Today's KNOWLEDGE Share
🔧 PVC Compounding: The Real Rheology Challenges Nobody Talks About
Rheology in PVC is far more complex than viscosity curves on a datasheet. Unlike many polymers, PVC does not melt cleanly. Its flow behaviour depends on fusion, lubricant interactions, stabilizer efficiency and how the polymer breaks down under shear and temperature. This makes process control both critical and difficult.
Two compounds with identical formulations can behave very differently in the extruder simply because of particle size distribution, porosity or plasticizer absorption rate. Small changes in shear stress or temperature profile can shift the melt from too elastic to too fragile, affecting die swell, surface finish and dimensional accuracy. The challenge grows when recyclate, fillers or impact modifiers are added, each altering the melt’s elasticity and flow resistance in its own way.
Consistent rheology is what separates a stable production line from one that struggles with pressure fluctuations, chatter marks or unpredictable melt quality. It requires collaboration between resin producers, stabilizer suppliers, compounders and machinery experts to understand how every component influences flow under real processing conditions.
In your experience, which factor affects PVC rheology the most during processing: shear profile, lubrication balance or the presence of recyclate?
source : Orbimind AB
#PVCCompounding #Rheology #Extrusion
No comments:
Post a Comment