Overview
Moisture control in PVC (polyvinyl chloride) production is critical to ensuring high-quality resin processing, extrusion stability, and final product performance. PVC resins and compounds can absorb moisture during storage, handling, conveying, or blending.
Excess moisture leads to surface defects, fisheyes, voids, porosity, poor fusion, die buildup, and product inconsistencies in extrusion, molding, calendaring, and compounding operations.
MoistTech’s IR-3000 NIR moisture sensor provides continuous, non-contact, real-time moisture measurement of PVC powder, pellets, and compounds. With ±0.1% accuracy and zero required maintenance, the IR-3000 is ideal for controlling process conditions where moisture can affect material flow, plasticization, energy usage, and overall product quality.
MoistTech’s moisture measurement is insensitive to color, temperature, particle size, and dust, making it ideal for the harsh environments typical in PVC manufacturing.
Why Measure Moisture
Precise moisture control in PVC manufacturing provides major operational and quality advantages.
Quality Assurance
Energy Efficiency
Reduced Waste
Process Stability
Safety
RECOMMENDED MEASUREMENT LOCATIONS
1. Raw PVC Resin / Powder Feed
PVC resin (and additives such as stabilizers, lubricants, fillers, and pigments) can retain moisture from transportation or storage. Measuring moisture at the raw material feed prevents:
- Caking or bridging in hoppers
- Inconsistent dosing and blending
- Steam generation or voids during extrusion
Typical moisture levels of incoming PVC resin range from 0.1–0.5% but can spike higher under humid conditions.
2. Post-Blender / Pre-Extruder
This is the most important measurement point. After blending PVC resin with additives, moisture must be at a low, uniform level to ensure:
- Consistent melt flow
- Predictable fusion behavior
- Smooth extrusion
- Prevention of die explosions, porosity, or bubbles
Target moisture before extrusion is typically 0.05–0.3%, depending on formulation.
3. Final Product Verification / Cooling Line
Moisture in the final PVC product influences:
- Dimensional stability
- Surface finish
- Mechanical strength
- Adhesion or coating performance
PVC pellets, profiles, sheets, films, and tubing should be verified at ≤0.1–0.3% moisture to ensure long-term performance and proper downstream behavior.
Understand the Process
Learn more about MoistTech’s moisture sensing technology. With MoistTech, you have the ability to sense moisture in your products making them even better. MoistTech Corp. has developed a wide variety of sensors and technology that will allow you to carefully inspect and track all your products moisture levels.