Vaporization Coulometry Moisture Analysis in Industrial Polyesters
Coulometric vaporization titration under ISO 15512 Method B2 quantifies trace moisture in industrial polyesters to prevent hydrolytic degradation during melt extrusion.
Dewpoint Dryer
Meaning
Resin conditioning machinery utilizes desiccated air loops to lower the moisture content of hygroscopic polymers below critical processing limits before they enter an injection moulding machine. A dewpoint dryer protects sensitive resins like polycarbonate and polyethylene terephthalate from hydrolytic degradation during melt processing. By continuously circulating dry air through the resin hopper, this equipment prevents cosmetic silver streaks and loss of mechanical strength in moulded parts.
Melt Protection
Moisture locked within undried polymer pellets vaporizes instantly inside the heated injection barrel. When processing engineering thermoplastics, the action of a dewpoint dryer prevents water molecules from breaking the long polymer chains during plasticization. This thermal hydrolysis severely reduces the impact strength of the finished part.
Having dry resin ensures that the physical properties of the moulded product match the published material datasheet.
Process Stability
Variations in ambient humidity can disrupt production lines that lack stabilized drying systems. In winter or dry climates, simple hot-air units might suffice, but a dewpoint dryer maintains a consistent negative forty-degree air supply regardless of seasonal weather changes. This stability prevents fluctuation in melt viscosity.
Viscosity shifts often cause part weight variation or flash defects.
Energy Efficiency
Smart regeneration cycles reduce the electricity demand of industrial desiccant beds. Heating the saturated desiccant only when the air reaches a set humidity threshold saves operating costs. Utilizing a dewpoint dryer optimizes this cycle to lower factory power consumption.