Polyphthalamides (PPA)

Polyphthalamides (PPA) are a class of semi-aromatic polyamides that combines the heat resistance typical of high-performance polymers with the processability of conventional polyamides. For the design engineer this means service temperatures of 180–230 °C, minimal water absorption of 0,15–0,5 %, and retained stiffness where PA66 can no longer cope.

How PPA differs from PA66

The structure of PA66 contains only aliphatic (-CH₂-) chains. In PPA an aromatic terephthalic ring (TPA, IPA) is added to them, which raises the melting temperature from 260 °C (PA66) to 290–310 °C (PPA), and the continuous service temperature from 100–120 °C to 170–200 °C. At the same time water absorption drops 5–10 times, while dimensional stability in a humid environment is comparable to that of mineral-filled PBT.

When to choose PPA

• Automotive under-the-hood space — thermostat housings, pistons, cooling-system fittings, turbocharger brackets.
• SMT electronics — connectors and housings that withstand reflow soldering at 240–260 °C without deformation.
• LED housings — colour and dimensional stability under prolonged heating at 110–130 °C.
• Metal replacement — brackets, pump housings, frames where geometric stability is required under thermal cycling and vibration.
• Hot aggressive media — pump components, fittings, seals in contact with chemicals at 150 °C+.

PPA series from Material Wizard

• Examid® HTN (high temperature nylon) — based on PA6T/6I and PA66/6T copolymers, reinforced with glass fibre and minerals. Service temperatures 180–220 °C. Grades GF30, GF35, GF50.
• Examid® PPA GF series — a broad range of glass-filled PPA: GF30 5VA, GF33 HSL, GF33 V0 IR, GF40 HSL, GF45 V0, GF50 HSL — from structural to flame-retardant halogen-free grades.
• AKROMID® T series — premium-class polyphthalamides. AKROMID T5 GF50: HDT up to 280 °C, tensile strength 240 MPa, flexural modulus 15 000 MPa.
• GRIVORY® HT (EMS-Grivory) — the HT1V-4 FWA series, certified for contact with food and drinking water.
• ForTii® Ace MX53 (DSM/Envalior) — premium PPA GF50 for components in extreme temperature and load conditions.
• Examid® PPA CF33 — a polyphthalamide with 33 % carbon fibre. It combines the heat resistance of PPA with the exceptional stiffness of CF filling.

PPA limitations

Processing PPA requires higher barrel temperatures (290–330 °C) and mould temperatures (130–160 °C). Not all injection moulding machines are suitable — the nozzle must be heated to 320–340 °C. Drying is mandatory: 4–8 hours at 80–100 °C. The price is 2–4 times higher than PA66, but 5–15 times lower than PPS, PEEK, PEI — which makes PPA an intermediate solution between engineering and high-performance polymers.

How to choose PPA for your product

Material Wizard will help you select a PPA for your specific service conditions: operating temperature, load, aggressive environment, dimensional-stability requirements. Request a free consultation — we will discuss your project and propose TDS for the relevant grades.