Polyimide

When purchasing Polyimide, you must prioritize thermal stability and mechanical properties. Ensure the material has a Glass Transition Temperature (Tg) exceeding 300°C for high-heat applications. For films (Kapton type), verify dielectric strength (typically ≥150 kV/mm) and tensile strength (≥150 MPa). If sourcing for aerospace or electronics, confirm the Coefficient of Thermal Expansion (CTE) matches your substrate to prevent delamination.

Polyimide products must adhere to RoHS (Restriction of Hazardous Substances) and REACH regulations, especially for electronics. For electrical insulation, UL 94V-0 flammability rating is a critical safety benchmark. If the material is used in aerospace, ensure the supplier provides AS9100 certification or meets specific MIL-SPEC standards.

Request a Certificate of Analysis (COA) for every batch. Conduct a shrinkage test at 200°C; high-quality PI film should show less than 0.1% dimensional change. For resins or powders, check for purity levels (≥99%) and moisture content, as excess moisture can cause brittleness during processing. Always use Made-in-China.com's audited supplier reports to verify factory production capacity.

The application determines the form: PI Films are essential for Flexible Printed Circuits (FPC) and motor insulation; PI Resins/Powders are used for high-performance molded parts like bushings or bearings in automotive engines; and PI Fibers are used in flame-retardant protective clothing or high-temperature filtration. Specify the end-use to the supplier to get the correct chemical formulation (thermosetting vs. thermoplastic).

The primary risk is material degradation due to improper storage (humidity and UV exposure). Ensure the contract specifies vacuum-sealed packaging with desiccant. Another risk is export control restrictions, as high-grade Polyimide can be classified as dual-use (civilian/military) technology. Always verify the HS Code (typically 3920.99 or 3911.90) with a customs broker before shipment.

Polyimide is a high-value engineering plastic; therefore, unit prices are sensitive to raw material (PMDA/ODA) fluctuations. Negotiate a tiered pricing structure based on annual volume rather than single orders. For customized thicknesses or widths, expect a higher MOQ (e.g., 500kg or 1000m). Request FOB pricing to maintain better control over international freight costs and insurance.

To ensure transaction security, use Secured Payment services on Made-in-China.com, which hold funds until you confirm receipt of goods. For large bulk orders, utilize Third-Party Inspection (such as SGS or Intertek) to conduct a pre-shipment inspection (PSI) to verify that the thickness, width, and dielectric properties meet your specifications before final payment.

For PI Films, use sea freight with temperature-controlled containers if crossing tropical zones to prevent adhesive aging (if pre-preg). For high-value PI Resins, air freight is preferred to reduce lead time and exposure to port humidity. Ensure all pallets are ISPM 15 compliant and labeled with 'Keep Dry' and 'Protect from Heat' warnings in both English and the destination language.