PET Flakes & Glass Fiber Twin Screw Pelletizing Line

The SUHUI PET flakes glass fiber twin screw pelletizing line produces high-performance engineering plastic pellets by compounding recycled PET flakes with glass fiber reinforcement (10–40% loading). The resulting composite pellets deliver significantly enhanced tensile strength, flexural modulus, thermal stability, and dimensional rigidity compared to unreinforced recycled PET.

Designed for the demanding requirements of automotive, electronics, and industrial component manufacturing, these glass fiber reinforced PET pellets replace virgin engineering plastics in applications including structural housings, gears, brackets, and load-bearing components. The twin-screw compounding process ensures precise, uniform glass fiber dispersion throughout the PET matrix with minimal fiber breakage and polymer degradation.

By repurposing post-consumer PET bottle flakes as the base matrix material, the SUHUI line supports sustainable, cost-effective production of high-value engineering plastic compounds that would otherwise require virgin PET resin.

Key Features of SUHUI PET Glass Fiber Twin Screw Pelletizing Line

• Co-Rotating Twin-Screw Extruder: High-torque, co-rotating twin screws with corrosion-resistant barrel lining ensure thorough mixing, homogeneous dispersion of glass fibers, and consistent compound quality.
• Wear-Resistant Components: Hardened alloy barrel segments and screw elements withstand the highly abrasive nature of glass fiber processing, extending service life significantly.
• Precise Gravimetric Fiber Dosing: Loss-in-weight gravimetric feeders control glass fiber content with high accuracy (±0.5%), enabling customized mechanical property profiles from 10% to 40% fiber loading.
• High-Temperature Processing Capability: Barrel heating zones reach up to 300°C to fully melt PET without degrading glass fiber sizing or polymer chains during compounding.
• Vacuum Degassing System: Integrated vacuum vent removes residual moisture, volatiles, and entrapped air from the melt, producing defect-free, void-free pellets.
• Strand Pelletizing Unit: Extruded strands are water-cooled and cut into uniform 2–5 mm pellets with low dust generation and consistent geometry.
• PLC Automated Control: Touchscreen control system adjusts barrel temperature profiles, screw speed, and gravimetric feeding ratios in real time for consistent output quality.
• Energy Recovery System: Heat exchangers and insulated barrel sections reduce thermal energy loss and lower power consumption by 15–20% compared to uninsulated designs.

PET Glass Fiber Compounding Process Workflow

1. PET Flake Pre-Drying: Recycled PET flakes are dried in a dehumidifying dryer to reduce moisture content below 0.02%, preventing hydrolytic degradation of polymer chains during high-temperature extrusion.
2. Glass Fiber Preparation: Pre-cut glass fiber rovings or chopped strands are stored in a humidity-controlled silo and fed via a dedicated gravimetric side feeder, maintaining precise moisture content to protect fiber sizing.
3. Gravimetric Feeding: Dried PET flakes and glass fibers are simultaneously and independently fed into the twin-screw extruder via separate gravimetric loss-in-weight feeders, maintaining the target fiber loading ratio.
4. Melting & Compounding: The co-rotating twin screws melt the PET flakes and progressively incorporate glass fibers into the polymer matrix through controlled kneading and distributive mixing elements.
5. Vacuum Degassing: A mid-barrel vacuum vent removes residual moisture, acetaldehyde, and other volatiles from the melt to produce void-free, high-clarity compound pellets.
6. Die Head Extrusion: The fully compounded PET/glass fiber melt is forced through a multi-hole strand die, producing multiple continuous strands of uniform cross-section.
7. Strand Cooling: Extruded strands pass through a water cooling bath to solidify and reduce strand temperature before cutting.
8. Pelletizing: Cooled strands are fed into a strand pelletizer that cuts them into uniform 2–5 mm cylindrical pellets with consistent length and low fines generation.
9. Screening & Quality Control: Pellets pass through a vibratory sieve to remove undersized fines and oversized pieces. Samples are tested for fiber content, IV value, and mechanical properties.
10. Packaging: Finished glass fiber reinforced PET pellets are conveyed to storage silos or automatically weighed and bagged for shipment to automotive, electronics, or industrial customers.