I.Overview
In the automotive electrophoretic painting process, the core role of deionized water is to prevent ions in water (such as Ca²⁺, Mg²⁺, Cl⁻, SiO₃²⁻, etc.) from interfering with the stability of electrophoretic paint, the performance of the coating film and subsequent processes, and to prevent defects such as pinholes, shrinkage holes, impurity particles and decreased adhesion in the coating. It is a key auxiliary material for ensuring coating quality and stabilizing the production process.
II.Main process
Process Flow of Traditional Ion - Exchange Resin Method:
Raw Water Pretreatment (Sand Filtration + Activated Carbon Filtration) → Ion Exchange (Cation Exchange + Anion Exchange) → Post - treatment (Mixed - bed Treatment + Precision Filtration)
Process Flow of Reverse Osmosis - Ion Exchange Method:
Raw Water Pretreatment (Multimedia Filtration + Cartridge Filtration) → Reverse Osmosis Treatment → Ion Exchange (Cation Exchange + Anion Exchange) → Post - treatment (Mixed - bed Treatment + Precision Filtration)
Process Flow of Reverse Osmosis - Electrodeionization (EDI) Method:
Raw Water Pretreatment (Disc Filtration + Ultrafiltration) → Reverse Osmosis Treatment → Electrodeionization (EDI) Treatment → Post - treatment (Terminal Precision Filtration)
III.Core attribute parameters (and control standards) of deionized water equipment
Parameter Category | Core Indicator | Control Standard for Automotive Electrophoretic Coating | ||||||
Purity Indicator | Conductivity | Product water ≤ 5μS/cm (for precision washing process, need ≤ 3μS/cm) | ||||||
Ion Control | Total Dissolved Solids (TDS) | ≤ 5mg/L | ||||||
Cations (Ca²⁺, Mg²⁺, etc.) | Concentration of each ion ≤ 0.1mg/L | |||||||
Anions (Cl⁻, SO₄²⁻, etc.) | Cl⁻ ≤ 0.1mg/L, SO₄²⁻ ≤ 0.5mg/L | |||||||
Physical Indicator | Particle Content | Number of particles > 0.2μm ≤ 10 particles/mL | ||||||
pH Value | 6.5 - 7.5 (neutral range) |
IV.Main application scenarios
Preparation and replenishment of electrophoresis bath solution
The final rinse after pretreatment
Multi-stage rinsing after electrophoresis
Cleaning of equipment and pipelines
V.Here is a guideline for you to get a proper quotation
Tell us the raw water/source of water(tap water, well water, or sea water, etc)
Provide water analysis report(TDS , conductivity, or resistivity, etc)
Required production capacity( 5m³/H, 50m³/H,or 500m³/H, etc)
What's the pure water used for( industrial,Food and Beverage,or agriculture, etc )