Manufacturing | Chemco Kandoi – rPET FIBC Bags Process

The production of rPET FIBC bags begins with high-quality recycled PET flakes, which is extruded, stretched, and woven into durable fabric. The material is then cut, printed, and stitched with key components such as lifting loops, baffles, liners, and discharge spouts. Bags undergo UV stabilisation and rigorous quality testing, including tensile strength, stacking, and drop tests, ensuring durability and compliance. Finally, they are compressed, baled, and packed for secure distribution, delivering sustainable and high-performance bulk packaging solutions.

Extrusion Process of making rPET FIBC bag

Extrusion Line

The extrusion process starts with the dehumidification of rPET flakes to achieve a moisture content of less than 50 ppm, essential for preventing hydrolytic degradation during melt processing. The dried flakes are fed into a twin-screw extruder, where precise temperature control between 260°C and 280°C ensures optimal melt viscosity and polymer flow. The molten polymer is then passed through a T-die, forming a thin sheet which is rapidly quenched on a chill roll to maintain dimensional stability and prevent crystallisation.

The sheet is slit into uniform tapes, which are stretched in a hot-air stretching unit at temperatures between 80°C and 120°C to achieve the desired tensile strength and elongation at break. These tapes are then annealed to reduce shrinkage, improve creep resistance, and enhance thermal stability for long-term use in demanding environments. The tapes undergo surface treatment to improve adhesion during lamination or printing. The final tapes, wound onto bobbins, are ready for the warp and weft interlacing process in circular or flat looms, producing high-strength woven fabric with excellent UV stability, chemical resistance, and dimensional accuracy, critical for industrial-grade rPET FIBC bags production and other heavy-duty textile applications.

Tape Line

The tape extrusion line is a critical stage in the manufacturing of rPET FIBC bags, enabling the production of high-strength woven fabric. Using advanced extrusion technology, recycled PET (rPET) flakes are melted, filtered, and extruded into a thin sheet, which is then precisely slit into narrow tapes.

These tapes pass through a controlled orientation process, where they are heated and drawn under regulated tension, aligning the polymer chains to enhance tensile strength, durability, and flexibility. The process is optimised with automatic width control, gravimetric dosing systems, and advanced IR heating zones, ensuring uniform orientation and high molecular alignment for superior mechanical properties.

The tape extrusion line incorporates energy-efficient drying systems, high-speed winding units, and real-time quality monitoring, ensuring consistent tape thickness, uniform denier, and excellent adhesion properties. The tapes undergo annealing, stabilising their molecular structure to prevent shrinkage and improve dimensional stability in rPET FIBC bags applications.

Additionally, UV stabilisation treatments can be applied to enhance weather resistance, making the tapes suitable for outdoor storage and prolonged exposure to sunlight. The result is a high-performance fabric tape with an exceptional strength-to-weight ratio, optimised for further processing in circular looms.

Tape line process to make rPET FIBC bags

Circular loom process to make rPET FIBC bags

Circular Looms

The circular weaving process is a cornerstone in rPET FIBC bags fabric production, where high-speed circular looms are employed to weave flat, circular, or U-panel woven fabrics. These looms use the stretched tapes produced in the tape stretching line to weave fabric with exceptional dimensional stability, high tear resistance, and low elongation properties.

The advanced loom technology is engineered for precision warp control, automatic weft compensation, and low-friction shuttle movement, ensuring uniform fabric density and minimal weaving defects. The servo-driven warp tension control system optimises fabric strength and enhances seam integrity, which is essential for heavy-duty industrial applications.

Equipped with automatic tape feeding, tension monitoring, and high-speed shuttle movement, these circular looms can operate at speeds exceeding 800 picks per minute, maximising productivity and operational efficiency. These looms ensure fabric consistency with electronically controlled warp breaks detection and automatic shut-off systems, reducing material wastage and downtime.

The woven fabric can be further enhanced with lamination or additional coatings, depending on the application requirements. With their low energy consumption, high output rates, and precision engineering, these circular looms are at the forefront of sustainable and efficient rPET FIBC bags manufacturing, delivering premium-quality fabric tailored for global bulk packaging demands.

rPET FIBC Bags Stitching

The fabric is wound onto rolls and transferred to the fabric conversion unit for precision cutting and stitching. The fabric is first die-cut into required panel dimensions based on the rPET FIBC bag specifications. These cut panels then move to the heavy-duty stitching section, where reinforced seams, lifting loops, filling and discharge spouts are integrated using high-tenacity rPET or polyester industrial threads, ensuring optimal tensile strength and load-bearing capacity.

During stitching, high-speed automated sewing machines apply multi-pass chain, overlock, or lockstitch techniques to achieve seam durability and structural integrity. If a liner is required, it is either thermally bonded or mechanically stitched to enhance moisture resistance and contamination control. The stitched assemblies then undergo rigorous tensile strength testing, visual inspections etc at quality control checkpoints to ensure seam integrity, dimensional accuracy, and compliance with industrial load standards. Once approved, the rPET FIBC bags are compressed and dispatched, meeting global performance and regulatory standards for bulk material handling and transportation.