Sourcing polyimide filament yarn from China

Zero duty across the relevant yarn constructions

Heading 5402 covers synthetic filament yarn other than sewing thread, not put up for retail sale. For polyimide filament yarn, the table identifies candidate lines for textured yarn, low-twist single yarn, higher-twist single yarn and multiple or cabled yarn. These descriptions are construction categories, rather than named polyimide entries.

Read from the UK Trade Tariff on 1 October 2026, all the listed candidate lines carried 0% duty for goods from China. The supplied record lists no anti-dumping or countervailing duties, suspensions or attached import controls for these lines.

Confirm the polymer composition, continuous-filament construction, texturing, twist and ply with your customs broker before selecting the commodity code. See the aramid filament yarn guide for wider heading context; do not choose an aramid line solely because the supplier describes the yarn as heat resistant.

Specify the polyimide grade and thermal performance

Specify the polymer grade, whether the yarn is wholly polyimide or blended, linear density, filament count, twist direction, ply, breaking strength, elongation and package build. Request composition evidence tied to the supplied grade and retain an approved package. Distinguish continuous filament from staple-spun yarn before comparing offers.

For thermal performance, agree the exposure temperature, duration, atmosphere, applied tension and the strength or dimensional change measured afterwards. Ask for results on the actual yarn grade rather than a resin brochure. Specify the finish and its compatibility with your weaving, coating or impregnation process.

UK REACH regulates chemicals placed on the market in Great Britain. Its restrictions can limit, ban or set conditions on placing substances on the market or using them. Request details of finishes and additives so applicable restrictions can be checked before purchase.

Worked duty example

Illustrative example, not a quote: An illustrative trial lot of untwisted polyimide filament yarn for a specialist weaving business under 5402 49 00 90, invoiced at £24,000 free on board, with £1,200 of freight and insurance to the UK. The customs value is £25,200. Duty at 0% is £0. Import VAT at 20% is charged on the customs value plus duty, £25,200, so it is £5,040. 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 yarn grade, composition declaration and batch records to the approved sample and shipment labels.

Mechanical properties: check linear density, filament count, twist, breaking strength and elongation against the agreed specification.

Thermal behaviour: repeat the agreed exposure test on shipment samples and compare retained strength and dimensional change with the approved lot.

Packages and running: check net yarn weight, winding, crushed cores, broken filaments and contamination; trial unwinding on your equipment before bulk processing.

What goes wrong

A heat-resistance claim without test conditions leaves the buyer unable to compare grades. A resin data sheet also leaves yarn strength, finish and processing behaviour untested. Agree acceptance criteria on yarn samples and record the grade and batch behind each result.

Broken filaments, uneven winding and unsuitable finishes can cause processing stops or poor coating adhesion. Mixing batches can hide variation until weaving begins. Keep batch identities separate and compare incoming samples with the retained package before releasing the lot.

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.