🧩 PA+MD – Mineral Filled Polyamide

(Technical polyamide modified with mineral powders (talc, silicates, calcium carbonate) for dimensional stability, smooth finish, and reduced shrinkage. Ideal for housings, covers, and precision parts where rigidity and a matte appearance are important.)

🔹 What is PA+MD

PA+MD is a polyamide (PA6 or PA66) filled with fine minerals, typically talc or silicates. These additives reduce cooling shrinkage, increase dimensional stability, and provide a uniform surface finish without a fibrous look. It is a preferred alternative to PA+GF when high mechanical reinforcement is not required, but precision and superior aesthetics are desired.

🔧 Composition

• Polyamide (PA6 / PA66): 70–85 %
• Minerals (talc, silicates): 15–30 %
• Additives: UV/thermal stabilizers, dyes.
• Density: 1.25–1.35 g/cm³.
• Melting Point: ≈ 250–260 °C.
• Chemical Resistance: Good (oils, solvents, fuels).
• Continuous Heat Resistance: 100–120 °C.

🚗 Where PA+MD is used in the automotive industry

Component	Example parts	Observations
Interior	Covers, frames, consoles	Matte finish, clean aesthetic look
Engine / Technical	Housings, spacers, shrouds	High dimensional stability
Electrical / Connect.	Non-impact technical parts	Good insulation, low shrinkage
Decorative / Aesthetic	Visible parts with fine texture	Smooth, non-fibrous surface

🔧 Welding Temperature and Methods

Method	Optimal Temperature	Observations
Hot Air	250 – 270 °C	Slow melting, good control
Heat Plate (Mirror)	240 – 260 °C	Clean, uniform joint
Manual Extrusion	240 – 260 °C	Suitable for flat, aesthetic areas

🔩 What to Weld PA+MD With (Material Compatibility)

PA+MD maintains basic polyamide compatibility but reacts more slowly to melting due to the mineral content.

✅ Compatible with:

• PA+MD ↔ PA6 / PA66 / PA610 / PA+GF / PC+PA / PMMA+PA – ideal.
• PA+MD ↔ PBT / PC+PBT – partially compatible.

❌ Incompatible with:

• PP, PE, PVC, PS, ABS, ASA, pure PMMA – different melting points.

💡 ReplastMD Recommendation:

Use PA66 rods or PA+MD rods at 260 °C. Maintain constant temperature and moderate airflow. For aesthetic repairs, smooth the area with a quick hot air pass after welding.

🏭 Manufacturers and Trade Names

• BASF: Ultramid® A3MT / B3MT
• DuPont: Zytel® MD30
• DSM: Akulon® MD
• Evonik: Vestamid® Mineral

🧠 How to Identify PA+MD

• Engraved marking: >PA6-MD<, >PA66-MD<, >MD20<, >MD30<.
• Matte, smooth surface, no gloss. No visible fibers.
• Blue flame, nylon smell.
• Softens at ≈ 250 °C, slow and stable melting.
• ReplastMD practical test: If the part is rigid, matte, and has no visible fibers when cut, and the marking contains >MD<, it is confirmed Mineral Filled Polyamide.

🛠️ PA+MD Welding at ReplastMD:

At our ReplastMD service center (Chisinau, Ciocana sector), we perform professional PA+MD welding for technical frames and covers, ensuring an aesthetic, rigid, and durable finish.