New additive system for rotational sintering

Moreover, Irgastab RM 68 contains a light stabilizer that complies with the UV8 weathering standard. This worldwide standard stipulates an elongation at break of at least 50 percent of the original value after 8,000 hours of exposure to accelerated weathering. This corresponds to outdoor use in a subtropical climate for at least three years. Irgastab RM 68 has been approved in polyethylene by the American Food and Drug Administration (FDA) for indirect contact with food products.

A case study shows how the effect of the special additive can be expressed in concrete figures: With a conventional additive formulation in a rock-and-roll machine, operating in three shifts of eight hours, forty-four 80-liter tanks can be produced per day. The cycle time is 33 minutes. With Irgastab RM 68, the cycle time can be cut back to 27 minutes. This shortening by six minutes translates into ten additional tanks per day per machine.

Extrapolated over an entire year (here 225 days), a manufacturer can thus produce about 2,300 extra tanks per machine. Moreover, the final product has a considerably lower yellowness index than products made using the conventional approach and, on top of it, it has better mechanical properties.

The results will vary for each individual manufacturer as a function of the type of machine, the properties of the plastic, the geometry of the parts and the wall thickness. For this reason, BASF has also developed a program that allows the savings for the customers to be calculated on an individual basis.

In comparison to other methods that process thermoplastics, such as blow molding or injection molding, it is true that rotational sintering is a niche process. Only about one percent of all plastics in Europe is processed by means of rotational sintering. In 2008, Irgastab RM 68 was introduced onto the American market – today still the main market for rotational sintering. But in Europe as well, this method now has become an alternative to blow-molding in recent years, especially for applications in the building sector, for toys and sports equipment as well as in the automotive and machine construction.

The reason for this can be ascribed to technological improvements in the process itself. The key aspect, though, is that rotational sintering can achieve decisive cost advantages in comparison to the technically very demanding blow molding method, particularly for small production runs of large blow-molded parts.

Thanks to the savings in terms of time and energy, but also due to the qualitative improvement of the final product, Irgastab RM 68 helps to optimize the process and thus contributes to its competitiveness in the market.