Polyethylene Terephthalate (PET) HS Code by Form: Resin, Flake, Film, Sheet and Preform

Polyethylene terephthalate is traded internationally in at least five physically and commercially distinct forms: resin, flake, film, sheet, and preform. Each form follows a different Harmonized System (HS) logic under Chapter 39. Resin in primary granular form is governed by heading 39.07; waste or scrap flake may fall under heading 39.15; non-cellular film and sheet fall under heading 39.20; and bottle preforms fall under heading 39.23. The six-digit HS level is harmonized; national eight- and ten-digit subdivisions vary by jurisdiction and must be verified against the importing country’s tariff schedule. Chapter 39 Note 6 defines primary forms to include granules and flakes, which creates classification tension for recycled PET flake. The article addresses the HS code by form and the technical parameters that determine classification.

What Determines Whether PET Resin Falls in Subheading 3907.61 or 3907.69?

PET resin in primary granular form is classified under heading 39.07, parent subheading 3907.60. The split is based on viscosity number. Material having a viscosity number of 78 ml/g or higher is assigned 3907.61; material below that value enters 3907.69. Intrinsic viscosity is measured on a dilute solution; ASTM D4603 uses a 60/40 phenol/1,1,2,2-tetrachloroethane mixture at 30 °C, and ISO 1628-5 provides a comparable capillary viscometer method. A bottle-grade PET resin with an IV of 0.82 dL/g therefore classifies as 3907.61 because 0.82 dL/g equals 82 ml/g. A fiber-grade resin with an IV of 0.64 dL/g classifies as 3907.69.

Unlike polyolefins, PET classification does not use melt flow rate because melt viscosity is strongly affected by hydrolysis and thermal degradation. The HS split uses dilute-solution viscosity because it tracks molecular weight under controlled solvent conditions. Both ASTM D4603-18 and ISO 1628-5 report viscosity number in millilitres per gram; conversion between IV in decilitres per gram and viscosity number in millilitres per gram is direct, with 1 dL/g equal to 100 ml/g. Because the legal threshold is 78 ml/g, a resin with IV 0.775 dL/g is 77.5 ml/g and falls under 3907.69, not 3907.61. This single-point cutoff creates tariff engineering risk when batch-to-batch IV variation crosses the boundary. Resin producers control IV within narrow limits, but storage under humid conditions can reduce delivered IV; the recorded viscosity on import documentation is therefore measured after drying.

Industrial polymerization lines for bottle resin use continuous melt-phase polycondensation followed by solid-state polycondensation to raise IV from approximately 0.60 dL/g to 0.78–0.85 dL/g. Vertical moving-bed SSP reactors operate at 200–220 °C under vacuum or inert gas. Pellet crystallizers upstream of SSP operate at 150–170 °C to prevent agglomeration. Twin-screw compounding with an L/D ratio of 32:1 to 44:1 is used for filled or nucleated resin, but standard bottle resin is melt-phase polycondensate followed by SSP. The final crystallized pellet remains free-flowing and retains primary-form character under Chapter 39 Note 6. Filled, nucleated, or masterbatch-dosed PET granules may remain in 3907.61 provided that the product is still a primary-form plastic. A compound pellet containing visible glass fibre or a layered structure intended as a moulding compound can shift classification away from heading 39.07 depending on the national ruling.

For recycled bottle flake entering customs, the typical six-digit classification is 3915.90 because the material is regarded as plastics waste, parings and scrap rather than a primary-form resin. The HS does not provide a separate six-digit subheading for clean hot-washed recycled PET flake. Chapter 39 Note 6 includes flakes in the primary-form list, which creates legal conflict: a hot-washed flake with controlled particle size, restored IV, and documented melt-filtration performance may be argued for 3907.61 if the intended use is remelting into packaging resin, but many administrations retain 3915.90 because the commercial character remains scrap or secondary raw material. The classification outcome depends on national customs rulings, the flake’s processing history, and the importer’s declared end-use.

On industrial bottle recycling lines, sorted bales are ground wet or dry, passed through air elutriation, hydrocyclone density separation, and hot-wash tanks with caustic at 80–95 °C. Final flake IV is typically measured by ASTM D4603 after drying; clean bottle flake may range from 0.70 dL/g to 0.80 dL/g depending on deposit material and thermal history. Moisture content after drying is specified below 0.5 wt% before conveying to solid-state polycondensation or extrusion. Residual polyethylene, label adhesive, and PVC contamination create processing bottlenecks; PVC levels below 10–30 ppm are often specified because higher concentrations cause acid-catalysed degradation during extrusion. Near-infrared sorting units on bottle lines are configured to reject PVC at detection levels below 10 ppm; carryover above this level reduces the processing window.

