Unsaturated Polyester Resin (UPR)
Liquid unsaturated polyester resin for fiberglass composites in marine and construction applications, supplied in primary form before curing. It enters HTS 3907.99.5050 as 'other polyesters' per predominant dicarboxylic acid/diol monomer content per subheading note (a).
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If for specific unsaturated polyester types
Some unsaturated polyesters have named subheadings; others fall to 3907.99 based on exact monomer specs.
If >30% soluble non-volatile matter as paint base
High-solids polyester solutions for paints classify in Chapter 32, not primary polymers.
If phenolic resin modified
Phenolic monomer dominance shifts to amino-resins heading per weight comparison rules.
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Import Tips & Compliance
• Include Safety Data Sheets (SDS) detailing uncured resin status and monomer composition for primary form verification
• Avoid common pitfall of classifying styrene-monomer blends incorrectly; styrene <5% keeps it polyester-dominant
• Confirm not chemically modified beyond base polymer to stay out of generic 'Other' provisions
Related Products under HTS 3907.99.50.50
Polybutylene Terephthalate (PBT) Resin
Polybutylene terephthalate (PBT) is a thermoplastic polyester resin in primary pellet form used for injection molding in automotive and electrical components. It falls under HTS 3907.99.5050 as 'other polyesters, other' because PBT is a polyester where terephthalic acid and butanediol monomers predominate by weight, not specifically named elsewhere in the heading.
Polytrimethylene Terephthalate (PTT) Pellets
PTT resin pellets are a polyester produced from terephthalic acid and 1,3-propanediol, used in textiles and engineering plastics. Classified in 3907.99.5050 as it qualifies as 'other polyesters' where the ester monomers predominate by weight over other units.
Polycaprolactone (PCL) Thermoplastic Pellets
Biodegradable polyester polycaprolactone resin in pellet form for 3D printing and adhesives. Falls under 3907.99.5050 as other polyesters with caprolactone as predominant repeating unit forming ester linkages.
Polyhydroxyalkanoate (PHA) Biopolymer Resin
PHA is a family of bio-based polyesters from bacterial fermentation, used in packaging films, in primary pellet form. Classified HTS 3907.99.5050 as other polyesters based on hydroxyalkanoic acid monomer units forming ester bonds predominating by weight.
Polyadipate Ester Resin Pellets
Polyadipate polyesters from adipic acid and diols, used as plasticizers and in polyurethane production, imported as primary pellets. HTS 3907.99.5050 covers these as other polyesters meeting predominant monomer criteria.
Copolyester Elastomer (COPE) Granules
Thermoplastic copolyester elastomers like Hytrel, combining hard polyester segments with soft polyether, supplied in primary granules. 3907.99.5050 applies as polyester blocks predominate by weight per classification notes.