{"id":9871,"date":"2026-08-22T03:09:38","date_gmt":"2026-08-22T03:09:38","guid":{"rendered":"https:\/\/tz-machinery.com\/?p=9871"},"modified":"2026-08-22T03:09:40","modified_gmt":"2026-08-22T03:09:40","slug":"make-pet-sheet-from-recycled-pet-flakes","status":"publish","type":"post","link":"https:\/\/tz-machinery.com\/vi\/make-pet-sheet-from-recycled-pet-flakes\/","title":{"rendered":"C\u00e1ch s\u1ea3n xu\u1ea5t t\u1ea5m PET ch\u1ea5t l\u01b0\u1ee3ng cao t\u1eeb m\u1ea3nh v\u1ee5n PET t\u00e1i ch\u1ebf"},"content":{"rendered":"

Processing 100% recycled PET bottle flakes (rPET) into high-clarity, thermoforming-grade sheet reels is one of the most profitable and sustainable choices in modern plastic packaging. However, rPET presents unique processing challenges\u2014primarily moisture sensitivity, intrinsic viscosity (IV) degradation, and impurities.<\/p>\n

To produce clear, durable PET sheets efficiently without excessive energy costs, manufacturers rely on modern extrusion technology such as parallel twin-screw extruders and ABA three-layer co-extrusion systems.<\/p>\n

Key Challenges in Processing Recycled PET Flakes<\/h2>\n

Before looking at machine configurations, it is critical to understand what happens when processing post-consumer PET bottle flakes:<\/p>\n

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  1. Hydrolysis & IV Loss:<\/strong> PET is hygroscopic. Moisture at high melt temperatures causes hydrolysis, breaking polymer chains and dropping intrinsic viscosity (IV), resulting in brittle sheets.<\/li>\n
  2. Impurity Inconsistencies:<\/strong> Recycled flakes often contain residual PVC, polyolefins (caps\/labels), or moisture variations.<\/li>\n
  3. Yellowing and Clarity Loss:<\/strong> Thermal degradation during prolonged heat exposure leads to optical defects and discoloration.<\/li>\n<\/ol>\n

    Step-by-Step Process: From Flakes to Finished Sheet Reels<\/h2>\n

    Step 1: Flake Preparation & Dosing<\/h3>\n

    Post-consumer bottle flakes are washed, metal-separated, and sorted by color. Multi-component gravimetric dosing units ensure precise feeding of rPET flakes, virgin PET chips, or masterbatch additives.<\/p>\n

    Step 2: Extrusion & Devolatilization (Drying vs. Non-Drying)<\/h3>\n

    Traditionally, PET required 4\u20136 hours of energy-intensive pre-drying and crystallization. Modern extrusion equipment bypasses this step.<\/p>\n

    Parallel Twin Screw PET Sheet Extrusion Machine<\/a> (Non-Drying Technology): Equipped with high-vacuum multi-stage degasification (vacuum systems down to < 5 mbar), parallel twin-screw extruders continuously extract moisture and volatiles directly from the melt. This prevents hydrolysis without requiring separate pre-drying equipment, significantly lowering energy consumption.<\/p>\n

    Step 3: Melt Filtration & Gear Pump Metering<\/h3>\n

    Because recycled bottle flakes carry microscopic contaminants, high-area continuous screen changers (backflush or hydraulic piston style) filter out particulate matter. A high-precision melt pump then maintains stable, pulse-free pressure into the T-die.<\/p>\n

    Step 4: Co-Extrusion & Layer Structuring (ABA Structure)<\/h3>\n

    To optimize material costs while maintaining superior surface properties, packaging manufacturers utilize co-extrusion.<\/p>\n

    ABA PET Three-Layer Sheet Co-Extrusion Lines<\/a>:<\/p>\n