Both high-temp. Different tiers. Know when to pay up.

For temperatures up to 220°C and most chemical environments: yes, PPS works. For 260°C continuous, biomedical implants, or ultra-pure applications: PEEK is required. Rule of thumb: if you're using PEEK "because we always did", evaluate PPS — often 70% cost reduction with acceptable performance. If PEEK-specific features matter (biocompatibility, 260°C, semiconductor-grade purity), stick with PEEK.

PEEK manufacturing: complex synthesis, specialty raw materials, limited global production (Victrex, Solvay, Evonik main producers). Production scale: PEEK ~5,000 tonnes/year globally, PPS ~50,000 tonnes/year. PEEK processing: requires 390-400°C melt temperature (specialty equipment). PPS: standard injection molding at 320°C. Both are premium vs commodity plastics ($2-5/kg) but PEEK is clearly premium within premium.

PEEK-OPTIMA (Invibio proprietary medical grade): FDA 510(k) cleared for implantable medical devices. Certified biocompatibility. Premium cost: $300-400/kg raw material. Industrial PEEK: same polymer but not medical-certified. $120-180/kg. For medical implants, PEEK-OPTIMA required; for industrial applications, standard PEEK adequate. Don't pay PEEK-OPTIMA premium unless medical implant.

Unfilled PEEK: best machinability, dimensional stability, biocompatibility. PEEK-GF30: higher strength, glass fibers abrade tools (use PCD). PEEK-CF30: carbon filled, even higher strength, ESD-safe. Filled PPS: glass is nearly always added (PPS-GF40 standard) — unfilled PPS has modest mechanical properties. For high-performance PPS parts, GF40 or mineral-filled grades dominate.

PEEK: 0.5% moisture absorption. Nylon 6/6 absorbs 8% — PEEK 16× more stable. Still, PEEK should be dried before injection molding. PPS: <0.02% moisture — essentially zero. PPS parts maintain dimensional stability in humid environments better than PEEK. For outdoor or high-humidity service requiring dimensional stability: PPS wins. For most indoor applications, PEEK moisture absorption isn't problematic.

PEEK unfilled: machines well, similar to aluminum. Sharp carbide tooling, moderate speeds. PEEK-GF or CF filled: abrasive — use PCD (polycrystalline diamond) tooling for production. PPS-GF40: also abrasive, similar PCD recommendation. Both materials need: sharp tooling, adequate cooling (compressed air or mist), chip evacuation to prevent melting from friction. Standard practices work for both — no unusual considerations.