Rod polyimide Meldin® 7021

sheettubeaeronautical

Overview
The Meldin® 7000 series is a thermosetting polyimide (PI-based) engineered for exceptional dimensional stability at elevated temperatures. The series shows less than 0.04% dimensional change after thermal cycling between 73°F (22.77°C) and 500°F (260°C) over 48 hours. Certain grades (e.g., Meldin® 7022) deliver a coefficient of thermal expansion comparable to aluminum. The compounds can be formulated with fillers to tailor mechanical, thermal and tribological performance. The series is processed via direct forming, enhancing cost-effectiveness and productivity for industrial production.

Tribological & Self-lubrication

• Self-lubricating Meldin® grades do not melt under high load (P) or high speed (V) conditions, compared with PTFE or typical thermoplastics.
• P × V limits: 300,000 psi·ft/min (10.5 W/mm²) in dry environments; exceeding 1,000,000 psi·ft/min (35.0 W/mm²) in liquid or grease-lubricated environments.

Notable grades

• Meldin® 7022: extremely low coefficient of thermal expansion (CTE) similar to aluminum.
• Meldin® 7021: contains ~15% by weight graphite fillers for self-lubrication — suitable for high-temperature bearings, seals, thrust washers and other low-wear components.
• Other grades (examples): Meldin® 7001, 7021, 7022, 7500 — each offering different balances of thermal oxidative stability, tensile strength, elongation, compressive modulus and CTE for targeted applications.

Applications

• Structural components in aviation and industrial applications where metal replacement and weight reduction are required.
• Semiconductor industry components where dimensional stability and purity are critical (possible replacement for aluminum, ceramics and high-performance plastics).
• High-temperature bearings, seals, thrust washers and other low-wear, high-temperature parts.

Standard Specifications
Materials: Polyimide (PI) based — engineered for extreme temperature service
Service conditions: Temperature: -200°C to +315°C; Mechanical strength: ~40 MPa
Manufacturing processes: Hot compression molding
Isostatic molding
Direct forming
Features: Tolerance control: ±10 µm (typ.)
Example dimensions: Rods: (φ) 80 mm × (L) 1 m
Tubes: (φ) 10.5 mm × (L) 50 mm
Sheets: (L,W) 300 mm × (T) 50 mm
Custom shapes: (L,W) 180 mm × (T) 50 mm

Characteristics / Technical specifications

• Dimensional stability: <0.04% variation after thermal cycling from 73°F (22.77°C) to 500°F (260°C) over 48 hours.
• Service temperature range: -200°C to +315°C.
• Mechanical strength: ~40 MPa.
• Manufacturing methods: hot compression molding, isostatic molding, direct forming.
• Tolerance control: approximately ±10 µm.
• Available forms: rods, tubes, sheets and custom shapes (sizes as listed above).
• Grades and options: multiple 7000-series grades (e.g., 7001, 7021, 7022, 7500) with filler options to tune mechanical, thermal and tribological properties.