BASF's PESU Forms Upper Piston of Coffee Machine's Brewing Unit

Italian household appliance company De'Longhi chose to use Ultrason E 3010 MR polyethersulfone (PESU) from BASF Corp., Florham Park, N.J., to manufacture the upper piston of the brewing unit in its new coffee machine Magnifica Ecam 22. The PESU reportedly contributes to the durability of the coffee maker by showing high heat and steam resistance up to 180 C/356 F, good mechanical properties as well as excellent dimensional stability at varying temperatures over a long period of time.

This injection molding grade PESU, which is optimized for easy demolding especially for complex parts, also meets De'Longhi's strict requirements regarding food contact and safety as well as processability and subsequent assembly. According to BASF, this combination of nearly temperature-independent mechanical properties with the absence of harmful substances allows Ultrason E 3010 MR to outperform materials like polyetherimide (PEI) which is also used in coffee machine applications. Moreover, this  higher-viscosity grade can be processed by injection-molding even for manufacturing parts with complex geometries like the upper piston which has long, filigree screw inserts with thin walls. This means long flow paths which have to be filled without air voids. The material’s good mechanical properties allow the piston to be securely mounted to the brewing unit with screws.

De'Longhi selected this PESU because components made of Ultrason E can be repeatedly exposed to superheated steam and largely retain both transparency and high mechanical strength. Tests conducted according to different ISO standards have shown that Ultrason E 3010 MR maintains its excellent mechanical properties even after 2,000 cyles of repeated steam sterilization at 134 C/273 F, also demonstrating a high resistance to stress cracking. These attributes supported the development of the ideal mold for the part using a mold flow analysis with BASF's Ultrasim simulation tool.  

Ultrason E 3010 MR is approved for food contact according to American and European specifications and contains no harmful substances.

Says Ruena Moro, plastic raw material buyer for Europe at De'Longhi, "We appreciate the characteristics of BASF’s Ultrason in this important component of our coffee machine. It contributes to the very good performance of the brewing unit which is the heart of any coffee machine. The upper piston is a complex technical part exposed to high stress in a challenging environment with superior demands on its continuous-use properties."