Exablend® POK GF50 S4 — High-Stiffness Polyketone with 50% Glass Fiber

Exablend® POK GF50 S4 — High-Stiffness Polyketone with 50% Glass Fiber

Exablend® POK GF50 S4 is a glass-filled compound based on polyketone, developed for precise structural parts that require high stiffness, low shrinkage, stable geometry after molding and reliable performance in technical environments.

The material combines the stiffness of a reinforced compound with the characteristic advantages of POK: low water absorption, chemical resistance, wear resistance and stability in assemblies where load, friction, temperature, fuel, oils or moisture act simultaneously.

Engineering rationale of the grade

POK GF50 S4 should be viewed not as a universal “strong plastic” but as a material for parts in which stiffness and geometric accuracy must be maintained not only after molding but also in service. The high glass fiber content produces a tensile modulus of up to 17 000 MPa, while the polyketone matrix adds stability in environments where standard PA, POM or PBT may have limitations.

The material performs best where the design simultaneously demands a high modulus, low shrinkage, chemical resistance, stable fits and predictable serial processing.

Typical applications

• structural automotive parts;
• under-hood components;
• rigid technical housings;
• electronic and electrical housing elements;
• precision gears;
• support and functional elements of mechanisms;
• parts considered for metal replacement;
• elements operating near fuel, oils or technical fluids.

Key advantages of Exablend® POK GF50 S4

• 50% glass fiber for high stiffness and shape stability;
• low linear shrinkage: 0.1–0.3% in the flow direction;
• tensile modulus of 17 000 MPa;
• flexural strength of 220 MPa;
• HDT of 205 °C at a load of 1.8 MPa;
• resistance to technical fluids, fuel-and-oil media and moisture;
• potential for metal replacement in moderately loaded parts;
• good suitability for precise molded parts with high geometry requirements.

Technical characteristics

The main physical-mechanical, thermal and processing characteristics of the material are given in the table below. For a correct assessment of the grade it is important to analyze not a single value but the full set of parameters: modulus, strength, impact strength, shrinkage, HDT and the material's behavior under real service conditions.

Processing recommendations

The material is intended for injection molding. For POK GF50 S4 it is important to control the melt temperature, residence time in the barrel, drying quality and mold filling. Because of the high glass fiber content, the abrasive effect on tooling, fiber orientation and possible anisotropy of properties in the finished part should be taken into account.

The temperature profile, drying parameters, injection pressure and recommended processing modes are best placed in a separate WordPress table to keep the page readable and avoid overloading the main description.

Design considerations

For POK GF50 S4 parts, it is advisable to account at the design stage for the flow direction, glass fiber orientation, the difference in shrinkage along and across the flow, weld line locations, wall thickness uniformity and the actual conditions of contact with fuel, oils, moisture or industrial chemicals.

The material delivers its best results when the grade, part geometry, mold and molding parameters are treated as a single engineering system.