight can be loaded into hPP compared to only 30% by weight of CaCO3-LLDPE or CaCO3-hPP masterbatch.

Shanghai Xiner also observed better dispersion using Vistamaxx PBE. “Getting a large amount of filler dispersed in a very small amount of polymer is one of the things that Vistamaxx can do really well, without affecting performance,” Mr Wang says. This higher loadability has had no effect on physical integrity, he adds.

Another benefit of increasing the CaCO3 loading level is being able to reduce the number of additives, which could bloom to part surface and lead to poor product performance.

So whether in raffia tape or injection moulded product, it’s possible to add more masterbatch and more filler, which reduces the cost of the total polymer used, and still have a very high quality product, as Mr Wang and his customers have experienced.

Processing benefits

Lower compounding temperature is a processing characteristic that can help lower costs in masterbatch operations, and consequently better margins both in the compounding and the finished product profits. The low melt-temperature of Vistamaxx 6202 PBE allows for a lower mixing temperature during the masterbatch compounding process, resulting in reduced energy consumption.

“This lower melting temperature makes it easier to melt products, melt with lessMercurial Victory CR7 Low