Polyketone makes a comeback

Germany's Lehmann & Voss & Co. (Hamburg) and its North American affiliate Lehvoss North America (Pawcatuck, CT) have debuted a series of high performance compounds based on polyketone (PK). The Luvocom 70 series is said to fill the gap between compounds based on technical polymers like PA6, PA66, and polyacetal (POM) and high performance polymers such as polyphenylene sulfide (PPS), polyetherimide (PEI), and polyaryletherketone (PAEK).

"The introduction is actually a re-launch," explained Michael Sandeen, Sales and Business Development Manager at Lehvoss. "Various Luvocom 70 products had been available until the year 2000 but had to be cancelled due to Shell Chemical's discontinuation of Carilon PK polymer production. With the polymer now available, Lehvoss decided to start the development of these new high performance compounds because of their unique and outstanding properties."

Although Lehvoss declines to identify the polymer source, one supplier in South Korea recently announced its entry into the market. Hyosung (Seoul) unveiled its in-house-developed polyketone material in November last year. Production is currently at a pilot scale of 1,000 tonnes annually at a plant that started up in 2012 at Ulsan, South Korea for premarketing and further research. Commercial production is expected to begin in June 2015.

Described as an "eco-friendly polymeric material," on account of it being based on carbon monoxide, PK is said to offer a 2.3-fold improvement in impact strength with a 30% improvement in chemical resistance compared with PA, whereas its wear-resistance is about 14 times greater than POM and it has off-gas properties equivalent to that of EVOH (ethylene vinyl alcohol).

Hyosung has invested 50 billion Won ($47 million) spread over 10 years in the resin's development and ready completed application and registration of 133 patents in Korea and 27 patents overseas, including the United States, Europe, China and Japan.

Hyosung expects application of Polyketone is very extensive, ranging from automotive components to industrial materials including as automotive interior and exterior components, engine and fuel component materials, electrical and electronic components, and packaging materials. According to Hyosung's polyketone project team, over 1 trillion Won's worth ($930 million) of added value is expected to flow from polyketone, primarily through its replacement of other materials, with up to 10 trillion won ($9.3 billion) generated throughout the industries involved by 2020, including polyketone-based parts and finishing goods manufacturing.

"With its unique profile, PK polymer is a multi-use material that offers inherently good tribological performance. "In many cases it is better than acetal and PA)," said Sandeen. "It can replace even high temperature resistant polymers in tribological applications." PK also offers good hydrolytic stability, low permeability, good weld line strength, and good processability with shorter cycle times compared to other technical polymers such as PA 66 and polyacetal.

"The polymer's low wear rate offers excellent advantages for gear wheels and bearings," said Sandeen. "Its low water absorption makes it suitable for applications where parts come in contact with moisture, and its high level of chemical resistance makes it suitable for applications such fuel filters and other fuel system components.  Its chemical resistance together with its mechanical properties and tribological performance makes it particularly suited for stock shapes and seals."

The LUVOCOM 70 line consists of three grades: 70-9045 reinforced with carbon fibers; 70-9046 lubricated with PTFE, and 70-9113/BK formulated for low wear and friction. Lehvoss will also develop made-to-measure compounds based on customers' needs.