Polimotor 2 uses 3D printing technology

Solvay Engineering Plastics’s Sinterline Technyl polyamide 6 (PA6) powder grade reinforced with a 40% loading of glass beads is being used in the Polimotor 2 engine. It will feature a 3D printed plenum chamber fabricated through selective laser sintering (SLS).

Solvay is the principal material sponsor for the highly anticipated Polimotor 2 project, led by legendary automotive innovator Matti Holtzberg who aims to design and manufacture a next-generation, all-plastic engine for competitive racing in 2016.

“Like the original Polimotor engine concept developed during the 1980s, Polimotor 2 is all about highlighting trailblazing polymer technologies, and their potential for revolutionising automotive performance and manufacturing,” said Holtzberg, who is also president of Composite Castings, LLC, based in West Palm Beach, Fla. “The plenum in the Polimotor 2 concept shares the same basic injection-moulded design from the original engine. But we found that a 3D printed version fabricated with Sinterline Technyl PA6 technology could perform just as reliably in an engine designed to withstand the rigors of competitive racing.”

Based on the same resin chemistry as Solvay’s Technyl polyamides, Sinterline PA6 powders are formulated to leverage the benefits of 3D printing for nylon components. Laser sintering and other 3D-printing processes improve productivity by quickly converting digital designs into functional parts without the time or cost required to first build a moulding tool and prototype. Thus, they can significantly accelerate the time-to-market for OEMs and Tiers.

Laser sintering applies the energy from a high-precision laser scanner to fuse Sinterline Technyl PA6 powders, layer by layer, until they form a finished 3D part with enhanced mechanical and thermal properties. Because parts are printed in successive layers, laser sintering can also quickly produce components that integrate complex internal features and functions.

“As the first PA6 powder range designed specifically for selective laser sintering, Sinterline materials take 3D printing a step further by enabling cutting-edge designs, enhanced performance properties approaching those of injection moulded nylon compounds,” said Dominique Giannotta, Sinterline Project Director for Solvay Engineering Plastics. “Polimotor 2’s validation of this advanced material technology underscores the active innovation at work at Solvay Engineering Plastics, and highlights its potential for solving new challenges in commercial automotive designs and on the racetrack.”

An automotive plenum is the pressurised chamber that uniformly distributes the air flow between an engine’s inlet and cylinders. The plenum in the Polimotor 2 engine will share similar specifications to those in today’s production-scale automobiles, which are typically injection-molded nylon with 2-3 mm wall thickness to withstand the 2-4 bars of positive air pressure inside.

Parts printed from Sinterline Technyl PA6 powders are capable of performing reliably in a conventional metal turbocharged engine, where radiant temperatures can reach as high as 121°C. Notably, however, the plenum in the Polimotor 2 concept will encounter comparably lower temperatures between 66°C and 93°C, due to the low thermal conductivity of the engine’s largely plastic composition.

The Polimotor 2 project aims to develop an all-plastic, four-cylinder, double-overhead CAM engine that weighs between 63-67 kg, or about 41 kg less than today’s standard production engine. In addition to the current plenum application, Holtzberg’s groundbreaking programme will leverage Solvay’s advanced polymer technology to develop up to ten engine parts. These include a water pump, oil pump, water inlet/outlet, throttle body, fuel rail and other high-performance components. In addition to Sinterline Technyl, Solvay materials targeted for use encompass Amodel polyphthalamide (PPA), KetaSpire polyetheretherketone (PEEK), AvaSpire polyaryletherketone (PAEK), Radel polyphenylsulphone (PPSU), Ryton polyphenylene sulphide (PPS) and Tecnoflon VPL fluoroelastomers.

(IMA)