The first question is why PEEK lends itself for additive manufacturing, in this case for the production of valve seats. The answer lies in its functionalities and subsequent price level.
Polyetheretherketone, a semi-crystalline thermoplastic polymer with a highly stable chemical structure, provides numerous advantages over other materials. PEEK is highly resistant to a wide range of chemical environments, even at high temperatures. It can be dissolved only in concentrated nitric acid or sulfuric acid.
Furthermore, it has a long life span. As a hard, rigid and resistant polymer, it has a low level of wear and a low friction coefficient as well as reduced maintenance cycles compared to metal components.
It is also resistant to hydrolysis: PEEK can be exposed to water, high pressures, and steam for a long period of time without presenting any serious deterioration. Last but not least, it has a high resistance to high temperatures: PEEK withstands continuous temperatures of 245°C maintaining its stability and without suffering damages.
Given this polymer’s price level, 3D printing could be an interesting option to cut costs, (production) time and reduce material waste. The company says it has the hard ware to print PEEK applications. Given the material's properties, this is not an easy feat.
Given the high thermal resistance of PEEK, the 3d production machinery must reach temperatures around 500°C to extrude. This is possible thanks to the evolution of FFF (fused filament fabrication) technology developed and patented by Roboze: the Beltless System. The mechatronic transmission of the X /Y axes is direct, thanks to the insertion of helical racks in direct contact with the pinion. These components are made of hardened steel. Traditional FFF systems have rubber belts that, regardless of the nature of the rubber, in the long run and at high temperatures, tend not to guarantee the accuracy and repeatability of printed parts, Roboze states.
Furthermore, the Roboze R&D team has developed an ad hoc extruder for printing highly viscous materials such as PEEK. The Roboze HVP extruder (patent pending, ed.) is an "engineering gem, the result of know-how and expertise in the R&D Roboze area and the CNC-machine park at Roboze’s manufacturing plant."
According to Roboze, the greatest demand for the production of PEEK valves is certainly that of the valve seat. This mainly has to do with the various sizing options 3D-printing can accommodate and the optimal use of valuable polymer material. As mentioned before, the advantages connect to additive manufacturing of these components are connected to speed, costs and customization of the part, but above all the absence of material waste that for these type of geometries is zero.
Its PEEK material is also certified Norsok M-710. A Roboze-representative says: "This certification adds value and cost effectiveness to developments and operations related to the oil industry. Therefore, the molded parts with our PEEK set a superior quality standard and represent the ideal solution for the needs of the oil & gas industry. The current market response in oil and gas, particularly for the production of valves, makes us very optimistic. Insiders (Roboze does not want to disclose names, ed.) are increasingly opting for our solutions and are recognizing the real value of Roboze technology associated with the high performance thermoplastics we offer."
Roboze srl produces 3D printers, materials and related services dedicated to additive manufacturing for extreme applications. Founded in Bari, Italy in 2013, the company distributes its products throughout the EMEA region. Roboze also has resellers in Israel and has recently opened its sales office in Chicago. Since Roboze’s 3D printer debut on the market, its proprietary technology widened its range of engineering polymers and superpolymers to simultaneously embrace multiple applications.