Sheet in PK 1000x500 mm natural

A sheet in PK is polyketone in semi-finished form, an engineering material that takes its place between POM and PA in the technical plastics range. The material is tough, impact resistant and has a chemical resistance that surprises many who test it for the first time.

The density is around 1.25 g/cm³, comparable with POM. In continuous duty the material handles temperatures up to about 100 degrees, and downward it copes to -30 degrees without losing impact resistance. The flammability rating is HB. Water absorption is around 0.4 percent, considerably lower than PA and somewhat lower than POM, which is a big advantage in damp environments where dimensional stability is critical.

The mechanical profile is the strongest side of PK. The material has high toughness and impact resistance, even at low temperatures, while it keeps good stiffness. That combination is not a given in the plastics world, where toughness is often bought at the cost of stiffness. PK also has very good fatigue strength, which matters in components that have to take cyclic load over a long time. Friction is low, wear resistance is high, and creep resistance is good under moderate load.

Chemically PK is unusually resistant. The material takes aggressive environments better than both POM and PA, including many organic solvents, fuels, oils and diluted acids. That opens the way for use in valves, stuffing boxes, pump parts and contact surfaces against process liquids where traditional engineering plastics would break down.

The sheet format is well suited to milled structural parts that cover larger areas: flat bearings, slide plates, guideways, valve components, wheel mounting plates and ramp parts. In food machinery PK is used in parts that come into contact with process liquids and cleaning agents. In the automotive industry the material turns up in driveline and fuel systems. In workshop terms PK works as an alternative to POM when you need better chemical resistance and higher impact strength, and can accept somewhat lower stiffness.

Machining is done with conventional chip removing methods. The material is friendly to turn and mill, with even chip formation and a good surface finish. Drilling works well with standard drills. Since the material creeps somewhat less than POM under heat, it is important to keep the machining temperature down so you do not get internal stress in the finished part. The sheet can be welded and bonded, although chemically resistant surfaces need mechanical machining or plasma treatment for good adhesion.

PK is not as widespread as POM or PA, which means the available thickness ranges and color options are often narrower. The natural color is beige to light yellow-white. When choosing thickness, count on the material being somewhat elastic, so parts where flatness is critical may need extra machining allowance.

For sliding surfaces and wear parts in damp environments the sheet at 1000x500 mm in natural fits well.

Do you need help deciding whether PK or POM suits your construction best? Get in touch and we will go through the requirements in detail.