Flake particle size is commonly distributed from 3 mm to 14 mm across the diagonal, with fines below 0.5 wt% through a 1 mm screen. Bulk density of washed bottle flake typically ranges from 250 kg/m³ to 450 kg/m³; this lower bulk density compared with cylindrical pellet resin influences freight and customs valuation but not the six-digit code. If the flake is melt-compounded into pellets, the bulk density rises above 700 kg/m³ and the primary-form classification under 3907.61 becomes more supportable. Without pelletization, the waste/scrap heading remains the dominant classification pathway in many customs territories. Advance ruling requests for 3907.61 treatment of recycled flake require mill certificates reporting bulk density, IV, moisture, and contaminant concentration.

Film and Sheet Share Heading 3920.62; Fabrication Route Determines Commercial Identity

Non-cellular, non-reinforced PET film and sheet are both classified under 3920.62 in the Harmonized System. The HS does not use thickness to separate film from sheet. ASTM D883 defines film as thickness below 0.25 mm and sheet as thickness equal to or above 0.25 mm. Biaxially oriented polyester film is produced by melt extrusion through a flat die, chill-roll quenching, and sequential or simultaneous biaxial stretching. Typical production thickness ranges from 12 µm to 250 µm. Amorphous PET sheet is often extruded at 0.25–1.5 mm and thermoformed into trays or blisters. Plain, corona-treated, or chemically primed film and sheet remain in 3920.62; lamination with other polymers or coating with an adhesive may move classification to a different heading depending on essential character.

Biaxial stretching ratios for BOPET typically fall between 3.0× and 4.0× in the machine direction and 3.0× and 4.5× in the transverse direction. Tensile strength of BOPET film measured under ASTM D882 typically ranges from 150 MPa to 260 MPa in the machine direction. Heat-set BOPET film can be tuned for low shrinkage; ASTM D1204 values at 150 °C are commonly below 2% for thermally stabilized grades. Extrusion lines for APET sheet use chill-roll temperatures of 25–45 °C to limit crystallinity and haze. Because the six-digit code is identical for film and sheet, the tariff declaration requires physical form, thickness, and surface treatment, but material composition remains the primary classification driver.

For sheet, a coextruded layer structure of PETG or recycled PET can affect classification if the PET content remains dominant; if the other polymer imparts the essential character, classification can shift to another subheading under heading 39.20 or to another heading. However, a monolayer APET or CPET sheet remains squarely under 3920.62 even when embossed or cut into rectangular blanks, because heading 39.20 covers plates, sheets, film, foil and strip. Laminated or printed structures require review under headings outside 3920.62 depending on the structure.

Because injection-molded PET preforms carry a finished neck thread and a molded body intended for stretch blow molding, they are classified as packaging articles under 3923.30 rather than as primary forms under heading 39.07 or intermediate products under heading 39.26. Harmonized System Explanatory Notes for heading 39.23 list preforms of plastics used for the manufacture of bottles, flasks, and similar articles. Preform shot weights for carbonated soft drink bottles commonly fall between 18 g and 60 g, and neck finishes such as the 28 mm PCO 1881 interface are specified by blow-molding equipment. A 48-cavity preform mould may require injection clamping force above 300 t, with hot-runner valve gates and robotic take-out plates. Six-digit classification remains 3923.30; national tariff lines may subdivide by article capacity, neck diameter, or weight.

Preform molding requires desiccant drying of PET resin to a moisture content below 50 ppm, typically at 160–180 °C and with a dew point of -40 °C or lower. Barrel temperatures are generally set between 270 °C and 295 °C, while hot-runner temperatures are held at 285–300 °C. Excess moisture or melt residence time above 300 °C increases acetaldehyde generation; for water bottle preforms, acetaldehyde content below 4 ppm is often specified by gas chromatographic headspace analysis. A preform lacking a finished neck finish or not shaped for container manufacture may fall outside heading 39.23, requiring review under other Chapter 39 provisions.

Classification under 3923.30 is not dependent on the polymer’s viscosity number; even a preform molded from lower-IV PET remains a packaging article rather than a primary-form pellet. The critical tariff characteristic is the presence of a neck finish, gate geometry, and the intended blow-molding transformation. The neck finish is injection molded to final dimensions and is not stretched during blow molding, so the preform is classified as an article of plastics even though the body remains unfinished. Rejected preforms that are ground into flakes for internal recycling change character and may again be classified as waste or scrap under heading 39.15, or as primary-form recycled material if pelletized and certified under 3907.61.