Project Location: Ecuador
Target Product: Solvent & Water-Based Exterior Wall Paint
Production Capacity: 15-20 Metric Tons per Day
Project Time: December 2024 - March 2025
Customer Challenge
The customer manufactures exterior wall paint that does not require a grinding system. They needed:
- Material density: 1,400 kg/m3
- Viscosity: 4,000-20,000 mPas
- Solids content: 70-80%
- Pre-dispersing kettle and finished product storage with low-speed agitator
- High working efficiency and energy-saving design due to rising local labor and energy costs
POLYC Solution
POLYC MACHINE designed an efficient pre-mixing and storage system:
- Pre-Dispersing: Concentric Double-Shaft Mixing Kettle (one high-speed shaft + one low-speed anchor mixing shaft), ideal for high solids content of 70-80%. Half-coil jacket for cooling to control material temperature during mixing. High-speed dispersing shaft with hydraulic lifting for thorough, even mixing.
- Finished Product Storage: Storage kettle with cup-type mixing blade. Unlike traditional paddle shafts, this design offers higher working efficiency and energy savings with high circulation performance, slotted version for multi-angle shear, strong suction effect, strong wall flow, circumferential speed up to 4 m/s, no bubbles, no dead corners, and no scaling.
Results
The customer inspected the equipment before shipment and confirmed satisfaction. The complete production line was shipped in March 2025, loaded in 7x 40HQ containers. The high-efficiency pre-mixing system and energy-saving low-speed agitators help the customer reduce labor and energy costs while maintaining consistent product quality.
Industry Context
Ecuador's construction coatings market has grown with urban development and infrastructure projects across coastal and Andean regions. Exterior wall paints with high solids content (70-80%) present unique mixing challenges: the high pigment and extender loading requires powerful dispersion to achieve proper film formation, while the resulting high viscosity (4,000-20,000 mPas) demands efficient low-speed agitation to maintain uniformity without introducing air entrainment.
Technical Highlights
| Parameter | Specification |
|---|---|
| Product | Solvent & Water-Based Exterior Wall Paint |
| Daily Capacity | 15-20 Metric Tons/day |
| Material Density | 1,400 kg/m³ |
| Viscosity Range | 4,000-20,000 mPas |
| Solids Content | 70-80% |
| Pre-Dispersing | Concentric Double-Shaft Mixing Kettle |
| Cooling | Half-coil jacket |
Engineering Approach
The concentric double-shaft design is particularly effective for high-solids formulations: the high-speed dispersing shaft generates shear for pigment wetting and deagglomeration, while the low-speed anchor shaft provides wall scraping and bulk circulation to prevent material from stagnating at the vessel walls. The cup-type mixing blade in the storage kettle offers superior circulation compared to traditional paddle designs, with circumferential speeds up to 4 m/s that maintain uniform pigment suspension without introducing air. The half-coil jacket provides efficient cooling during the high-shear dispersion stage, where mechanical energy conversion can raise product temperature by 15-25°C if uncontrolled.
Process Design Rationale
This line produces exterior wall paint that does not require a grinding stage, so the engineering effort moves from particle size to mixing and heat management. At 70-80% solids and 4,000-20,000 mPas, a single-shaft mixer leaves dead zones near the wall and bottom. The concentric double-shaft kettle solves that with two motions at once: a high-speed dispersing shaft for wet-out and a low-speed anchor that continuously scrapes the wall and brings material back into the shear zone.
The half-coil jacket is the second design decision. High-solids mixing converts mechanical energy into heat quickly, and without cooling the batch viscosity drifts as the temperature climbs. Cooling during mixing keeps the rheology stable, which in turn keeps dosing and filling consistent. In the storage stage, the cup-type blade replaces a conventional paddle: its slotted geometry creates circumferential flow at up to 4 m/s, which keeps the finished product uniform without generating the bubbles and wall scaling that paddle shafts tend to produce in high-solids paints.
Quality and Acceptance Checks
Acceptance for a non-grinding paint line concentrates on what the process actually controls: viscosity after each addition, solids content, density and batch temperature. Mixing uniformity is checked by sampling from more than one point in the kettle, since the failure mode here is stratification rather than fineness. Storage-kettle performance should also be verified after a standing period, because a blade that mixes well but separates on standing has not solved the customer's problem.
Specifying a Similar Line
Buyers should specify daily tonnage, product density and viscosity range, solids content, the number of formulations, cooling-water availability and temperature, storage volume required, and the container loading plan for export. The last item is easy to overlook but directly affects skid design: this line shipped in seven 40-foot containers, and a layout that ignores transport limits can force a redesign at the packing stage.
Related Equipment
Learn more about the mixing technology: Concentric Double-Shaft Mixer and High-Speed Disperser.
Recommended equipment
Concentric Double Shaft Mixer is the relevant POLYC MACHINE configuration for this application.