Dry-Free Energy Saving PET Sheet Extrusion Line
Features
Dry-Free Energy Saving PET Sheet Extrusion Line Process Flow Diagram
Chuangbo’s no-pre-crystallization no-drying PET sheet extrusion solutions include single-layer sheet production lines as well as twin-screw co-extrusion lines designed for multi-layer composite sheets (three-layer co-extrusion). We also offer upgrade and retrofitting services for traditional single-screw sheet extrusion lines to improve their efficiency and performance.
PET Extruder Specifications
| Model | TSH52 | TSH65 | TSH75 | TSH85 | TSH95 | TSH115 |
| Motor Power (kW) | 45 | 75 | 132 | 160 | 250 | 450 |
| Torque Rating (T/A³) | 9.8 | 9.3 | 10.7 | 8.9 | 9.2 | 8.9 |
| Screw Speed (r/min) | 266 | |||||
| Heating Power (kW) | 22.44 | 27.5 | 42.7 | 56 | 69.7 | 128.9 |
| Screw Diameter (mm) | 51.4 | 62.4 | 71 | 81 | 93 | 115.5 |
| Length-to-Diameter Ratio (L/D) | 40 | |||||
| Output (kg/h) | 150/250 | 200/350 | 300/500 | 400/600 | 600/800 | 800/1000 |
Projects
PET Sheet Extrusion Line
Challenges In PET Sheet Production
What Is PET Sheet?
PET (Polyethylene Terephthalate) is a polymer made from the condensation of terephthalic acid and ethylene glycol. It is typically off-white or pale yellow in color and is one of the most impact-resistant thermoplastics. PET sheets are widely used in industries such as decorative films, various packaging materials, household appliances, and precision instruments. They offer the following advantages:
- Excellent mechanical properties, with high tensile strength, impact resistance, and good folding endurance.
- Outstanding barrier properties, resistant to oils, fats, dilute acids, dilute alkalis, and most solvents.
- Excellent resistance to both high and low temperatures, with long-term usability in temperatures ranging from -40°C to 120°C.
- High transparency, UV-blocking properties, and good gloss.
- Non-toxic, odorless, hygienic, and safe, with recyclability that meets international environmental standards.
Water Absorption Characteristics Of PET Material
PET’s molecular chain structure contains hydrophilic groups (-COOR), making it a highly polar polymer that is easily water-absorptive. Completely dry PET chips, when exposed to air, can absorb up to 500 ppm of water within 30 minutes.
The equilibrium water absorption rate of APET is 0.4%. Such a high moisture content can cause severe hydrolysis of the PET melt during processing, rendering the product unsuitable for use.
Water in PET chips exists in two forms: adsorbed water and bound water. Adsorbed water can be removed at 120°C, while bound water, accounting for approximately 0.02%, requires a temperature of 140°C to be eliminated.
The Influence Of Water In PET Material Processing
Water content in PET can lead to hydrolysis during processing. At 280°C, hydrolysis is more than 5,000 times more severe than thermal oxidation degradation and thermal degradation. Hydrolysis is most intense within the first 5 minutes of PET melting and gradually slows down afterward. The effects include:
- A significant decrease in melt viscosity and molecular weight.
- The final product may bubble, become brittle, or yellow.
- Mechanical properties such as tensile strength and impact resistance are reduced.
- The transparency of the product deteriorates.
Traditional "Pre-crystallization-Drying-Melting Extrusion" Production Process
After drying, the PET resin’s moisture content is controlled to below 50 ppm before further processing.
Disadvantages:
- Time-consuming, with pre-crystallization and drying taking over 4 hours.
- High energy consumption, accounting for about 40% of the total energy used in PET processing.
- Long production line process and significant equipment investment.
Why Choose Chuangbo's PET Sheet Extrusion Line？
Chuangbo’s PET Extrusion Production Line ensures efficient, high-quality production of PET sheets, significantly reducing the cost of the final product.
Chuangbo PET Non drying Sheet Extrusion Production Process
Design Principles:
- The solid section of the extruder should be as long as possible to ensure uniform heating of the PET chips, allowing the residual moisture to evaporate from the chips.
- The extruder must have a solid venting capability, allowing as much water vapor as possible to be expelled before the PET melts.
- The melt venting process must be completed within a short period, as hydrolysis is most intense during the first 5 minutes of melting. Therefore, the venting process should not exceed 1 minute.
- The melt section and melt transport section of the screw should be designed with flexible threads to provide low shear during PET melting and transport, achieving low-temperature extrusion and preventing thermal degradation of PET.
Characteristics
Chuangbo high-capacity, efficient PET no-drying co-rotating twin-screw venting extruder can process bottle-grade PET chips with an initial moisture content of up to 5000 ppm, while controlling viscosity reduction to within 0.04 dl/g.
- High Air Extraction Capacity:The vacuum system equipped with the Chuangbo THS75-unit has an air extraction capacity of over 3600 m³ per hour, equivalent to the combined air extraction capacity of 13 NASIM 2BV5 (7.5kW) water-ring vacuum pumps.
- High Vacuum Degree: Achieves a vacuum degree of ≥99%.
- High-Torque Extruder Units:The torque level (N·m/cm³) is ≥9.
-When processing PET, the high-torque model maintains a low average shear rate, reducing the impact of screw shear on material degradation.
-The residence time of materials is shortened, minimizing the effects of high temperature on the materials.
-The unique screw combination ensures the following requirements are met:
- Effective plasticization of raw materials.
- No over-shear degradation of the melt.
- Stable melt extrusion with minimal pressure fluctuations.
- Formation of effective melt sealing, ensuring high vacuum extraction.
- No material spillage at the vacuum port.
- Comprehensive Energy Consumption (SEI):The SEI for typical units with drying devices is approximately 0.58 kW/kg, while the SEI for Chuangbo’s no-drying twin-screw unit is about 0.38 kW/kg, resulting in a 35% energy-saving rate.
- High Precision in System Pressure Closed-Loop Control:The system’s temperature control accuracy is ±1°C for each zone. Pre-pump pressure closed-loop control ensures stable sheet extrusion.
- Compact Unit, High Automation.
The production line consists of: Loss-in-weight feeder → Extruder → Melt filter → Melt pump → Die → Three-roll cooler → Thickness gauge → Edge trimming device → Haul-off Unit → Winder → Fully automated control system.
