PP+CaCO3 Filler Masterbatch Extrusion Line in Saudi Arabia
- Clients in: Filler Masterbatch
Project Background
In the Middle East (such as Saudi Arabia), producers of pipes, films, and injection-molded products frequently add inorganic fillers to optimize polymer performance and control overall costs. This makes PP and PE-based Calcium Carbonate (CaCO3) filler masterbatches highly demanded materials in the region.
Recently, USEON successfully completed the FAT (Factory Acceptance Test) of an SAT-75 twin-screw extrusion line for a Saudi client. The core technical target of this project was to achieve a 70% CaCO3 loading rate in a PP homopolymer matrix while meeting a throughput requirement of 900-1000 kg/hr. To address this, the client selected USEON’s highly configured caco3 filler masterbatch extruder solution.
Project Highlights
- Throughput Verification: Under the PP + 70% CaCO3 formulation, the FAT results achieved the project target throughput, reaching up to 1000 kg/hr during testing.
- Formulation Adaptability: With corresponding process adjustments, this filler masterbatch machine supports the customer’s future production of PE + CaCO3 compounds.
- Feeding Stability: The integration of an X-type twin-screw loss-in-weight feeder, designed for low bulk density powders, helps improve the stability of continuous powder feeding.
- Devolatilization: Equipped with a 7.5Kw dual-stage water-ring vacuum system to help manage the entrapped air and moisture introduced by the large volume of powder.
Technical Analysis & System Configuration
In the extrusion process of highly filled PP+CaCO3 systems, the stable feeding of powder is often the critical factor affecting the overall line capacity. To improve powder introduction efficiency and overall feeding stability, USEON adopted a split-feeding design in this system: the polymer pellets enter the main feed port via a vacuum loader, while the CaCO3 powder (accounting for 70% of the formulation) is metered by the X-type twin-screw loss-in-weight feeder and introduced into the downstream barrel section by the CWJ-63 side feeder. This design helps incorporate the powder into the molten polymer phase for subsequent wetting and dispersion.
In the plasticizing and compounding section, considering the target throughput and potential future material compatibility, this USEON CaCO3 compounding line was configured with an extended L/D ratio of 52:1. The extended L/D provides sufficient process length for downstream feeding, dispersive mixing, and venting arrangement, allowing the equipment to utilize appropriate shearing and kneading elements to disperse the CaCO3 powder into the matrix resin. For further insights into how we optimize screw profiles through advanced twin screw extrusion for high filler compounds, you can refer to our technical article: the equipment configuration and process guide for the pp caco3 filler extruder.
Meanwhile, addressing the potential need to switch to PE+CaCO3 production, the equipment’s modular screw design and multi-zone independent temperature control system allow the line to be adapted for different base resins subject to process adjustments, thereby expanding the application scope of this compounding line.
Furthermore, to ensure melt quality before extrusion, the downstream section is equipped with a venting and devolatilization module. Coupled with the die-face / water-ring pelletizing system (WRP1000)—which is well-suited for high-filler, low-melt-strength materials—the equipment operated at a screw speed of 600 rpm during FAT. The pellet appearance and dispersion performance were verified on-site in line with the project acceptance target.
Project Video
FAQs
A: For high-loading PP or PE CaCO3 compounds, longer L/D configurations are often considered, depending on the formulation, throughput target, venting requirements, and screw design. In this USEON project, the 52:1 L/D ratio provided sufficient downstream length to incorporate side feeding and vacuum venting zones, while offering an adequate processing window for the polymer to wet and mix the large volume of powder.
A: Yes, subject to formulation, temperature profile, screw configuration, and target throughput requirements. While the FAT for this project verified the PP homopolymer formulation, the USEON SAT-75 twin-screw extruder features a modular design. With corresponding process adjustments, the line can be adapted to compound PE (polyethylene) + CaCO3 masterbatches.
A: Direct main feeding of a large amount of light CaCO3 powder can reduce feeding efficiency and stability due to poor powder flowability and the entrained air. The side feeder introduces the powder further downstream into the already melted polymer. This approach helps improve powder introduction efficiency, enhances overall feeding stability, and allows entrapped air to vent backwards through an atmospheric port.
A: When polyolefins (PP or PE) are heavily filled with 70% CaCO3, the melt strength of the compound typically decreases. This can make traditional strand pelletizing challenging due to the risk of strand breakage. The die-face / water-ring pelletizing system cuts the melt directly at the die face, avoiding the strand-handling step required in strand pelletizing and contributing to more consistent pellet quality.