SAT75 TPV/TPE Reaction Extrusion Pelletizing Line
- Clients in: Thermoplastic Elastomers
Project Abstract
- Client Requirements: TPV dynamic vulcanization + TPE compounding; Capacity 250~450 kg/h; Extremely high requirements for consistency in physical properties.
- Core Challenges: Narrow residence time window for reaction; High viscosity and torque; Risk of slippage due to high oil content; Stickiness of soft materials.
- Solution: SAT75 (L/D 56) reaction extrusion extruder + Multi-port liquid injection system + 250kW Water-cooled PM motor + UWP500 Underwater pelletizing system.
- Delivered Value: Achieved continuous stable operation at target capacity; Significantly improved pellet uniformity; Reduced reliance on manual experience through automated interlocking.
Project Background
This project involves a customized pelletizing line for a manufacturer of thermoplastic elastomers. The client’s formulation system is complex, covering both conventional TPE (Thermoplastic Elastomer) compounding and the dynamic vulcanization process for TPV (Thermoplastic Vulcanizate).
Since TPV production involves in-situ vulcanization and shear dispersion of the rubber phase within the plastic phase, it imposes strict requirements on the extruder’s Residence Time Distribution (RTD), shear intensity, and temperature control window. Additionally, the process requires the addition of a significant proportion of process oil, and the final product has low hardness (soft material). Ensuring uniform mixing and preventing pellet agglomeration were the core engineering design considerations for this project.
Therefore, the control focus of this project relies on the synergy of four key aspects: Residence time window (L/D ratio & screw configuration) + Sectional temperature control + Sectional liquid injection/absorption + Pelletizing & cooling method.
Process Challenges & Engineering Solutions
Addressing the three major pain points in elastomer processing—”Difficult Reaction,” “Difficult Feeding,” and “Difficult Pelletizing”—we implemented the following targeted designs:
| Core Process Challenge | Engineering Design | Technical Value & Effect |
|---|---|---|
| Dynamic Vulcanization ControlInsufficient reaction time leads to incomplete vulcanization; excessive shear causes uncontrolled temperature rise. | L/D = 56 Configuration+ Sectional temperature control strategy | • Provides a sufficient residence time window for reaction. • Facilitates in-situ vulcanization and fine dispersion of the rubber phase. • Improves process stability and consistency of physical properties. |
| High Viscosity & Torque LoadHigh viscosity of elastomer melt places high load on the host machine; traditional motors are noisy and less efficient. | 250kW Water-cooled PM Motor+ R+W Safety Coupling | • Maintains high torque output at low speeds with higher energy efficiency. • Water-cooled design prevents dust intake, ensuring a cleaner environment. • Coupling provides mechanical overload protection to minimize equipment damage risks. |
| Oil Injection & Slippage RiskInjecting a large amount of liquid at once can cause screw slippage and formulation drift. | Multi-port Injection System(Injection ports reserved at barrels 2/3/6/7/8) | • Sectional injection prevents local over-lubrication. • Promotes gradual absorption of oil by the base resin. • Stabilizes extrusion pressure and reduces formulation deviation. |
| Soft Material AgglomerationSoft pellets have a high friction coefficient; traditional strand pelletizing causes strand breakage, sticking, or "tailing." | UWP500 Underwater Pelletizing System+ Uniform temperature die plate | • Cutting and cooling occur simultaneously; water flow instantly removes heat. • Significantly reduces the risk of pellet agglomeration (sticking). • Pellets are rounder with more controllable size consistency. |
System Configuration (Typical)
To ensure high availability and replicability of the production line, the project adopted the following high-standard configurations:
- Extruder System: SAT75 Twin Screw Extruder, L/D 56, High-torque gearbox.
- Drive System: Keyuan 250kW Water-cooled Permanent Magnet (PM) Motor, low noise and energy-saving.
- Feeding System: Main feeder + Side feeder + Multi-channel liquid injection control (equipped with high-precision flow meters).
- Pelletizing System: UWP500 Underwater Pelletizer (includes 12×0.6kW die heating, 15kW water circulation temperature control, and centrifugal dryer).
- Control Logic: Full-line interlock control, integrated with “One-key Start” and “One-key Stop” logic.
Project Video
Project Summary & Delivery Results
Operational Performance
- Process Stability: Main motor torque and die pressure remained stable within the client’s target capacity range, with fluctuations within controllable limits.
- Pellet Quality: Compared to traditional strand cooling processes, pellet roundness is improved, and the issue of soft material sticking is effectively suppressed.
- Operation & Maintenance: The interlock and one-key start/stop logic reduce critical manual steps, lowering the probability of downtime caused by human error.
Project Overview
The project has been successfully delivered. The SAT75 twin screw extruder unit demonstrated excellent torque stability when processing high-viscosity TPV formulations. The L/D 56 design provided a wider processing window, addressing the issues of “insufficient reaction/large fluctuations” previously encountered by the client on short L/D equipment.
The application of the UWP500 Underwater Pelletizing System enabled the continuous and smooth production of low-hardness TPE materials that were previously difficult to process, enhancing the market competitiveness of the final product.
Scope of Application
This solution is particularly suitable for processing high-elasticity, sticky TPV and oil-filled TPE materials requiring reaction extrusion. For special formulations containing high volatiles or strong corrosive systems, please contact us for specific material selection and venting optimization assessments.
Note: Client information has been anonymized in compliance with the Non-Disclosure Agreement (NDA).