Sheet in PPS CW50 625x525 mm natural

A sheet in PPS CW50 is polyphenylene sulfide reinforced with 50 percent carbon fiber weave. This is the stiffest grade in the PPS family. The high fiber content gives a combination of modulus of elasticity, tensile strength and dimensional stability at the top among fiber reinforced PPS grades. The carbon weave conducts electricity, so the grade does not suit applications that require insulation.

PPS as a base is a thermoplastic in the high performance segment. The material handles 220 °C continuously and short peaks considerably higher. The lowest working temperature is about -20 °C. The fire rating is V0 according to UL 94 and water absorption is negligible, so the material holds its dimensions even in damp or hot environments. Chemical resistance is broad and covers acids, bases and most organic solvents; the exception is strong oxidizing acids such as concentrated sulfuric acid and fuming nitric acid.

The high carbon fiber content gives the sheet a high flexural modulus and tensile strength, while the coefficient of thermal expansion drops further compared with GF40. That means parts with set tolerances keep their fit across an unusually wide temperature range, and that creep under constant load is very low. The stiffness is retained far up in temperature, which makes the grade suitable for high temperature components where stiffness is decisive.

Sheet in PPS CW50 is used where a combination of extreme stiffness and thermal stability is needed. Typical applications are support plates and fixtures in furnaces and soldering equipment, mechanical fixtures for wafer processing, valve and pump housing parts in chemical process industry, as well as structural components where the plastic is to replace aluminum without adding electrical problems. In the automotive industry similar grades are used in high temperature zones under the hood, and in the process industry in parts that have to take heat and a chemical environment.

Machining is similar to GF40 but demands more of the tools, since the fiber content is higher and the material is more abrasive. Carbide tools with a sharp edge are the minimum, and polycrystalline diamond gives the longest tool life. Moderate depths of cut, a high cutting speed and an even feed help to cut the fibers instead of pulling them out of the matrix. Drilling is done best with pecking for chip space, and milling with a climb cutting strategy gives the most even surface. PPS CW50 is stiff but relatively brittle, so avoid sharp corners and stress concentrations in the design.

Thicknesses and sheet formats normally follow the same range as the other PPS grades, but since the material is expensive it pays to start from a starting piece close to the final measurement. In advanced machining a mild stress relief around 180 °C before the finish can give more stable final measurements.

Are you unsure whether CW50 is the right grade, or whether GF40 is enough? Get in touch, we go through the design and the load picture together.

Carbon fiber reinforced PPS composite in format 625x525 mm and natural color, a PPS matrix with woven carbon fiber. The weave makes the board very stiff and it is used for light, dimensionally stable parts that also have to take heat. The small format is intended for cut-out parts, not whole panels.