PET Bottle Sorting: Why PET Blister Trays Must Be Removed for High-Quality Clear Flakes

Producing high quality clear PET flakes—critical raw material for chemical fiber factories making long fibers—depends on strict material purity. A key step: removing PET blister trays during sorting. Below’s why this separation is non-negotiable, how viscosity differences impact flake quality, and how DATABEYOND enables precise sorting.

The Core Goal: Separating for Targeted Recycling

PET recycling follows a “grade-specific” logic to maximize value:

· High quality clear PET flakes (long fiber feedstock): Require high pure class, high-viscosity transparent PET (e.g., beverage bottles). Any contamination ruins their suitability for long fibers, which demand uniform strength and clarity.

· Low quality clear and blue PET flakes (short fiber feedstock): Can accept PET blister trays, along with blue/transparent PET items like oil bottles, wide-mouth bottles, and aged bottles. These lower-grade flakes are ideal for short fibers, where minor viscosity variations are less impactful.

PET blister trays must be diverted to the second stream—they’re incompatible with high-quality clear flake production.

Viscosity Differences: The Hidden Quality Killer

PET materials’ intrinsic viscosity (IV) directly determines flake performance:

· Transparent PET bottles (high-quality stream): IV ranges from 0.72–0.85 dL/g, optimized for durability and uniform melting (PET Recycling Association, 2024).

· PET blister trays: IV is lower (0.55–0.65 dL/g) to enable thin, flexible molding.

If blister trays mix with bottle PET:

· The blended IV drops, making clear flakes too weak for long fiber extrusion.

· Uneven melting causes defects like fiber breakage, failing chemical fiber factory quality standards.

DATABEYOND: AI-Powered Precision Separation

DATABEYOND’s sorting technology ensures accurate diversion of PET blister trays:

· Its extensive solid waste database includes detailed profiles of PET bottles vs. blister trays (e.g., shape, structural features).

· Leading AI and computer vision tech identifies blister trays by visual cues (flat, thin design vs. rigid bottle shapes)—even when crushed or mixed with other PET.

This precision ensures high-quality clear PET flakes meet long fiber production demands, while blister trays are redirected to secondary recycling streams. For recyclers targeting premium markets, DATABEYOND’s data-driven sorting turns material separation into a competitive advantage.