Casting Unsaturated Polyester Resin

Low-viscosity unsaturated polyester resin designed for casting cultured marble countertops and decorative solid surfaces. It qualifies under HTS 3907.91.5000 as other unsaturated polyester in primary forms, with predominant monomer units per subheading note (a). Typically cured with fillers like ATH for opacity.

Import Duty Rates by Country of Origin

Origin CountryMFN RateCh.99 SurchargesTotal Effective Rate
🇨🇳China6.5%+35.0%41.5%
🇲🇽Mexico6.5%+10.0%16.5%
🇨🇦Canada6.5%+10.0%16.5%
🇩🇪Germany6.5%+10.0%16.5%
🇯🇵Japan6.5%+10.0%16.5%

Alternative Classifications

This product could be classified differently depending on its characteristics or intended use.

3907.91Same rate: 41.5%

If specifically 'for artificial teeth'

Subheading 3907.91.10 carves out polyesters for dental use, separating from general 'other' unsaturated.

2835.29Lower: 14.1% vs 41.5%

If imported with phosphate fillers exceeding polymer weight

Phosphates and polyphosphates as additives dominate if over 50%, shifting from polymer heading.

3901.30Lower: 15.3% vs 41.5%

If copolymer with 95% ethylene units

Subheading note (a)(2) places specific copolymers like ethylene-vinyl acetate under 3901.30 if meeting weight threshold.

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Import Tips & Compliance

Test for gel time compliance with buyer specs during customs hold; provide MSDS detailing uncured resin status; segregate from saturated resins to prevent mixing errors

Related Products under HTS 3907.91.50.00

Unsaturated Polyester Resin for Fiberglass

A liquid unsaturated polyester resin in primary form used as a base for composite materials in boat hulls and automotive parts. It falls under HTS 3907.91.5000 as an unsaturated polyester, not specifically named elsewhere, meeting the subheading note for polymers where the monomer units predominate by weight. Supplied in drums for industrial compounding with fiberglass reinforcement.

Gelcoat Unsaturated Polyester Resin

Thixotropic unsaturated polyester resin formulated as gelcoat for surface finishes on fiberglass reinforced plastics in marine and RV applications. Classified in HTS 3907.91.5000 as 'other' unsaturated polyester in primary liquid form, per polymer classification rules based on predominant monomer content. Used prior to curing with MEKP hardener.

Marine-Grade Unsaturated Polyester Resin

Iso-polyester resin variant with enhanced water resistance for boat building and underwater composites. Falls under HTS 3907.91.5000 as other unsaturated polyester in primary form, classified by predominant comonomer weight under Chapter 39 notes. Ortho or iso-phthalic based formulations.

Clear Polyester Casting Resin

Crystal-clear unsaturated polyester resin for embedding objects in paperweights and art sculptures. Classified HTS 3907.91.5000 for other unsaturated polyesters in primary forms, adhering to monomer predominance rules. Low odor, styrene-monomer diluted.

Spray-Up Unsaturated Polyester Resin

Medium-reactivity unsaturated polyester resin optimized for spray-up fabrication of large FRP parts like tubs and pools. HTS 3907.91.5000 covers this as other unsaturated polyester, primary form per weight-based polymer notes. Compatible with continuous roving.

Iso-NPG Unsaturated Polyester Resin

Neopentyl glycol (NPG) modified isophthalic unsaturated polyester resin for corrosion-resistant panels and tanks. Under HTS 3907.91.5000 as other unsaturated polyester in primary forms, with NPG units predominant but not chemically modified per notes. High HDT properties.