High Tensile PET Strap Production Line 450MPa 150kg/H Plastic Strap Making

High Tensile PET Strapping Extrusion Line Precision Stretching Orientation Unit Heavy Duty Packaging

The CM-PET65-HTS is a specialized high-tensile PET strap extrusion line that places molecular orientation engineering at the center of its design philosophy. While conventional production lines treat stretching as a downstream afterthought, this system integrates a precision longitudinal stretching station directly into the core process architecture. The result is a line capable of producing PET strapping with tensile strength exceeding 450 MPa — performance that enables direct substitution of steel strapping in heavy-duty applications including steel coil bundling, lumber mill strapping, and concrete block unitization.

At the heart of the stretching system is a 5-roll progressive orientation unit housed within a temperature-controlled hot air oven. Each of the five chrome-plated stretching rolls is independently driven by a dedicated servo motor, enabling precise speed ratio adjustments between successive roll pairs. This graduated stretching approach distributes the total draw ratio across multiple stages, allowing the PET molecular chains to orient gradually without inducing internal stress concentrations. The hot air oven maintains a uniform temperature field of 80-130°C with ±2°C accuracy through multiple cross-flow air circulation ducts and a high-precision thermocouple array. Operating at the optimal orientation temperature above the glass transition temperature but well below the crystalline melting point ensures maximum chain alignment without premature crystallization.

The extrusion subsystem features a 65mm single-screw extruder optimized for high-viscosity PET grades. A vented barrel design with a vacuum pump assists in removing residual moisture and volatiles during plastication, complementing the upstream dehumidification dryer. The melt is delivered to a flat coat-hanger die specifically engineered for uniform flow distribution across the full die width. After exiting the die, the cast sheet passes through a three-roll polishing stack that establishes precise initial thickness before entering the stretching oven. A heat-setting station downstream of the stretching unit anneals the oriented strap under controlled tension, locking in molecular orientation while relieving residual stresses that could cause dimensional instability during storage or use.

• 450MPa Tensile Performance: Engineered molecular orientation achieves strap strength on par with light-gauge steel strapping, enabling material cost reduction and elimination of steel band corrosion issues in outdoor storage.
• 5-Roll Progressive Stretching: Individually servo-driven chrome-plated rolls with graduated draw ratios distribute orientation stress evenly, preventing neck-in defects and ensuring uniform mechanical properties across the full strap width.
• Precision Hot Air Oven: Multi-duct cross-flow air circulation with ±2°C uniformity maintains the optimal molecular mobility window for PET orientation without surface degradation or premature crystallization.
• Heat-Setting Annealing: Post-stretch controlled-temperature annealing releases internal stresses while preserving orientation, delivering dimensionally stable strap that maintains flatness in coil form.
• Vented Extrusion Barrel: Integrated vacuum venting removes residual moisture and volatiles during processing, providing a critical secondary defense against PET hydrolytic degradation.
• Three-Roll Polishing Stack: Precision-ground mirror-finish rolls establish uniform sheet thickness and surface quality prior to stretching, eliminating gauge bands that cause uneven orientation.
• Digital Draw Ratio Control: HMI touchscreen interface allows operators to set target draw ratios by simply entering desired tensile strength values, with the PLC calculating and executing the required roll speed cascade.

This high-tensile strapping line is specifically designed for manufacturers targeting the industrial packaging sector where steel strapping replacement is a compelling value proposition. The 450 MPa tensile strength enables reliable bundling of hot-rolled steel coils weighing 3-5 tonnes, securing lumber packs for export container shipping, and unitizing concrete masonry products on pallets. PET strap offers distinct advantages over steel: it remains elastic under load, maintaining tension even when packaged goods settle or compress during transport; it eliminates rust staining on finished products; and it can be safely cut without the spring-back hazard associated with steel strapping. The line is validated for processing both virgin PET resin and high-quality washed bottle flake, providing feedstock flexibility that helps manufacturers optimize raw material costs. The integrated heat-setting station ensures the finished strap remains flat and dimensionally stable during extended coil storage in warehouse environments with fluctuating temperature and humidity levels.

Every CM-PET65-HTS line completes a rigorous 60-hour factory acceptance test that includes a 36-hour continuous production run with tensile strength sampling conducted at 2-hour intervals per ASTM D3950 standards. All stretching rolls are individually balanced to G2.5 grade and undergo laser alignment verification before shipment. The hot air oven is factory-calibrated with a 50-point temperature mapping to validate the ±2°C specification. Export packaging consists of ISPM 15 compliant plywood crates with molded polyethylene foam cushioning, VCI corrosion protection on all precision-ground surfaces, and a vacuum-sealed accessory container holding the spare parts kit. Our field service team provides on-site commissioning including full process recipe development for the customer's specific PET feedstock grade, staff training covering operation, troubleshooting, and quality control procedures, and a 12-month warranty on all mechanical and electrical components.