Sourcing polyimide film from China

Polyimide film: 0% duty

Heading 3920 covers non-cellular plastic plates, sheets, film, foil and strip that are not reinforced, laminated, supported or similarly combined with other materials. Its dedicated polyimide line describes foil and strip that is uncoated or coated or covered solely with plastic. The table shows forms within the same commodity line.

Read from the UK Trade Tariff on 30 September 2026, polyimide under 3920 99 21 00 carried 0% duty for goods from China. The supplied tariff record lists no anti-dumping or countervailing duty, suspension or attached import control for this line.

Confirm the commodity code against the material and complete construction, especially for adhesive-backed or metal-clad products. Self-adhesive film and reinforced or laminated sheet are classified elsewhere. See plastic film and sheet for the wider heading.

Specify the polyimide grade and construction

Specify polymer grade, thickness and tolerance, width, roll length, core dimensions, colour, surface treatment and any plastic coating. Describe the intended use, such as electrical insulation or a substrate for further processing. Agree acceptable pinholes, scratches, edge damage and splices before approving the sample.

Ask for batch test results for dielectric breakdown, tensile strength, elongation and dimensional change after your processing heat cycle. Test samples in the intended assembly rather than accepting a temperature claim alone. For UK REACH, substances in articles may require registration if intended to be released during use; clarify any intended release with the supplier.

Worked duty example

Illustrative example, not a quote: Illustrative order: 20 rolls of uncoated polyimide film under 3920 99 21 00, invoiced at £30,000 free on board, with £2,000 of freight and insurance to the UK. The customs value is £32,000. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £32,000, so it is £6,400. With no duty, the only import tax is the VAT, which a VAT-registered importer can usually reclaim. The import duty and VAT guide explains each step.

Inspection checklist

Dimensions: measure thickness across the width and along unwound samples; check slit width and roll length against the order.

Surface: inspect against transmitted light for pinholes, inclusions and thin patches; check scratches, creases and coating uniformity.

Performance: compare batch results with the agreed specification and trial samples through the intended heat and insulation process.

Rolls: check winding alignment, crushed cores, edge damage, moisture protection and labels showing grade and batch. Use the inspection guide to define the inspection brief.

What goes wrong

A film can look acceptable on the roll but fail after processing. Thickness variation, pinholes and embedded particles can undermine insulation performance. Shrinkage or curl can disrupt registration during further processing, while poor winding and damaged edges make unwinding difficult.

Keep an approved sample and compare incoming batches with it. Agree how the supplier will identify splices and segregate defective lengths. Check that the test report covers the supplied grade, thickness and coating rather than a different film in the factory's range.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For repeat volumes, see container programmes.