Sourcing polyimide resin from China

Polyimide resin duty and classification

Read from the UK Trade Tariff on 22 November 2026, heading 3911 covers specified resins and other polymers in primary forms. For polyimide resin, establish the chemistry and manufacturing route before choosing the residual condensation-polymer line. The table includes related named polymers for comparison; these are not interchangeable descriptions of polyimide resin.

The selected lines carry 0% duty for goods from China, with no anti-dumping or countervailing measure and no suspension recorded. The tariff attaches import and export waste controls. For Chinese resin supplied as waste, confirm the applicable requirements with your customs broker. Waste moving under notification controls cannot be shipped until the destination, dispatch and transit authorities have consented.

Give your broker the composition, physical form, monomer information and technical datasheet to confirm the commodity code. Keep resin procurement separate from finished-film procurement; see the polyimide film guide.

Specify chemistry, resin form and curing behaviour

Specify whether you need fully imidised powder or a precursor solution, and identify the intended moulding, coating or composite process. Agree particle-size distribution for powder, or solvent identity, solids content and viscosity test conditions for solution. State filler content, moisture, residual volatiles, storage conditions and the curing schedule used for sample approval.

Obtain composition information and a safety data sheet before committing to a grade. Before selling imported substances or mixtures in Great Britain, confirm chemical classification responsibilities with HSE; the importer must ensure correct chemical labelling and packaging.

Worked duty example

Illustrative example, not a quote: Illustrative pilot-production shipment of polyimide resin powder, assuming classification is confirmed under 3911 90 19 90, invoiced at £18,000 free on board, with £1,500 of freight and insurance to the UK. The customs value is £19,500. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £19,500, so it is £3,900. 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

Identity: match the producer, grade and batch number to the approved sample, technical datasheet and certificate of analysis.

Material: check powder for agglomerates and contamination; check solution for sediment, gel particles and viscosity against the agreed method.

Process: trial a retained batch sample using your agreed drying and curing schedule, checking bubbles, cracking and adhesion where relevant.

Packing: inspect liners, drum seals and leakage on arrival; compare production and storage records with the supplier's stated shelf life.

What goes wrong

A supplier may offer a related imide polymer instead of the approved chemistry. Powder agglomerates can disrupt feeding, while changes in solution viscosity or solids content alter coating behaviour. Moisture and residual solvent can produce voids during curing. A certificate without test conditions makes batch comparisons unreliable.

Approve the material in your own process and agree batch acceptance methods before shipment. Keep a retained sample and hold any batch that differs from the agreed specification. Use a product-specific inspection brief.

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.